HK1182267B - Devices and methods for multi-band wireless communication and bandwidth management - Google Patents

Description

Method and apparatus for multi-band wireless communication and bandwidth management

Technical Field

The field of the invention relates generally to multi-band wireless systems and more particularly, but not exclusively, to methods for transmitting and receiving multi-band signals in a WPAN/WLAN environment.

Background

Technological advances have allowed digitization and compression of a vast amount of voice, video, imaging, and data information. The need to transmit data between stations (stations) in wireless radio communication requires reliable data streams to be received at high data rates. It would be advantageous to provide a method for reliable multi-band communication between two or more stations, wherein communication over a communication channel in the multi-band communication is less robust than alternative channels.

Disclosure of Invention

The present invention provides a method of wireless communication between stations along a plurality of frequency channels, comprising: scanning a first channel to locate a beacon transmitted by an access point; detecting the beacon in the first channel, wherein the beacon comprises an element indicating availability of a second channel; monitoring the second channel to determine a quality of service of the second channel; transmitting an association request frame to the access point using the first channel to request communication in the second channel in response to a quality of service of the second channel; and receiving an association response frame from the access point to confirm association with the station.

The present invention also provides a method for synchronized multi-band wireless communication between an access point and a station, comprising: associating the access point with the station along a first channel; receiving a reservation request from the station on the first channel to reserve a second channel; transmitting, by the access point, an acknowledgement in response to the reservation request on the first channel; reserving bandwidth allocation for the station in the second channel; transmitting a reservation response to the station in the second channel based on the reservation request; transmitting a data frame from the access point to the station using the bandwidth allocation.

The present invention also provides a method for asynchronous multiband wireless communication between an access point and a station, comprising: associating the station with the access point along a first channel; transmitting a Request To Send (RTS) signal from the station using the first channel, the RTS signal comprising an element indicating a request to communicate on a second channel; receiving a Clear To Send (CTS) signal from the access point using the first channel; receiving a polling frame from the access point using the second channel; and transmitting a data frame to the access point using the second channel.

The present invention also provides a system for multiband wireless communication, comprising: a host processor; a flash memory device; a random access memory; and a transceiver configured to communicate in the 2.4/5GHz and 60GHz bands by: locating a beacon transmitted in the 2.4/5GHz band, wherein the beacon includes an element indicating availability of the 60GHz band, determining a quality of service of the 60GHz band, transmitting an association request frame using the 2.4/5GHz band in response to the quality of service of the 60GHz band, requesting communication in the 60GHz band, and receiving an association response frame to confirm association.

Drawings

The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which:

fig. 1 is a block diagram illustrating a station communicating in a wireless network using multiple communication channels.

Fig. 2 is a flow diagram illustrating one embodiment of an association mechanism for a multi-band wireless system.

Figure 3 is a diagram of one embodiment of a discovery and association mechanism for a multi-band wireless system.

Fig. 4 is a diagram of one embodiment of a multi-band bandwidth reservation mechanism for synchronous data communications.

Figure 5 is a diagram of one embodiment of a multi-band random access and polling mechanism for asynchronous data communications.

Detailed Description

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.

Embodiments of methods and systems for multi-band wireless communication and bandwidth management are described herein. In the following description, numerous specific details are set forth, such as descriptions of discovery and association mechanisms for multi-band wireless systems, in order to provide a thorough understanding of embodiments of the present invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

It would be an advancement in the art to provide a discovery and association mechanism for a multi-band wireless system that communicates over multiple channels or frequency bands. As an example, a wireless station may include a host processor, a flash memory device, a random access memory, and a transceiver configured to communicate sequentially or simultaneously over a lower frequency network and a millimeter wave (mm wave) network using Wireless Local Area Network (WLAN) and Wireless Personal Area Network (WPAN) technologies. MM wave communication is desirable for relatively high throughput communication while providing high frequency multiplexing potential. However, mm-wave communication links operating in the 60GHz band (57-66 GHz) are less robust than those operating at lower frequencies (e.g., the 2.4GHz and 5GHz bands) due to the two oxygen absorptions that attenuate signals over long distances and its short wavelength that provides attenuation through obstacles such as walls and ceilings. The use of a second communication link operating at one or more lower frequencies may provide one or more channels for discovery and association of stations that would otherwise be unable to communicate at the higher frequencies. By providing for association and discovery between multi-band stations for both synchronous and asynchronous data services, a mechanism for enabling efficient and robust communication using multi-band stations may provide enhanced data communication efficiency.

