HK1165655A - A wlan access point and a method for use in a wlan access point - Google Patents

Abstract

The invention includes a wireless local area network (WLAN) access point and a method for use in a wireless local area network (WLAN) access point. The WLAN access point comprises: a media independent handover-handover (MIHHO) component configured to generate media independent handover (MIH) information to facilitate handover, the MIH information comprising, for each of at least one identified networks, a network identifier and an MIH capability indicator indicating supported MIH services; and a transmitter configured to transmit a probe response message including the MIH information. The invention includes a method and apparatus for mobility handling across different wireless technologies by efficiently performing alternate network discovery and enabling a mobile station to select the most desirable candidate radio access technology, depending on parameters such as location and network policy settings.

Description

WLAN access point and method used in WLAN access point

The present application is a divisional application of an invention patent application having an application date of 2006, month 1 and day 17, application number 200680002632.5, entitled "method and system for system discovery and user selection".

Technical Field

The present invention relates to wireless communications. More particularly, the present invention relates to network discovery and selection in geographic areas where more than one cellular and/or IEEE802 wireless communication system is available.

Background

Both wired and wireless communication systems are well known in the art. In recent years, the widespread development of different types of networks has resulted in more than one type of network being available over a geographic area. Communication devices have been developed to integrate two or more network access technologies on a single communication device. For example, there are some communication devices that integrate the ability to communicate over more than one type of wireless standard, such as an IEEE 802.X compliant Wireless Local Area Network (WLAN) standard, and cellular technology, such as Code Division Multiple Access (CDMA), global system for mobile communications (GSM), and General Packet Radio System (GPRS) standards. Communication via each standard is referred to as a communication mode, and devices capable of communicating via more than one communication standard are referred to as multi-mode devices.

However, existing systems that support the integration of two or more network access technologies into one device do not provide for interworking between the different access technologies. In addition, a communication device that supports multi-mode functionality does not provide the ability to determine which access technology is available from the location of the device, or to assess the desirability of different access technologies available at the location of the device, much less to select the best available technology.

In existing approaches, a multimode handset may turn on multiple radio modems and scan for available networks, frequencies, and cells for each radio access technology. However, having two or more radios and modems perform the scanning function may consume a significant amount of power and system resources. Also, this approach does not discover the services available on each available network, nor does it select a preferred network.

Accordingly, there is a need to evaluate and select a preferred network from a plurality of available networks without being limited by the prior art.

Disclosure of Invention

The invention discloses a wireless local area network WLAN access point, which comprises: a media independent handover-handover MIHHO component configured to generate media independent handover MIH information for facilitating handover, the MIH information including, for each of at least one designated network, a network identifier and an MIH capabilities indicator indicating MIH services supported; and a transmitter configured to transmit a probe response message including the MIH information.

The invention also discloses a method used in the WLAN access point, which comprises the following steps: generating Media Independent Handover (MIH) information for facilitating handover, the MIH information including, for each of at least one designated network, a network identifier and an MIH capabilities indicator indicating supported MIH services; and transmitting a probe response message including the MIH information.

The present invention comprises a method and apparatus for facilitating mobility handling between different wireless technologies by efficiently discovering available networks for a wireless transmit/receive unit (WTRU), determining the services available on those networks, and selecting the most appropriate available radio access technology based on parameters such as service requirements, available services, location, and policy settings.

Drawings

The invention will be understood in more detail from the following description, given by way of example and understood in conjunction with the accompanying drawings, in which:

figure 1 is a diagram of a wireless transmit/receive unit (WTRU) located in a geographic area commonly served by a WLAN and a cellular network;

figure 2 is a block diagram of a dual mode WTRU;

figure 3 shows a handover of a communication session from a 3GPP BS to a WLAN BS between a dual mode WTRU and a correspondent node (CoN);

figure 4 is a signaling diagram showing network initiated/WTRU controlled system discovery;

FIG. 5 is a flow diagram of a method for discovering integrated and other services among multiple available radio access technologies;

figure 5a is a signaling diagram illustrating a system discovery and access dual mode WTRU;

FIG. 6 is a flow chart of a method of signaling used when system discovery fails;

FIGS. 7a and 7b are flow diagrams of a method of signaling used when system authentication fails; and

fig. 8a and 8b are signaling diagrams showing 802.X and 3GPP interworking system access failures.

Detailed Description

The present invention will hereinafter be described with reference to the drawing figures, in which like numerals represent like parts.

When referred to herein, the term wireless transmit/receive unit (WTRU) includes, but is not limited to, a User Equipment (UE), a Mobile Station (MS), a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, the term Base Station (BS) includes but is not limited to a base station, a Node-B, a site controller, an Access Point (AP), or any other type of interfacing device capable of operating in a wireless environment.

The present invention includes an apparatus and method for facilitating mobility handling between different wireless technologies by efficiently performing network discovery, determining services available on the discovered networks, and facilitating a WTRU to select a preferred radio access technology from a plurality of available radio access technologies based on parameters such as service requirements, available services, location, and network policy settings.

