WO2015066429A1 - Access network discovery and selection function (andsf) support for group communication system enablers (gcse) - Google Patents

Abstract

A method and apparatus for receiving a group communication is disclosed herein. A method at a wireless transmit/receive unit (WTRU), includes receiving an Access Network Discovery and Selection Function (ANDSF) message including information regarding available group communications and receiving a group communication based on the information. The Group communication information may be combined with access network information.

Description

ACCESS NETWORK DISCOVERY AND SELECTION FUNCTION (ANDSF) SUPPORT FOR GROUP COMMUNICATION SYSTEM

ENABLERS (GCSE)

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. provisional application no. 61/898,925 filed November 1, 2013, which is incorporated by reference as if fully set forth.

BACKGROUND

[0002] Group communication, which means the delivery of voice calls to a group of users, may be a key feature of today's public safety systems such as Tetra and P25. Now as Long Term Evolution (LTE) technology is positioned to support future public safety systems, 3GPP is working to enable LTE/Evolved Packet Core (EPC) systems to support group communications. A study item, Group Communication System Enablers (GCSE) for LTE (GCSE_LTE), is being discussed in 3GPP system aspects (SA) and radio access network (RAN) working groups. The study aims to provide group communications of various media (voice, video, data, and the like) among entitled group members via E- UTRAN. It is mainly targeted for WTRUs/users under the LTE network coverage, although out-of-coverage users may also join the group communication through a WTRU-to-Network relay. There is also a group communication feature in the ProSe study, which mainly deals with group communication among out of coverage WTRUs using Device-to-Device technology.

SUMMARY

[0003] A method and apparatus for receiving a group communication is disclosed herein. A method at a wireless transmit/receive unit (WTRU), includes receiving an Access Network Discovery and Selection Function (ANDSF) message including information regarding available group communications and receiving a group communication based on the information. The Group communication information may be combined with access network information.

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0008] Figure 2 is an example of the high level architecture of a Group

Communication System Enablers (GCSE) system;

[0009] Figure 3 is an example a general Management Object (MO) structure for ANDSF policies;

[0010] Figure 3A is an example of a policy node;

[0011] Figure 3B is an example of a discovery information node;

[0012] Figure 3C is an example of the WTRU_Location node;

[0013] Figure 3D is an example of the ISRP node;

[0014] Figure 3E is an example of the WTRU_Profile node;

[0015] Figure 4 is an example of a WTRU in communication with a

Home ANDSF (H -ANDSF) or Visiting ANDSF (V-ANDSF);

[0016] Figure 5 is an example of an independent group communication information retrieval procedure;

[0017] Figure 6 is an example ANDSF Management Object (MO) structure design; [0018] Figure 7 is an example of the structure of the Group

Communication Info node of the ANDSF MO;

[0019] Figure 8 is an example of a combined access network information and group communication information retrieval procedure;

[0020] Figure 9 is an example of an ANDSF server in communication with GCSE servers either directly or through a GCSE-Interworking Function (IWF) entity; and

[0021] Figure 10 is an example of a procedure for propagating a change in group information to a UE through a GCSE IWF and an ANDSF.

DETAILED DESCRIPTION

[0022] Figure 1A is a diagram of an example communications system

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

[0023] As shown in Figure 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and/or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, consumer electronics, and the like.

[0024] The communications systems 100 may also include a base station

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

[0025] The base station 114a may be part of the RAN 104, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals within a particular geographic region, which may be referred to as a cell (not shown). The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In another embodiment, the base station 114a may employ multiple -input multiple -output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell.

[0026] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0027] More specifically, as noted above, the communications system

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

[0028] In another embodiment, the base station 114a and the WTRUs

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

[0029] In other embodiments, the base station 114a and the WTRUs

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

[0030] The base station 114b in Figure 1A may be a wireless router,

Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown in Figure 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the core network 106.

[0031] The RAN 104 may be in communication with the core network

106, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high- level security functions, such as user authentication. Although not shown in Figure 1A, it will be appreciated that the RAN 104 and/or the core network 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may be utilizing an E-UTRA radio technology, the core network 106 may also be in communication with another RAN (not shown) employing a GSM radio technology.

[0032] The core network 106 may also serve as a gateway for the

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

[0033] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities, i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102c shown in Figure 1A may be configured to communicate with the base station 114a, which may employ a cellular -based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0034] Figure IB is a system diagram of an example WTRU 102. As shown in Figure IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0035] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While Figure IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip. [0036] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In another embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0037] In addition, although the transmit/receive element 122 is depicted in Figure IB as a single element, the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0038] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, for example.

[0039] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light- emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The nonremovable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0040] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel- cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0041] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location- determination method while remaining consistent with an embodiment.

[0042] The processor 118 may further be coupled to other peripherals

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

[0043] Figure 1C is a system diagram of the RAN 104 and the core network 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the core network 106.

[0044] The RAN 104 may include eNode-Bs 140a, 140b, 140c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 140a, 140b, 140c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 140a, 140b, 140c may implement MIMO technology. Thus, the eNode-B 140a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0045] Each of the eNode-Bs 140a, 140b, 140c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown in Figure 1C, the eNode-Bs 140a, 140b, 140c may communicate with one another over an X2 interface.

[0046] The core network 106 shown in Figure 1C may include a mobility management gateway (MME) 142, a serving gateway 144, and a packet data network (PDN) gateway 146, and an ANDSF 148. While each of the foregoing elements are depicted as part of the core network 106, it will be appreciated that any one of these elements may be owned and/or operated by an entity other than the core network operator.