Embodiments of the multi-band station may be used for a variety of applications. Some embodiments of the invention may be used in conjunction with different devices and systems, such as, for example, transmitters, receivers, transceivers, transmitter-receivers, wireless communication devices, wireless Access Points (APs), modems, wireless modems, Personal Computers (PCs), desktop computers, mobile computers, laptop computers, notebook computers, tablet computers, server computers, set-top boxes, handheld computers, handheld stations, Personal Digital Assistant (PDA) devices, handheld PDA devices, Mobile Stations (MSs), graphical displays, communication stations, networks, wireless networks, Local Area Networks (LANs), wireless LANs (wlans), Metropolitan Area Networks (MANs), wireless MANs (wmans), Wide Area Networks (WANs), wireless WANs (wwans), according to existing Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.11a, 802.11b, 802.11e, wireless networks (LANs), wireless LANs (wlans), wireless networks (MANs), wireless MANs (wmans), wireless networks (wwans), wireless networks, 802.11g, 802.11h, 802.11i, 802.11n, 802.16d, 802.16e standards and/or future and/or derivative versions of the above and/or Long Term Evolution (LTE) operated devices and/or networks, Personal Area Networks (PANs), Wireless PANs (WPANs), units and/or devices that are part of the above WLAN and/or PAN and/or WPAN networks, one-way and/or two-way radio communication systems, cellular radiotelephone communication systems, cellular telephones, radiotelephones, Personal Communication System (PCS) devices, PDA devices incorporating wireless communication devices, multiple-input multiple-output (MIMO) transceivers or devices, single-input multiple-output (SIMO) transceivers or devices, multiple-input single-output (MISO) transceivers or devices, Multiple Receiver Chain (MRC) transceivers or devices, transceivers or devices having "smart antenna" technology or multiple antenna technology, or the like. Some embodiments of the invention may be used in conjunction with one or more types of wireless communication signals and/or systems, such as Radio Frequency (RF), Infrared (IR), Frequency Division Multiplexing (FDM), Orthogonal FDM (OFDM), Time Division Multiplexing (TDM), Time Division Multiple Access (TDMA), extended TDMA (E-TDMA), General Packet Radio Service (GPRS), extended GPRS, Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), CDMA2000, multi-carrier modulation (MDM), discrete multi-tone (DMT), Bluetooth (RTM), ZigBee (TM), or the like. Embodiments of the invention may be used in various other apparatuses, devices, systems and/or networks.

Turning now to the drawings, fig. 1 is a block diagram illustrating stations, such as communication stations (130 a and 130 b), a graphical display (120), mobile stations (110 a and 110 b), and access points (100 a and 100 b) that communicate using multi-band radio signals in a multi-band wireless network 140. Access point 110a may communicate with another access point 100b and with stations, such as stations (CS) 130a and 130 b. CS130a and 130b may be fixed or substantially fixed stations. In some embodiments, access point 100a may communicate using multi-band radio signals that include a first channel 150 and a second channel 160. In this embodiment, first channels 150 are 2.4GHz frequency bands and/or 5GHz frequency bands and second channels 160 are 60GHz frequency bands, although the scope of the invention is not limited in this respect. Access point 100a may also communicate with other stations such as mobile station 110a and graphical display 120. In some embodiments, access point 100a and mobile station 110a operate as part of a peer-to-peer network (P2P). In other embodiments, the access point 100a and the mobile station 110a operate as part of a mesh network, where communications may include packets routed on behalf of other wireless stations of the mesh network (e.g., the mobile station 110 b). Fixed wireless access, wireless local area networks, wireless personal area networks, portable multimedia streaming, and localized networks such as in-vehicle networks are examples of some applicable P2P and mesh networks.