The present invention enables a multi-mode WTRU, such as a dual mode WTRU that supports both a cellular network and a Wireless Local Area Network (WLAN), to turn off WLAN scanning when a user is connected to the cellular network, thereby conserving WTRU battery power. When the WLAN is in the vicinity of a dual mode WTRU, the cellular network instructs the dual mode WTRU and thus the dual mode WTRU begins scanning for WLANs. In a preferred embodiment of the present invention, the cellular network notes the geographic location of the WLAN in its service area. The cellular network also tracks the location of the WTRU. Various methods may be used to determine the location of the WTRU, such as triangulation, general geographic area description, or Global Positioning System (GPS) assisted methods. Based on the cellular network's knowledge of the WLAN location and the WTRU's location, the cellular network may determine whether a WLAN is present in the vicinity of the WTRU. If so, the cellular network signals to the WTRU that a WLAN exists in its vicinity. The WTRU then starts a WLAN discovery procedure. In a preferred embodiment, the cellular network is a 3GPP network and the WLAN is an IEEE 802.X wireless network. The method can extend WTRU battery power without compromising the effectiveness of WLAN system discovery.

Figure 1 shows a dual mode WTRU150 that may communicate with WLAN and 3 GPP. The WTRU150 has just moved to the WLAN service area 110. WLAN communication services are provided by the WLAN BS 120 within the WLAN service area 110. The WLAN service area 110 is surrounded by a 3GPP cell 130. The 3GPP communication service is provided by the 3GPP BS 140 within the cell 130. The WTRU150 initially communicates with the 3GPP BS 140 via a wireless connection. In accordance with the present invention, when WTRU150 moves to WLAN service area 110, WTRU150 notes that a WLAN is available as previously described. WTRU150 discovers available services via WLAN BS 120. WTRU150 now decides whether it should hand off its communication from 3gpp BS 140 to WLAN BS 120. If so, the handover is initiated.

Figure 2 is a block diagram of a dual mode WTRU 150. WTRU150 includes a 3GPP component 240 capable of communicating with 3GPP BS 140 using a 3GPP communication standard; a WLAN component 220 capable of communicating with the WLAN BS 120 using a WLAN communication standard; and a media independent handover-handover (MIHHO) component 230 associated with Media Independent Handover (MIH) functionality. The MIH function facilitates discovery of available networks, determines a preferred network among a plurality of available networks, and facilitates handover from one network to another network.

Figure 3 is a diagram illustrating a handover of an ongoing communication session between dual mode WTRU150 and a correspondent node (CoN) 300. The communication session is initially conducted via 3GPP component 240 and 3GPP BS 140 within WTRU 150. Additional network components (not shown) are typically located between 3GPP BS 140 and CoN 300. A potential alternate communication path between WTRU150 and CoN 300, including WLAN BS 120, is shown in dashed lines. Additional network components (not shown) are also typically located between the WLAN BS 120 and the CoN 300. In a preferred embodiment, the 3GPP network maintains a database of the locations of WLANs whose service areas overlap with the service areas of the 3GPP network itself, and tracks the location of WTRU 150. The WLAN component 220 in the WTRU150 remains off until the 3GPP network indicates the presence of a WLAN in its vicinity to the WTRU 150. By comparing the location of WTRU150 to the location of the last known WLAN, the 3GPP network determines when a WLAN is present in the vicinity of WTRU 150. The 3GPP network then sends information about available WLANs to WTRU 150. This information may be sent in a dedicated message, beacon frame, or the like. WTRU150 reads the system information and determines whether a handover to WLAN is required. If so, WTRU150 initiates a handover procedure.

The information used to determine the location of WTRU150 may include information gathered from triangulation, general geographic area descriptions, GPS-assisted methods, and the like. In addition, the 3GPP system may allocate a specific Temporary Mobile Station Identity (TMSI) space for a routing area, a location area, or a service area supporting WLAN services. Alternatively, the WTRU may use a Radio Frequency (RF) signature or fingerprint identification to determine the availability of the WLAN system. In this case, the WTRU establishes a relationship between the 3GPP radio frequency channel signature for channels placed at specific locations within the cellular network and the underlying wireless terrestrial networks (e.g., WLANs) covered by the 3GPP RF channel coverage area. This relationship is used to mark the WTRU for the presence of a WLAN network when the WTRU detects the presence of an RF signature. This information is stored in a database within the WTRU and may be dynamically updated when the relationship should be modified.