[0047] The MME 142 may be connected to each of the eNode-Bs 142a,

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

[0048] The serving gateway 144 may be connected to each of the eNode

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

[0049] The serving gateway 144 may also be connected to the PDN gateway 146, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. An access router (AR) 150 of a wireless local area network (WLAN) 155 may be in communication with the Internet 110. The AR 150 may facilitate communications between APs 160a, 160b, and 160c. The APs 160a, 160b, and 160c may be in communication with STAs 170a, 170b, and 170c. The STAs 170a, 170b, 170c may be dual mode WLAN devices capable of performing WLAN operations while also being able to perform LTE operations like the WTRUs 102a, 102b, 102c. The APs 160a, 160b, and 160c and STAs 170a, 170b, and 170c may be configured to perform the methods disclosed herein.

[0050] The core network 106 may facilitate communications with other networks. For example, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to circuit- switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the core network 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the core network 106 and the PSTN 108. In addition, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to the networks 112, which may include other wired or wireless networks that are owned and/or operated by other service providers.

[0051] Herein, the terminology "UE" includes but is not limited to a wireless transmit/receive unit (WTRU), a station (STA), a mobile station, a fixed or mobile subscriber unit, an AP, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, a mobile Internet device (MID) or any other type of user device capable of operating in a wireless environment.

[0052] Figure 2 is an example of the high level architecture of a Group

Communication System Enablers (GCSE) system, where the Multipoint Service (MuSe) interacts with the 3GPP Evolved Packet System (EPS) entities to provide the multipoint service functionality. The MuSe 201 may utilize at least a portion of the existing Evolved Media Broadcast Multicast Service (eMBMS) system.

[0053] The MuSe 201 may be connected to the GCSE application server

202. MuSe 201 may also be connected to eNB203, MME 205, and P-GW 206.

[0054] The group communication may not only be delivered through multipoint service, it may also be delivered through the traditional EPS unicast service. It may be the GCSE application server's function to decide whether multipoint service or unicast service may be used.

[0055] The Access Network Discovery and Selection Function (ANDSF) is an entity introduced by 3GPP as part of the Release 8 set of specifications, within an EPC of the System Architecture Evolution (SAE) for 3GPP compliant mobile networks. The purpose of the ANDSF may be to assist WTRUs in discovering non-3GPP access networks— such as Wi-Fi or WIMAX— that may be used for data communications in addition to 3GPP access networks (such as HSPA or LTE), and to provide the WTRUs with rules for policing the connection to these networks. [0056] An ANDSF may provide the following information to a WTRU, based on operator configuration: Inter-System Mobility Policy (ISMP); Inter- System Routing Policy (ISRP); and Discovery Information.

[0057] ISMP may include network selections rules for a WTRU with no more than one active access network connection (for example, either LTE or Wi-Fi). ISRP may provide network selection rules for a WTRU with potentially more than one active access network connection (for example, both LTE and Wi-Fi). Such a WTRU may employ Internet Protocol (IP) Flow Mobility (IFOM), Multiple Access PDN Connectivity (MAPCON), or non- seamless Wi-Fi offload according to operator policy and user preferences. Discovery Information may include a list of networks that may be available in the vicinity of the WTRU and information assisting the WTRU to expedite the connection to these networks.

[0058] The ANDSF may communicate with the WTRU over the S14 reference point, which is essentially a synchronization of an Open Mobile Alliance Device Management (OMA-DM) Management Object (MO) specific to the ANDSF.

[0059] Figure 3 is an example of a general Management Object (MO) structure for ANDSF policies. The ANDSF policies are illustrated as disclosed in Section 4.2 of Version 12.2.0 of the 3GPP TS 24.312 standard. The MO 300 may include the following parameters: a Policy node 300(a), a Discoverylnformation node 300(b), a WTRU_Location node 300(c), an ISRP node 300(d), a WTRU_Profile node 300(e), and an Extension (Ext) node 300(f).

[0060] Figure 3A is an example of a policy node. The Policy node 300(a) may act as a placeholder for ISMP information. The Policy node 300(a) may include a rule priority 301, prioritizedaccess 302,

[0061] The rule priority 301 may represent the priority given to one particular rule and is represented as a numerical value. In case more than one valid ISMP rule exists, the WTRU may treat the rule with the lowest RulePriority value as the rule having the highest priority among the valid rules. If the WTRU finds multiple rules with the same priority, the choice of the rule may be WTRU implementation specific. If there are no matching access networks according to the rule, the WTRU may use other rules with the same priority. If there are no matching access networks according to any rule with a certain priority, the WTRU may use rules with lower priority.

[0062] The prioritizedaccess 302 may indicate the preferred access for one particular rule. The AccessTechnology 302(a) may indicate a prioritized access technology.

[0063] The Accessld 302(b) may represent an access network identifier.

The Accessld 302(b) may contain an identifier for a specific radio access network. Only SSID for WLAN and NAP-ID for WiMAX radio access network are contained in this leaf. Accesslds in numerical format may be encoded as character string. The Accessld 302(b) may be represented by Unicode characters encoded as UTF-8 and formatted using Normalization Form KC (NFKC). The absence of an AccessID 302(b) may indicate that the WTRU may consider any available radio access network of the defined access technology.

[0064] The SecondaryAccessId 302(c) may represent a secondary access network identifier. The SecondaryAccessId 302(c) may contain an identifier for a specific radio access network. Only HESSID for WLAN radio access network may be contained in the SecondaryAccessID 302(c). The SecondaryAccessId 302(c) may only be present when the corresponding Accessld 302(b) for a WLAN radio access network is present.

[0065] The AccessNetworkPriority 302(d) may represent an access technology priority. In case more than one valid PrioritizedAccess 302 are available and if the value of the priority belongs to the range 1-250, the WTRU may consider the access network (with the corresponding access identifier if present) with the lowest AccessNetworkPriority 302(d) value as the access network (with the corresponding access identifier if present) having the highest priority. The same AccessNetworkPriority 302(d) value may be used for more than one Accessld 302(b) and more than one Access Technology 302(a). If more than one Accessld 302(b) or more than one Access Technology 302(a) with the same value of the AccessNetworkPriority 302(d) are available, the WTRU may select one of them in an implementation dependent way. If the WTRU is not able to find an access network according to ANDSF policies, it is implementation dependent how to proceed with network selection.

