HK1138464A - Wireless communication components and methods for multiple system communications - Google Patents

Description

Wireless communication assembly and method of multi-system communication

The patent application of the invention is divisional application of the invention patent application with the international application number of PCT/US2004/013013, the international application date of 2004 of 28.4.2004 and the application number of 200480014649.3 in the Chinese national stage, and the invention is named as a wireless communication assembly and a multi-system communication method.

Technical Field

The present invention relates to components and methods for wireless communication in multiple systems, and more particularly to mobile wireless transmit/receive units (WTRUs), such as from a universal terrestrial radio system (UMTS) to a local area network (WLAN) or vice versa, that are capable of continuous communication when switching from having a first type of wireless connection to having a second type of wireless connection.

Background

Wireless communication systems are well known in the art. Typically such systems include communication stations to transmit and receive wireless communication signals between each other. In the case of network systems, such as mobile cellular systems, there are two types of communication stations, base stations that provide access to the infrastructure of the network, and wireless transmit/receive units (WTRUs) that perform wireless communications with the base stations.

The reliance on wireless communication is increasing at home, office, and travel. It is common for a user to have several different WTRUs, such as different homes, offices, and mobile wireless telephones. Accordingly, it is desirable to replace multiple WTRUs with a single WTRU because it can be used in the home, office, and travel.

In many commercial networks, a network of base stations is provided, each capable of conducting multiple concurrent wireless communications with appropriate types of WTRUs. A standard has been developed and implemented for global connectivity of wireless systems. The widely used standard is global system for mobile telecommunications (GSM). This system is considered a second generation mobile radio system (2G) and is followed by its revision (2.5G). GPRS and EDGE are examples of 2.5G technologies that can provide relatively high speed data services for (2G) GSM networks. Each of these standards attempts to enhance existing standards with additional features and improvements. In month 1 of 1998, the european telecommunications standards institute, the special mobile group (ETSI SMG), has agreed on the radio access plan of a third generation radio system, known as the Universal Mobile Telecommunications System (UMTS). Further implementing the UMTS standard, the third generation partnership project (3GPP) has been made 12 months in 1998. The 3GPP is continually striving for a common third generation mobile radio standard.

A typical UMTS system architecture according to the 3GPP specifications is illustrated in fig. 1 a. The UMTS network architecture includes a Core Network (CN) interconnected with a UMTS Terrestrial Radio Access Network (UTRAN) via an interface such as Iu which carries details in publicly available 3GPP specification documents.

The UTRAN is configured to provide wireless telecommunication services to users via WTRUs, i.e., User Equipments (UEs) in 3GPP, via a wireless interface Uu. The UTRAN has base stations, referred to as node Bs of 3GPP, which collectively provide geographic coverage for wireless communications with UEs. In UTRAN, one or more groups of node Bs connect different Radio Network Controllers (RNCs) via an interface Iub in 3 GPP. The UTRAN may have several groups of node Bs connected to different RNCs, two nodes being illustrated in fig. 1a for example. When more than one RNC is in the UTRAN, inter-RNC communication is performed over an Iur interface.

A UE typically has a local utms (hn) network, which handles registration and payment services. By standardizing the Uu interface, Ues may communicate via different UMTN networks, e.g., serving different coverage areas. At this time, the other network is generally called a Foreign Network (FN).

Under the current 3GPP specifications, the core network functions of the UE's HN are coordination and handling of authentication, authorization and accounting (AAA functions). When a UE travels outside its UMTS network, the HN's core network, with its ability to coordinate with AAA, enables the UE's to utilize foreign networks so that the FN may enable the UE to effect communications. To assist in this activity, the core network includes a local area register (VLR) to track UE's as it is the HN and a guest address register (VLR). A home service provider (HSS) HLR handles AAA functions in a co-located manner.

Under current 3GPP specifications, the core network is configured to interface with external systems such as the public mobile network (PLMN), the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN), and other Real Time (RT) services via an RT service interface. A core network also supports non-real time services with the Internet. The permanent connectivity of the core network to other systems allows users to communicate over their home UMTS network using Ues, beyond the range of the HN's. Visiting UE's may talk over a visiting UMTS network beyond the UTRAN service area of the visiting UMTS's.

