WO2012048090A2 - Devices, systems and methods for dynamic spectrum management (dsm) - Google Patents

Abstract

A dynamic spectrum management (DSM) server, system and method are described. The DSM server includes a cognitive engine. The cognitive engine receives a service request for an allocation of spectrum for secondary use, determines whether the DSM server is able to resolve the service request, and transmits the request to another DSM server on a condition that the DSM server is not able to resolve the service request.

Description

DEVICES, SYSTEMS AND METHODS FOR DYNAMIC SPECTRUM

MANAGEMENT (DSM)

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent

Application Serial No. 61/390,525, filed October 6, 2010, the contents of which are hereby incorporated by reference.

BACKGROUND

[0002] Most of the radio spectrum in the United States has already been allocated for use by some type of wireless device. This leaves very little unallocated spectrum available for new wireless devices. It is predicted that with the rapid growth of global mobile network data traffic, the U.S. will face increasingly severe bandwidth shortage (i.e., a bandwidth crunch). However, while most of the radio spectrum has already been allocated, measurements have shown that most of the allocated spectrum is only lightly utilized at any given point in time. The obvious inefficient use of the radio spectrum has motivated a closer look at the current spectrum regulatory policies and spurred the advent of technologies such as dynamic spectrum management (DSM) and cognitive radios, which may offer solutions to the bandwidth crunch problem.

SUMMARY

[0003] Dynamic spectrum management (DSM) servers, systems and methods are described. A DSM server includes a cognitive engine. The cognitive engine receives a service request for an allocation of spectrum for secondary use, determines whether the DSM server is able to resolve the service request, and transmits the request to another DSM server on a condition that the DSM server is not able to resolve the service request. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings wherein:

[0005] FIG. 1A is a system diagram of an example communications system in which one or more disclosed embodiments may be implemented:

[0006] FIG. IB is a system diagram of an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A;

[0007] FIG. 1C is a system diagram of an example radio access network and an example core network that may be used within the communications system illustrated in FIG. 1A;

[0008] FIG. 2 is a block diagram illustrating an embodiment of a basic building block of a dynamic service management (DSM) architecture;

[0009] FIG. 3 is a block diagram illustrating an architecture of a sensing processor of a DSM server according to an embodiment;

[0010] FIG. 4 is a block diagram of an embodiment of a cognitive engine;

[0011] FIG. 5 is a flow chart illustrating an embodiment of a method that may be implemented by a sensing controller of the sensing processor of the DSM server;

[0012] FIG. 6 is a signal diagram illustrating example message flows of the sensing processor of the DSM server;

[0013] FIG. 7 is a signal diagram illustrating example message flows of a cognitive engine of a DSM server according to a method for allocating spectrum to, and configuring a transceiver of, a DSM client;

[0014] FIG. 8 is a diagram of an embodiment of a composite DSM connection;

[0015] FIG. 9 is a diagram of another example composite DSM

connection; [0016] FIG. 10 is a diagram of another example composite DSM connection;

[0017] FIG. 11 is a diagram of another example composite DSM connection;

[0018] FIG. 12 is a diagram of another example composite DSM connection implemented with regard to neighborhood/enterprise multimedia and infotainment delivery applications;

[0019] FIG. 13 is a diagram of another example composite DSM connection implemented in a mobile ad hoc network (MANET);

[0020] FIG. 14 is a diagram of another example composite DSM connection formed among several different DSM systems;

[0021] FIG. 15A is a flow diagram illustrating an example method for determining a type of address to use for a DSM server;

[0022] FIG. 15B is a flow diagram illustrating an example method of determining when and how to set up a composite DSM connection;

[0023] FIGs. 16A and 16B are a flow diagram illustrating a method that may be implemented in a DSM server;

[0024] FIG. 17 is a diagram of an embodiment of a centralized DSM system;

[0025] FIG. 18 is a diagram of an embodiment of a distributed DSM system;

[0026] FIG. 19 is a diagram of an embodiment of a hybrid DSM system;

[0027] FIG. 20 is a signal diagram of a method of operating a distributed mode;

[0028] FIG. 21 is a signal diagram illustrating an embodiment of a method of information fusion;

[0029] FIG. 22 is a diagram illustrating embodiments of sensing request, sensing response, configuration request, configuration response, test request and test response messages implemented using 802.11 frames;

[0030] FIG. 23 is a flow diagram illustrating a method of information fusion that may be implemented by a sensing processor; [0031] FIG. 24 is a signal diagram illustrating an embodiment of a method of information combining using a use-and-discard approach;

[0032] FIG. 25 is a flow diagram illustrating an embodiment of a method of information combining using a use-and-discard approach that may be implemented in a sensing processor;

[0033] FIGs. 26A and 26B are a signal diagram illustrating an embodiment of a method of information fusion using radio device sensitivity information;

[0034] FIG. 27 is a flow diagram illustrating an embodiment of a method of sensory node registration including radio device sensitivity information;

[0035] FIG. 28 is a flow diagram illustrating an embodiment of a method of information fusion using radio device sensitivity information that may implemented in a sensing processor;

[0036] FIG. 29 is a flow diagram illustrating an embodiment of a method of sensory node registration including retrieval of location information;

[0037] FIG. 30 is a flow diagram illustrating an embodiment of a method of assigning sensing tasks to sensory nodes and performing information fusion accounting for the location information;

[0038] FIG. 31 is a flow diagram illustrating an embodiment of a method of information fusion using signal-to-noise ratio (SNR)-based hard combining using weighting;

[0039] FIG. 32 is a flow diagram illustrating an embodiment of information fusion by estimating (Pf, P_m);

[0040] FIG. 33 is a block diagram illustrating an embodiment of information fusion for a hybrid mode;

[0041] FIG. 34 is a flow diagram illustrating an embodiment of a method for obtaining correlation information; and

[0042] FIG. 35 is a flow diagram illustrating an embodiment of a method of sensing task assignment and information fusion using correlation information. DETAILED DESCRIPTION

[0043] FIG. 1A is a diagram of an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), and the like.

[0044] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and/or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, consumer electronics, and the like.

[0045] The communications systems 100 may also include a base station

114a and a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the core network 106, the Internet 110, and/or the networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

[0046] The base station 114a may be part of the RAN 104, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals within a particular geographic region, which may be referred to as a cell (not shown). The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In another embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell.

[0047] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0048] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

[0049] In another embodiment, the base station 114a and the WTRUs 102a,

102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

[0050] In other embodiments, the base station 114a and the WTRUs 102a,

102b, 102c may implement radio technologies such as IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0051] The base station 114b in FIG. 1A may be a wireless router, Home

Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the core network 106. [0052] The RAN 104 may be in communication with the core network 106, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 and/or the core network 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may be utilizing an E-UTRA radio technology, the core network 106 may also be in communication with another RAN (not shown) employing a GSM radio technology.

[0053] The core network 106 may also serve as a gateway for the WTRUs

102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and the internet protocol (IP) in the TCP/IP internet protocol suite. The networks 112 may include wired or wireless communications networks owned and/or operated by other service providers. For example, the networks 112 may include another core network connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0054] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities, i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0055] FIG. IB is a system diagram of an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It will be appreciated that the WTRU 102 may include any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0056] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0057] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In another embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0058] In addition, although the transmit/receive element 122 is depicted in

FIG. IB as a single element, the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0059] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, for example.

[0060] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown). [0061] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0062] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location- determination method while remaining consistent with an embodiment.

[0063] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like.

[0064] FIG. 1C is a system diagram of the RAN 104 and the core network

106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the core network 106.

[0065] The RAN 104 may include eNode-Bs 140a, 140b, 140c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 140a, 140b, 140c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 140a, 140b, 140c may implement MIMO technology. Thus, the eNode-B 140a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0066] Each of the eNode-Bs 140a, 140b, 140c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown in FIG. 1C, the eNode-Bs 140a, 140b, 140c may communicate with one another over an X2 interface.

[0067] The core network 106 shown in FIG. 1C may include a mobility management gateway (MME) 142, a serving gateway 144, and a packet data network (PDN) gateway 146. While each of the foregoing elements are depicted as part of the core network 106, it will be appreciated that any one of these elements may be owned and/or operated by an entity other than the core network operator.

[0068] The MME 142 may be connected to each of the eNode-Bs 142a, 142b,

142c in the RAN 104 via an Si interface and may serve as a control node. For example, the MME 142 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 142 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA. [0069] The serving gateway 144 may be connected to each of the eNode Bs

140a, 140b, 140c in the RAN 104 via the Si interface. The serving gateway 144 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The serving gateway 144 may also perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0070] The serving gateway 144 may also be connected to the PDN gateway

146, which may provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0071] The core network 106 may facilitate communications with other networks. For example, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the core network 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the core network 106 and the PSTN 108. In addition, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to the networks 112, which may include other wired or wireless networks that are owned and/or operated by other service providers.

[0072] In dynamic spectrum management (DSM), wireless devices may be permitted to dynamically access spectrum that is being underutilized by its primary users. Because DSM may enable wireless devices to make secondary use of underutilized spectrum, DSM may enable higher throughput, more reliable communications, and coexistence and convergence of various wireless technologies. For example, WiFi devices may operate in the TV White Space (TVWS) spectrum to achieve higher throughput or longer communication ranges. As another example, the public safety band may become too crowded in a disaster rescue operation, and DSM may enable wireless devices to access spectrum in other bands that are being underutilized and, therefore, may enable users of these devices to reliably communicate in such emergency situations.

[0073] In DSM embodiments described herein, access to underutilized spectrum by secondary spectrum users (referred to herein as DSM clients) may be controlled by a server (referred to herein as a DSM server) based on certain conditions, such as current usage of the spectrum by primary (or licensed) users, current usage of the spectrum by other secondary (or unlicensed) users and spectrum access policies or rules associated with the spectrum. To determine whether the spectrum is being underutilized at a given time, the DSM server may select one or more nodes (e.g., sensory nodes) to sense the spectrum as part of a sensing task using spectrum sensing techniques such as energy detector- based sensing, waveform-based sensing, cyclostationarity-based sensing, radio identification-based sensing and matched-filtering. Then, the DSM server may decide whether the spectrum is being underutilized (and, thus, potentially available for secondary use) based on the sensing results provided by the one or more nodes. The DSM server may also check databases that contain policies associated with the spectrum to determine whether use of the spectrum by secondary users is permitted and, if so, if there are any restrictions on such use.

[0074] A composable DSM architecture is also described herein that builds on the basic client-server DSM model. More specifically, DSM service may be provided by a DSM server to a DSM client by establishing an atomic DSM connection between them. However, if, for example, a DSM server is unable to resolve a DSM service request from a DSM client (e.g., it needs to access spectrum-related policies but cannot access the required database), the DSM server may form another atomic DSM connection with another DSM server, forming a composite DSM connection. The composable DSM architecture may enable use of DSM in a wide range of communication systems and DSM applications, whether the underlying system is centralized or distributed, single- hop or multi-hop, cellular based or IEEE 802.11 based, etc. [0075] Cooperative sensing, which may occur when a DSM server selects more than one node to sense the spectrum for a particular sensing task, may be desirable in some cases because it may increase diversity and provide a solution to the hidden-terminal problem. In cooperative sensing, since multiple sensing results are provided as part of a single sensing task, a decision is made as to whether the spectrum is available for use by secondary users based at least on the multiple results. The process of making an overall decision based on multiple sensing results may be referred to as "data fusion" or "information combining." In an embodiment, data fusion may be executed at the DSM server. Data fusion techniques are also described herein that account for factors in addition to the sensing results themselves (e.g., latency, memory limitations, reliability of each sensing result and efficiency).

[0076] FIG. 2 is a block diagram illustrating an embodiment of a basic building block 200 of a DSM architecture (referred to herein as the atomic DSM connection). The illustrated atomic DSM connection 200 includes a DSM server 202 and a DSM client 204. As described below the DSM server and the DSM client may be included in the same device or in different devices, which may include, for example, a wireless transmit/receive unit (WTRU) and/or a base station. The DSM client 204 may require DSM service in that it needs to dynamically use some spectrum but does not know what spectrum to access or how. To access the spectrum, the DSM client 204 may request DSM service from the DSM server 202. The DSM server 202 may provide DSM service to DSM clients 204 in response to received DSM service requests by allocating available spectrum for each requesting DSM client 204 to use based on spectrum sensing results and other constraints (e.g., policy limitations on use of a particular spectrum). The DSM server 202 may also coordinate spectrum sensing amongst sensing nodes. The DSM server 202 and DSM client 204 are illustrated as separate entities, but they may be located either in a single device or in separate devices. [0077] The illustrated DSM server 202 includes a cognitive engine 206, a sensing processor 208, a radio access technology (RAT) capability database 210 and a policy and spectrum interface database 212. The cognitive engine 206 may generate spectrum allocations and modem configurations for DSM clients 204 based on service requests received from one or more DSM clients 204, spectrum sensing results provided by the sensing processor 208, radio access technology (RAT) information for the DSM clients 204 stored in the RAT capability database 210, and spectrum availability information and spectrum access constraints obtained, for example, through the Internet 226 from exterior databases such as the TVWS database 220, the Federal Communications Commission (FCC) policies database 222 and/or other databases 224. Spectrum availability information and spectrum access constraints obtained from external databases may be stored in the policy and spectrum interface database 212.

[0078] The policy and spectrum interface database 212 may be configured to carry out policy translation, exterior spectrum database connection, and caching. By way of example, regulatory policies may be written in a formal language that is different from the one used to implement the cognition functions of a cognitive radio. For example, the regulatory policies may be written in Common Logic Controlled English (CLCE), an easy-to-understand formal language that supports full first-order logic with equality supplemented with an ontology for sets, sequences, and integers. On the other hand, the cognitive engine may be written in Prolog, which is widely used for first-order logic programming. In this example, the policy and spectrum interface database 212 may translate the CLCE scripts to Prolog syntax.