Referring now to fig. 4, an ongoing communication session 40 between a dual mode WTRU150 and a correspondent node (CoN)300 is shown. User data flow is between the WTRU150 and the CoN 300 over a 3GPP network 44 including a 3GPP Radio Access Network (RAN) and a Core Network (CN). In step 1, the 3GPP network 44 sends WTRU150 information regarding available IEEE 802.X compliant WLANs 46, including medium access points (MAs) and Access Gateways (AGs). The 3GPP component 240 in the WTRU150 reads the WLAN system information and determines whether the content of the information can be used for system reselection by the WLAN system 46. In step 2, the 3GPP component 240 in the WTRU150 extracts relevant WLAN 46 system information that may be used to determine whether a handover to the WLAN system 46 is warranted and forwards the information to the MIHHO component 230 in the WTRU 150. The WLAN 46 system information includes information required for the WTRU150 to determine whether a handover to WLAN 46 is warranted and the WTRU forwards the information to the MIHHO component 230 of WTRU 150. WTRU150 then scans for WLANs 46 in its vicinity. Alternatively, as shown by the dashed line in step 2, WLAN component 220 in WTRU150 may perform periodic scanning continuously or when prompted by system information received from 3GPP component 240.

In step 3, relevant WLAN system 46 INFORMATION extracted from INFORMATION sent by 3GPP system 44 is forwarded to MIHHO component 230 in a message, here designated as a link system INFORMATION (LINK SYSTEM INFORMATION) message. Alternatively, as shown by the dashed line in step 3, the information obtained by WTRU150 during the periodic scan is forwarded to MIHHO component 230 in a message, here designated as a link detection (LINKDETECTED) message. If the WLAN is accessible, WTRU150 detects the WLAN 46 beacon frame. The beacon frame may be used to identify handover-specific information such as whether all or part of the media independent handover service is supported (e.g., indicated by a specific 802.21 flag or similar method broadcast on the beacon frame). The beacon frame may also be used to indicate other services available on the WLAN 46. The switch-specific information may be updated manually or dynamically. Alternatively, WTRU150 may attempt to obtain WLAN 46 system information through a probe request/response message pair or through access to a database in a candidate system.

In step 4, the MIHHO component 230 in the WTRU150 determines that one or several WLAN networks may be suitable for reselection based on available information (e.g., explicit indication, RF signature, geographic location, manual or automatic scanning, specific TMSI allocation, etc.). In step 5, the MIHHO component 230 computes a potential candidate list for handover selection. In step 6, the MIHHO component 230 evaluates the various candidates based on, for example, various criteria of the system operator and known WLAN system 46 capabilities (e.g., quality of service (QoS), data transmission speed, etc.). The MIHHO component 230 determines preferred candidates for handover and triggers WLAN system access by sending a message to the Media Access Control (MAC) layer to request a handover-related action, where the message is designated as a MIH handover (MIH _ SWITCH) message.

Fig. 5 is a flow diagram illustrating discovery of integrated and other services among multiple available radio access technologies, where the MIHHO component 230 in WTRU150 receives system information via WLAN beacons. WTRU150 performs a scanning procedure to find a WLAN network, step 510. Scanning may be active or passive and may result in more than one WLAN being discovered. Upon detecting the WLAN beacon frame, the WTRU150 determines whether MIH handover information is supported, step 520. If so, WTRU150 reads the contents of the MIH handover information, step 530. The MIH specific information is manually or dynamically set and updated by AN MIH function existing in a WLAN Access Network (AN). Any MIH information found in the beacon frame (e.g., system operator identification, W-APN, vicinity maps, and system capabilities) is communicated to the WTRU's MIHHO component 230 via a message, here designated as a link system information message, step 540. The information is processed and WTRU150 determines that the WLAN system is a suitable candidate for system access, step 550. The MIH function evaluates the WLAN with other available Access Networks (ANs) and determines that the WLAN is a preferred AN, step 560. The MIH function triggers authentication and association with the preferred AN (i.e., discovered WLAN) through AN MIH _ SWITCH message to the MAC layer, step 570. A WLAN specific authentication and association procedure is performed on the selected WLAN system, step 580. Authentication may be via Extended Authentication Protocol Over LAN (EAPOL). It should be noted that in addition to the WTRU scanning for WLANs as prompted by the 3GPP network, the WTRU may scan at power up.

In the WLAN authentication procedure, WTRU150 provides the WLAN with a network access id (nai). Based on the NAI, the Access Gateway (AG) may trigger an extended authentication protocol-authentication and key protocol (EAP-AKA) authentication and relay the authentication message to a 3GPP authentication, authorization, and accounting (AAA) server. The AG may also route AAA messages to other servers to provide other services. The AG may use the NAI to determine whether WTRU150 requires a particular level of service, e.g., basic or extra service. The NAI may also be used to route messages to a particular port that provides a particular service, such as network capabilities available to this particular user or group of users.

The AG may also determine the level of service that the WTRU needs based on the NAI that triggered the authentication procedure, or based on the authentication procedure itself. The AG may determine that the WTRU may receive basic service even if the authentication procedure fails for the extra level of service. If the AG is not able to route the authentication request, it may respond to the WTRU by indicating available AAA servers in which the authentication request may be routed. If the WTRU determines that none of the AGs are suitable, the WTRU may decide to return to the scanning phase.