Under current 3GPP specifications, the core network provides RT service external connectivity via a Gateway Mobile Switching Center (GMSC). The core network provides NRT services, known as General Packet Radio Service (GPRS) external connections, via a Gateway GPRS Support Node (GGSN). In this regard, a particular NRT service may be present for real-time communication by the user because of the speed of communication and the associated buffering of the TDD data packets that make up the communication. An example of such communication is voice over internet communication, which is as normal telephone for the user as implemented by the switching network, but is in fact an Internet Protocol (IP) connection over a packet data service.

A standard interface called GI is commonly used between the GGSN of CN's and the internet. The GI interface may be used with mobile internet protocols, such as mobile IP v4 or mobile IP v6, as specified by the Internet Engineering Task Force (IETF).

Under the current 3GPP specifications, in order to provide RT and NRT services from external sources for UEs of radio links of 3GPP systems, UTRAN must properly interface with CN, since it is an Iu interface function. To this end, the core network includes a Mobile Switching Center (MSC) coupled to the GMSC and a Serving GPRS Support Node (SGSN) coupled to the GGSN. Both coupled to the HRL, the MSC is typically combined with a guest address register (VLR).

The Iu interface separates between a circuit communication (Iu-CS) interface and a packet switched communication (Iu-PS) interface. The MSC is connected to the RNCs of the UTRAN via the Iu-CS. The Serving GPRS Support Node (SGSN) is coupled to the RNC of the UTRANs via the Iu-PS interface for packet data services.

HLR/HSS is the CS side of interface Gr with point-type and core network, MSC and GMSC supporting AAA function through a Mobile Application Part (MAP) protocol. The SGSN and GGSN of CN are connected by an interface called Gn and Gp.

Another type of radio system, known as a Wireless Local Area Network (WLAN), may be configured to perform wireless communications with WTRUs equipped with WLAN modems. WLAN modems are currently being incorporated by manufacturers into many conventional communication and computing devices.

For example, cell phones, personal digital assistants, and laptop computers are all built with one or more modems. Accordingly, there is an increasing need to facilitate communications for WTRUs having WLAN modems and other different types of networks.

A well-known local area network environment, i.e., a base station, having one or more WLAN Access Points (APs) has been built in accordance with IEEE802.11 b. The wireless service area of u 1WLANs may be limited to a specifically defined geographic area, referred to as a "hot spot". Such a wireless communication system has been excellent in airports, coffee shops and hotels. Access to such a network typically requires a user's authentication procedure. The protocols for such systems have not been fully standardized in the WLAN technology area because the IEEE802 family of standards is evolving. As mentioned above, the CN of UMTS has been designed to communicate with other networks, such as WLANs.

In each of the different environments, WTRUs may be provided with UTMS and WLAN capabilities without the use of different WTRUs, e.g., packet PCs with independent UMTS and WLAN and PCMCIA card adapters. The standalone card component allows a user to utilize different types of networks via a single device without providing a WTRU that can switch from one type of network to another without losing connectivity. For example, a mobile WTRU communicating with or seeking to communicate with a target WTRU may travel to a poor signal quality area where the particular type of network serving the target WTRU becomes periodic or discontinuous. In this case, it is desirable that the WTRU be able to roam in the same type of network and yet be able to switch to a different type of network to maintain a continuous basis for communication.

Disclosure of Invention

A mobile wireless transmit/receive unit (WTRU), components and methods therefore provide for maintaining continuous communication capability when switching from a first type of wireless system to a second type of wireless system.

Preferably, the WTRU is configured to switch from a Universal Mobile Telecommunications System (UMTS) to a Wireless Local Area Network (WLAN) or vice versa while continuous communication is in progress. The present invention is preferably implemented by providing an n application agent to control signaling and a communication agent for user data flow, which may be embedded in an Application Specific Integrated Circuit (ASIC).