[0079] The policy and spectrum interface database 212 may also store the relevant policies (e.g., FCC policies) and spectrum availability information (e.g., from the TVWS database) that it has fetched from exterior sources, as described above. When the database 212 retrieves such information for a certain service request, the information may be needed for other devices in the future. Caching may reduce communication overhead and latency for future DSM service, thus improving the efficiency of the system.

[0080] The RAT capability database 210 may store information about the capability of the RATs of DSM clients 204. The RAT capability information may include, for example, operating frequency ranges, types of modulation, transmission power levels, and coding rates. The information may be used to decide whether a spectrum allocation or a transceiver configuration is feasible for a DSM client 204. When a DSM client 204 registers with a DSM server 202, the DSM client 204 may provide its RAT capability information to the DSM server 202, and the information may be stored in the RAT capability database 210. The DSM server 202 may refer to the RAT capability database 210 for feasible spectrum allocation and configuration options for each DSM client 214.

[0081] The illustrated DSM client 204 includes a spectrum sensing unit

214, a service mapper 216 and a configurable transceiver 218. DSM clients 204 may be spectrum users, which may send service requests to, and receive spectrum allocations from, a DSM server 202. DSM clients 204 may also be configured to sense the spectrum and provide spectrum sensing results to the DSM server 202. The DSM server 202 may use the spectrum sensing results received from the DSM clients 204 to make a determination as to whether spectrum is available for secondary use and, if so, to allocate spectrum for the DSM clients 204 to use accordingly.

[0082] The spectrum sensing unit 214 may conduct spectrum sensing periodically. The sensing may be synchronized across the network (e.g., energy detection in synchronized silent periods), asynchronous (e.g., using feature detection rather than energy detection to detect the presence of primary users or other secondary users in the spectrum), or a combination of the two.

[0083] Parameters of the configurable transceiver 218 may be reconfigured.

The configuration may be entirely controlled by the DSM server 202 or may be controlled partially by the DSM server 202 and partially by the DSM client 204. [0084] The service mapper 216 may map service requirements of DSM clients 204 to a standard format that is agreed upon by both the DSM clients 204 and the DSM server 202. The service request may be in terms of amounts of spectrum or quality of service (QoS) requirements (e.g., data rate or delay). With the service mapping, the design of the DSM server 202 may focus on resolving a limited number of services, thus making the architecture more modular and simplifying the design. At the same time, the service mapper 216 may allow the DSM client 204 to have diverse service requests. The support for a new service request may be enabled by simply extending the service mapper 216.

[0085] FIG. 3 is a block diagram 300 illustrating the architecture of the sensing processor 208 of the DSM server 202 according to an embodiment. The illustrated sensing processor 208 includes a sensing controller 301, a correlation analyzer 302, a capability registry 304, an information fusion unit 306, a location- based fast frequency selection unit 308, a sensory nodes correlation database 310, a sensory nodes configuration database 312, and a sensing results database 316. The sensing processor 208 may collect sensing information from sensory nodes (e.g., sensory nodes 204a and 204b) and process the sensing information to facilitate decision making in the cognitive engine 206. Resulting spectrum availability information may be stored in a database (e.g., the sensory nodes correlation database 310, the sensory nodes configuration database 312, and/or the sensing results database 316) and may be accessible to the cognitive engine 206. In addition, the sensing processor 208 may receive a spectrum inquiry indicating, for example, requested spectrum sensing goals from the cognitive engine 206 and adjust the sensing activity carried out by the DSM clients 204 (e.g., sensory nodes 204a and 204b and/or neighbor DSMs 204c and 204d) accordingly. The sensory nodes may be dedicated spectrum sensors or DSM clients with spectrum sensing capability. In an embodiment, the sensing processor 208 includes a neighbor DSM sensing configuration database 314 for use in a distributed mode to store sensing configuration of neighbor DSMs (e.g., neighbor DSMs 204c and 204d). In the distributed mode, several DSM units may be connected and may share their sensing results with one another to increase the coverage area and improve sensing reliability. The distributed mode is described in more detail below with respect to FIGs. 18 and 20.

[0086] The correlation analyzer 302 may analyze correlations among sensing results at different sensory nodes. To perform correlation analysis, the sensing controller 301 may send a sensing test request to the sensory nodes. The test request may include information about which sensory nodes are to apply what kind of testing procedure. Once a sensory node receives a test request, it may perform requested operations and, in response, send a test response message to the correlation analyzer 302. The correlation analyzer 302 may execute certain analysis algorithms on the sensing test results received from all the participant sensory nodes. The correlation analyzer 302 may then store the correlation analysis results into the sensory nodes correlation database 310.

[0087] The capability registry 304 may collect and store sensing capability information of all registered sensory nodes.

[0088] The information fusion unit 306 may combine sensing results from multiple sensory nodes and make an overall decision on whether a certain spectrum is occupied by primary users. The information fusion unit 306 may store the decision, and any individual sensing results received from sensory nodes, in the sensing results database 316. Methods for combining sensing results from multiple sensory nodes are described in more detail below with respect to FIGs. 21-35.

[0089] The location-based fast frequency selection unit 308 may perform some priority ordering of available channels based on past sensing results. The location-based fast frequency selection unit 308 may be called under certain conditions. For example, if a channel availability inquiry needs to be replied to within a very short time period such that conducting a complete external sensing operation may not meet this latency requirement, then the location-based fast frequency selection unit may be called to reduce the overall sensing time. [0090] The sensory nodes configuration database 312 may include a list of parameters for each registered sensory node. The parameters may include working spectrum, location, RF device sensitivity, computational capability, supporting sensing schemes, latency condition, transmission power and others (e.g., PHY/antenna descriptions). The working spectrum parameter may indicate the frequency range that a sensory node may cover. The location parameter may indicate the location information of the sensory node. For example, it may indicate the relative location of a sensory node to the DSM unit or the absolute location of the sensory node. The RF device sensitivity parameter may indicate the sensitivity level of a radio device equipped at the sensory node, which may be used as an indication of the reliability of that sensory node. Such information may be used, for example, at the information fusion unit 306. The computational capability parameter may indicate the computational capability of the sensory node. The supporting sensing schemes parameter may indicate the sensing schemes that the sensory node may implement. The latency condition parameter may indicate the delay that the sensory node may incur when implementing a sensing task. The RF device sensitivity, computational reliability and supporting sensing schemes parameters may help the sensing controller 301 to determine whether a sensory node is qualified for a sensing task. The transmission power may indicate the transmission power of the sensory node. This may help the sensing controller 301 to know the PHY feature of the sensory node. Table 1 shows an example of data format in the sensory nodes configuration database.

Table 1

Working Location RF device Computational Supporting Latency Transmission Spectrum sensitivity capability sensing power

schemes

Sensory 100MHz- (lm, 3m) -85 dBm 2^nd class Energy <800ms 2 dBm node 1 1GHz detection,

direct

spectrum

estimation

Sensory 50MHz~ (4m, - - 70 dBm 3^rd class Covariance- <ls -3 dBm node 2 300GHz 20m) based [0091] The sensory nodes correlation database 310 may be a n x n matrix, with n being a number of registered sensory nodes in a network. The n x n matrix may be a symmetric matrix with diagonal elements being 1. Every other element in the matrix may be a correlation coefficient between 0 and 1. Table 2 illustrates an example of the sensory nodes correlation database 310.

Table 2

[0092] The sensing results database 316 may record historical sensing results for each spectrum inquiry from the cognitive engine 206. Each record may contain parameters including, for example, an inquiry frequency parameter, an inquiry location parameter, an inquiry time parameter, a participant sensory nodes parameter, a sensing schemes parameter, an information combining schemes parameter, an overall sensing results parameter and a correctness of sensing result parameter. Table 3 shows an example of overall sensing records.

Table 3

[0093] The sensing results database 316 may also create a matrix-formed database for each registered sensory node, recording the sensing histories of the sensory node. Each column of the matrix may indicate a spectrum band on which the sensory node performed sensing. Each row of the matrix may indicate a location and a time when the sensory node performed sensing. Each element of the matrix may include a sensing result from a sensory node. If the sensing result is a hard decision, then the information of whether this decision is true, or not, may also be stored in the database.

[0094] Table 4 shows an example sensing results database. In table 4, the element on the first column and the first row is (Hi, Correct). This indicates that, in this example, the sensory node made a sensing operation at time ti and location (xi, yi) on the frequency band centered at fi. Its decision, Hi, is that a primary user is present and the decision is correct.

Table 4

[0095] FIG. 4 is a block diagram 400 of an embodiment of the cognitive engine 206. The illustrated cognitive engine 206 includes a conformance reasoner 404, a service provisioner 402 and an allocated spectrum database 406. The cognitive engine 206 may act upon service requests received from DSM clients 204 and generate desired spectrum allocations that conform to spectrum access policies. The cognitive engine 206 may also configure the transceivers 218 of DSM clients 204. In addition, the cognitive engine 206 may coordinate event- based spectrum sensing.

[0096] The conformance reasoner 404 may check whether a proposed transmission opportunity conforms to regulatory policies and user-defined policies. The proposed transmission opportunity (e.g., a spectrum allocation and a transceiver configuration) may be allowed if the conformance check passes. Alternatively, the conformance reasoner 404 may provide candidate transmission opportunities that conform to regulatory policies and user-defined policies.

[0097] The service provisioner 402 may try to satisfy service requests made by DSM clients 204. The service provisioner 402 may also select an optimal spectrum allocation and transceiver configuration from all candidate solutions that satisfy the service requests. The service provisioner 402 may also coordinate event-based spectrum sensing. When a DSM client 204 detects a licensed user at times other than pre-scheduled time slots, the DSM client 204 may send an alert message to the service provisioner 402. Responsive to receiving the alert message, the service provisioner 402 may check whether the alert message warrants a closer evaluation of the current spectrum activity based on spectrum access needs. If it determines that the alert message warrants a closer evaluation, the service provisioner 402 may generate and send to the sensing processor 208 a spectrum inquiry. The spectrum inquiry may request that DSM clients 204 change their method of spectrum sensing. If the alert message does not warrant a closer evaluation, the alert may be ignored.

[0098] The allocated spectrum database 406 may record active spectrum allocations. The service provisioner 402 may avoid using spectrum marked as being allocated in the allocated spectrum database 406 regardless of what the sensing processor 208 and any exterior sources indicate about such spectrum.

[0099] FIG. 5 is a flow chart 500 illustrating an embodiment of a method that may be implemented by the sensing controller 301 of the sensing processor 208 of the DSM server 202. When a sensory node (such as sensory nodes 204a and 204b in FIG. 2) joins the network, it may first register to the sensing controller 301. In element 502, the sensing controller 301 may determine whether a sensory node has joined the network. If so, in element 504, the sensing controller 301 may update the sensory node's configuration information by sending a configuration request message to the sensory node requesting sensing capability information of that sensory node. The returned sensing capability information may be processed at the capability registry 304 and stored in the sensory nodes configuration database 312. According to the configuration information, the sensing controller 301 may send a sensing test request message to all the sensory nodes to collect correlation information between the newly joined sensory node and other sensory nodes already in the sensing sub-network. In element 506, the returned sensing test results may be processed at the correlation analyzer 302 and stored in the sensory node's correlation database 310.

[0100] If the sensing controller 301 determines in element 502 that a sensory node has not joined the network, in element 508, the sensing controller 301 may determine whether a sensory node has changed its condition. If the sensing controller 301 determines in element 508 that a sensory node has some change of its condition, including, for example, exiting the sensing sub-network, the sensing controller 301 may update the sensory node's configuration database 312, the sensory node's correlation database 310 and the sensing results database 316 in element 510.

[0101] If the sensing controller 301 determines in element 508 that a sensory node has not changed its condition, in element 512, the sensing controller 301 may determine whether a spectrum inquiry has been received from the cognitive engine 206. If the sensing controller 301 determines that it has received a spectrum inquiry in element 512, it may analyze the spectrum inquiry to determine if there is a need to begin a complete sensing task in element 514.

[0102] If the sensing controller 301 decides to perform a new sensing task in element 514, in element 518, the sensing controller 301 may schedule a sensing task by checking the sensory nodes configuration database 312 and the sensory nodes correlation database 310 to determine which sensory nodes should participate in the current sensing task, which sensing schemes should be used and which combining schemes should be used. The sensing controller 301 may then send a sensing request to the corresponding sensory nodes in element 520 and to the information fusion block 306 in element 522. If it receives a notice from the information fusion block 306, the sensing controller 301 may check the sensing results stored in the sensing results database 316. In element 524, the sensing controller 301 may send the sensing results back to the cognitive engine.

[0103] If the sensing controller 301 decides not to perform a complete sensing task in element 514, in element 516, it may send a request to the location-based fast frequency selection unit 308. If the sensing controller 301 receives a reply from the location-based fast frequency selection unit 308, it may check the results and proceed to element 518.

[0104] FIG. 6 is a signal diagram 600 illustrating example message flows of the sensing processor 208 of the DSM server 202. The messages illustrated in FIG. 6 may be implemented, for example, in different layers (e.g., the MAC layer or IP layers).

[0105] When a node (e.g., a sensory node 204) first joins the sensing subnetwork, it may first register with the sensing controller 301 of the sensing processor 208 (illustrated as registration 602 in FIG. 6).

