WO2008107778A1

WO2008107778A1 - Method and apparatus for providing multicast data service

Info

Publication number: WO2008107778A1
Application number: PCT/IB2008/000510
Authority: WO
Inventors: Ravi Pandey; Roman Pichna
Original assignee: Nokia Corporation; Nokia Inc.
Priority date: 2007-03-05
Filing date: 2008-03-05
Publication date: 2008-09-12

Abstract

An approach is provided for joining a multicast group. A join message originated from a mobile host for joining a multicast group associated with a multicast service is intercepted. Authentication of a user subscription and associated policy is requested for the multicast service, wherein a serving gateway of the mobile host joins the multicast group in response to the authentication, and the mobile host is added to a multicast distribution list of the serving gateway.

Description

METHOD AND APPARATUS FOR PROVIDING MULTICAST DATA SERVICE

RELATED APPLICATIONS

This application claims the benefit of the earlier filing date under 35 U.S.C. §119(e) of U.S. Provisional Application Serial No. 60/893,043 filed March 5, 2007, entitled "Method and Apparatus For Providing Multicast Data Service," the entirety of which is incorporated herein by reference.

BACKGROUND

[0002] Radio communication systems, such as a wireless data networks (e.g., WiMAX (Worldwide Interoperability for Microwave Access) systems, DVB (Digital Video Broadcasting)-H (Handheld) systems, and spread spectrum systems (such as Code Division Multiple Access (CDMA) networks), Time Division Multiple Access (TDMA) networks, etc.), provide users with the convenience of mobility along with a rich set of services and features. This convenience has spawned significant adoption by an ever growing number of consumers as an accepted mode of communication for business and personal uses. To promote greater adoption, the telecommunication industry, from manufacturers to service providers, has agreed at great expense and effort to develop standards for communication protocols that underlie the various services and features. One area of effort involves multicast services in support of bandwidth intensive applications, such as audio and video streaming.

SOME EXEMPLARY EMBODIMENTS

[0003] Therefore, there is a need for an approach for providing efficient multicast, which can co-exist with already developed standards and protocols.

[0004] According to one embodiment of the invention, a method comprises intercepting a join message originated from a mobile host for joining a multicast group associated with a multicast service. The method also comprises requesting authentication of a user subscription and associated policy for the multicast service, wherein a serving gateway of the mobile host joins the multicast group in response to the authentication, and the mobile host is added to a multicast distribution list of the serving gateway.

[§§§5] According to another embodiment of the invention, an apparatus comprises a logic configured to intercept a join message originated from a mobile host for joining a multicast group associated with a multicast service. The logic is further configured to request authentication of a user subscription and associated policy for the multicast service. The apparatus also comprises a serving gateway of the mobile host joins the multicast group in response to the authentication, and the mobile host is added to a multicast distribution list of the serving gateway.

[0006] According to one embodiment of the invention, a method comprises generating a join message for joining a multicast group associated with a multicast service. The method also comprises transmitting the join message to an access network according to a multicast address, wherein the access network includes an intercept node configured to intercept the join message and to request authentication of a user subscription and associated policy for the multicast service. The method also comprises receiving a join acceptance message in response the join message to indicate addition to a multicast distribution list if the user subscription and the associated policy are authenticated.-

[0007] According to yet another embodiment of the invention, an apparatus comprises a processor configured to generate a join message for joining a multicast group associated with a multicast service. The apparatus also comprises a transceiver coupled to the processor and configured to transmit the join message to an access network according to a multicast address, wherein the access network includes an intercept node configured to intercept the join message and to request authentication of a user subscription and associated policy for the multicast service. The transceiver is further configured to receive a join acceptance message in response the join message to indicate addition to a multicast distribution list if the user subscription and the associated policy are authenticated. [0008] Still other aspects, features, and advantages of the invention are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the invention. The invention is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings:

[©OKI] FIG. 1 is a diagram of a communication system capable of providing multicast- broadcast service, according to an exemplary embodiment of the invention;

[0011] FIG. 2 is a diagram of a communication system having an architecture compatible with Worldwide Interoperability for Microwave Access (WiMAX), according to an embodiment of the invention;

[0012] FIG. 3 is a diagram of an exemplary communication system providing Internet

Protocol (IP) multicast with home agent routing;

[0013] FIG. 4 is a diagram of an exemplary communication system providing IP multicast with foreign agent routing;

[0014] FIG. 5 is a diagram of an exemplary communication system providing IP multicast with combined home agent and foreign agent routing;

[0015] FIG. 6 is a flowchart of a multicast join procedure, according to an embodiment of the invention;