A preferred WTRU of the present invention includes a protocol engine having at least two wireless communication interfaces, each configured to interface with a different type of wireless network wireless link. Each communication interface is configured to communicate data to a common application processing component via control signals and users. An application agent is provided that is configured to monitor control signaling between a lower layer protocol engine and an upper layer protocol processing component. A communication agent is provided having a data buffer and defining a switchable data path for a user between the upper application processing component and a selected wireless interface. Preferably, the application agent is associated with the communication agent to control data buffering and data path switching by the communication agent such that data flow to a first wireless interface of the protocol engine is buffered during communication while a wireless link to a different second wireless interface of the protocol engine is established during communication, and the communication agent data path is switched to the second wireless interface, the buffered data being released via the second wireless interface after the wireless link is established during communication.

In one embodiment, the communication proxy datapath is configured to transmit packet-switched data, and a datapath is configured for link-switching data between the upper-layer application processing components and the UMAS radio interface.

Preferably, the application agent includes a link monitor and is configured to trigger activation of the wireless link in accordance with predetermined criteria for a monitored link data conference. The application agent may also include an application conference manager configured to control signaling during establishment of a wireless link via different wireless interfaces, and a workshop unit configured to maintain and switch the content of transmitted messages during establishment of a wireless link via different wireless interfaces. Accordingly, the application agent may include a Subscriber Identity Module (SIM) reader configured to read a SIM containing the user's identity.

A preferred radio link handoff method is provided for a wireless transmit/receive unit (WTRU) to switch from a first type of wireless network to a second type of wireless network during a communication, wherein a protocol engine of the WTRU has first and second wireless communication interfaces configured to communicate with the first and second types of wireless networks, each communication interface configured to communicate data to a common application processing component via control signals and a user. A data buffer and a switchable data path are provided for user data between the upper layer application processing component and a selected wireless interface. Control signaling is monitored between the lower layer protocol engine and the upper layer application processing component. The data buffer and the data path switching should be controlled such that a data stream to a first radio interface of the protocol engine is buffered during the communication and a radio link for a second radio interface of the protocol engine is established during the communication, and the data path is switched to the second radio interface and the buffered data is released via the second radio interface after the radio link is established during the communication.

Other advantages and objects of the present invention will become more apparent to those skilled in the art after considering the following drawings.

Drawings

FIG. 1a is a schematic diagram illustrating a typical UMTS system in accordance with 3GPP specifications.

Figure 1b illustrates an example of a mobile WTRU traveling from a local WLAN to a LAN station operating in a different network while maintaining continued communication in accordance with the principles of the invention.

Figure 2a is a block diagram of a multi-network enabled WTRU in accordance with the present invention.

Figure 2b illustrates a block diagram of a multi-network interface of a multi-network enabled WTRU of the present invention.

Fig. 2c is a process diagram illustrating a handover from a wireless connection via WLAN to a wireless connection via UMTA without losing connectivity in accordance with the present invention.

Figure 3 illustrates a multi-network operating environment for a multi-network enabled WTRU of the present invention.

FIG. 4a is a diagram of a UMTS device architecture configured for interfacing with a computing device, such as via a standard PCMCIA/HBA interface.

FIG. 4b is a block diagram of a preferred embodiment of the dual UMTS/WLAN network device architecture of the present invention designed for use with computing devices, such as via a standard PCMCIA/HBA interface.

Figure 5a is a block diagram illustrating a preferred example of the functional details of the application proxy component of a WTRU of the present invention.

Figure 5b is a block diagram illustrating a preferred example of the functional details of the communication proxy component of a WTRU of the present invention.

Fig. 6a is a protocol stack diagram illustrating a preferred location for operation of the novel components in the UE, UTRAN and SGSN in 3GPP context.

Fig. 6b is a protocol stack diagram illustrating a preferred location for operation of the novel components of the present invention in a WLAN.

FIG. 7 is a diagram illustrating the location of novel components operating with WIN CE.

Detailed Description

The present invention is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout.

The term base station includes, but is not limited to, a base station, node B, site controller, Access Point (AP) or wireless environment that provides WTRUs with wireless access to a network associated with the base station.