[0106] The sensing processor 208 may transmit a configuration request message 604 to the sensory node 204. The configuration request message 604 may request the sensory node 204 to provide its configuration information to the sensing processor 208. In response to receiving a configuration request message 604 from the sensing processor 208, the sensory node 204 may transmit a configuration response message 606 to the sensing processor 208. The configuration response message 606 may contain the requested configuration information (e.g., the items described above that may be stored in the sensory nodes configuration database 312).

[0107] In response to receiving a configuration response message 606, the sensing processor 208 may transmit a test request message 610 to the sensory node 204. The test request message 610 may request the sensory node 204 to perform certain operations for sensory node correlation analysis. In response to receiving a test request message 610 from the sensing processor 208, the sensory node 204 may transmit a test response message 612 to the sensing processor 208. The content of the test response message 612 may depend on correlation analysis schemes used. For example, if a basic received signal strength indicator (RSSI) scan using automatic gain control (AGC) is used, the test response message 612 may include RSSI values.

[0108] The sensing processor 208 may transmit one or more synchronization messages (e.g., messages 614-616 illustrated in FIG. 6) to the sensory node 204. The synchronization messages 614-616 may include synchronization information for the sensory node 204.

[0109] The cognitive engine 206 may transmit a spectrum inquiry message

618 to the sensing processor 208. The spectrum inquiry message 618 may include information such as a spectrum of interest, a location of interest, a latency requirement and whether it is a periodic sensing request or an event triggered sensing request. In response to receiving a spectrum inquiry message 618 from the cognitive engine 206, the sensing processor 208 may transmit a sensing request 620 to one or more sensory nodes 204 registered with the sensing processor 208. The sensing request message 620 may request that each of the one or more sensory nodes 204 receiving the sensing request message 620 perform certain sensing operations. In response to receiving a sensing request message 620, each of the one or more sensory nodes 204 receiving the sensing request message 620 may transmit a sensing response message 624 to the information fusion block 306 of the sensing processor 208. The content of the sensing response message 624 may depend on information fusion schemes used. For example, if a hard combining scheme is used, the sensing response message 624 may be a 1-bit decision. If a soft combining scheme is used, the message may include soft sensing information.

[0110] In response to receiving sensing response messages 624, the information fusion block 306 may analyze and combine the received sensing response messages 624 and transmit a spectrum response message 626 to the cognitive engine 206 including the overall sensing result (e.g., whether the requested channel is occupied by a primary user or not).

[0111] FIG. 7 is a signal diagram 700 illustrating example message flows of a cognitive engine 206 of a DSM server 202 according to a method for allocating spectrum to, and configuring a transceiver 218 of, a DSM client 204. The messages illustrated in FIG. 7 may be implemented in different layers (e.g., the MAC layer or IP layers). [0112] A DSM client 204 may register with a DSM server 202, forming a

DSM connection. During registration, the DSM client 204 may transmit a device registration request 702 to the cognitive engine 206 and inform the DSM server 202 of its RAT capabilities (e.g., the range of operating frequencies, types of supported modulations, coding schemes and coding rates). In response to receiving a device registration request 702, the cognitive engine 206 may respond with a device registration response message 704. The device registration request message 702 may be generated by a device when it first registers with another device. The former device may become a DSM client 204 and the latter device may become a DSM server 202. Information included in the device registration request message 702 may include a device identifier (ID) (e.g., UE identifier, IP address), device type (e.g., portable/personal or fixed), information on the channel over which the DSM client 204 will receive registration reply messages, RAT parameters (e.g., operating frequencies, supported types of modulations, coding schemes, and coding rates) and location information. The device registration response message 704 may confirm the success of the registration process and may include the ID of the DSM client 204, among other possible information.

[0113] The service mapper 216 of the DSM client 204 may then map the quality of service (QoS) requirements of the DSM client 204 into one of a number of standard services, form a service request 706 and transmit the service request 706 to the DSM server 202. The service request 706 may be handled by the cognitive engine 206 and, in particular, by the service provisioner 402. The service request message 706 may be generated by a DSM client 204 when the DSM client 204 needs to access spectrum dynamically to satisfy certain QoS requirements from applications running on the DSM client 204. Information included in the service request message 706 may include a service type, a service quantity and location information.

[0114] The service provisioner 402 may retrieve the RAT capability information for the DSM client 204 stored in the RAT capability database 210 by transmitting a RAT capability inquiry message 708 to, and receiving a RAT capability response message 710 from, the RAT capability database 210. The service provisioner 402 may generate and send a RAT capability inquiry message 708 to the RAT capability database, which may provide the requested information by sending the response message. The RAT capability inquiry message 708 may include the ID of the DSM client. The RAT capability response message 710 may include detailed information on the RAT capability of the DSM client 204, including the various RAT parameters described above.

[0115] The service provisioner 402 may also instruct the conformance reasonser 404 to fetch policies relevant to the DSM client 204 by transmitting a policy inquiry message 712 to, and receiving a policy response message 714 from, the policy and spectrum interface database 212. The conformance reasoner 404 may make sure that any spectrum allocation and transceiver configuration generated by the DSM server 202 conforms to regulatory policies and user- defined policies. The service provisioner 402 may instruct a policy translator and cache to fetch relevant policies by sending the policy inquiry message 712, and the policy databases (e.g., FCC policy databases) may send the requested information to a policy translator and cache module. Information included in the policy inquiry message 712 may include a spectrum of interest, a location and a device type.

[0116] The service provisioner 402 may also retrieve spectrum availability information from the sensing processor 208 by transmitting a spectrum inquiry message 722 to, and receiving a spectrum response message 724 from, the sensing processor 208. The service provisioner 402 may also retrieve spectrum availability information from the policy and spectrum interface database 212 and the allocated spectrum database 406.

[0117] The service provisioner 402 may run a spectrum allocation and transceiver configuration process using the obtained RAT capability, policy and spectrum information and transmit a spectrum allocation message 726 to the DSM client 204. It may also update the allocated spectrum database 406. By way of example, the policy and spectrum interface database 212 may transmit an external database update inquiry 728 to, and receive an external database update response 730 from, the cognitive engine 206. The service provisioner 402 may retrieve the spectrum availability information from the policy and spectrum interface database 212 in order to have a more reliable assessment on the spectrum activity. This process may save the operations of the sensing processor 208. For example, if the TVWS database 220 indicates that a channel is not available, then there may be no need to resort to the sensing processor 208. Information included in the inquiry message 728 may include location information for the DSM client 204 and its surroundings and possibly other information. The external database update response message 730 may include the requested location information and whether spectrum is available at that location.

[0118] External databases may need information from the DSM server 202 regarding local spectrum usage conditions. Accordingly, the information in the external database update inquiry message 728 may include a spectrum of interest and a location. The external database update response message 730 may provide detailed information. These two messages may help with maintenance of the databases (e.g., the TVWS database 220).

[0119] A DSM client 204 may send a sensing event alert message 732 to its associated DSM server 202 when the DSM client 204 detects certain spectrum activity indicating the presence of primary or other secondary users during time periods other than the pre-scheduled spectrum sensing time periods. The service provisioner 402 may analyze the sensing event alert message 732 and decide whether there is need for further evaluation of the situation. If there is a need, the service provisioner 402 may transmit a spectrum inquiry message 618 (e.g., illustrated in FIG. 6) to the sensing processor 208, asking the sensing processor 208 to provide spectrum availability information on the spectrum of interest. If the sensing processor 208 detects the presence of primary users, the service provisioner 402 may need to find an available spectrum for the DSM client. Subsequently, the service provisioner 402 may send a spectrum allocation message 726 and transceiver configuration message (not shown) to the DSM client 204. If the sensing processor 208 does not detect the presence of primary users, or the service provisioner 402 decides not to evaluate the situation, the service provisioner 402 may transmit a sensing event ignore message 734 to the DSM client 204.

[0120] Referring back to FIG. 2, when a DSM client 204 makes a service request to a DSM server 202, the DSM server 202 may not always be able to resolve the service request itself (e.g., because it does not have access to a database that includes policies required to determine whether requested spectrum is available or restricted). If the DSM server 202 is able to resolve the service request itself (for example, by allocating spectrum for the service request or rejecting the service request), a single atomic DSM connection may suffice. However, if the DSM server 202 cannot resolve the service request, a DSM composition scheme may be needed. In an example DSM composition scheme, the DSM server 202 may initiate a second atomic DSM connection. This process may be repeated until the service request is resolved (e.g., by initiating second, third, fourth, etc. DSM connections). The resulting DSM architecture is referred to herein as a composite DSM connection.

[0121] FIG. 8 is a diagram 800 of an embodiment of a composite DSM connection 810. In the illustrated embodiment, a node 802 requires access to spectrum but does not have all the information it needs to decide what spectrum it can access and how. So the node 802 sets up a first atomic DSM connection 803 with a second node 804. In the first atomic DSM connection 803, the node 802 is the DSM client and the second node 804 is the DSM server 202. However, the second node 804 does not have all the information it requires to resolve the service request from the node 802, so the second node 804 may initiate a second DSM connection 805 with a third node 806. The node 804 is now both the DSM server 202 for the first atomic DSM connection 803 and the DSM client 204 for the second DSM connection 805. However, node 806 also does not have sufficient information to resolve the service request from the node 804, so it initiates a third DSM connection 807 with a fourth node 808. The fourth node 808 has sufficient information to resolve the service request from the node 806 and sends a service resolution (e.g., a spectrum allocation or rejection) to the node 806. Upon receiving the service resolution from the node 808, the node 806 generates a service resolution and transmits the generated service resolution to the node 804, which generates and transmits a service resolution to the node 802. As a result, the service request initially made by node 802 is resolved.

[0122] With the ability to compose, a more complex DSM architecture may be formed adaptively and network-wide cooperation may be naturally supported. The complexity of the resulting DSM architecture may be on an as-needed basis, which lends itself to desired efficiency. With the composition capability, the DSM architecture is able to encompass a wide range of communication systems and DSM applications, as described with respect to FIGs. 9-14 below.

[0123] FIG. 9 is a diagram 900 of an example composite DSM connection.

In the embodiment illustrated in FIG. 9, a wireless transmit/receive unit (WTRU) 906 may initiate a first DSM connection 910 with a radio network controller (RNC) 918 of a wireless network 902 (e.g., a UMTS cellular network) via a base station 916 to request spectrum. The RNC 906 may not have the resources to resolve a service request from the WTRU 906 (e.g., it does not have access to the FCC database 908 or other databases that provide functions similar to the ones that the FCC database provides) and may, therefore, initiate a second DSM connection 912 with a GGSN 920. The GGSN 920 may also not have the resources to fulfil the service request (e.g., it also does not have access to the FCC database) and may, therefore, initiate a third DSM connection 914 with a server (not shown) on the internet 904 running the FCC databases 908. On a condition that the server on the internet 904 running the FCC databases 908 is able to resolve the request, the server may generate and transmit a service resolution to the GGSN 920, which may, in response, generate and transmit a service resolution to the RNC 918, which may, in response, generate and transmit a service resolution to the WTRU 906 that sent the original service request. [0124] FIG. 10 is a diagram 1000 of another example composite DSM connection. In the illustrated embodiment, the TVWS database 1008 runs a DSM server. A device 1002 (e.g., a device such as a modified 802.11 device or an 802. llaf device) may directly establish an atomic DSM connection 1010 with the TVWS database 1008 via an access point (AP) 1004 over the internet 1006. Here, the composite DSM connection includes a single atomic DSM connection 1010 because the server that runs the TVWS database 1008 has access to the TVWS database 1008 and has DSM server capabilities and, therefore, is able to fulfil the service request itself.

[0125] FIG. 11 is a diagram 1100 of another composite DSM connection. In practice, it may not be realistic to allow the TVWS database to run a DSM server due to the potentially large number of DSM clients 204 that may need access to the TVWS database. Instead, a TVWS database 1114 may provide only a subset of the functions that a full-blown DSM server provides. Here, a device 1104 may set up both a DSM client 1104 and a DSM server 1102 on itself and use the DSM server 1106 to exchange information with the TVWS database 1114 via an AP 1110 over the internet 1112. Here, the DSM client 1104 sets up a first DSM connection 1108 with the DSM server 1106, and the DSM server 1106 initiates a second DSM connection 1116 with a server (not shown) on the internet 1112 running the TVWS database 1114 via the AP 1110. The server running the TVWS database 1114 is able to resolve the service request because it has access to the TVWS database 1114.

[0126] FIG. 12 is a diagram 1200 of another example composite DSM connection implemented with regard to neighborhood/enterprise multimedia and infotainment delivery applications, which may use DSM to access more spectrum in order to support high-bandwidth multimedia applications in a neighborhood or enterprise setting. Here, a wireless local access network (WLAN) device with modified 802.11 RAT may initiate a first DSM connection 1210 with a neighborhood multimedia sharing controller (NMSC) 1204. The NMSC 1204 may not have access to the TVWS database and, therefore, may initiate a second DSM connection 1212 with a node 1206 on a wireless network 1220. The node 1206 may also not have access to the TVWS database 1208 and, therefore, may initiate a third DSM connection 1214 with a server on the internet 1230 running the TVWS database 1208. Since the server on the internet 1230 has access to the TVWS database 1208, the server may resolve the request by generating and transmitting a service resolution to node 1206, which may generate and transmit a service resolution to the NMSC 1204, which may generate and transmit a service resolution to the WLAN device 1202 to resolve the original service request.