[0066] The ValidityArea 303 may act as a placeholder for location conditions for a particular rule. The validity condition of ValidityArea 303 may be considered valid when at least one of 3GPP_Location 303(a), or 3GPP2_Location 303(b) or WiMAX_Location 303(c), or WLAN_Location 303(d), or Geo_Location 303(e) is a match. If the ValidityArea 303 is present and empty (for example, none of the nodes 3GPP_Location 303(a), 3GPP2_Location 303(b), WiMAX_Location 303(c), WLAN_Location 303(d) or Geo_Location 303(e) exist), then the ValidityArea 303 may not be considered when evaluating the validity of the corresponding rule. If the WTRU may not deduce its location by any means, only rules without ValidityArea 303 or rules with empty ValidityArea 303 may be considered for valid rule.

[0067] The 3GPP_Location 303(a) may act as a placeholder for 3GPP location descriptions. If the WTRU is currently aware that it is located in the coverage area described by at least one instance, the WTRU may consider the corresponding rule as valid. In case of overlapping validity domains of multiple policy rules, RulePriority 301 may be used as discriminator.

[0068] The PLMN 303(a)(1) may indicate a PLMN code for one particular 3GPP location condition for the ISMP rule. The TAC 303(a)(2) may indicate a Tracking Area Code for one particular 3GPP location condition for the ISMP rule. The LAC 303(a)(3) may indicate a Location Area Code for one particular 3GPP location condition for the ISMP rule.

[0069] The GERAN_CI 303(a)(4) may indicate a cell identity for one particular GERAN network related location description. The GERAN_CI 303(a)(4) value may be set to the Cell Identity, CI, obtained from lower layers of the WTRU. The value of GERAN_CI 303(a)(4) may be coded as a bit string with fixed length of 16 bits.

[0070] The UTRAN_CI 303(a)(5) may indicate a cell identity for one particular UTRAN network related location description. The UTRAN_CI 303(a)(5) value may be set to the UTRAN Cell Identity and may be obtained from lower layers of the WTRU. The value of UTRAN_CI 303(a)(5) may be coded as a bit string with fixed length of 28 bits.

[0071] The EUTRA_CI 303(a)(6) may indicate a cell identity for one particular E-UTRA network related location description. The EUTRA_CI 303(a)(6) value may be set to the cell identity part of the Evolved Cell Global Identifier and may be obtained from lower layers of the WTRU. The value of EUTRA_CI 303(a)(6) may be coded as a bit string with fixed length of 28 bits.

[0072] The 3GPP2_Location 303(b) may act as a placeholder for 3GPP2 location descriptions. If the WTRU is currently aware that it is located in the coverage area, the WTRU may consider the corresponding rule as valid. In case of overlapping validity domains of multiple policy rules, RulePriority 301 may be used as discriminator. If ANDSF provides 3GPP2_Location 303(b) as a validity area, either the lx 303(b)(1) or HRPD 303(b)(2) interior node, or both, may be provided.

[0073] The interior node may act as a placeholder for one or more

3GPP2 lx 303 (b)(1) RAT location descriptions. If the location is indicated with more than one leaf (for example, SID 303(b)(l)(i) and at least one leaf out of NID 303(b)(l(ii) or BaseJD 303(b)(l)(iii) are present), the WTRU may consider 3GPP2 location 303(b) validity condition for the particular rule to be fulfilled only if all the present leaf values in the node match with the location of the WTRU.

[0074] The SID 303(b)(l)(i) may indicate a System Identification code for one particular 3GPP2 lx 303(b)(1) RAT location condition for the ISMP rule. The NID 303(b)(l)(ii) may indicate a Network Identification code for one particular 3GPP2 lx 303(b)(1) RAT location condition for the ISMP rule. The BaseJD 303(b)(l)(iii) may indicate a Base Station Identification code for one particular 3GPP2 lx 303(b)(1) RAT location condition for the ISMP rule.

[0075] The HRPD 303(b)(20 may act as a placeholder for 3GPP2 HRPD

RAT location descriptions. If the WTRU is currently aware that it is located in the coverage area, the WTRU may consider the corresponding rule as valid. [0076] This SectorJD 303(b)(2)(i) may indicate a Sector Identification code for one particular 3GPP2 HRPD 303(b)(2) RAT location condition for the ISMP rule. The length of Sector ID contained in this node may be 128 bits.

[0077] This Netmask 303(b)(2)(ii) may indicate a Netmask code for one particular 3GPP2 HRPD 303(b)(2) RAT location condition for the ISMP rule. The length of Netmask contained in this node may be 8 bits. The mask contained in this leaf may be applied to the SectorJD 303(b)(2)(i) bit string.

[0078] The WiMAX_Location 303(c) may act as a placeholder for

WiMAX location descriptions. If the WTRU is currently aware that it is located in the coverage area, the WTRU may consider the corresponding rule as valid. In case of overlapping validity domains of multiple policy rules, RulePriority 301 may be used as discriminator.

[0079] The NAP-ID 303(c)(1) may indicate the Network Access Provider for a particular WiMAX location condition for the ISMP rule. The BS-ID 303(c)(2) may indicate the BS identifier for a particular WiMAX location condition for the ISMP rule.

[0080] The WLAN_Location 303(d) may act as a placeholder for WLAN location descriptions. If the WTRU is currently aware that it is located in the coverage area, the WTRU may consider the corresponding rule as valid. In case of overlapping validity domains of multiple policy rules, RulePriority 301 may be used as discriminator. The WTRU may ignore WLAN_Location 303(d) that is present and does not contain at least one of the non-empty leaves (for example, HESSID 303(d)(1), SSID 303(d)(2) or BSSID 303(d)(3)).