The term WTRU as used herein includes, but is not limited to, a User Equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. WTRUs include personal communication devices such as telephones, video telephones, and internet telephones that have network connectivity. In addition, WTRUs include mobile personal computing devices such as PDAs and notebook computers with wireless modem-like functionality. Mobile or address-convertible WTRUs are referred to as mobile units.

The present invention provides continuous calls over different types of radio access networks having one or more network base stations through which WTRUs are provided with wireless access services. The present invention is particularly useful in conjunction with mobile units, i.e., mobile WTRUs are useful when they enter or travel through the geographic coverage areas provided by base stations of different types of networks. For example, figure 1b illustrates a mobile WTRU located at three different addresses 10a, 10b, 10 c. At address 10a the WTRU makes a wireless call with the AP12 of the local WLAN and at address 10B the WTRU makes a wireless call with the node-B13 of the UMTS while traveling between the local WLAN and the office WLAN. At address 10c, the WTRU talks to an AP15 of the office WLAN. Network continuity is provided by the connection of the UTMS' CN14 to office WLANs. The WTRU10 of the present invention takes advantage of network continuity to maintain ongoing calls initiated in the local WLAN 10a and to continue as it transitions to 10c by switching between WLAN and UTMS wireless communications.

In accordance with the present invention, WTRUs are configured for at least two different types of network operation, preferably by being equipped with devices that provide UMTS UE functionality and Wireless Local Area Network (WLAN) WTRU functionality, such as 802.11(b) (WiFi) or Bluetooth compliant functionality. The present invention may provide for continuous calls for any type of other wireless network system interconnected with other types of networks.

Referring to fig. 2, a protocol engine 20 is provided having at least different types of wireless communication interfaces 22, 24. Each communication interface 22, 24 is configured to communicate data to an application processing component 26 representing a conventional overlay communication system via control and user communications. Preferably, a wireless communication interface 22, 24 is configured for UMTS wireless communication and another configuration for 802.11WLAN communication.

The present invention provides for the insertion of an application proxy (APP)30 and communication proxy (COM)32 between the upper layer application processing components 26 at the wireless interfaces 22, 24. The APP and COM components 30 and 32 handle control and user data as "middleware" that can assist in leveraging the different technologies of the underlying base system to improve performance capabilities. The application agent 30 and the communication agent 32 may provide a two-tier middleware architecture that readily integrates different network technologies and provides seamless service to users without requiring changes to the conventional protocol architecture of the respective wireless networks.

The APP30 is configured to monitor and control signaling between the lower protocol engine 20 and the upper application processing component 26. All user communication data flows through the COM32, which COM32 acts as a switch for the upper layer application handling component 26 to direct the data to the appropriate wireless interface 22, 24 within the lower layer protocol engine 20.

The middleware components 30 and 32 may be implemented in WTRUs without corresponding network components. The APP30 and COM32 may operate within this single WTRU plan to maintain wireless communication sessions while handing off networks. Thus, dual mode operation may be supported in a WTRU without full network support and without "context switching", or without termination of "call attention".

For example, if the WTRU10 implements a UMTS wireless communication and travels to the WLAN service area via the interface 22, the call is preferably switched to WLAN wireless communication via the interface 24 in WTRU-only mode as follows. The protocol engine 20 provides link state information that is received and evaluated by the APP30 and determines to switch to WLAN wireless communications. This determination may be based on the quality of service "QoS" of existing UMTS or other factors such as disclosed by the application owned by the inventor of U.S. patent application No. 10/667,633. When the APP30 determines that ongoing UMTS communications should be handed over to a WLAN, the APP30 signals and the COM32 prepares for the handover, the COM32 begins to buffer all communications data generated by the upper layer application processing component 26 for wireless transmission. Accordingly, the processing component 26 continues to generate user data for communication without interruption. The APP30 notifies the upper layer application processing component 26 that the handover is ongoing, with a delay in which it can expect to receive the wireless data until the handover is complete. The APP30 then directs the protocol engine 20 to establish a wireless WLAN connection via the interface 24 to which UMTS communications are handed over.