The AG may allow access to basic services (e.g., internet services) or to ports that may provide further information to WTRU 150. The AG may also select to provide a default Packet Data Gateway (PDG) address. If this is the case, the WTRU may decide to connect to the default PDG. This procedure may be automatic or may be based on configuration parameters within the AG and/or WTRU. Alternatively, access may be denied.

According to the present invention, information regarding system capabilities is transmitted by the MAC layer to the MIH function in the WTRU150 using link system information messages. The MIH function may determine that one or more values within the system information parameters for available WLANs do not satisfy a requirement for system access. For example, the system operator is barred, the required service is not available, or the quality of service (QoS) is not sufficient. If the MIH function determines that the parameters provided by the information service do not meet the internally configured requirements, the MIH function commands the MAC layer to return to the scanning phase using MIH _ SCAN messages.

Figure 5a is a signaling diagram illustrating system discovery and access by dual mode WTRU 150. In step 1, upon power up or system reselection, the WTRU150 performs a scanning procedure (active or passive) to discover WLAN networks. When a beacon frame is detected, the WTRU150 first identifies whether MIH information is supported, and if so, the WTRU150 reads the contents of the information. MIH specific information is set and updated manually or dynamically by the access network MIHHO component 500. Any MIH information found in the beacon frames (e.g., system operator identification, W-APN, vicinity maps, and system capabilities) is communicated to the WTRU's MIHHO component 230 via link system information messages.

In step 2, the information is processed and the WTRU150 determines that the WLAN system 46 is a suitable candidate for system access. Thus, MIHHO component 230 commands WLAN authentication and association using a message to the MAC layer, here designated as a MIH _ SWITCH message.

In step 3, a WLAN specific authentication and association procedure is performed on the selected WLAN system. The MIHHO component 230 notifies the 3GPP party that a handover is about to begin.

In step 4, WLAN Access Gateway (AG) MIHHO component 500 triggers WLAN 3GPP authentication and authorization using EAP-AKA protocol. The WTRU's 3GPP component 240 uses its assigned network access id (nai) to indicate to the WLAN AG 46 its associated 3GPP AAA server. Successful routing results in the establishment of an IPsec tunnel carrying an EAP-AKA message.

In step 5, upon successful authentication and authorization, WTRU150 obtains a local IP address from a local DHCP server.

Fig. 6 is a flow chart showing signaling used when system discovery fails. As previously described, MIH information discovered within beacon frames (e.g., system operator identification, W-APN, vicinity maps, and system capabilities) is communicated to WTRU MIHHO component 230 via link system information messages. The MIHHO component 230 determines that one or more values provided within the WLAN system information parameters do not satisfy system access requirements, such as the system operator being barred, quality of service (QoS) not being sufficient, or a better candidate being identified in a potential set of nearby provided in the message, step 610. The MIH function commands the MAC layer to return to the scanning phase, step 620.

Figures 7a-7b are flow diagrams showing signaling used when system authentication fails. Referring to figure 7a, the MIH function has determined that communication via a discovered WLAN is desired, step 710. The wtru MIH function triggers an authentication process by sending an MIH _ SWTICH message to the MAC layer, step 720. The authentication process may include using Wired Equivalent Privacy (WEP). Note that in order to determine if the user needs further EAP-AKA authentication that allows access to a particular service (e.g., 3GPP Internet Multimedia Service (IMS)), the WTRU may use a specific WEP default key. The AG may use a default key to determine whether to handle EAPOL authentication or whether basic internet access is authorized.

If authentication fails, system entry is denied, step 730. This may occur, for example, if WEP authentication fails, or if the NAI provided does not resolve any 3GPP servers. The WTRU may then return to the scanning phase, step 740. Alternatively, if the NAI cannot be resolved, the AG may direct the WTRU to a local server for further processing, such as to provide basic services. The AG MAC may provide the MIH function with information about the key used in the WEP procedure. The MIH function may then determine whether to approve further authentication procedures, step 750, based on, for example, a default key used during WEP authentication. Note that WEP is not considered a secure authentication procedure in this context. Instead, WEP is used here to identify users that need further authentication.

If further authentication procedures are approved, the MIH function triggers a cellular authentication attempt, e.g., using EAPOL authentication procedures, step 760. The aaaaaag component may act as an authenticator between the WTRU supplicant and the AAA authentication server, e.g., using an IPsec tunnel. If the AG cannot route the authentication request, then the EAPOL cellular authentication attempt fails, STEP 770. The AG may respond by indicating an available AAA server that can route the request. If the WTRU determines that there is no suitable AG, the WTRU may return to the scanning phase, step 780. If the AG can find a suitable authentication server using the NAI provided by the WTRU, the WTRU may attempt authentication with the server, step 715. In this case, the AG may relay the authentication message between the WTRU and the authentication server, step 725.

Referring to fig. 7b, the WTRU may fail the cellular authentication procedure, step 735. If so, all accesses are denied and the WTRU returns to the scanning phase, step 736. Alternatively, only access to specific services, such as 3GPP services, may be denied and access to basic services may be provided, step 737.