[0127] FIG. 13 is a diagram 1300 of another example composite DSM connection implemented in a mobile ad hoc network (MANET). The embodiment of the MANET illustrated in FIG. 13 includes peer nodes 1302, 1304, 1306 and 1308. Each of the peer nodes 1302, 1304, 1306 and 1308 may have different knowledge about policies and spectrum usage in the network. Here, the peer node 1302 may initiate a first DSM connection 1310 with the peer node 1304 by sending a service request to the peer node 1304. On a condition that the peer node 1304 does not have sufficient information to fulfil the service request, the peer node 1304 may initiate a second DSM connection 1312 with the peer node 1306 by sending a service request to the peer node 1306. On a condition that the peer node 1306 does not have sufficient information to fulfil the service request, the peer node 1306 may initiate a third DSM connection 1314 with the peer node 1308 by transmitting a service request to the peer node 1308. On a condition that the peer node 1308 has sufficient information to fulfil the service request, the peer node 1308 may generate and transmit a service resolution to the peer node 1306, which may, in response, generate and transmit a service resolution to the peer node 1304, which may, in response, generate and transmit a service resolution to the peer node 1302 to fulfil its original service request.

[0128] FIG. 14 is a diagram 1400 of another example composite DSM connection formed among several different DSM systems. Here, the DSM architecture supports cooperation among the different DSM systems by establishing atomic or composite DSM connections between the DSM servers of the different DSM systems. For example, three DSM systems are illustrated in FIG. 14: a WLAN 1406, a home network 1402 and a MANET 1404. Each of the three DSM systems includes a DSM server. In particular, an AP 1418 may be the DSM server for the WLAN 1406, a home NodeB 1414 may be the DSM server for the home network 1402 and a MANET gateway node 1416a may be the DSM server for the MANET 1404. The WLAN 1416 may further include devices such as modified 802.11 devices 1420a, 1420b and 1420c. The home network 1402 may further include devices such as a zigbee node 1412a, a zigbee node 1412b and a modified 802.11 device 1410. The MANET may further include devices such as modified 802.11 devices 1416b, 1416c, 1416d, 1416e, and 1146f. The three DSM servers may cooperate by establishing atomic/composite DSM connections between them (e.g., DSM connections 1490a, 1490b, 1490c, 1490d and 1490e illustrated in FIG. 14). Databases, such as the TVWS database 1440 and the FCC policies database 1430 may be accessible to the DSM servers via the internet 1450.

[0129] In order to set up a composite DSM connection (which may include the atomic DSM connection as a special case), two types of messages may need to be sent: a service request message and a service resolution message. A service request message may include information such as an address of the beneficiary, a maximum number of DSM connections allowed, location information of the beneficiary, a time duration for the requested spectrum access and radio parameters of the beneficiary. The address of the beneficiary may include, for example, the address of the DSM client (the initial source) that will eventually use the spectrum, the address of the DSM client (the source) that is sending the service request, and the address of the DSM server (the destination) that will handle the service request. The type of address may be an IP address, a MAC address or a WTRU identifier, for example. With regard to the maximum number of DSM connections allowed, every time a next hop atomic DSM connection is established, the maximum number of atomic DSM connections may be decreased by one. This may avoid forming an excessively long composite DSM connection. With regard to radio parameters of the beneficiary, the idea is that in a composite DSM connection, the first DSM server may want to hide this information from other DSM servers to reduce the communication overhead, and in this case, the radio parameters may not be included in the message. If the first DSM server hides this information, it needs to properly form a service request that does not affect the eventual resolution of the original service request. The radio parameters may include, but are not limited to, possible operating frequency ranges and/or bandwidths, possible transmission power levels and possible coding rates and/or modulation schemes.

[0130] A hierarchical coding scheme may be used to encode the types of radio parameters and reserve certain codes for further extension. The three-tier coding scheme shown in Table 5 below may be used to encode the types of radio parameters related to frequency and modulation.

Table 5

[0131] To fully specify the radio parameters, values of the radio parameters are given as well. In example shown in table 5, for Freq. range (0), the frequency chunks, which may or may not be contiguous, are listed.

[0132] The types of service requests should be diverse enough to support various applications, and the number of types should be small enough to minimize complexity. A service request may be one of the following types: rate based, volume based and best effort. With regard to rate based service requests, the DSM client may specify a desired data rate, and the DSM server may allocate spectrum to the DSM client and other involved devices to support the specified data rate. With regard to volume based service requests, the DSM client may specify an amount of data it needs to transmit, and the DSM server may allocate enough spectrum and time duration to deliver the requested amount of data. Volume based service requests may be especially suitable for file download applications. With regard to best effort service requests, the DSM client may not quantify its needs. Here, the DSM server may allocate spectrum to the DSM client and other involved devices to the extent possible. Service requests from all DSM clients may be considered together in deciding the best effort allocation for each DSM client. An example format of a DSM service request message is illustrated below in Table 6.

Table 6

[0133] A service resolution message may deliver a service resolution from a

DSM server back to a DSM client and may include information such as an address of the source of the service resolution message, an address of the destination of the service resolution message, an address of the beneficiary of the DSM service, and a service resolution. The service resolution may specify the spectrum allocation if the service request can be satisfied or may reject the service request otherwise. If a spectrum allocation is made, the DSM server may also provide certain transceiver configurations, and the types of configurations may be taken from the radio parameters provided by the DSM client.

[0134] To set up a composite DSM connection, which layer an atomic DSM connection should be at must be determined. Further, how the DSM client knows the address of the DSM server must be determined. Further, when and how a composite DSM should be set up must be determined. Procedures making these determinations are described below, and particularly with respect to FIGs. 14 and 15.

[0135] With respect to which layer an atomic DSM connection should be at, if the DSM connection is physically across multiple hops, the address of the DSM client and DSM server may be network layer addresses such as IP addresses. However, if the DSM connection physically is only one-hop, lower layer addresses, such as MAC addresses, can be used instead. In the one-hop case, lower layer addresses may be used because it eliminates the processing and delay incurred during inter-layer communications.

[0136] The criterion for determining when to use network layer addresses or lower layer addresses may be based on whether the DSM server is within the communication range of the DSM client. One way of doing this is for the DSM client to first check the lower layer (lower than network layer) addresses of the nodes that be reached directly. If the DSM server is identified to be among them, the DSM client may use lower layer addresses. Otherwise, the DSM client may use network layer addresses.

[0137] FIG. 15A is a flow diagram 1500a illustrating an example procedure for determining what type of address to use for a DSM server. On a condition that a device A needs to set up an atomic DSM connection with a device D, in element 1552, the device A may retrieve device D's address addr_D from a DSM server list L. In decision block 1554, the device A may determine whether the address addr_D is a MAC layer address. If so, decision block 1556 is entered. If no, element 1562 is entered.

[0138] In decision block 1556, a determination may be made whether addr_D is marked as a neighbor. If not, a failure may be reported in element 1564. If yes, in element 1558, addr_D may be used for the DSM server, and, in element 1560, an atomic DSM connection may be initiated. [0139] In element 1562, addr_D may be translated to MAC layer addresses using ARP. In element 1556, it may be determined whether the translation was successful. If not, element 1574 is entered. If yes, decision block 1568 is entered.

[0140] In element 1574, the not translated addr_D may be used for the

DSM server. Then, in element 1576, an atomic DSM connection may be initiated.

[0141] In decision block 1568, it may be determined whether the translated addr_D is marked as a neighbor. If not, element 1574 (described above) may be entered. If yes, element 1570 may be entered, and the translated addr_D may be used for the DSM server. Then, in element 1572, an atomic DSM connection may be initiated.

[0142] With respect to how the DSM client may know the address of the

DSM server, there are a number of ways for a DSM client to do this. First, the DSM client may know the address of the DSM server when it registers with a device that runs as a DSM server. Second, the DSM server may periodically broadcast its identity to advertise that it provides DSM service and is open to accept new DSM clients. Third, in a hierarchical network, such as a cellular network, an end user device may use the address of its parent (e.g., an RNC in UMTS, an eNodeB in LTE, etc.) as the default DSM server.

[0143] With respect to when and how to set up a composite DSM connection, the DSM client may maintain a list of DSM servers and may follow a procedure such as the embodiment of the method illustrated in the flow chart 1500B of FIG. 15B. On a condition that a device needs to access spectrum, in element 1502, it may be determined whether spectrum has been allocated. If so, in element 1504, the device may transmit the communication using the allocated spectrum. If not, element 1506 may be entered.

[0144] In element 1506, a list L of DSM servers may be created by making a copy of available DSM servers. Then, in element 1510, it may be determined whether the list is empty (e.g., if no DSM servers are available). If the list is empty, a failure may be reported in element 1512. If the list is not empty, a first DSM server on the list that has not been contacted for the current DSM service may be chosen, and a service request to the chosen DSM server may be generated. In element 1514, an atomic DSM connection may be setup with the chosen DSM server.

[0145] In element 1516, whether setup was successful may be determined.

If setup was determined to be unsuccessful, the chosen DSM server may be removed from the list L in element 1518, element 1508 may be re-entered, and another DSM server may be chosen. If no other DSM server is available, the spectrum access attempt may be terminated.

[0146] If setup was determined to be successful in element 1516, a service request may be sent in element 1520. Then, in element 1522, it may be determined whether a service resolution was received within a predetermined timeout period. If the service resolution is received with the predetermined timeout period, and the service resolution provided access to the spectrum, the transceiver may be reconfigured and the spectrum may be accessed to transmit a communication in element 1524. If the service resolution is not received within the predetermined timeout period, another DSM server may be chosen from the list L in element 1508 (if one is available). If no DSM server is available, the attempt to access the spectrum may be terminated.

[0147] FIGs. 16A and 16B are a flow diagram 1600 illustrating a method that may be implemented in a DSM server. On a condition that a DSM server receives a service request, the DSM server may determine in element 1602 whether a maximum connection count is greater than 0. If not, the DSM server may discard the service request message in element 1604. If yes, the DSM server may decrease the maximum connection count by 1 in element 1606, run spectrum allocation algorithms in element 1608 and determine whether the DSM server is able to resolve the service request in element 1610.

[0148] If the DSM server determines that it is able to resolve the service request in element 1610, the DSM server may send a service resolution message (either an allocation of spectrum or a rejection of the service request) in element 1612. If the DSM server determines that it is unable to resolve the service request in element 1610, the DSM server may create a list L of available DSM servers by making a copy of all available DSM servers. Then, in element 1616, the DSM server may look up the DSM server list L and, in element 1618, determine whether the list L is empty. If the list L is determined to be empty in element 1618, the DSM server may send a service resolution indicating that the service request is rejected in element 1620. If the list L is determined to not be empty in element 1618, the DSM server may set up an atomic DSM connection with the first DSM server on the list L in element 1622 and then determine whether the setup was successful in element 1624.

[0149] If the DSM server determined that the setup was not successful in element 1624, the DSM server may remove the chosen DSM server from the list L in element 1626 and choose another DSM server from the list L in element 1616 (if one is available). If the DSM server determined that the setup was successful in element 1624, the DSM server may proceed to send a service request in element 1628. Then, in element 1620, the DSM server may determine whether it received a service resolution message within a predetermined timeout period. If not, the chosen DSM server may be removed from the list L in element 1626 and a new DSM server may be chosen in element 1616 (if one is available). If the DSM server determined that it received a service resolution message within the predetermined timeout period, the DSM server may form a service resolution message in element 1632 and transmit the service resolution message (e.g., an allocation of spectrum or a rejection of the service request) in element 1634.

[0150] The composable DSM architecture may support centralized, distributed or hybrid DSM systems, for example, by controlling a DSM server advertisement message. A DSM server advertisement message may include information such as an address of the initiator of the message and a time-to-live (TTL) field that may decrease by 1 each time the message is forwarded.

[0151] In a centralized DSM system, only one device may serve as a DSM server. That device may broadcast an advertisement message throughout the DSM system. The TTL field in the advertisement message may be set such that the broadcast message may reach any device in the network. As a result of the broadcast, all other devices in the network may know the existence of the DSM server, and each device may establish an atomic DSM connection with the DSM server.

[0152] FIG. 17 is a diagram 1700 of an embodiment of a centralized DSM system. The example system illustrated in FIG. 17 is a home network with a home NodeB 1702 serving as the DSM server. Devices 1704, 1706, 1708 and 1712 are able to establish a direct atomic DSM connection with the home NodeB 1702. Device 1710, however, may establish an atomic DSM connection with the home NodeB 1702 via a relay node (in this example, device 1712). The devices 1704, 1706, 1708, 1710 and 1712 may be, for example, one or more of a modified 802.11 device and a zigbee device.

[0153] In a distributed DSM system, every device in the system may serve as a DSM server. By controlling the TTL field in its advertisement message, a DSM client may establish an atomic DSM connection with devices that are TTL hops away. The TTL field may be set to 1 so that a device may only establish an atomic DSM connection with those devices within its direct communication range. However, not all possible atomic DSM connections may be established. Rather, the establishment may be based on the needs of the DSM applications. Also, composite DSM connections may be formed from atomic DSM connections. In the distributed mode, several DSM units may be interconnected and may share their sensing results with each other to increase the coverage area and improve sensing reliability.

[0154] FIG. 18 is a diagram 1800 of an embodiment of a distributed DSM system. The example system illustrated in FIG. 18 includes a plurality of devices 1802, 1804, 1806, 1808, 1810, 1812, 1814, 1816 and 1818, each of which may act as a DSM server. The TTL may be set to 1 so that each device 1802, 1804, 1806, 1808, 1810, 1812, 1814, 1816 and 1818 may establish an atomic DSM connection only with devices within their direct communication range (indicated by the double-sided arrows in FIG. 18). The illustrated devices 1802, 1804, 1806, 1808, 1810, 1812, 1814, 1816 and 1818 may be, for example, modified 802.11 devices.