The protocol engine 20 signals the APP30 after the WLAN connection is established. The APP30 then signals the completion of the handover to the COM32, which COM32 then switches the direction of the user's communication data from the UMTS interface 22 to the WLAN interface 24 and releases the buffered data to the WLAN interface for updating and continuing the call. The APP also signals that the handoff is complete to the upper layer application processing component 26 so that the bi-directional user data for the call can continue traveling through the COM32 and WLAN interface 24. Finally, the APP30 informs the protocol engine to let the UMTS release the UMTS connection.

To improve operation, corresponding APP and COM components may be provided in the network with which the WTRU10 is communicating. FIG. 2b provides an outline of the layout of the components. Network systems interfacing between UMTS systems and WTAN systems are typically based on Packet Switched (PS) data flow, such as using an Internet Protocol (IP). Figure 2b illustrates a WTRU configured to enable network handover of packet switched IP sessions. CS voice signal data may pass from the UMTS interface through the APP, but utilizes voice communication over IP protocols, where the voice data is processed in packets, which may be implemented in WLAN and UMTS.

As shown in fig. 2b, the APP30 of the WTRU10 proxies signaling between higher layers and the COM 22 over the wireless interface 22, 24. The WTRU10 is configured to pass PS data from and to the wireless interfaces 22, 24 through the COM 32. Preferably UMTS and WLAN systems have UTRANs and APs configured with corresponding communication agents implemented with the physical layer air interfaces described above in fig. 2 b. A corresponding application proxy is preferably provided within the IP node of the network system. Network side APPs and COMs provide network support for inter-network handover.

In the multi-network system illustrated in figure 2b, an example of a WTRU10 switching from a WLAN connection to a UMTS connection during a call supported by the network is illustrated in figure 2 c. During the presence of a WLAN session, control and user data are passed through WTRUs APP30 and COM32, respectively, and through the WTRUs communication link via the AP of the WLAN. User data passes through COM of AP, and control data passes through to network APP. When the communications link reports data to the WTRU APP30, the APP determines that the follow-link should be switched to UMTS based on this report, the WTRU APP30 signals the WTRU COM32 to begin buffering uplink user traffic data, and signals the network APP which in turn signals the AP COM to begin buffering link user traffic data. The WTRU com32 preferably stores contention data associated with user data, records the last received downlink packet from the AP, and identifies the last received downlink packet to the WTRU APP 30. The WTRU APP30 then directs the WTRU interface to set up a UMTS link. When the UMTS link is available, it is established and the UMTS utran-enabled WTRU link is validated against the WTRU APP 30. The WTRU APP30 then confirms this setup to the WTRU COM32 and signals the network APP with preferably UMTS connection related information including AAA and QoS information. The WTRU COM32 also preferably signals the information content associated with the user communication data to the UTRAN COM. The WTRU APP30 also signals the network APP with the identity of the last received downlink packet and a request to resume communication, which is in turn signaled by the network APP to the AP COM. The APCOM then releases the buffered downlink data to the UTRAN COM, preferably starting from the next consecutive packet identified following the last received downlink packet. The buffered data is then exchanged via the UMTS connection through the WTRU COM32 and the UTRAN COMM. The communication then continues via the UMTS connection in the normal manner.

Referring to fig. 3, a block diagram of a WTRU10 including the contents of a multi-network environment for internet connectivity is illustrated. The WLAN network includes an Access Point (AP) connected to a WLAN gateway having an associated WLAN aaa tracking component. The UMTS includes a UTRAN and AAA, SGSN and GGSN core network elements. The WLAN interfaces with the Internet via a WLAN gateway, and the UMTS interfaces with the Internet via a GGSN component of a UMTS CN. Preferably, there is an AAA interface between the WLAN AAA and UMTS AAA components.