Fig. 2 is a flow diagram illustrating one embodiment of an association mechanism for a multi-band wireless network. In element 200, a station, such as the graphical display 120, scans a first channel to locate a beacon transmitted by the access point 100. In this embodiment, the first channels 150 are 2.4GHz spectral bands and/or 5GHz frequency band channels. The first channel 150 may be configured to communicate over the 802.11 standard, such as the protocol developed by 802.11 Very High Throughput (VHT). The lower frequency beacon transmitted in the first channel 150 includes information indicating that the access point 100 is capable of operating in the second channel 160. Second channel 160 may be configured to communicate via an MM wave (e.g., 60 GHz) protocol such as 802.15.3 c.

In element 210, a lower frequency beacon is detected by the station, and information in the lower frequency beacon or other information element indicates to the station that the second channel 160 is available for data communications. This information is obtained by decoding the received lower frequency beacons from the first channel 150. In addition, the time offset between the lower frequency beacon and the high frequency beacon is also included in the lower frequency beacon. This offset allows the station to listen for only a portion of the high frequency beaconing period (beaconing period), which may be a relatively small portion of time compared to the high frequency beaconing period. As a result, the efficiency of the discovery process may be improved, and the energy consumption used in the discovery process may be reduced.

In this embodiment, the second channel 160 is a 60GHz band. In element 220, the station monitors the second channel 160 to locate the high frequency beacon and determines whether the station can reliably communicate over the second channel, for example, by determining a quality of service (QOS) of the second channel based on parameters such as channel loading and interference. If the QOS of the second channel is above a threshold, which may be defined as a value sufficient to provide reliable communications for the type of data communicated on the second channel 160, then an association request (ASS-REQ) frame is transmitted to the access point 100 using the first channel 150 to request communications in the second channel 160 (element 250). Otherwise, the station may associate with the access point 100 using the first channel 150. If the station does transmit an association request frame as detailed in element 250, the access point 100 transmits and the station receives an association response frame (ASS-RSP) to confirm association with the station in element 260.

Fig. 3 is a diagram of one embodiment of a discovery and association mechanism for a multi-band wireless system in accordance with the method described in fig. 2. The first channel 150 and the second channel 160 communicate with respect to a communication timeline 305. In this embodiment, the first channel 150 communicates using a series of lower frequency beacon intervals 310 in accordance with the 802.11 protocol, where each lower frequency beacon interval 310 includes a beacon. The first lower frequency beacon 315 transmitted in the first channel 150 is an essential feature in the wireless Medium Access Control (MAC) protocol that conveys association information. For example, a first lower frequency beacon 315 may be transmitted from access point 100 to mobile station 110 in fig. 1. The first lower frequency beacon 315 includes an element that indicates the availability of the second channel 160 (e.g., the higher frequency 60GHz band). In this embodiment, the second channel 160 communicates according to the 60GHz protocol using a series of higher frequency beacon intervals 365, where each higher frequency beacon interval 365 includes a beacon, such as a first high frequency beacon 340 and a second high frequency beacon 345.

A beacon offset 335 is provided to avoid overlapping the first lower frequency beacon 315 with the first high frequency beacon 340. In this embodiment, the beacon offset 335 is a predetermined value transmitted in the first lower frequency beacon 315. In addition, the first lower frequency beacon 315 includes MAC address information for the interface of the first channel 150 and the second channel 160. The MAC address information allows a station, such as the mobile station 110, the graphical display 120, or the communication station 130, to identify a first lower frequency beacon 315 and a first high frequency beacon 340 corresponding to the same access point 100. In this embodiment, the first beacon 315 transmitted in the first channel 150 includes a channel number associated with the second channel 160 in which the access point 100 operates. Conversely, the first high frequency beacon 340 transmitted in the second channel 160 includes the channel number associated with the first channel 150 in which the access point 100 operates, and also includes a beacon offset 335 relative to the first low frequency beacon 320 operating in the first channel 150. In another embodiment, MAC address information, channel number information, and/or beacon offset 335 are also included in probe request (probequest) and/or probe response (probesponse) frames (not shown) for active scanning purposes.