[0081] The HESSID 303(d)(1) may indicate the HESSID for a particular

WLAN location condition for the ISMP rule. The SSID 303(d)(2) may indicate the SSID for a particular WLAN location condition for the ISMP rule. The BSSID 303(d)(3) may indicate the AP identifier for one particular WLAN location condition for the ISMP rule.

[0082] The Geo_Location 303(e) may act as a placeholder for

Geographical location descriptions for one ISMP rule. If the WTRU is currently aware that it is located in the area described, the WTRU may consider the corresponding rule as valid. In case of overlapping validity domains of multiple policy rules, RulePriority 301 may be used as discriminator.

[0083] The Circular 303(e)(1) may act as a placeholder for circular areas location descriptions for one ISMP rule. The AnchorLatitude 303(e)(l(i) may indicate the latitude value of the center of the circular area. The AnchorLongitude 303(e)(l)(ii) may indicate the longitude value of the center of the circular area. The Radius 303(e)(l)(iii) may indicate the radius value of the circular area.

[0084] The Roaming 304 may indicate the roaming condition for the

ISMP rule. The WTRU may consider a rule with the Roaming 304 present as valid only if the current roaming state (roaming/not roaming) of the WTRU matches the one indicated in the Roaming value.

[0085] The PLMN 305 may indicate a PLMN code of the operator, which created this policy.

[0086] The TimeOfDay 306 may indicate the time of day condition for the ISMP rule. The validity condition of TimeOfDay 306 may be considered valid when the time of day in the current time zone, as indicated by the WTRU, matches at least one time interval indicated in the TimeOfDay 306. If the WTRU does not support calendar or clock application, only rules without TimeOfDay 306 or rules with empty TimeOfDay 306 may be considered for valid rule.

[0087] The TimeStart 306(a) may act as a place holder containing a time of day. The TimeStop 306(b) may act as a place holder containing a time of day. The DateStart 306(c) may act as a place holder containing a date. The WTRU handling of semantical error where DateStart 306(c) indicates a date that does not exist may be WTRU implementation specific. The DateStop 306(d) may act as a place holder containing a date. The WTRU handling of semantical error where DateStop 306(d) may indicate a date that does not exist may be WTRU implementation specific. [0088] The UpdatePolicy 307 may indicate the update policy for the

ISMP. The UpdatePolicy 307 value may be used by the WTRU to determine whether or not to request an update of its ISMP when the rule is no longer considered to be valid by the WTRU.

[0089] The Discoverylnformation 300(b) may act as a placeholder for access network discovery information. The operator may provide information on available access networks through the ANDSF. The WTRU may use the information as an aid in discovering other access networks.

[0090] Figure 3B is an example of a discovery information node. The

Discoverylnformation node 300(b) may act as a placeholder for access network discovery information. The operator may provide information on available access networks through the ANDSF. The WTRU may use the information as an aid in discovering other access networks.

[0091] The AccessNetworkType 308 may represent the type of an access network. The value of AccessNetworkType 308 may indicate the type of the network for which discovery assistance information is provided.

[0092] The AccessNetworkArea node 309 may act as a placeholder for a description of the location where one particular access network is expected to be available. If the WTRU is aware that it is located in at least one of the locations described under this node, the WTRU may assume the corresponding access network to be available. If the AccessNetworkArea node 309 is present and empty (for example, none of the nodes 3GPP_Location 309(a), 3GPP2_Location 309(b), WiMAX_Location 309(c), WLAN_Location 309(d) or Geo_Location 309(e) exist), then the AccessNetworkArea node 309 may not be considered when evaluating the discovery information.

[0093] The 3GPP_Location node 309(a) may act as a placeholder for

3GPP location descriptions. If the WTRU is currently aware that it is located in the coverage area described by this node, the networks described in the correspondent AccessNetworklnformationRef 310 are expected to be available.

[0094] The PLMN 309(a)(1) may indicate a PLMN code for one particular 3GPP location description. The TAC 309(a)(2) may indicate a Tracking Area Code for one particular 3GPP location description. The LAC 309(a)(3) may indicate a Location Area Code for one particular 3GPP location description. The GERAN_CI 309(a)4) may indicate a GERAN Cell Identity for one particular 3GPP network related location description. The UTRAN_CI 309(a)(5) may indicate a UTRAN Cell Identity for one particular 3GPP network related location description. The EUTRA_CI 309(a)(6) may indicate an E-UTRA Cell Identity for one particular 3GPP network related location description.

[0095] The 3GPP2_Location node 309(b) may act as a placeholder for

3GPP2 location description. If the WTRU is currently aware that it is located in the coverage area described by this 3GPP2_Location node 309(b), the networks described in the correspondent AccessNetworklnformationRef 310 are expected to be available. If ANDSF provides 3GPP2_Location in AccessNetworkArea node 309, either the lx 309(b)(1) or HRPD 309(b)(2) interior node, or both, may be provided.

[0096] The lx node 309(b)(1) may act as a placeholder for one or more

3GPP2 lx RAT location descriptions. The SID 309(b)(l)(i) may indicate a System Identification code for one particular 3GPP2 lx RAT location description. The NID 309(b)(l)(ii) may indicate a Network Identification code for one particular 3GPP2 lx RAT location description. The Base_ID 309(b)(l)(iii) may indicate a Base Station Identification Code for one particular 3GPP2 lx RAT location description.

[0097] The HRPD node 309(b)(2) may act as a placeholder for one or more 3GPP2 HRPD RAT location descriptions. The SectorJD 309(b)(2)(i) may indicate a Sector Identification code for one particular 3GPP2 HRPD RAT location description. The Netmask 309(b)(2)(ii) may indicate a Netmask code for one particular 3GPP2 HRPD RAT location description.