In the multi-network system illustrated in fig. 3, an example of switching from a WLAN connection to a UMTS connection during a call with an internet-connected device 40 is as follows. When the communication link status indicates WTRU APP30 that the link should switch to the WLAN link, WTRU APP30 signals WTRU COM32 to begin buffering link user communication data upward. The WTRU COM32 also stores contention information related to user data, records the last downlink packet received from the UTRAN, and identifies the last received downlink packet to the WTRU APP 30. The WTRU APP30 then receives AAA context information from the UMTS AAA, controls and directs the WTRU interface to set up the UMTS link. A WLAN link is then established, verified to the WTRU APP30 via the WTRU link of the WLAN UTRAN. The WTRU APP30 then confirms the establishment of the WLAN link to the WTRU COM32 and preferably appropriately converts AAA content data and signals the WLAN AAA component. The wtru com32 then releases the buffered uplink data to the internet-connected device 40. Communication then continues normally at the WTRU10 and the internet connected device 40 via the WLAN connection.

Referring to fig. 4a and 4b, there is shown an implementation of APP and COM components configured to interface with a computing device, such as via a standard PCMCIA/HBA interface. Figure 4a illustrates a layout diagram of a UMTS device architecture design configured to interface with a computing device, such as via a standard PCMCIA/HBA interface. Non-access stratum (NAS), Access Stratum (AS), layer 1 control (LEC) and physical layer (layer 1) components control signaling and user data, including data path descriptions of Packet Switched (PS) and Circuit Switched (CS) data paths. The NAS layer is coupled to a standard computer interface for coupling via a standard PCMCIA/HBA interface connector.

Fig. 4b illustrates a modification of the device of fig. 4a to provide a dual UMTS/WLAN network device architecture in accordance with the principles of the present invention. An application agent 30 is processed in the control signal path between the NAS layer and the computer interface. A communication agent 32 is coupled with the APP30 for processing in the PS data path between the NAS layer and the computer interface. The preparation of WLAN interface components preferably includes an 802.11 compliant physical layer, layer 1 control components and 802.11 compliant Medium Access Control (MAC) and Logical Link Control (LLC) components. The Medium Access Control (MAC) and Logical Link Control (LLC) components have a control signal path coupled to the APP30 and a PS data path coupled to the COM 32.

Fig. 5a and 5b illustrate preferred detailed configuration layouts of APP30 and COM32 components. The APP30 preferably includes a communication module coupled to the central processing unit. The communication module has an external connection for coupling to higher layer processing (applications), via the WLAN interface of LLC control (LLC), via the UMTS interface of NAS level control (NAS), and COM32 (COM). An L1 connection is provided directly to the physical layer to assist in monitoring link status.

The APP30 preferably includes a link monitor, an application session manager, a studio unit and a Subscriber Identity Module (SIM) readout component associated with the central processing unit. The link monitoring component is configured to monitor link status and trigger a handoff from one type of wireless network link to another, if selected criteria are met. The application call manager is configured to control signaling during the handover. The configuration of the inter-working unit may maintain and translate AAA, QoS profiles and other content information transmitted during handoff. The SIM reader is configured to read the SIM contained in the user's identity for AAA functions.

The COM32 is preferably configured with a control component, a switch/buffer device and a read/write (R/W) device. The control module is configured to control the switching of PS data between the UMTS and WLAN interfaces, depending on the type of wireless connection, and has a connection coupled to the APP30 for receiving control signals. The switch/buffer and R/W device are configured in the PS data path between the two interfaces and higher layer processing. The switch/buffer has a WLAN connection (LLC) and a UMTS connection (PS), the PS data flow being controlled by the control component via one or other connections. The switch/buffer and the R/W device are used to interrupt the data flow from the higher layer connection (IP data) and to buffer the data received during handover, whereupon the buffered data is released when a new network connection is established, whereupon the data path is switched by the control component.

For completeness, figures 6a and 6b are used to illustrate network locations for the APP and COM in the preferred WTRU and UMTS and WLAN protocol stacks. Fig. 6a illustrates APP in the Control Plane (CP) protocol stack and COM location in the User Plane (UP) protocol stack of the UMTS network, a WLAN AP and WLAN gateway configured with an 802.11 compliant wireless interface and an 802.3 inter-WLAN interface.