In fig. 3, a station, such as mobile station 110, is powered on or initialized at station initialization 360. The station is configured to search for a beacon, e.g., a second lower frequency beacon 320, over a low frequency beacon search interval 350. The beacon then searches for a second high frequency beacon 345 on the second channel 160 within the high frequency beacon reception and association interval 355 using the MAC address information, channel number information, and/or beacon offset 335. The background then proceeds with association with the access point 100 using the association request frame 325 and the association response frame 330. As a result, more data transmissions may be communicated between the station and the access point 100 over the second channel 160 or the first channel 150.

Fig. 4 is a diagram of a multi-band bandwidth reservation mechanism for synchronous data communication between an access point 100 and a station according to one embodiment of the invention. The station in this embodiment is the mobile station 110 of fig. 1 and is associated with the access point 100 as depicted in fig. 3. The mobile station 100 attempts to communicate with the access point 100 to transmit synchronous data traffic, such as a video data stream. The transmission of the data stream over the second channel 160 may be provided by a reservation of the bandwidth of the second channel 160 by means of a control message transmitted using the first channel transmission 150.

Mobile station 110 may request a bandwidth allocation by sending a reservation request frame 410 addressed to access point 100 on first channel 150. The reservation request frame 410 sent by the mobile station 110 may include information such as the type of data traffic, the amount of channel time required, the channel allocation frequency, and other data. The mobile station 110 then waits for a request acknowledgement 420, a high priority transmission, during a short interframe space 415. The first channel 150 may transmit data for other stations in the low frequency beacon interval 310 and may be busy during time block 425. The mobile station 110 switches to the second channel 160 for a reservation response frame, which may be included in the second high frequency beacon 345, transmitted during a contention-based access period (CAP) 430, or otherwise. The contention-based access period 430 is a portion of a higher frequency beacon interval 365 with unreserved or open channel time allocation or access. The reservation response frame describes a channel time scheduled transmission 440 that includes one or more data blocks 445, one or more short interframe spaces 415, and one or more scheduling acknowledgements 450 during a contention free period 435.

The second channel 160 may be used by one or more stations, such as the mobile station 110, the graphical display 120, and the one or more communication stations 130, while using the control information in the first channel 150 to reserve bandwidth in the second channel 160. The access point 100 reserves the channel time allocation in the second channel 160 and either advertises the channel time allocation in the first high frequency beacon 340 or sends a reservation response to the mobile station 110 on the second channel 160, in response to receiving the reservation request frame 410 from the mobile station 110. In another embodiment, if the mobile station 110 does not successfully transmit the reservation request frame 410 on the first channel 150 after a predetermined number of attempts, the mobile station 110 may use the second channel 160 for reserving bandwidth on the second channel 160 even though priority is given to the first channel 150 for such control information exchange.

Fig. 5 is a diagram of an embodiment of a multi-band random access and polling mechanism for asynchronous data communication between an access point 100 and a station, in accordance with an embodiment of the present invention. The station in this embodiment is mobile station 110 of fig. 1 and is associated with access point 100 as depicted in fig. 3. Mobile station 110 attempts to communicate with access point 100 to transmit asynchronous data traffic, such as bursty data flows. The transmission of the burst data stream over the second channel 160 may be provided using a polling mechanism over the second channel 160 and using control messages transmitted over the first channel 150. The control messages in this embodiment are a Request To Send (RTS) frame 510 and a Clear To Send (CTS) frame 515 separated by a short interframe space 415.