[0155] In a hybrid DSM system, only a subset of devices in the system may serve as DSM servers. A hybrid DSM system may be enforced by controlling the DSM server advertisement.

[0156] FIG. 19 is a diagram 1900 of an embodiment of a hybrid DSM system. The example system illustrated in FIG. 19 includes a MANET 1910, a wireless network 1920 (e.g., an LTE network) and a home network 1930. The MANET 1910 includes a plurality of devices 1912, 1914, 1916, 1918 and 1920 (e.g., modified 802.11 devices). One of the devices in the MANET 1910, device 1912, may be a gateway device which advertises as a DSM server. The wireless network 1920 may include a base station 1922 (e.g., an eNodeB), which advertises as a DSM server. The home network 1930 may includes a plurality of devices 1932, 1934, 1936, and 1938. The devices 1934, 1936 and 1938 may be, for example, one or more of zigbee nodes and modified 802.11 devices. The device 1932 may be a home NodeB, which advertises as a DSM server.

[0157] In the example system illustrated in FIG. 19, only the base station

1922, the MANET gateway 1912 and the home NodeB 1932 may advertise as DSM servers. Due to communication range and RAT limitations, a zigbee node in the home network (e.g., device 1934) may hear only the DSM server advertisement from the home NodeB 1932 and, thus, may choose the home NodeB 1932 as its DSM server, which in turn may only hear the DSM server advertisement from the base station 1922 and may choose the base station 1922 as its DSM server. As a result, a hybrid DSM system may be configured. Some of the DSM functionality may be distributed to the home NodeB 1932 and the MANET gateway 1912, while the DSM subsystems (e.g., the home network 1930 and the MANET 1910) may be centralized.

[0158] The distributed mode is described in more detail with respect to

FIGs. 3 and 20. In FIG. 3, the neighbor DSM sensing configuration database 314 may be included in devices that are capable of operating in distributed mode. The DSM sensing configuration database 314 may be used to store sensing configuration information from neighbor DSMs and/or configuration information of sensory nodes controlled by neighbor DSM units. For each sensory node controlled by a neighbor DSM unit, the parameters may include a working spectrum, a location, RF device sensitivity, computational capability, supporting sensing schemes, latency condition, transmission power and other information. The neighbor DSM sensing configuration database 314 may also contain the collaborative level between the local DSM unit and the neighbor DSM unit. This information may indicate how many resources of the neighbor DSM unit may be used by the local DSM unit. Table 7 shows an example of the data form in the neighbor DSM sensing configuration database 314.

Table 7

[0159] The neighbor DSN sensing configuration database 314 may be simplified by ignoring the details of the sensors controlled by the neighbor DSM units. Table 8 shows an example of a simplified data format in the neighbor DSM sensing configuration database 314. As shown in Table 7, the parameters may include working spectrum, location coverage, average RF device sensitivity, average computational capability, all supporting sensing schemes, average latency and cooperative level. Table 8

[0160] FIG. 20 is a signal diagram 2000 of a method of operating a distributed mode. Before the method illustrated in FIG. 2000 begins, the following elements (not shown) may be carried out. In particular, when a sensory node joins a network, it may first register to the sensing controller 301 of the DSM server 202. The sensing controller 301 of the DSM server 202 may then send a configuration request message for sensing capability information of the sensory node. The returned sensing capability information may then be processed at the capability registry unit 304 of the DSM server 202 and stored in the sensory nodes configuration database 310 of the DSM server 202. According to the configuration information, the sensing controller 301 of the DSM server 202 may then send a sensing test request message to all sensory nodes in the network in order to collect the correlation information between the newly joined sensory node and the other sensory nodes already in the sensing sub-network. The returned sensing results may be processed at the correlation analyzer unit 302 of the DSM server 202 and stored in the sensory nodes correlation database 310 of the DSM server.

[0161] The sensing processor 208 of the sensing controller 301 of the DSM server 202 may then send a neighbor sensing configuration update message 2002 to the sensing processors 208a of any neighboring nodes to inform them of this update. The neighbor configuration update message 2002 may be sent periodically or instantaneously. For example, another neighbor configuration update message 2006 may be transmitted at a later point in time. A neighbor configuration update message (e.g., messages 2002, 2006 and 2012 illustrated in FIG. 20) may include information that is included in a neighbor DSM sensing configuration database 314.

[0162] When a sensory node (e.g., a neighbor sensory node) has a change of its condition, including, for example, exiting the sensing sub-network, the sensing processor 208a of the neighbor sensory node may update its sensory nodes configuration database, its sensory nodes correlation database and its sensing results database and send a neighbor configuration update message 2004 to the neighbor DSM sensing processors 208 (e.g., the sensing processor 208 of the DSM server 202). When a sensing controller receives a neighbor configuration update message, it may simply update the neighbor DSM configuration database 316.

[0163] When the sensing controller 301 of the DSM server 202 receives a spectrum inquiry from the cognitive engine 206, or receives a neighbor sensing request 2008 from a neighbor DSM unit, it may first analyze the sensing request to see if there is a need to begin a new local sensing task, it can simply resort to the existing sensing results database, or there is a need to begin a new neighbor sensing task. The neighbor sensing request message 2008 may include information such as a spectrum of interest, a location of interest, a sensing latency requirement, and sensing/combining schemes. If the sensing controller decides to perform a new local sensing task, it may check the sensory nodes configuration database 312 to determine which sensory nodes should participate in the current sensing task by using what kinds of sensing schemes. It may then send a sensing request to the corresponding sensory nodes and the information fusion unit. When the sensing controller 301 receives the notice from the information fusion unit, it may check the sensing results stored in the sensing results database 316. Finally, it may send the sensing results back to the cognitive engine or the requesting neighbor DSM unit. [0164] If the sensing controller 301 decides to resort to a neighbor DSM unit, it may check the neighbor DSM sensing configuration database to determine which DSM unit should participate in the current sensing task. It may then send a neighbor sensing request message 2008 to the corresponding neighbor DSM sensing processor 208a and the information fusion unit. The neighbor sensing processor 208a may then send sensing results in a neighbor sensing response message 2010, which may be stored in the sensing results database 316. The neighbor sensing response message 2010 may be sent from the neighbor sensing processor 208a to the information fusion block 306 of the DSM server 202. The information contained in this message may depend on information fusion schemes used. For example, if a hard combining scheme is used, then the message may be a 1-bit decision. If a soft combining scheme is sued, the message may include the soft sensing information.

[0165] When the sensing processor 208 receives the notice from the information fusion unit 306, it may check the sensing results stored in the sensing results database 316 and send the sensing results back to the cognitive engine 206 or requesting neighbor DSM unit. Neighbor DSM units may be updated with a neighbor configuration update message 2012.

[0166] If the sensing controller 301 decides to not perform a new sensing task, it may send a request to a proactive interference detector. When it receives the notice from the proactive interference detector, it may check the results and send them to the cognitive engine 206 or the requesting neighbor DSM unit.

[0167] As described above, the information fusion unit 306 may combine sensing results from a plurality of sensory nodes and make an overall decision as to availability of requested spectrum based on a combination of the sensing results received from the plurality of sensory nodes. Combining techniques may generally be classified into three categories: hard combining, hard combining with side information and soft combining.

[0168] In hard combining, each sensory node in a network may send a DSM unit a binary decision as to whether a signal is present on the spectrum. An example hard combining rule is the k-out-of-n-rule, which may reduce to the "AND" rule if k = n, the "OR" rule if k = 1 and the majority rule if k = n/2.

[0169] In hard combining with side information, sensory nodes may send a

DSM unit information in addition to the binary decision. The additional information, such as the sensory node's signal-to-noise ratio (SNR), the sensory node's detection probability and the sensory node's false alarm probability, may indicate the reliability of the sensing decision. This information may help the DSM unit to make a better overall decision as to whether the spectrum is in use by primary users. Corresponding information combining rules may include, for example, the selection rule, the switch- and- stay rule and the Chair- Varshney rule.

[0170] In soft combining, instead of sending a DSM unit binary decisions, sensory nodes may send the DSM unit some soft information, such as detected energy level and SNR. Corresponding information combining rules may include, for example, the equal-gain rule and the maximal-ratio rule.

[0171] According to the "AND" rule for hard combining, the information fusion unit 306 of FIG. 3 may declare the presence of a primary user on a particular spectrum if all the sensory nodes participating in a sensing task declare the presence of the primary user. To execute this fusion rule, the information block may wait for the decisions from all of the sensory nodes. This may be time-consuming, as each sensory node may need to run a basic sensing operation and send its decision to the information fusion unit 306. If a sensory node experiences difficulty in computing or transmission traffic, then it may result in a large delay at the information fusion unit 306. Subsequently, the latency requirements of a wireless application may not be met.

[0172] In an embodiment of a DSM server 208, the information fusion unit

306 may be configured to implement a modified "AND" rule by declaring a presence of a primary user on the spectrum if all decisions received from the sensory nodes participating in the sensing task over a predetermined time period declare the presence of the primary user on the spectrum. [0173] In another embodiment of a DSM server 208, the information fusion unit 306 may be configured to implement a modified "OR" rule based only on decisions received from the sensory nodes participating in the sensing task over a predetermined time period.

[0174] In another embodiment of a DSM server 208, the information fusion unit 306 may be configured to implement a modified K out of N rule by declaring a presence of a primary user on the spectrum if more than a fraction of K/N out of the decisions received within a predetermined time period declare the presence of the primary user on the spectrum.

[0175] In another embodiment of a DSM server 208, the information fusion unit 306 may be configured to implement one or more of a modified Advanced AND rule, a modified Advanced OR rule and a modified (Pf, P_m)-based rule by executing these rules only on the decisions received from sensory nodes within a predetermined time period.

[0176] In another embodiment of a DSM server 208, the information fusion unit 306 may be configured to implement a modified switch and stay rule by following a decision reported by a sensory node if its decision was used in a previous decision, if its signal-to-noise ration (SNR) is above a threshold and if its sensing decision is received by the information fusion unit 306 within a predetermined time period. Otherwise, the information fusion unit 306 may find the sensory node with the largest SNR among the set of all sensory nodes whose decisions are received by the information fusion unit 306 within a predetermined time period. The information fusion unit 306 may then follow the decision of this sensory node.

[0177] In another embodiment of a DSM server 208, the information fusion unit 306 may be configured to implement one or more soft combining rules based on soft information received within a predetermined time period.

[0178] FIG. 21 is a signal diagram 2100 illustrating an embodiment of a method of information fusion. A cognitive engine 206 may transmit a spectrum inquiry message 2110 to a sensing processor 208. The spectrum inquiry message 2110 may include a latency requirement for the sensing processor 208 to consider when carrying out information fusion. The sensing processor 208 may analyze the spectrum inquiry message 2110 and assign the sensing task to a plurality of sensory nodes (e.g., sensory nodes 2102, 2104 and 2106). The sensing processor 208 may then send sensing request messages (e.g., sensing request messages 2112, 2114 and 2116) to the sensory nodes assigned to the sensing task (e.g., sensory nodes 2102, 2104 and 2106, respectively). The sensing request messages 2102, 2104 and 2106 may include information such as a sensing results type, sensing techniques to be applied, the sensing latency requirement, channels to be sensed and other requests such as routing of sensing results.

[0179] Each of the sensory nodes 2102, 2104 and 2106 receiving a sensing request 2112, 2114 or 2116 from the sensing processor 208 for a sensing task may attempt to complete sensing operations requested in the sensing request in accordance with the latency requirement provided in the sensing request (e.g., complete sensing operations within a specified time limit). Once the sensing operation is finished, the sensory node may check to see if it met the latency requirement. If so, the sensory node may send a sensing response message to the sensing processor 208. Otherwise, the sensory node may not send a message. In the embodiment illustrated in FIG. 21, the sensory nodes 2102 and 2104 met the latency requirement and sent sensing response messages 2118 and 2120, respectively, to the sensing processor 208.

[0180] In block 2124, the sensing processor 208 may then combine all of the sensing results received during a predetermined time out period 2122. All sensing response messages that may be received after the time out period 2122 has expired (e.g., sensing response message 2128) may be discarded (block 2130). After applying one or more combining schemes, such as described above, the sensing processor may generate a spectrum response message 2126 including the combined sensing results and provide it to the cognitive engine 206.

[0181] Sensing request (2202), sensing response (2204), configuration request (2206), configuration response (2208), test request (2210) and test response (2212) messages may be implemented using 802.11 frames, as illustrated in FIG. 2200. The frame body of an 802.11 management frame may include an identifier for the type of sensing related frame employed (e.g., "000" for a sensing request message 2202, "001" for a sensing response message 2204, "010" for a configuration message 2206, "011" for a configuration response message 2208, "2210" for a test request message 2210 and "101" for a test response message 2212). The frame body for each type of message may also include the contents of the message. For example, the frame body for the sensing request message 2202 may include a sensing results type, latency requirement, requested sensing frequency bands and other requests. The sensing latency requirement may be in microseconds.

[0182] FIG. 23 is a flow diagram illustrating a method of information fusion that may be implemented by a sensing processor 208. In element 2302, responsive to receiving a spectrum inquiry from a cognitive engine 206, the sensing processor 208 may select sensory nodes to participate in a sensing task relating to the received spectrum inquiry and transmit sensing request messages to the selected sensory nodes. In element 2304, the sensing processor 208 may wait for sensing response messages from the sensory nodes in response to the sensing request messages.