However, the cellular AAA server may successfully authenticate the WTRU, step 745. If so, the WTRU may proceed to obtain the local IP address, e.g., via Dynamic Host Control Protocol (DHCP) or Address Resolution Protocol (ARP), step 755. Using the WLAN access point name (W-APN) network ID and operator ID, the WTRU constructs a full domain name (FQDN). The WTRU then requests IP address resolution to gain access to the Packet Data Gateway (PDG), step 765. The WTRU attempts to obtain a PDG address based on the FQDN (e.g., W-APN or Public Land Mobile Network (PLMN) ID). If the Domain Name Server (DNS) does not resolve the FQDN to any PDG IP address, the WTRU is unable to access the PDG in the existing WLAN network, step 775. The WTRU may then choose to return to the scanning phase, step 776, or choose to satisfy local WLAN services only, step 777.

However, if the DNS returns a valid PDG IP address, the WTRU establishes a PDG-oriented tunnel, such as an L2TP tunnel, step 785. The WTRU then listens for a proxy announcement message from the PDG, step 713. If an agent advertisement message is not received, the WTRU sends an agent solicitation, step 723. However, if an agent advertisement message is received from the PDG, the WTRU may obtain the Care of Address (COA: Care of Address) directly from these messages without requiring a special request through an agent solicitation message, step 714.

If no response to the agent solicitation is received, e.g., if MIP is not supported, the WTRU may use its local IP address for transparent access to the internet for basic ISP services, or may request activation of a Packet Data Protocol (PDP) context, step 733. WTRU-PDG tunnel IP traffic may be routed directly from the WTRU to the internet via the PDG tunnel. This scenario does not provide seamless mobility beyond the PDG domain. However, if a response to the agent solicitation is received, the WTRU may update its COA in its home agent, step 724. Any messages intended for the WTRU will be redirected by the home agent to the new COA.

Fig. 8a and 8b include signaling diagrams showing 802.X and 3GPP interworking system access failures. In step 1, upon power up or system reselection, the WTRU150 performs a scanning procedure (active or passive) to discover WLAN networks. When a beacon frame is detected, the WTRU150 first identifies whether MIH information is supported and, if so, the WTRU150 reads the contents of the MIH information. MIH specific information may be set and updated manually (through a management system) or dynamically through AG MIHHO component 500.

In step 2, any MIH information found in the beacon frame (e.g., system operator identification, W-APN, vicinity maps, and system capabilities) is transmitted to the WTRU's MIHHO component 230 via a link system information message. The MIHHO component 230 determines that one or more values provided within the system information parameters do not satisfy the requirements for system access. For example, the system operator may be barred, not have sufficient quality of service (QoS), or identify better candidates in the set of potential neighbors provided in the message. This situation represents the first failure case. This is indicated in fig. 8a by a circled "1".

In step 3, if MIHHO component 230 determines that the parameters provided by the system services do not meet the requirements of the internal configuration, then MIHHO component 230 commands the MAC layer to return to the SCAN phase using MIH SCAN (MIH _ SCAN) messages.

In step 4, if MIHHO component 230 determines that the internally configured requirements are met, then MIHHO component 230 triggers WEP authentication using a MAC layer oriented MIH _ switch message. Note that in order to determine if the user needs further EAP-AKA authentication that allows access to a particular service (e.g., 3GPP IMS), the WTRU150 may use a particular WEP default key. The AG may use a specific default key to determine whether EAPOL authentication should be further processed or basic internet access is authorized.

In step 5, the WTRU150 is authenticated according to the current 802.11WEP procedure.

In step 6, if WEP authentication fails, system access is denied. The WTRU150 may then return to the scanning phase. This situation represents a second failure case, represented by the circled "2" in FIG. 8 a.

In step 7, the AG MAC 800 may provide information to the AG MIHHO component 500 about the keys used in the WEP procedure if WEP authentication fails, unlike the WTRU150 returning to the scanning phase. This allows the MIH function to determine whether to approve further authentication procedures, e.g., based on the NAI provided, e.g., based on a default key used during WEP authentication. Note that WEP is not considered a secure authentication process. Herein, WEP is used primarily to identify a particular user that requires further authentication. If the NAI provided is not resolved by any 3GPP server, the AG 46 may deny access or direct the WTRU150 to a local server for further processing, e.g., to provide basic services. This is indicated in FIG. 8B by the encircled "3".

In step 8, the AG MIHHO component 500 triggers EAPOL authentication procedure using a message, here designated as MIH _ SYSCAP message.

In step 9, the AG 46 performs EAPOL procedures. The AG AAA component 800 will act as an authenticator between the supplicant (WTRU 150) and the authentication server 810 (AAA). The AG 46 uses the NAI provided during the initial message exchange to determine that the AAA server 810 should perform the authentication procedure. If the AG 46 is not able to route the authentication request, the AG 46 response indicates the available AAA servers in which the request can be routed. If the WTRU150 determines that there is no suitable AG, the WTRU may decide to return to the scanning phase. This is shown in FIG. 8B with a circled "4".

Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone (without the other features and elements of the preferred embodiments) or in various combinations with or without other features and elements of the present invention.

Examples

1. A method for a multi-mode wireless transmit/receive unit (WTRU) to be aware of a Wireless Local Area Network (WLAN).

2. The method of embodiment 1 wherein the WTRU is a User Equipment (UE), a Mobile Station (MS), a fixed or mobile subscriber unit, a pager, a cellular handset, or a portable computer.

3. A method as in any preceding embodiment wherein the WLAN is substantially compatible with the IEEE802 family of standards.

4. The method as in any preceding embodiment wherein the WLAN is substantially compatible with at least one of the IEEE 802.X, 802.11X, 802.11a, 802.11b, 802.11g, 802.11i, 802.16, or 802.16a standards.

5. The method of any preceding embodiment wherein the WTRU communicates with a cellular network.

6. The method of embodiment 5 wherein the cellular network is substantially compatible with Code Division Multiple Access (CDMA), global system for mobile communications (GSM), General Packet Radio System (GPRS), or 3GPP technologies.

7. The method of any preceding embodiment wherein the WTRU establishes a communicative coupling with the WLAN.

8. A method as in any preceding embodiment wherein the location of the WLAN is provided to the cellular network.

9. A method as in any preceding embodiment wherein the WLAN is substantially proximate to a service area of the cellular network.

10. The method of any preceding embodiment, wherein the WLAN overlaps a service area of the cellular network.

11. A method as in any preceding embodiment wherein the WLAN is within a service area of a cellular network.

12. A method as in any preceding embodiment wherein the location of the WLAN is maintained in a database of the cellular network.

13. A method as in any preceding embodiment wherein the location of the WLAN is estimated based on the location and range of a WLAN Base Station (BS) transmitter.

14. The method of any preceding embodiment wherein the location of the WTRU is tracked.

15. The method of any of the preceding embodiments, wherein the tracked location of the WTRU uses information derived from at least one of triangulation, universal geographic area description, Global Positioning System (GPS), Temporary Mobile Station Identification (TMSI) space, and Radio Frequency (RF) signature.

16. The method of any preceding embodiment wherein the location of the WTRU is compared to the location of the WLAN.

17. The method of any preceding embodiment wherein the location of the WTRU is compared to the location of the WLAN by the cellular network.

18. The method of any preceding embodiment wherein it is detected when the WTRU is in the vicinity of the WLAN so that the WTRU can establish a communicative coupling with the WLAN.

19. The method of any preceding embodiment wherein the WTRU is informed that a WLAN is in its vicinity.

20. The method of any preceding embodiment wherein the cellular network informs the WTRU that a WLAN is in its vicinity and sends information about the WLAN to the WTRU in a dedicated message.

21. The method of any preceding embodiment wherein the cellular network informs the WTRU that a WLAN is in its vicinity and sends information about the WLAN to the WTRU in a beacon frame.

22. A method as in any preceding embodiment, wherein the information about the WLAN comprises an indication of handover functions supported by the WLAN.

23. The method of any preceding embodiment, wherein the information about the WLAN comprises an indication of at least one service available on the WLAN.

24. The method of any preceding embodiment wherein the information about the WLAN from which the indication to the WTRU is generated is manually updated.

25. The method of any preceding embodiment wherein the information about the WLAN from which the indication to the WTRU is generated is dynamically updated.

26. The method of any preceding embodiment, wherein determining whether the WTRU should establish a communicative coupling with the WLAN.

27. The method of any preceding embodiment wherein the WTRU establishes a communicative coupling with the WLAN if it is determined that the WTRU should.

28. The method of any previous embodiment, wherein the WTRU obtains WLAN system information via a probe request/response message with the WLAN.

29. The method of any previous embodiment, wherein the WTRU obtains WLAN system information by accessing a database within the WLAN.

30. The method of any preceding embodiment wherein the WTRU determines whether it should establish a communicative coupling with the WLAN.

31. The method of any preceding embodiment, wherein the cellular network determines whether the WTRU should establish a communicative coupling with the WLAN.

32. The method of any preceding embodiment wherein the WTRU establishing a communicative coupling with the WLAN includes a scan of the WLAN by the WTRU.

33. The method of embodiment 32 wherein the scanning is active.

34. The method of embodiment 32 wherein the scanning is passive.

35. The method of embodiment 32 wherein the scanning is performed periodically.

36. The method of any preceding embodiment, wherein a plurality of available WLANs are detected in the vicinity of the WTRU with which the WTRU may establish a communicative coupling.

37. The method of embodiment 36 wherein the WTRU calculates a list of available WLANs.

38. The method of embodiment 37 wherein a preferred WLAN with which the WTRU may establish a communicative coupling is determined.