[0098] The WiMAX_Location node 309(c) may act as a placeholder for

WiMAX location descriptions. If the WTRU is currently aware that it is located in the coverage area described by this node, the networks described in the correspondent AccessNetworklnformationRef 310 are expected to be available. The NASP-ID 309(c)(1) may indicate the Network Access Provider for a particular WiMAX location description. The BS-ID 309(c)(2) may indicate the BS identifier for a particular WiMAX location description.

[0099] The WLAN_Location node 309(d) may act as a placeholder for

WLAN location descriptions. If the WTRU is currently aware that it is located in the coverage area described by this node, the networks described in the correspondent AccessNetworklnformationRef 310 are expected to be available. The WTRU may ignore the WLAN_Location node 309(d) that is present and does not contain at least one of the non-empty leaves (for example, HESSID 309(d)(1), SSID 309(d)(2) or BSSID 309(d)(3)).

[0100] The HESSID 309(d)(1) may indicate the HESSID for a particular

Home WLAN Specific Identifier location description. The SSID 309(d)(2) may indicate the SSID for a particular WLAN location description. The BSSID 309(d)(3) may indicate the AP identifier for one particular WLAN location description.

[0101] This Geo_Location node 309(e) may act as a placeholder for geographical location descriptions for location of one or more access networks. If the WTRU is currently aware that it is located in the area described by this Geo_Location node, the networks described in the correspondent AccessNetworklnformationRef 310 are expected to be available.

[0102] The Circular node 309(e)(1) may act as a placeholder for circular areas location descriptions. The AnchorLatitude 309(e)(l)(i) may indicate the latitude value of the center of the circular area. The AnchorLongitude 309(e)(l)(ii) may indicate the longitude value of the center of the circular area. The Radius 309(e)(l)(iii) may indicate the radius value of the circular area.

[0103] The AccessNetworklnformationRef 310 may represent a reference to an access network information object. The value of AccessNetworklnformationRef 310 may be a reference to an object with access network type specific information.

[0104] The PLMN 311 may indicate a PLMN code of the operator which created this discovery information. [0105] Figure 3C is an example of the WTRU_Location node. The

WTRU_Location node 300(c) may act as a placeholder for describing the current location of the WTRU.

[0106] The 3GPP_Location node 312 may act as a placeholder for 3GPP location descriptions. If the WTRU is registered on a 3GPP network, the WTRU may insert the parameters of the 3GPP network on which the WTRU is registered. The WTRU may insert the parameters of other 3GPP networks it has discovered when updating this node.

[0107] The PLMN 312(a) may indicate a PLMN code for one particular

3GPP network related location of the WTRU. The TAC 312(b) may indicate a Tracking Area Code for one particular 3GPP network related location of the WTRU. The LAC 312(c) may indicate a Location Area Code for one particular 3GPP network related location of the WTRU. The GERAN_CI 312(d) may indicate a GERAN Cell Identity for one particular 3GPP network related location description. The UTRAN_CI 312(e) may indicate a UTRAN Cell Identity for one particular 3GPP network related location description. The EUTRA_CI 312(f) may indicate an E-UTRA Cell Identity for one particular 3GPP network related location description.

[0108] The 3GPP2_Location node 313 may act as a placeholder for

3GPP2 network related location description of WTRU's position. The WTRU may insert the parameters of all the 3GPP2 networks it has discovered when updating this node.

[0109] The lx node 313(a) may act as a placeholder for one or more

3GPP2 lx RAT network related location descriptions of WTRU's position. The SID 313(a)(1) may indicate a System Identification code for one particular 3GPP2 lx RAT location used to indicate WTRU position. The NID 313(a)(2) may indicate a Network Identification code for one particular 3GPP2 lx RAT location used to indicate WTRU position. The Base_ID 313(a)(3) may indicate a Base Station Identification code for one particular 3GPP2 lx RAT location used to indicate WTRU position. [0110] The HRPD node 313(b) may act as a placeholder for one or more

3GPP2 HRPD RAT location descriptions of WTRU position. The SectorJD 313(b)(1) may indicate a Sector Identification code for one particular 3GPP2 HRPD RAT location used to indicate WTRU position. The Netmask 313(b)(2) may indicate a Netmask code for one particular 3GPP2 HRPD RAT location used to indicate WTRU position.

[0111] The WiMAX_Location node 314 may act as a placeholder for

WiMAX location descriptions. The WTRU may insert the parameters of all the WiMAX networks it has discovered when updating this node. The NAP-ID 314(a) may indicate the Network Access Provider for a particular WiMAX network related location of the WTRU. The BS-ID 314(b) may indicate the BS identifier for a particular WiMAX network related location of the WTRU.

[0112] The WLAN_Location node 315 may act as a placeholder for

WLAN location descriptions. If the WTRU is associated with a WLAN and authenticated using EAP-SIM, EAP-AKA or EAP-AKA' based authentication via the WLAN, the WTRU may insert the parameters of the WLAN with which the WTRU is associated and via which the WTRU is authenticated. The WTRU may insert the parameters of other WLANs it has discovered when updating this node. The HESSID 315(a) may indicate the HESSID for a particular WLAN network related location of the WTRU. The SSID 315(b) may indicate the SSID for a particular WLAN network related location of the WTRU. The BSSID 315(c) may indicate the AP identifier for one particular WLAN network related location of the WTRU.

[0113] The Geo_Location node 316 may act as a placeholder for one or more WTRU Geo_Location location descriptions. If the WTRU is aware of its geographical position, it may insert the coordinates of its position in this Geo_Location node. The Latitude 316(a) may indicate the latitude value of the position of the WTRU. The Longitude 316(b) may indicate the longitude value of the position of the WTRU.