Mobile station 110 initiates communication by transmitting a request-to-send frame 510 on first channel 150. The mobile station 110 indicates that it wants to exchange data on the second channel 160 using a request-to-send frame 510. A clear to send frame 515 is transmitted and a switch time 520 is experienced before a polling frame 530 is transmitted in the second channel 160. Mobile station 110 switches to second channel 160 during switching time 520 and waits for a polling frame 530 to be transmitted by access point 100. After a short interframe space 415, the mobile station 110 is allowed to transmit its data frame 535. Polling frame 530, short interframe space 415, and data frame 535 comprise directional communications 525 between access point 100 and mobile station 110. The mechanism illustrated in fig. 5 is one embodiment in which the first channel 150 is used to efficiently allocate bandwidth in the second channel 160 for the transmission of bursty data traffic.

While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. In the description and claims, the terms "coupled" and "connected," along with their derivatives, may have been used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, "connected" may be used to indicate that two or more elements are in direct physical or electrical contact with each other, while "coupled" may further mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Modifications may be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the drawings. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.

Claims (12)

1. A method of wireless communication over a plurality of frequency channels in a wireless communication device, comprising:

scanning a first channel to locate a beacon transmitted by an access point;

detecting the beacon in the first channel, wherein the beacon comprises an element indicating availability of a second channel;

transmitting a request frame to the access point over the first channel to request communication over the second channel; and

receiving a response frame from the access point in response to the request frame;

the method further includes the wireless communication device associating with the access point on the first channel and the second channel; and

the beacon in the first channel further comprises an offset value indicating a timing difference between the beacon in the first channel and a beacon in the second channel.

2. The method of claim 1, wherein the first channel is in a 2.4/5GHz band.

3. The method of claim 1, wherein the second channel is in a 60GHz frequency band.

4. An apparatus for multi-band wireless communication, comprising:

a processor;

a memory; and

a transceiver configured to communicate in first and second frequency bands by:

scanning a first channel in the first frequency band to locate a beacon transmitted by an access point;

detecting the beacon in the first channel, wherein the beacon comprises an element indicating availability of a second channel in a second frequency band;

transmitting a request frame to the access point over the first channel to request communication over the second channel;

receiving a response frame from the access point in response to the request frame; and

communicating with the access point over the second channel after the receiving;

wherein the device is configured to associate with the access point on the first channel and the second channel; and

wherein the beacon in the first channel further comprises an offset value indicating a timing difference between the beacon in the first channel and a beacon in the second channel.

5. The apparatus of claim 4, wherein the first channel is in a 2.4/5GHz band.

6. The apparatus of claim 4, wherein the second channel is in a 60GHz band.

7. A method of wireless communication over a multi-band channel in a wireless communication device, comprising:

transmitting a beacon over a first channel in a first frequency band, wherein the beacon comprises an element indicating availability of a second channel in a second frequency band;

receiving a request frame from a wireless communication device over the first channel, the request frame requesting communication over the second channel;

transmitting a response frame to the wireless communication device in response to the request frame, an

Communicating with the wireless communication device over the second channel after the transmitting the response;

the method further includes the wireless communication device associating with the wireless communication device on the first channel and the second channel; and

the beacon in the first channel further comprises an offset value indicating a timing difference between the beacon in the first channel and a beacon in the second channel.

8. The method of claim 7, wherein the first channel is in a 2.4/5GHz band.

9. The method of claim 7, wherein the second channel is in a 60GHz frequency band.

10. A first wireless communications device for multi-band wireless communications, comprising:

a processor;

a memory; and

a transceiver configured to communicate in first and second frequency bands by:

transmitting a beacon over a first channel in a first frequency band, wherein the beacon comprises an element indicating availability of a second channel in a second frequency band;

receiving a request frame from a second wireless communication device over the first channel, the request frame requesting communication over the second channel;

transmitting a response frame in response to the request frame to the second wireless communication device over the first channel, an

Communicating with the second wireless communication device over the second channel after the transmitting of the response;

wherein the first wireless communication device is configured to associate with the second wireless communication device on the first channel and the second channel; and

the beacon in the first channel further comprises an offset value indicating a timing difference between the beacon in the first channel and a beacon in the second channel.

11. The first wireless communications device of claim 10, wherein the first channel is in a 2.4/5GHz frequency band.

12. The first wireless communications device of claim 10, wherein the second channel is in a 60GHz frequency band.