[0183] In element 2306, the sensing processor 208 may determine whether the time out period has expired. If so, in element 2310, the sensing processor 208 may combine all of the sensing results that have been received up until that point in time and provide a spectrum response message to the cognitive engine. If the time out period has not expired, in element 2308, the sensing processor 208 may determine whether sensing response messages have been received from all of the sensory nodes that were selected to participate in the sensing task. If all of the sensing response messages have been received, the sensing processor 208 may combine results from all of the sensing response messages and provide a spectrum response message to the cognitive engine. If not, element 2304 may be re-entered, and the sensing process 208 may continue to wait for sensing response messages from sensory nodes.

[0184] Besides latency restrictions on information fusion algorithms from, for example, wireless applications, the information fusion unit 306 may also have memory limitations, which may lead to infeasibilities for some information fusion algorithms, especially if a number of sensory nodes involved in a sensing task is large.

[0185] The memory at the information fusion unit 306 may not be a problem for most hard combining schemes because only one bit from each sensory node may be recorded. However, for hard combining schemes with side information or soft combining schemes, the information fusion unit 306 may need to record a lot of soft information. Here, a use-and- discard approach may be used where whenever a sensing processor 306 receives a sensing result from an individual sensory node, it may combine the sensing result with an overall metric and discard that individual sensing result. A similar approach may be used for hard combining schemes if desired.

[0186] In the hard combining schemes (e.g., AND, OR, and k out of N rules), the information fusion unit 306 may accumulate the summation of decisions whenever it is available. Once a decision is counted, the single-bit decision may be discarded. Such an approach may be extended to hard combining schemes with side information, such as Advanced AND, Advanced OR, and Pf, Pm-based schemes. For the "switch and stay" rule, the information fusion unit 306 may only need to record the largest SNR and its corresponding decision and the SNR and decision of the sensory node that was previously followed. This may avoid recording all the SNR values and the corresponding decisions from all the other sensory nodes. Such an approach may be extended to soft combining schemes, such as 2-bit energy value, equal gain combining and evidence theory- based schemes.

[0187] FIG. 24 is a signal diagram 2400 illustrating an embodiment of a method of information combining using a use-and-discard approach. The sensing processor 208 may analyze the spectrum inquiry message and assign the sensing task to a plurality of sensory nodes (e.g., sensory nodes 2102, 2104 and 2106). A cognitive engine 206 may transmit a spectrum inquiry to a sensing processor 208. The sensing processor 208 may then send sensing request messages (e.g., sensing request messages 2410, 2412 and 2414) to the sensory nodes assigned to the sensing task (e.g., sensory nodes 2402, 2404 and 2406, respectively). As the sensing processor 208 receives sensing response messages 2416, 2420 and 2424 from the sensory nodes 2401, 2404 and 2406, respectively, the sensing processor may combine the sensing results received in the sensing response message and discard the individual sensing results (blocks 2418, 2422 and 2426). The sensing processor 208 may then send a spectrum response message 2428 to the cognitive engine 206 including the combined sensing results.

[0188] FIG. 25 is a flow diagram 2500 illustrating an embodiment of a method of information combining using a use-and-discard approach that may be implemented in a sensing processor 208. In response to receiving a spectrum inquiry from a cognitive engine 206, in element 2502, the sensing processor 208 may select a plurality of sensory nodes to participate in a sensory task relating to the spectrum inquiry and send sensing request messages to the selected sensory nodes. In element 2504, the sensing processor 208 may wait to receive sensing response messages from the selected sensory nodes providing their individual sensing results. In element 2506, in response to receiving a sensing response message from one of the selected sensory nodes, the sensing processor 208 may combine the sensing results into an overall metric and discard the individual sensing results. In element 2508, the sensing processor 208 may determine whether sensing results messages have been received from all of the selected sensory nodes. If yes, in element 2510, the sensing processor may make an overall decision on spectrum occupancy based on the final metric and transmit a spectrum response communicating the overall decision to the cognitive engine 206. If not, element 2504 may be re-entered, and the sensing processor 208 may continue waiting to receive sensing responses from the remaining ones of the selected sensory nodes.

[0189] According to an embodiment, an information fusion unit 306 may weightily combine hard sensing results from multiple sensory nodes in order to obtain a reliable overall decision. The weight of the hard sensing results may depend on the SNR at the corresponding sensory node or may depend on a false alarm probability Pf and a miss detection probability P_m estimated by the corresponding sensory node. This may be because these parameters imply a reliability level of a sensory node.

[0190] Besides the SNR and the (Pf, P_m), another parameter indicating a reliability level of a sensing decision may be the sensitivity of the radio device included in the corresponding sensory node. If a sensory node is equipped with a more sensitive radio device, then its decision may have a larger weight in the information fusion process.

[0191] Information about a sensitivity of a radio device may be collected when a sensory node registers with a DSM sever or when a sensory node participates in a cooperative sensing task. Since a sensitivity of a radio device may be related to a cost of the device (e.g., the more expensive the device, the more sensitive the device), a cost of a radio device may be used as a metric for the sensitivity level in an embodiment.

[0192] By way of example, the quality of radio devices may be categorized into p classes where a first class radio device may be the highest quality and a p^th class radio device may be the lowest quality. In this example, an information fusion block may declare a presence of a primary user if equation (1) below is satisfied.

2¾./¾≥ L, Equation 1 where ni is the number of sensory nodes that are equipped with the i^st class radio devices and ki is the parameter with ki > k2 > ... kp. It follows from the relations among ki that the decision from a sensory node equipped with a lower class radio device may play a more important role in the overall decision.

[0193] FIGs. 26A and 26B are a signal diagram 2600 illustrating an embodiment of a method of information fusion using radio device sensitivity information. The sensitivity level information of a radio device may be processed by a capability registry unit 304 and stored in a sensory nodes configuration database 312 when a sensory node registers with a DSM unit. Specifically, a sensing processor 208 may transmit a configuration request message 2608 to a sensory node 2602, a configuration request message 2614 to a sensory node 2604 and a configuration request message 2620 to a sensory node 2606. Each configuration request message 2608, 2614 and 2620 may include information such as working spectrum, location, computational power, supporting sensing techniques and RF device sensitivity level. Each sensory node 2602, 2604 and 2606 may transmit a configuration response message 2610, 2616 and 2622, respectively, back to the sensing processor 208 and include its RF device sensitivity level information in the configuration response message that it transmits. Example formats for a configuration request message and a configuration response message are illustrated in FIG. 22.

[0194] A capability registry unit 304 of the sensing processor 208 may process each of the configuration response messages 2610, 2616 and 2622 and store the RF device sensitivity level information for each of the sensory nodes 2602, 2604 and 2606 retrieved from each of the messages in a sensory nodes configuration database 312 (blocks 2612, 2618 and 2624).

[0195] When the sensing processor 208 receives a spectrum inquiry 2626 from a cognitive engine 206, a sensing controller 301 of the sensing processor 208 may select sensory nodes to participate in a sensing task relating to the spectrum inquiry 2626. The sensing controller 301 may make this decision based on the sensitivity levels of each of the sensory node's radio devices (e.g., during registration) (block 2628). In the example embodiment illustrated in FIGs. 26A and 26B, the sensing controller 301 may select sensory nodes 2602 and 2606 to participate in the sensing task and transmit sensing request messages 2630 and 2632 to the sensory nodes 2602 and 2606, respectively. When the information fusion unit 306 receives sensing response messages 2634 and 2636 from the sensory nodes 2602 and 2606, respectively, it may retrieve the RF device sensitivity level information of each sensory node from the sensory nodes configuration database 312 and use the retrieved information to adjust the weight of the sensing results (block 2638). The sensing processor 208 may send a spectrum response 2640 with the combined sensing results to the cognitive engine 206.

[0196] FIG. 27 is a flow diagram 2700 illustrating an embodiment of a method of sensory node registration including radio device sensitivity information. In element 2702, a sensing controller 301 may send a configuration request message to a sensory node. In element 2704, in response to receiving the configuration request message, the capability registry 304 may store the sensitivity level information into the sensory nodes configuration database 312 to complete the sensory node registration.

[0197] FIG. 28 is a flow diagram 2800 illustrating an embodiment of a method of information fusion using radio device sensitivity information that may implemented in a sensing processor 208. In response to receiving a spectrum inquiry from a cognitive engine 206, in element 2802, a sensing controller may assign sensory nodes to a sensing task relating to the spectrum inquiry based on the sensitivity level information of each of the registered sensory nodes. In element 2804, when the information fusion unit 306 receives a sensing response message from a sensory node, it may retrieve the sensory level information that was stored in the sensory nodes configuration database 312 during registration. In element 2806, the information fusion unit 306 may combine sensing results received from the selected sensory nodes using a proposed combining scheme and weighting the sensing results received from the selected sensory nodes based on the sensory level information from each of the sensory nodes. The sensing processor 208 may then transmit a spectrum response to the cognitive engine 206.

[0198] If the distance from the sensory nodes to the potential primary user is available to the information fusion unit 306, then the distance information may be used as an indicator of the reliability of the sensory nodes. The closer a sensory node is to a primary user of the spectrum, the more reliable the sensing results provided by the sensory node may be. By way of example, location information for a digital television station may be obtained from a TVWS database (e.g., TVWS database 220).

[0199] FIG. 29 is a flow diagram 2900 illustrating an embodiment of a method of sensory node registration including retrieval of location information. In element 2902, a sensing processor 208 may send a configuration request message to a sensory node including a request for location information. In response to the configuration request message, the sensing processor 208 may receive a configuration response message including the requested location information. In response to receiving the configuration response message, in element 2904, the capability registry unit 304 of the sensing processor 208 may process the location information included in the configuration response message and store it in the sensory nodes configuration database 310. The location information included in the configuration response message may be a relative location of the sensory node to the DSM unit or may be an absolute location of the sensory node.

[0200] FIG. 30 is a flow diagram 3000 illustrating an embodiment of a method of assigning sensing tasks to sensory nodes and performing information fusion accounting for the location information. In response to receiving a spectrum inquiry from a cognitive engine 206, in element 3002, a sensing controller 301 may determine which sensory nodes to assign to a sensing task related to the sensing inquiry. The determination may be based on the location of the sensory nodes. In element 3004, in response to receiving a sensing response message from a sensory node, an information fusion unit 306 of a sensing processor 202 may retrieve the location information of the sensory node from the sensory nodes configuration database 312. In element 3006, the information fusion unit 306 may combine sensing results received from the sensory nodes assigned to the task using a proposed scheme and weighting the responses based on the location information. The closer the sensory node is to the potential primary user, the larger the weight the sensing results of the sensory node may be given in the combined sensing results.

[0201] Each sensory node may measure a local interference temperature.

The measured interference temperature may be used as side information in combining individual sensing results. If a sensory node is located in an environment having a high interference temperature, then it may experience large interference and its sensing results may be less reliable.

[0202] The determination of the local interference temperature may be based on a sensor's previous sensing results, which may be stored in a sensing results database 316. A location-based fast frequency selection unit 308 may analyze the location interference temperature based on the previous sensing results.

[0203] In some existing SNR-based hard combining schemes, such as

Advanced AND and Advanced OR, SNR information from each sensory node may be used by the information fusion unit 306 to determine whether the sensory node's decision should be applied. Such a decision is a kind of hard decision. However, a soft version of the decision may be used. Instead of a "yes-or-no" decision, weights may be applied on the decisions made by individual sensory nodes based on their SNR values.

[0204] By way of example, an information fusion unit 306 may make the overall sensing decision based on equation (2) below.

f(u₁,...,u_N,SNR_i,...,SNR_N) = Equation 2

where SNR_max denotes the largest SNR among all the sensory nodes.

[0205] FIG. 31 is a flow diagram 3100 illustrating an embodiment of a method of information fusion using SNR-based hard combining using weighting, as described above. In element 3102, an information fusion unit 306 may find the largest SNR among all sensory nodes (SNR_max) from a list of SNRs. In element 3104, the information fusion unit 306 may calculate a ratio of SNR/SNR_max for each of the sensory nodes. In element 3108, the information fusion unit 306 may calculate the metric (e.g., equation 2) using a list of sensing results, and, in element 3106, compare the calculated metrics with a threshold (e.g., Ti). The information fusion unit 306 may then provide a combined sensing result in a fusion output that is based on weighting using the SNRs of the sensory nodes.

[0206] A switch and stay scheme of information fusion may be suitable for a centralized mode because, although an information fusion unit 306 usually follows a specific sensory node's decision, it may still need to collect the decisions from all of the sensory nodes for the switch purpose once the sensory node experiences low SNR. The switch and stay rule may also be applied in a distributed mode as follows. The sensory nodes may exchange their sensing results and SNR values with neighbor sensory nodes. A sensory node may follow the decision of a neighbor sensory node until its SNR is below a certain threshold. Otherwise, the sensory node may switch to another neighbor sensory node with the largest SNR.

[0207] To execute a (Pf, P_m)-based rule at the information fusion unit 306, each sensory node may send to the information fusion unit 306 not only its sensing decision but also a false alarm probability and a miss detection probability of the decision. These probabilities may be obtained in the process of running a basic sensing algorithm, possibly by applying extra information like an SNR. However, in some scenarios, the computation of the false alarm probability and the miss detection probability at the sensory nodes may be difficult due to various reasons, e.g. computational limitation or battery limitation at the sensory nodes. Further, the bandwidth between sensory nodes and the DSM may be restricted. Hence, the transmission of these probabilities from the sensory nodes to the DSM unit may be problematic. Accordingly, a modified (Pf, P_m)-based scheme may be used in which the computation of the false alarm probability and the miss detection probability for each sensory node may be performed at the information fusion unit 306. Though the information fusion unit 306 may not run a basic sensing operation and the SNR at each sensory node may not be available at the information fusion unit 306, it may still estimate these probabilities based on the previous performance at that sensory node. Specifically, it may obtain the statistics of these two probabilities based on the sensing history of the sensory node. The extra load at the information fusion unit 306 for the modified (Pf, P_m)- based scheme may be to record as many as possible of the past sensing results of all the sensory nodes.