[0114] The RPLMN 317 may indicate a PLMN code of the registered PLMN the WTRU is connected to. [0115] Figure 3D is an example of the ISRP node. The ISRP node 300(d) may act as a placeholder for policies for ISRP. The ISRP node 300(d) may include a ForFlowBased node 318, ForServiceBased node 319, ForNonSeamlessOffload node 320, Roaming 321, PLMN 322, and UpdatePolicy 323.

[0116] The ForFlowBased node 318 may represent flow distribution container indicating data distribution among accesses based on flow description. The ForServiceBased node 319 may represent flow distribution container indicating data distribution among accesses based on APN. The ForNonSeamlessOffload node 320 may represent a flow distribution container indicating data permissible for non- seamless WLAN offload routing based on flow description.

[0117] The Roaming 321 may indicate the roaming condition for the

ISRP rule. The WTRU may consider a rule with the Roaming 321 present as valid only if the current roaming state (roaming/not roaming) of the WTRU matches the one indicated in the Roaming value. The PLMN 322 may indicate a PLMN code of the operator, which created this ISRP rule. The UpdatePolicy 323 may indicate the update policy for the ISRP.

[0118] Figure 3E is an example of the WTRU_Profile node. The

WTRU_Profile node 300(e) may act as a placeholder for describing the information characterizing the WTRU. TheOSId 324 may indicate the operating system identifier of the WTRU. The format of the operating system identifier may be a Universally Unique IDentifier (UUID).

[0119] The DevCapability 325 may indicate the device capability of the

WTRU and ANDSF may use this information to adapt the ANDSF MO information to the capabilities of the WTRU.

[0120] The Ext 300(f) in Figure 3 may be an interior node for where the vendor specific information about the ANDSF MO is being placed (vendor meaning application vendor, device vendor, and the like). Usually the vendor extension is identified by vendor specific name under the ext node. The tree structure under the vendor identifier may not be defined and may include one or more un- standardized sub-trees.

[0121] According to the GCSE service requirement, the group communication may be restricted to a defined geographic area. GCSE Groups may, by definition, be of system wide scope. Optionally, GCSE Groups may be geographically restricted. The system may provide a mechanism to restrict all Group Communications for a given GCSE Group to a defined geographic area. In this case Group Members may be able to receive and/or transmit only within this geographic area. The system may provide a mechanism to redefine the geographic area for a GCSE Group that has a defined geographic area. The system may provide a mechanism to override geographic area restrictions for a GCSE Group for a particular Group Communication transmission. The system may provide a mechanism to restrict a particular Group Communication transmission to a defined geographic area within the geographical scope of that group. In this case only Receiver Group Members within the geographic area may receive the Group Communication.

[0122] A group member may be interested in whether communication with a particular group with which it belongs is available/supported in the area in which it is currently located. If communication with the group is available, then the user may launch the group application and start to register/join the group, read the related system information, and prepare for group communication.

[0123] A straightforward way to inform the WTRUs of the group communication availability in certain areas may be through eNode B system information broadcasting. However, the system information broadcasting of group communication availability may have a few drawbacks. First, a new system information block (SIB) may need to be defined for this purpose. If there are many groups to be supported in a cell, the SIB may be very large, and it may waste radio resources if there are not many group members in the cell. Second, when a particular group service area changes, for example, an eNode B no longer belongs to a particular group's service area, the related SIB may need to be updated. If the existing SIB update procedure is followed, this may force all of the WTRUs to check the SIB update. Third, for an eNode B to be aware of whether it belongs to a particular group service area, it may need input from other network entities such as Operations, Administration, and Maintenance (OAM). It may be tedious to update each affected eNode B when the service area configuration changes. Additionally, the group service area configuration may be dynamic, and even OAM may not have this information. The eNode Bs may then have to interface with a Group application server to obtain such information.

[0124] In view of the drawbacks associated with system information broadcasting, an ADNSF server may provide WTRUs with the interested group communication availability information, based on either the WTRU's location or the WTRU's subscribed/interested group, or a combination of both. Similar to the access network discovery, the WTRU may request the ANDSF to provide the group communication availability information ("PULL mode") or the network may initiate the transmission of the information to the WTRU based on one or more triggers.

[0125] Figure 4 is an example of a WTRU in communication with a

Home ANDSF (H -ANDSF) or Visiting ANDSF (V-ANDSF). Similar to the access network discovery information exchange, the WTRU 401 may communicate with the Home ANDSF (H-ANDSF) 402 or Visiting ANDSF (V- ANDSF) 403 (when roaming) in a way of Client-Server communication to retrieve the interested group communication information. The group communication information retrieval may be independent of the current access network discovery information retrieval. Alternatively, the group communication information retrieval process may be combined with the access network discovery information retrieval process.

[0126] In an independent group communication information retrieval process, the WTRU and the ANDSF may use a separate Management Object extensible Markup Language (MO/XML) structure which may be dedicated to the group communication information and different from the current access network discovery MO.

[0127] Figure 5 is an example of independent group communication information retrieval procedure. A pair of messages, namely Group Communication Info Request 503 and Group Communication Info Response 504, is communicated between a WTRU 501 and an ANDSF 502.

[0128] In the Group Communication Info Request message 503, the

WTRU 501 may provide the following information. WTRU capability may indicate the WTRU's capability for group communication support, such as whether it supports eMBMS broadcasted group communication or only supports unicasted group communication, whether it supports certain medias (for example, voice, video, data, and the like) in the group communication, and the like. WTRU location may indicate the WTRU's current location, which could be represented by 3GPP area IDs (tracking area identity (TAI), Cell ID, Home eNode B ID), MBMS area IDs (MBSFN area ID, MBMS service area ID, and the like) or GPS coordinates. Interested Groups may indicate the groups that the WTRU 501 is subscribed to or is interested in. The groups may be represented by group names or group IDs.