39. The method of embodiment 38 wherein the WTRU determines the preferred WLAN by evaluating WLAN information including at least one of a system operator, quality of service (QoS), and data transmission speed.

40. A method for use by a wireless transmit/receive unit (WTRU) in communication with a first network using a first access technology to facilitate handover of the WTRU to a preferred network using a second access technology.

41. The method of embodiment 40 wherein Media Independent Handover (MIH) functionality and/or MIH information is used to facilitate handover.

42. The method of embodiment 41 wherein the MIH information is available for each of a plurality of identified networks.

43. The method as in any one of embodiments 41-42, wherein the MIH information comprises at least one of a network identifier, a network location, a system operator identifier, a system capability, a quality of service (QoS) parameter, and a radio access type.

44. The method as in any one of embodiments 41-42, wherein the MIH information comprises a network data transfer speed for at least one network.

45. The method as in any one of embodiments 41-42, wherein the MIH information comprises network policy settings for at least one network.

46. The method as in any one of embodiments 41-45, wherein the MIH information is received over a beacon frame.

47. The method as in any embodiments 41-45, wherein the MIH information is received via dedicated frames

48. The method as in any one of embodiments 41-45, wherein the MIH information is received over a broadcast channel

49. The method as in any one of embodiments 41-48, wherein at least a portion of the MIH information is retrieved from a database on the network.

50. The method as in any one of embodiments 41-49, wherein the MIH information is evaluated to determine a preferred network.

51. The method as in any embodiments 40-50 wherein a handover of the WTRU to a preferred network is initiated.

52. A multi-mode wireless transmit/receive unit (WTRU).

53. The WTRU of embodiment 52 being capable of receiving and processing information regarding at least one wireless local area network, WLAN, in the vicinity of the WTRU.

54. The WTRU as in any one of embodiments 52-53 being capable of determining which of a plurality of possible communication connections is a preferred connection.

55. The WTRU as in any one of embodiments 52-54 being capable of establishing a preferred communication connection.

56. The WTRU as in any one of embodiments 52-55 comprising a cellular component configured to communicate with a cellular network via a communicable connection.

57. The WTRU as in any one of embodiments 52-56 comprising a WLAN component for communicating with a WLAN via a communicative connection.

58. The WTRU as in any one of embodiments 52-57 comprising a medium independent handover-handover (MIHHO) component.

59. The WTRU of embodiment 58 wherein the MIHHO component is capable of facilitating discovery of available networks, determining which of a plurality of possible communication connections is a preferred connection, and facilitating establishment of the preferred communication connection.

60. The WTRU as in any one of embodiments 56-59 wherein the cellular network is one of a Code Division Multiple Access (CDMA) system, a global system for mobile communications (GSM), a General Packet Radio System (GPRS), and a 3 GPP-compliant system.

61. The WTRU as in any one of embodiments 53-60, wherein the WLAN is an IEEE 802.X compatible WLAN.

62. The WTRU as in any one of embodiments 52-61 comprising a Global Positioning System (GPS) receiver that provides information regarding the location of the WTRU to a cellular network.

63. The WTRU as in any one of embodiments 52-62 configured to obtain information about WLANs in the vicinity of the WTRU by at least one of a message received from a cellular network containing information about the WLANs, probe request/response message pairs with the WLANs, and a database within an access WLAN, and configured to extract WLAN information from the information about the WLANs.

64. The WTRU as in any one of embodiments 58-63 wherein the MIHHO component is configured to use the WLAN information to determine whether the WTRU should establish a communicative coupling with the WLAN.

65. The WTRU as in any one of embodiments 53-64 wherein the establishment of the preferred communication connection is initiated by scanning for WLANs.

66. The WTRU of embodiment 65 wherein the scanning is active or passive.

67. The WTRU as in any one of embodiments 65-66 wherein scanning is performed periodically until the WTRU detects a WLAN.

68. The WTRU as in any one of embodiments 52-67 wherein a plurality of available WLANs are detected in the vicinity of the WTRU with which the WTRU may establish a communicative coupling.

69. The WTRU as in any one of embodiments 58-68 wherein the MIHHO component is configured to determine a preferred WLAN with which to establish a communicative coupling.

70. The WTRU as in any one of embodiments 58-69 wherein the MIHHO component is configured to determine the preferred WLAN by evaluating WLAN information including at least one of a system operator, quality of service (QoS), and data transmission speed.

71. The WTRU as in any one of embodiments 58-70 wherein the MIHHO component is configured to receive MIH information to facilitate handover of the WTRU between the WLAN and the cellular network.

72. The WTRU of embodiment 71, the MIH information comprising a network identifier, a network location, a system operator identifier, a system capability, a quality of service (QoS) parameter, and a radio access type for each of the plurality of identified networks.

73. The WTRU as in any one of embodiments 71-72, wherein the MIN information includes a data transmission speed for each network.

74. The WTRU as in any one of embodiments 71-73, wherein the MIN information includes network policy settings for each network.