[0208] According to the modified (Pf, P_m)-based scheme, the information fusion unit 306 may need to estimate the (Pf, P_m) for a certain sensory node. The estimation may be based on the previous sensing results of that sensory node, which may be stored in the sensing results database.

[0209] FIG. 32 is a flow diagram 3200 illustrating an embodiment of information fusion by estimating (Pf, P_m). The information fusion unit 306 may first retrieve, from a sensing results database 316, a list of past sensing results and a list of past channel occupations for a certain sensory node. Then, it may estimate the (Pf, P_m) as illustrated in FIG. 32. In element 3102, the information fusion unit 306 may count a number of occurrences that satisfy (Si=0, Ti=l). In element 3104, the information fusion unit 306 may count a number of occurrences that satisfy (Ti=l). In element 3006, the result provided in element 3102 may be divided by the result provided in element 3104 to provide the P_m for the sensory node. In element 3106, the information fusion unit 306 may count a number of occurrences that satisfy (Si=l, Ti=0). In element 3108, the information fusion unit 306 may count a number of occurrences that satisfy (Ti=0). In element 3110, the result provided in element 3106 may be divided by the result provided in element 3108 to provide Pf. [0210] In a cognitive radio system with multiple sensory nodes, the basic sensing algorithm applied at one sensory node may be different from that applied at another sensory node. This may result from a difference in hardware/software amongst sensory nodes. For example, an expensive sensory node may deploy a sophisticated sensing algorithm, while a cheaper sensory node may deploy a simpler sensing algorithm.

[0211] If all the sensory nodes send to the information fusion block the same type of sensing results (including, for example, hard decision of its sensing results, hard decision with the same type of side information and same type of soft sensing information), then the information fusion unit 306 may simply use the existing combining schemes. However, all of the sensory nodes may not send the same kind of sensing information. For example, some sensory nodes may send their hard decisions, some sensory nodes may send their hard decisions with side information, and other sensory nodes may send soft sensing information. The fusion of sensing information in this example may not be straightforward. To address this situation, information fusion may be performed as follows.

[0212] First, each type of soft sensing information may be combined using existing schemes. The combined hard decision may be replicated by a number of participating sensory nodes. Second, hard decisions may be combined with each type of side information using existing schemes. The combined hard decision may be replicated by the number of participating sensory nodes. Third, hard decisions may be combined using hard combining, either from sensory nodes' direct report or from the above two elements.

[0213] In supporting the hybrid combining schemes, the sensing request message sent from the sensing processor to a sensory node may include the information on the type of sensing results, as well as the sensing schemes to be used. For example, a code "000" may be used for hard decisions, a code "001" may be used for hard decisions with side information of SNR, a code "010" may be used for hard decisions with side information of (P_m, Pf), a code "011" may be used for soft decisions with energy level, etc. These codes may be included in the sensing results type field of the sensing request message and/or in the sensing response message.

[0214] FIG. 33 is a block diagram 3300 illustrating an embodiment of information fusion for a hybrid mode. In the illustrated embodiment, a distributor 3302 may receive sensing results of different types and sort the sensing results by type (e.g., side information of type 1, side information of type n, soft information of type 1, and soft information of type 2). Then, each type may be combined and multiplied independently. For example, in element 3304a, sensing results for side information of type 1 may be hard combined using the side information of type 1. In element 3304b, the hard decisions from element 3304a may be multiplied by a number of sensing results of this type and provided to a hard combining unit 3312. Similarly, in element 3306a, sensing results for side information of type n may be hard combined using the side information of type 2. In element 3306b, the hard decisions from element 3306 a may be multiplied by a number of sensing results of this type and provided to the hard combining unit 3312. Similarly, in element 3308a, sensing results for soft information of type 1 may be soft combined. In element 3308b, hard decisions provided as a result of element 3308a may be multiplied by a number of sensing results of this type and provided to the hard combining unit 3312. Similarly, in element 3310a, sensing results for soft information of type n may be soft combined. In element 3310b, hard decisions provided as a result of element 3310a may be multiplied by a number of sensing results of this type and provided to the hard combining unit 3312. The hard combining unit 3312 may hard combine the hard decisions provided as a result of elements 3304b, 3306b, 3308b and 3310b and provide fusion outputs based thereon.

[0215] Sensing results from sensory nodes may be highly correlated if the sensory nodes are in the shadow of the same obstacle because the sensory nodes may have highly correlated shadow fading. The correlated sensing results may significantly decrease the performance of information fusion algorithms. One way to address this problem may be to identify the correlated sensory nodes and then to use the sensing results from the uncorrelated sensory nodes only. The correlation of sensory nodes may be analyzed using different techniques.

[0216] In an embodiment, the correlated sensory nodes may sense the channel in turns, for example, in a round-robin fashion. Advantages to this approach may include a savings in battery time of sensory nodes, a reduction in communication traffic to the information fusion unit 306 and increased accuracy of information fusion algorithms. With respect to battery life, if a sensory node is known to have correlated sensing results with others, then it may not need to serve for every sensing request and, therefore, will save the battery life of the sensory node. With respect to reduction in communication traffic to the information fusion unit 306, since transmission from some sensory nodes may not be needed if they have correlated sensing results to others, an amount of transmissions to the information fusion block may be reduced. With respect to increased accuracy of information fusion algorithms, since redundant information may be filtered out at the information fusion unit 306, it may increase the performance of the combining schemes, which may be based on independent inputs.

[0217] Correlation among sensory nodes may vary with frequency. If sensory nodes are in the same shadow, then their sensing results may be more correlated at low frequency than those at high frequency. Subsequently, fewer sensory nodes from a correlated sensory node set may be needed to sense the low frequency band, while more sensory nodes from the set may be needed to sense the high frequency band.

[0218] FIG. 34 is a flow diagram 3400 illustrating an embodiment of a method for obtaining correlation information. In element 3402, when a sensory node joins or exits a network, or has mobility activities, a sensing controller 301 may send a test request message to the sensory nodes. The test request message may contain instructions on how to do the test. The sensory nodes receiving the test request message may follow the instruction provided in the test request message and generate a test response message including its testing results. The test response message may be transmitted to the sensing processor 208. In element 3404, when the sensing processor 208 receives the testing response message, the correlation analyzer 302 may analyze the sensing results correlation among the sensory nodes and, in element 3406, store the resulting correlation information in the sensory nodes correlation database 310.

[0219] FIG. 35 is a flow diagram 3500 illustrating an embodiment of a method of sensing task assignment and information fusion using correlation information. In element 3502, in response to receiving a spectrum inquiry from a cognitive engine 206, the sensing controller 301 may select sensory nodes to participate in a sensing task related to the spectrum inquiry, accounting for the channel frequency and sensor nodes' correlation information in its selection. In element 3506, in response to receiving sensing response messages from the selected sensory nodes, the information fusion unit 306 may retrieve the correlation information of the sensory nodes from the sensory nodes correlation database 310. In element 3508, the information fusion unit 306 may combine results received from the selected sensory nodes using the retrieved correlation information and a proposed combining scheme.

[0220] EMBODIMENTS

[0221] 1. A dynamic spectrum management (DSM) server comprising a cognitive engine configured to receive a service request for an allocation of spectrum for secondary use.

[0222] 2. The DSM server of embodiment 1, wherein the cognitive engine is further configured to determine whether the DSM server is able to resolve the service request.

[0223] 3. The DSM server of embodiment 1 or 2, wherein the cognitive engine is further configured to transmit the request to another DSM server on a condition that the DSM server is not able to resolve the service request.

[0224] 4. The DSM server of any one of embodiments 1-3, wherein the cognitive engine is further configured to generate and transmit a service resolution on a condition that the DSM server is able to resolve the service request.

[0225] 5. The DSM server of embodiment 4, wherein the service resolution provides one of the allocation of the spectrum for secondary use or a rejection of the service request.

[0226] 6. The DSM server of embodiment 4 or 5, wherein the service resolution provides the allocation of the spectrum in a television white space (TVWS) frequency band.

[0227] 7. The DSM server of any one of embodiments 1-6, wherein the cognitive engine is configured to determine that the DSM server is able to resolve the service request on a condition that the DSM server has access to information included in one of a television white space (TVWS) database, a Federal Communications Commission (FCC) policies database or another database that provides functions similar to the functions provided by one of the TVWS database or the FCC policies database.

[0228] 8. The DSM server of any one of embodiments 1-7, wherein the cognitive engine comprises a conformance reasoner configured to ensure that the allocation of the spectrum for secondary use conforms with at least one of regulatory policies, user-defined policies or spectrum availability information associated with the allocated spectrum.

[0229] 9. The DSM server of embodiment 8, wherein the cognitive engine further comprises a service provisioner configured to retrieve the regulatory policies and the spectrum availability information from a policy and spectrum interface database.

[0230] 10. The DSM server of embodiment 9, wherein the policy and spectrum interface database is configured to retrieve the regulatory policies and the spectrum availability information from at least one external database.

[0231] 11. The DSM server of any one of embodiments 1-10, further comprising an allocated spectrum database configured to store information indicating the allocated spectrum, wherein the service provisioner is further configured to avoid allocating spectrum that has already been allocated for secondary use based on the information stored in the allocated spectrum database.

[0232] 12. The DSM server of any one of embodiments 1-11, further comprising a sensing processor configured to provide information to the cognitive engine indicating a current usage of the spectrum by primary users of the spectrum.

[0233] 13. The DSM server of embodiment 12, wherein the sensing processor comprises a sensing controller configured to select at least one sensory node to participate in a sensing task corresponding to the service request by sensing the current usage of the spectrum.

[0234] 14. The DSM server of embodiment 13, wherein the sensing controller is further configured to process sensing results received from the at least one sensory node as a result of the sensing task.

[0235] 15. The DSM server of embodiment 14, wherein the sensing controller is further configured to provide the information to the cognitive engine indicating the current usage of the spectrum by the primary user of the spectrum based at least on the processed sensing results.

[0236] 16. The DSM server of embodiment 14 or 15, wherein the sensing processor further comprises a correlation analyzer configured to analyze correlations among the sensing results received from the at least one sensory node and store the results of the analysis in a sensory nodes correlation database.

[0237] 17. The DSM server of any one of embodiments 13-16, wherein the sensing processor further comprises a capability registry configured to retrieve sensing capability information from sensory nodes registered with the DSM server regarding at least one sensing capability of the respective sensory nodes registered with the DSM server and store the retrieved sensing capability information in a sensory nodes configuration database.

[0238] 18. The DSM server of embodiment 16 or 17, wherein the sensing controller is configured to select the at least one sensory node to participate in the sensing task based on at least one of the results of the correlation analysis stored in the sensing nodes correlation database and the sensing capability information stored in the sensing nodes configuration database.

[0239] 19. The DSM server of any one of embodiments 12-18, wherein the sensing processor further comprises a location-based fast frequency selection unit configured to select spectrum to satisfy the service request based on past sensing results on a condition that the service request is subject to a latency requirement.

[0240] 20. The DSM server of any one of embodiments 12-18, wherein the sensing processor further comprises an information fusion unit configured to receive individual spectrum sensing results related to usage of a spectrum by primary users from each one of a plurality of sensory nodes.

[0241] 21. The DSM server of embodiment 20, wherein the information fusion unit is further configured to determine whether the spectrum is being used for communications by the primary users.

[0242] 22. The DSM server of embodiment 21, wherein the information fusion unit is further configured to provide a decision on whether the spectrum is being used for the communications by the primary users.

[0243] 23. The DSM server of embodiment 22, wherein the information fusion unit is further configured to store the decision and the individual spectrum sensing results in a sensing results database.

[0244] 24. The DSM server of embodiment 22 or 23, wherein the cognitive engine is further configured to transmit a service resolution that provides the allocation of the spectrum for secondary use on a condition that the decision provided by the information fusion unit indicates that the spectrum is not being used for communications by the primary users.

[0245] 25. The DSM server of any one of embodiments 21-24, wherein the information fusion unit is configured to determine that the spectrum is being used for communications by the primary users on a condition that all of the spectrum sensing results received during a predetermined time period indicate that the spectrum is being used by the primary users.

[0246] 26. The DSM server of any one of embodiments 21-25, wherein the information fusion unit is configured to determine that the spectrum is being used for communications by the primary users on a condition that a predetermined fraction of the spectrum sensing results received during a predetermined time period indicate that the spectrum is being used by the primary users.

[0247] 27. The DSM server of any one of embodiments 21-26, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users by combining each of the individual spectrum sensing results received from each one of the plurality of sensory nodes into an overall metric.

[0248] 28. The DSM server of embodiment 27, wherein the information fusion unit is further configured to discard each of the individual spectrum sensing results in response to combining it into the overall metric.

[0249] 29. The DSM server of any one of embodiments 22-28, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users by assigning a weight to each of the individual spectrum sensing results based on a reliability level of the respective individual spectrum sensing result.

[0250] 30. The DSM server of embodiment 29, wherein the information fusion unit is further configured to determine whether the spectrum is being used for communications by the primary users by combining each of the individual spectrum sensing results into an overall metric using the weight assigned to each of the individual spectrum sensing results.

[0251] 31. The DSM server of embodiment 29 or 30, wherein the reliability level of the respective individual spectrum sensing results is based on at least one of a signal-to-noise ratio (SNR), a false alarm probability (Pf), a miss detection probability (P_m), a sensitivity of a radio device included in each respective sensory node, a distance from each respective sensory node to a primary user of the spectrum, or a local interference temperature measured by each respective sensory node.