The ability to establish interworkings between UMTS and WLAN (standard 802.11) is extreme to the evolved path in the present dual mode WTRU, including roaming, handover and seamless handover. The network interface strategy is mentioned in the 3GPP technical report TR 29.934. The present invention addresses the seamless handover situation by providing an architecture that supports seamless handover without coupling or decoupling, or tight coupling plans.

The new APP and COM components can be extended to integrate any access technology. Fig. 7 is a diagram illustrating the location of these components in the wireless interface device (UE + WLAN engineering), operating on WIN CE content as illustrated in fig. 4 b.

Example properties of COM proxies include the ability to abstract transport mechanisms to upper layers. Although the above-described PS data is used, the COM on the user plane may be implemented in CS and/or PS data to route user data, depending on the current system connected. From a UMTS perspective, COM components are preferably located on top of the PDCP/RLC/MAC/PHY protocols. COM may be implemented as a generic software component that may be adapted to any access technology.

Example attributes of an access Agent (APP) include picking all applications in the call and presentation layer. The APP is preferably located in the signaling (control) plane (CP), collects link quality reports, and has the ability to trigger handovers and assist in call re-establishment.

The APP and COM components are preferably implemented on a single integrated circuit, such as an Application Specific Integrated Circuit (ASIC), which also includes UMTS and WLAN interface components. Portions of the processing elements may also be implemented on multiple separate integrated circuits.

WTR configurations and methods are described above for use with UMTS and WLAN systems. The present invention may be implemented in any wireless communication system in which WTRUs are configured to communicate with various types of wireless networks.

Claims (12)

1. A wireless transmit/receive unit, the wireless transmit/receive unit comprising:

a lower layer protocol engine comprising a plurality of wireless communication interfaces including at least one IEEE802.xx wireless communication interface, wherein the at least one IEEE802.xx wireless communication interface comprises a physical layer component and a Media Access Control (MAC) component; and

a middleware component coupled with the lower-layer protocol engine and configured for:

monitoring communication between the lower layer protocol engine and an upper layer application processing component; and

the link state information is evaluated to determine if a handover is required.

2. The wtru of claim 1 wherein the middleware component is configured to transmit the link state information to an Access Point (AP).

3. The wireless transmit/receive unit of claim 1, wherein the middleware component is configured for communicating with an IEEE802.XX Logical Link Control (LLC) component.

4. The wtru of claim 1 wherein the link state information comprises a handover command, and wherein the wtru is configured to perform a handover from a first one of the plurality of wireless communication interfaces to a second one of the plurality of wireless communication interfaces in response to the handover command.

5. The WTRU of claim 4, wherein the first wireless communication interface is a cellular wireless communication interface and the second wireless communication interface is an IEEE802.XX wireless communication interface.

6. The wireless transmit/receive unit of claim 4, wherein the first wireless communication interface is an IEEE802.XX wireless communication interface.

7. The wtru of claim 6 wherein the first wireless communication interface is an IEEE 802.16 wireless communication interface and the second wireless communication interface is an IEEE802.11 wireless communication interface.

8. A wireless transmit/receive unit, the wireless transmit/receive unit comprising:

a plurality of communication interfaces, each of the plurality of communication interfaces comprising a physical layer and a media access control layer; and

a middleware component coupled with the plurality of communication interfaces and configured for monitoring the plurality of communication interfaces and determining whether a handoff to one of the plurality of communication interfaces is required.

9. The wtru of claim 8 wherein the determination of whether a handover to one of the plurality of communication interfaces is required is based on received control data.

10. The wtru of claim 8 wherein the determination of whether a handover to one of the plurality of communication interfaces is required is based on received communication data.

11. The wtru of claim 8 wherein the determination of whether a handover to one of the plurality of communication interfaces is required is based on a quality of service.

12. The wtru of claim 8, further comprising:

at least one upper component coupled to the middleware component;

wherein the middleware component is configured for selecting a communication interface transparently to the at least one upper layer component.