75. The WTRU as in any one of embodiments 71-74, wherein the MIH information is received over a beacon frame.

76. The WTRU as in any one of embodiments 71-74, wherein the MIH information is received over a dedicated frame.

77. The WTRU as in any one of embodiments 71-74, wherein the MIH information is received over a broadcast channel.

78. The WTRU as in any one of embodiments 71-77, wherein a portion of the MIH information is retrieved from a database on the network and is not sent as broadcast information.

79. A Wireless Local Area Network (WLAN) Access Point (AP).

80. The AP of embodiment 79, comprising a Media Independent Handover (MIH) device configured to send MIH information to facilitate handover between the WLAN and a cellular network of a wireless transmit/receive unit (WTRU).

81. The AP of embodiment 80, wherein the MIH information comprises a network identifier, a network location, a system operator identifier, a system capability, a quality of service (QoS) parameter, and a radio access type for each of the plurality of identified networks.

82. The AP as in any one of embodiments 80-81, wherein the MIH information comprises a data transfer speed for each network.

83. The AP as in any embodiments 80-82, wherein the MIH information comprises network policy settings for each network.

84. The AP as in any one of embodiments 80-83, wherein the MIH information is sent via beacon frames.

85. The AP as in any one of embodiments 80-83, wherein the MIH information is sent over dedicated frames.

86. The AP as in any one of embodiments 80-83, wherein the MIH information is sent over a broadcast channel.

87. An AP as in any of embodiments 80-86, wherein a portion of the MIH information is retrieved from a database on the network.

88. An AP as in any of embodiments 80-87, wherein the MIH information comprises a network identifier, a network location, a system operator identifier, a system capability, a quality of service (QoS) parameter, and a radio access type for each of a plurality of identified networks.

89. The AP as in any embodiments 80-88, wherein the MIH information comprises a data transfer speed for each network.

90. The AP as in any embodiments 80-89, wherein the MIH information comprises network policy settings for each network.

91. The AP as in any one of embodiments 80-90, wherein the MIH information is sent over a beacon frame.

92. The AP as in any one of embodiments 80-90, wherein the MIH information is sent over dedicated frames.

93. The AP as in any one of embodiments 80-90, wherein the MIH information is sent over a broadcast channel.

94. An AP as in any of embodiments 80-93, wherein a portion of the MIH information is retrieved from a database on the network.

Claims (20)

1. A wireless local area network, WLAN, access point, the WLAN access point comprising:

a media independent handover-handover MIHHO component configured to generate media independent handover MIH information for facilitating handover, the MIH information including, for each of at least one designated network, a network identifier and an MIH capabilities indicator indicating MIH services supported; and

a transmitter configured to transmit a probe response message including the MIH information.

2. The WLAN access point of claim 1, wherein the MIH information further comprises a network policy setting.

3. The WLAN access point of claim 1, wherein the MIHHO component is configured to communicate the MIH information via a beacon frame.

4. The WLAN access point of claim 1, wherein the MIHHO component is configured to communicate the MIH information via a dedicated frame.

5. The WLAN access point of claim 1, wherein the MIHHO component is configured to transmit the MIH information via a broadcast channel.

6. The WLAN access point of claim 1, wherein the supported MIH services include MIH event services, MIH command services, and MIH information services.

7. The WLAN access point of claim 1, wherein the WLAN access point is configured to operate in accordance with an IEEE 802.11x standard, and the MIHHO component is configured to communicate the MIH information via a beacon frame.

8. The WLAN access point of claim 1, wherein the MIH information further comprises, for each of the at least one designated network, a system operator identifier, a system capability, a quality of service (QoS) parameter, and a radio access type.

9. The WLAN access point of claim 1, wherein the MIH information further comprises a network location for each of the at least one designated network.

10. The WLAN access point of claim 1, wherein the probe response message is transmitted on receipt of a probe request message.

11. A method for use in a wireless local area network, WLAN, access point, the method comprising:

generating Media Independent Handover (MIH) information for facilitating handover, the MIH information including, for each of at least one designated network, a network identifier and an MIH capabilities indicator indicating supported MIH services; and

transmitting a probe response message including the MIH information.

12. The method of claim 11 wherein the MIH information further comprises a network policy setting for each of the at least one network.

13. The method of claim 11 wherein the MIH information is transmitted via a beacon frame.

14. The method of claim 11 wherein the MIH information is transmitted via a dedicated frame.

15. The method of claim 11 wherein the MIH information is transmitted over a broadcast channel.

16. The method of claim 11 wherein the supported MIH services comprise MIH event services, MIH command services and MIH information services.

17. The method of claim 11, wherein the WLAN access point is configured to operate in accordance with an IEEE 802.11x standard.

18. The method of claim 11, wherein the MIH information further comprises, for each of the at least one designated network, a system operator identifier, a system capability, a quality of service QoS parameter, and a radio access type.

19. The method of claim 11 wherein the MIH information further comprises a network location.

20. The method of claim 11, wherein the probe response message is transmitted if a probe request message is received.