[0252] 32. The DSM server of embodiment 31, wherein the information fusion unit is configured to estimate the Pf and P_m for at least one of the plurality of sensory nodes based on a previous performance of the at least one of the plurality of sensory nodes.

[0253] 33. The DSM server of any one of embodiments 20-32, wherein the individual spectrum sensing results received from each one of the plurality of sensing nodes include different types of sensing decisions including hard decisions, hard decisions with different types of side information and different types of soft sensing information.

[0254] 34. The DSM server of any one of embodiments 22-33, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users by combining each of the different types of soft sensing information.

[0255] 35. The DSM server of embodiment 34, wherein the information fusion unit is further configured to determine whether the spectrum is being used for communications by the primary users by combining the hard decisions with each of the different types of side information.

[0256] 36. The DSM server of embodiment 34 or 35, wherein the information fusion unit is further configured to determine whether the spectrum is being used for communications by the primary users by combining the hard decisions.

[0257] 37. The DSM server of any one of embodiments 22-36, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users based on the individual sensing results received from sensory nodes that are not correlated.

[0258] 38. The DSM server of any one of embodiments 1-37, wherein the

DSM server is selected from the group consisting of a radio network controller (RNC), a gateway general packet radio service (GPRS) support node (GGSN), a server running a Federal Communication Commission (FCC) database, a server running a television white space (TVWS) database, a neighborhood multimedia sharing controller (NMSC), a node on a wireless network, a peer node on a mobile ad hoc network (MANET), a home NodeB on a home network, and an access point (AP) on a wireless local area network (WLAN).

[0259] 39. A dynamic spectrum management (DSM) system comprising a wireless transmit/receive unit (WTRU) configured to transmit a service request for an allocation of spectrum for secondary use.

[0260] 40. The DSM system of embodiment 39, further comprising a first

DSM server configured to receive the service request, determine whether the first DSM server is able to resolve the service request, and on a condition that the first DSM server determines that it is not able to resolve the service request, forward the service request to a second DSM server.

[0261] 41. The DSM system of embodiment 40, wherein the second DSM server is configured such that on a condition that the second DSM server is not able to resolve the service request, the second DSM server forwards the service request to a third DSM server.

[0262] 42. The DSM system of embodiment 41, wherein the DSM system is a wireless network, the first DSM server is a radio network controller (RNC), the second DSM server is a gateway general packet radio service (GPRS) support node (GGSN) and the third DSM server is a server running a Federal Communication Commission (FCC) database or another database that provides functions similar to the functions provided by one of the TVWS database or the FCC policies database.

[0263] 43. The DSM system of embodiment 40, wherein the DSM system is a wireless local area network (WLAN), the first DSM server is a server running on the WTRU and the second DSM server is a server running a television white space (TVWS) database. [0264] 44. The DSM system of embodiment 41, wherein the DSM system is a neighborhood multimedia network, the first DSM server is a neighborhood multimedia sharing controller (NMSC), the second DSM server is a node on a wireless network and the third DSM server is a server running a television white space (TVWS) database.

[0265] 45. The DSM system of embodiment 40, wherein the DSM system is a mobile ad hoc network (MANET), and the WTRU, the first DSM server and the second DSM server are peer nodes on the MANET.

[0266] 46. The DSM system of embodiment 41, wherein the first DSM server, the second DSM server and the third DSM server are servers on different wireless networks.

[0267] 47. The DSM system of embodiment 41, wherein the first DSM server is an access point on a wireless local area network (WLAN), the second DSM server is a home NodeB on a home network and the third DSM server is a MANET gateway node on a MANET.

[0268] 48. A method of dynamic spectrum management (DSM) comprising receiving a service request for an allocation of spectrum for secondary use.

[0269] 49. The method of embodiment 48, further comprising determining whether a DSM server is able to resolve the service request.

[0270] 50. The method of embodiment 49, further comprising transmitting the request to another DSM server on a condition that the DSM server is not able to resolve the service request.

[0271] 51. The method of embodiment 49 or 50, further comprising generating and transmitting a service resolution on a condition that the DSM server is able to resolve the service request.

[0272] 52. The method of embodiment 51, wherein the service resolution provides one of the allocation of the spectrum for secondary use and a rejection of the service request. [0273] 53. The method of embodiment 51 or 52, wherein the service resolution provides the allocation of the spectrum in a television white space (TVWS) frequency band.

[0274] 54. The method of any one of embodiments 48-53, wherein the

DSM server is able to resolve the service request on a condition that the DSM server has access to information included in one of a television white space (TVWS) database and a Federal Communications Commission (FCC) policies database.

[0275] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer- readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

" " "

Claims

CLAIMS What is claimed:

1. A dynamic spectrum management (DSM) server comprising: a cognitive engine configured to:

receive a service request for an allocation of spectrum for secondary use,

determine whether the DSM server is able to resolve the service request, and on a condition that the DSM server is not able to resolve the service request, transmit the request to another DSM server.

2. The DSM server of claim 1, wherein the cognitive engine is further configured to generate and transmit a service resolution on a condition that the DSM server is able to resolve the service request.

3. The DSM server of claim 2, wherein the service resolution provides one of the allocation of the spectrum for secondary use or a rejection of the service request.

4. The DSM server of claim 2, wherein the service resolution provides the allocation of the spectrum in a television white space (TVWS) frequency band.

5. The DSM server of claim 2, wherein the cognitive engine is configured to determine that the DSM server is able to resolve the service request on a condition that the DSM server has access to information included in one of a television white space (TVWS) database, a Federal Communications Commission (FCC) policies database or another database that provides functions similar to the functions provided by one of the TVWS database or the FCC policies database.

6. The DSM server of claim 3, wherein the cognitive engine comprises a conformance reasoner configured to ensure that the allocation of the spectrum for secondary use conforms with at least one of regulatory policies, user-defined policies or spectrum availability information associated with the allocated spectrum.

7. The DSM server of claim 6, wherein the cognitive engine further comprises a service provisioner configured to retrieve the regulatory policies and the spectrum availability information from a policy and spectrum interface database.

8. The DSM server of claim 7, wherein the policy and spectrum interface database is configured to retrieve the regulatory policies and the spectrum availability information from at least one external database.

9. The DSM server of claim 7, further comprising an allocated spectrum database configured to store information indicating the allocated spectrum, wherein the service provisioner is further configured to avoid allocating spectrum that has already been allocated for secondary use based on the information stored in the allocated spectrum database.

10. The DSM server of claim 1, further comprising a sensing processor configured to provide information to the cognitive engine indicating a current usage of the spectrum by primary users of the spectrum.

11. The DSM server of claim 10, wherein the sensing processor comprises a sensing controller configured to:

select at least one sensory node to participate in a sensing task corresponding to the service request by sensing the current usage of the spectrum,

process sensing results received from the at least one sensory node as a result of the sensing task, and provide the information to the cognitive engine indicating the current usage of the spectrum by the primary user of the spectrum based at least on the processed sensing results.

12. The DSM server of claim 10, wherein the sensing processor further comprises a correlation analyzer configured to analyze correlations among the sensing results received from the at least one sensory node and store the results of the analysis in a sensory nodes correlation database.

13. The DSM server of claim 12, wherein the sensing processor further comprises a capability registry configured to retrieve sensing capability information from sensory nodes registered with the DSM server regarding at least one sensing capability of the respective sensory nodes registered with the DSM server and store the retrieved sensing capability information in a sensory nodes configuration database.

14. The DSM server of claim 12, wherein the sensing controller is configured to select the at least one sensory node to participate in the sensing task based on at least one of the results of the correlation analysis stored in the sensing nodes correlation database and the sensing capability information stored in the sensing nodes configuration database.

15. The DSM server of claim 10, wherein the sensing processor further comprises a location-based fast frequency selection unit configured to select spectrum to satisfy the service request based on past sensing results on a condition that the service request is subject to a latency requirement.

16. The DSM server of claim 10, wherein the sensing processor further comprises an information fusion unit configured to: receive individual spectrum sensing results related to usage of a spectrum by primary users from each one of a plurality of sensory nodes, determine whether the spectrum is being used for communications by the primary users, and provide a decision on whether the spectrum is being used for the communications by the primary users.

17. The DSM server of claim 16, wherein the information fusion unit is further configured to store the decision and the individual spectrum sensing results in a sensing results database.

18. The DSM server of claim 16, wherein the cognitive engine is further configured to transmit a service resolution that provides the allocation of the spectrum for secondary use on a condition that the decision provided by the information fusion unit indicates that the spectrum is not being used for communications by the primary users.

19. The DSM server of claim 16, wherein the information fusion unit is configured to determine that the spectrum is being used for communications by the primary users on a condition that all of the spectrum sensing results received during a predetermined time period indicate that the spectrum is being used by the primary users.

20. The DSM server of claim 16, wherein the information fusion unit is configured to determine that the spectrum is being used for communications by the primary users on a condition that a predetermined fraction of the spectrum sensing results received during a predetermined time period indicate that the spectrum is being used by the primary users.

21. The DSM server of claim 16, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users by combining each of the individual spectrum sensing results received from each one of the plurality of sensory nodes into an overall metric.

22. The DSM server of claim 16, wherein the information fusion unit is further configured to discard each of the individual spectrum sensing results in response to combining it into the overall metric.

23. The DSM server of claim 16, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users by:

assigning a weight to each of the individual spectrum sensing results based on a reliability level of the respective individual spectrum sensing result, and combining each of the individual spectrum sensing results into an overall metric using the weight assigned to each of the individual spectrum sensing results.

24. The DSM server of claim 23, wherein the reliability level of the respective individual spectrum sensing results is based on at least one of a signal-to-noise ratio (SNR), a false alarm probability (Pf), a miss detection probability (P_m), a sensitivity of a radio device included in each respective sensory node, a distance from each respective sensory node to a primary user of the spectrum, or a local interference temperature measured by each respective sensory node.

25. The DSM server of claim 24, wherein the information fusion unit is configured to estimate the Pf and P_m for at least one of the plurality of sensory nodes based on a previous performance of the at least one of the plurality of sensory nodes.

26. The DSM server of claim 10, wherein the individual spectrum sensing results received from each one of the plurality of sensing nodes include different types of sensing decisions including hard decisions, hard decisions with different types of side information and different types of soft sensing information.

27. The DSM server of claim 26, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users by:

combining each of the different types of soft sensing information, combining the hard decisions with each of the different types of side information, and

combining the hard decisions.

28. The DSM server of claim 10, wherein the information fusion unit is configured to determine whether the spectrum is being used for communications by the primary users based on the individual sensing results received from sensory nodes that are not correlated.

29. The DSM server of claim 1, wherein the DSM server is selected from the group consisting of a radio network controller (RNC), a gateway general packet radio service (GPRS) support node (GGSN), a server running a Federal Communication Commission (FCC) database, a server running a television white space (TVWS) database, a neighborhood multimedia sharing controller (NMSC), a node on a wireless network, a peer node on a mobile ad hoc network (MANET), a home NodeB on a home network, and an access point (AP) on a wireless local area network (WLAN).

30. A dynamic spectrum management (DSM) system comprising: a wireless transmit/receive unit (WTRU) configured to transmit a service request for an allocation of spectrum for secondary use; and

a first DSM server configured to receive the service request, determine whether the first DSM server is able to resolve the service request, and on a condition that the first DSM server determines that it is not able to resolve the service request, forward the service request to a second DSM server.

31. The DSM system of claim 30, wherein the second DSM server is configured such that on a condition that the second DSM server is not able to resolve the service request, the second DSM server forwards the service request to a third DSM server.

32. The DSM system of claim 31, wherein the DSM system is a wireless network, the first DSM server is a radio network controller (RNC), the second DSM server is a gateway general packet radio service (GPRS) support node (GGSN) and the third DSM server is a server running a Federal Communication Commission (FCC) database or another database that provides functions similar to the functions provided by one of the TVWS database or the FCC policies database.

33. The DSM system of claim 30, wherein the DSM system is a wireless local area network (WLAN), the first DSM server is a server running on the WTRU and the second DSM server is a server running a television white space (TVWS) database.

34. The DSM system of claim 31, wherein the DSM system is a neighborhood multimedia network, the first DSM server is a neighborhood multimedia sharing controller (NMSC), the second DSM server is a node on a wireless network and the third DSM server is a server running a television white space (TVWS) database.

35. The DSM system of claim 31, wherein the DSM system is a mobile ad hoc network (MANET), and the WTRU, the first DSM server and the second DSM server are peer nodes on the MANET.

36. The DSM system of claim 31, wherein the first DSM server, the second DSM server and the third DSM server are servers on different wireless networks.

37. The DSM system of claim 36, wherein the first DSM server is an access point on a wireless local area network (WLAN), the second DSM server is a home NodeB on a home network and the third DSM server is a MANET gateway node on a MANET.

38. A method of dynamic spectrum management (DSM) comprising: receiving a service request for an allocation of spectrum for secondary use, determining whether a DSM server is able to resolve the service request, and on a condition that the DSM server is not able to resolve the service request, transmitting the request to another DSM server.

39. The method of claim 38, further comprising generating and transmitting a service resolution on a condition that the DSM server is able to resolve the service request.

40. The method of claim 39, wherein the service resolution provides one of the allocation of the spectrum for secondary use and a rejection of the service request.

41. The method of claim 39, wherein the service resolution provides the allocation of the spectrum in a television white space (TVWS) frequency band.

42. The method of claim 39, wherein the DSM server is able to resolve the service request on a condition that the DSM server has access to information included in one of a television white space (TVWS) database and a Federal Communications Commission (FCC) policies database.