[0129] The ANDSF 502 may transmit a Group Communication Info

Response message 504 in response to the Group Communication Info Request message 503. The Group Communication Info Response message 504 may include group communication information available in the same RAT that the Group Communication Information Request 503 was transmitted in. For example, the group communication information may include available group communications using an LTE network. The group communication information provided by the ANDSF server in Group Communication Info Response may include the following. First, the available group communications existing in the vicinity of the WTRU 501 may be represented by the "group name" or "group ID." Second, for each available group, other group information besides the group name or ID may be provided. For example, the group server access information may be provided, such as server Uniform Resource Identifier (URI) or IP address. The information may indicate whether the group is open or restricted, the size of the group, and whether it is unlimited or limited to a certain number. Security information may be indicated, as well as the areas where this group is available, which may be represented by the 3GPP area IDs such as a public land mobile network (PLMN) ID, a tracking area Identity (TAI), a Cell_ID, or the geographical area which may be denoted by GPS coordinates and radius.

[0130] The unicast/broadcast mode support may indicate whether this group supports only unicasted group communication or broadcasted group communication or both. The technology used for broadcasted group communication (for example, eMBMS based) may also be indicated. The operation mode, such as "Receive Only" or "Transmit and Receive" that the WTRU is allowed for a particular group may be indicated. The operation mode may also be further linked to an area, which means that for the same group, a group member may have different operation modes in different areas. The media types that the group supports, such as voice, data, video, and the like, may be indicated, as well as additional information.

[0131] Figure 6 is an example ANDSF Management Object (MO) structure design. Figure 7 is an example of the structure of the Group Communication Info node of the ANDSF MO. The ANDSF MO structure shown in Figures 6 and 7 may facilitate the information exchange described above.

[0132] A new MO structure for use in the Group Communication

Request message and Group Communication Response message may be designed. As shown in Figure 6, the MO 600 may include the information described above, and may comprise a WTRU_Location node 601, a WTRU_Interested_Group node 602, a Group Communication Info node 603, and an Ext node 604.

[0133] The WTRU_Location node 601 may include a 3GPP Location node 601(a) and a Geo-Location node 601(b). The 3GPP Location node 601(a) may include PLMN 601(a)(1), TAC 601(a)(2), Cell ID 601(a)(3), and MBSFN Area ID 601(a)(4). Geo-Location node 601(b) may include AnchorLongitude 601(b)(1) and AnchorLatitude 601(b)(2).

[0134] The WTRU_Interested_Group 602 may include a Group Name node 602(a) and a Group ID node 602(b)

[0135] As shown in Figure 7, the Group Communication Info node 603 may have an Available Groups node 701, a Group Mode node 702, a Server Access Info node 703, a Security Info node 704, a Technology node 705, an Operation Mode node 706, and a Media Types node 707.

[0136] The Available Groups node 701 may include a Group Name

701(a) and a Group ID 701(b). The Group Mode node 702 may include whether it is open 702(a) or closed 702(b). The Technology node 705 may include a unicast 705(a) option or broadcast 705(b) option. The Operation node 706 may include Rx only 706(a) or Tx and Rx 706(b). The Media Types node 707 may include voice 707(a), data 707(b), and video 707(c).

[0137] As an alternative to the process shown in Figure 5, the group communication information retrieval process may be combined with the access network discovery information retrieval process, and the existing Access Network Info Request/Access Network Info Response message pair may be reused, with an update to the message content and the related MO structure. In this combined procedure, the ANDSF server may determine whether the group communication information may be provided together with access network discovery information based on WTRU capability information or WTRU location information or other indication/information.

[0138] Figure 8 is an example of a combined access network information and group communication information retrieval procedure. A combined access network information and group communication information retrieval procedure may take advantage of the fact that the information in both procedures may be related to the WTRU's location, and may be especially useful for those WTRUs that are interested in both access network discovery/selection and group communications. A WTRU may request the two kinds of information in a single request, as shown in Figure 8. WTRU 801 may transmit an Access Network Info Request 803 to an ANDSF 802. In response the ANDSF 802 may transmit an Access Network Info Response 804 t the WTRU 801.

[0139] In the Access Network Info Request 803, the WTRU 801 may provide additional "interested groups" information in addition to information regarding the WTRU's capability and location. For the WTRU's capability information, the WTRU 801 may provide additional capabilities related to group communication in addition to the capabilities related to the access network selection. For the WTRU's location information, the WTRU 801 may provide additional location identifications that are specific to the group communication, such as an MBMS area ID.

[0140] In response to the Access Network Info Request message 803, the

ANDSF 802 may transmit an Access Network Info Response message 804 to the WTRU 801. The message may include inter- system mobility policies, access network discovery information, inter- system routing policies, and group communication information.

[0141] The ANDSF MO for access network selection may be updated to accommodate the combined access network information and group communication information retrieval, with an additional Group Communication Info node and an updated WTRU Location node, which may have group communication specific location IDs. The updated WTRU Location node may be similar to that depicted in Figure 6, and the additional Group Communication Info node may be similar to that depicted in Figure 7.

[0142] The ANDSF server may push the group communication related information to the WTRUs when there is a change in the information in certain areas. The change of the group communication information may be made by the OAM system.

[0143] Figure 9 is an example of an ANDSF server in communication with GCSE servers either directly or through a GCSE-Interworking Function (IWF) entity. As shown by XI 904 in Figure 9, the ANDSF server 901 may be connected to a GCSE Interworking Function (IWF) entity 906 and may receive changes from the IWF dynamically, as described below. Alternatively, as shown by X2 905 in Figure 9, the ANDSF server 901 may also have a direct interface with certain group communication servers 903 and may receive updates from the group communication servers. WTRUs 908 may be connected to the ANDSF server 901 via EPC 907.

[0144] Figure 10 is an example of for propagating a change in group information to a WTRU through a GCSE IWF and an ANDSF. The group communication server 1001 may create a new group 1005. The group communication server 1001 may transmit a Group Information Update 1006 to the GCSE IWF 1002. The Group Information Update 1006 may include a new group ID, a group service area, and the like. The GCSE IWF 1002 may transmit a Group Information Update 1007 to the ANDSF 1003. The Group Information Update 1007 may include the new group ID, one or more 3GPP area IDs, and the like. The ANDSF 1003 may PUSH 1008 some or all of the information in the Group Information Update to WTRUs 1004.

[0145] The group communication server 1001 may also include Group

Member IDs. The GCSE IWF 1002 may query the related 3GPP database (for example, HSS or MME) to translate these member IDs into 3GPP user IDs or IP addresses. The GCSE IWF 1002 may pass the 3GPP user IDs or IP address to the ANDSF 1003 in the Group Information Update 1007. The ANDSF 1003 may PUSH 1008 the new group communication information only to those WTRUs 1004.

[0146] Embodiments

1. A method for receiving a group communication at a wireless transmit/receive unit (WTRU), the method comprising:

receiving an Access Network Discovery and Selection Function (ANDSF) message including information regarding available group communications.

2. The method as in embodiment 1, further comprising:

receiving a group communication based on the information. 3. The method as in any one of embodiment 1-2, wherein the information regarding available group communications is based on a location of the WTRU.

4. The method as in any one of embodiment 1-3, wherein the information regarding available group communications is based on a capability of the WTRU.

5. The method as in any one of embodiment 1-4, wherein the information regarding available group communications is based on interested groups of the WTRU.

6. The method as in any one of embodiment 1-5, wherein the ANDSF message is received in response to a request from the WTRU.

7. The method as in any one of embodiment 1-6, wherein the ANDSF message, received from an ANDSF server, is triggered by an input from a Group Communication System Enablers (GCSE) server or a GCSE Inter working Function (IWF).

8. The method as in any one of embodiment 1-7, further comprising: receiving access network information.

9. The method as in embodiment 8, wherein the access network information is based on a location of the WTRU.

10. The method as in embodiment 9, wherein the location information includes at least one of an Media Broadcast Multicast Service (MBMS) area identifier, a Cell ID, a tracking area identifier (TAI), and GPS coordinates.

11. A wireless transmit/receive unit (WTRU) for receiving a group communication comprising:

a receiver configured to receive an Access Network Discovery and Selection Function (ANDSF) message including information regarding available group communications.

12. The method as in embodiment 11, further comprising:

the receiver further configured to receive a group communication based on the information. 13. The method as in any one of embodiment 11-12, wherein the information regarding available group communications is based on a location of the WTRU.

14. The method as in any one of embodiment 11-13, wherein the regarding available group communications is based on a capability of the WTRU.

15. The method as in any one of embodiment 11-14, wherein the information regarding available group communications is based on interested groups of the WTRU.

16. The method as in any one of embodiment 11-15, wherein the ANDSF message is received in response to a request from the WTRU.

17. The method as in any one of embodiment 11-16, wherein the ANDSF message, received from an ANDSF server, is triggered by an input from a Group Communication System Enablers (GCSE) server or a GCSE Inter working Function (IWF).

18. The method as in any one of embodiment 11-17, wherein the receiver is further configured to receive access network information.

19. The method as in embodiment 18, wherein the access network information is based on a location of the WTRU.

20. The method as in embodiment 19, wherein the location information includes at least one of an Media Broadcast Multicast Service (MBMS) area identifier, a Cell ID, a tracking area identifier (TAI), and GPS coordinates.

[0147] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer- readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto -optical media, and optical media such as CD- ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

CLAIMS What is claimed is:

1. A method for receiving a group communication at a wireless transmit/receive unit (WTRU), the method comprising:

receiving an Access Network Discovery and Selection Function (ANDSF) message including information regarding available group communications; and

receiving a group communication based on the information.

2. The method of claim 1, wherein the information regarding available group communications is based on a location of the WTRU.

3. The method of claim 1, wherein the information regarding available group communications is based on a capability of the WTRU.

4. The method of claim 1, wherein the information regarding available group communications is based on interested groups of the WTRU.

5. The method of claim 1, wherein the ANDSF message is received in response to a request from the WTRU.

6. The method of claim 1, wherein the ANDSF message, received from an ANDSF server, is triggered by an input from a Group Communication System Enablers (GCSE) server or a GCSE Interworking Function (IWF).

7. The method of claim 1, further comprising:

receiving access network information.

8. The method of claim 7, wherein the access network information is based on a location of the WTRU.

9. The method of claim 8, wherein the location information includes at least one of an Media Broadcast Multicast Service (MBMS) area identifier, a Cell ID, a tracking area identifier (TAI), and GPS coordinates.

10. A wireless transmit/receive unit (WTRU) for receiving a group communication comprising:

a receiver configured to receive an Access Network Discovery and Selection Function (ANDSF) message including information regarding available group communications; and

the receiver further configured to receive a group communication based on the information.

11. The WTRU of claim 10, wherein the information regarding available group communications is based on a location of the WTRU.

12. The WTRU of claim 10, wherein the regarding available group communications is based on a capability of the WTRU.

13. The WTRU of claim 10, wherein the information regarding available group communications is based on interested groups of the WTRU.

14. The WTRU of claim 10, wherein the ANDSF message is received in response to a request from the WTRU.

15. The WTRU of claim 10, wherein the ANDSF message, received from an ANDSF server, is triggered by an input from a Group Communication System Enablers (GCSE) server or a GCSE Interworking Function (IWF).

16. The WTRU of claim 10, wherein the receiver is further configured to receive access network information.

17. The WTRU of claim 16, wherein the access network information is based on a location of the WTRU.

18. The WTRU of claim 17, wherein the location information includes at least one of an Media Broadcast Multicast Service (MBMS) area identifier, a Cell ID, a tracking area identifier (TAI), and GPS coordinates.