[0016] FIG. 7 is a diagram of a communication system providing multicast support in

WiMAX access in which join execution is performed in a home agent, according to an embodiment of the invention;

[0017] FIG. 8 is a diagram of a message flow providing join execution in the home agent of the system of FIG. 7, according to an embodiment of the invention; [§018] FIG. 9 is a diagram of a communication system providing multicast support in

WiMAX access in which join execution is performed in a foreign agent (e.g., user anchor access service network (ASN) gateway), according to an embodiment of the invention;

[001.9] FIG. 10 is a diagram of a message flow providing join execution in the user anchor

ASN gateway of the system of FIG. 9, according to an embodiment of the invention;

[0020] FIG. 11 is a diagram of a communication system providing multicast support in

WiMAX access in which join execution is performed in a serving node (e.g., serving access service network (ASN) gateway), according to an embodiment of the invention;

[0021] FIG. 12 is a diagram of a message flow providing join execution in the serving ASN gateway of the system of FIG. 11 , according to an embodiment of the invention;

[0022] FIG. 13 is a diagram of a message flow of an IP multicast session start procedure, according to an embodiment of the invention;

[§023] FIG. 14 is a diagram of hardware that can be used to implement an embodiment of the invention; and

[0024] FIG. 15 is a diagram of exemplary components of a mobile station capable of operating in the system of FIG. 1, according to an embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0025] An apparatus, method, and software for providing an efficient multicast mechanism are disclosed. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It is apparent, however, to one skilled in the art that the embodiments of the invention may be practiced without these specific details or with an equivalent arrangement. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention.

[0026] Although the embodiments of the invention are discussed with respect to an Internet Protocol (IP) multicast service using a WiMAX (Worldwide Interoperability for Microwave Access) technology, it is recognized by one of ordinary skill in the art that the embodiments of the inventions have applicability to any type of communication services and equivalent technologies. Additionally, IGMP (Internet Group Management Protocol) and MLD (Multicast Listener Discovery) are described in the various embodiments; it is contemplated that other equivalent protocols can be implemented.

[0027] FIG. 1 is a diagram of a communication system capable of providing multicast- broadcast service, according to an exemplary embodiment of the invention. According to an exemplary embodiment, a communication system 100 includes one or more wireless terminals (e.g., mobile station, unit, or device), such as user equipment (UE) 10Ia-IOIn, that are within a coverage area of an access network 103. In this example, the access network 103 is a WiMAX Access Service Network (ASN). As such, the UEs 10Ia-IOIn can be referred to as mobile subscriber stations (MSSs). Although only a single ASN 103 is depicted, it is recognized that multiple ASNs can exist. The access network 103, which includes one or more base stations (BSs) 105a-105m configured to communicate with the UEs 10Ia-IOIn, provides the WIMAX access services. As shown, the access network 103 communicates with a multicast-broadcast data network 107. In an exemplary embodiment, the system 100 of FIG. 1 is configured to tailor WiMAX signaling for an Internet Protocol multicast broadcast service (MCBCS) approach. WBVIAX access services can include datacast services, such as packet-based television service or other audio or video streaming services.

[0028] One such packet-based television service is that of Internet Protocol Television (IPTV). This technology relies on the Internet Protocol for providing consumers with access to television programming.

[0029] Traditionally, IPTV services are mainly supported through wired broadband connections, such as digital subscriber line (DSL) and cable modems. Wirelessly broadcasting bandwidth intensive packetized TV signals, which contain both audio and video data, to a large group of subscribers has received significant attention in the telecommunications industry, largely because of the developments in high-speed, wireless network as well as sophisticated transmission technologies (e.g., multicast technology).

[0030] Multicast technology permit IPTV providers to selectively transmit packetized IPTV data wirelessly to targeted groups of subscribers rather than broadcasting (which can unnecessarily consume network resources). That is, multicasting is especially attractive from the point of view of the service provider precious bandwidth can be conserved. By way of example, the system of FIG. 1 is described with respect to multicasting using IP - i.e., IP multicast (IP-M) - to provide wireless multicast-broadcast services (MCBCS), such as IPTV, over the access service network (ASN) 103.

[OCBl] Traditionally, multicasting, however, would require directly interfacing a multicast IP home agent (MIP HA) of a connectivity service network (CSN) to an ASN as specified by the Internet Engineering Task Force (IETF) within various request for comments (RFC). This approach unfortunately consumes precious resources, as it is based on using the MIP HA to replicate packets and to unicast the packets towards the mobile terminals. This approach, in fact, does not take advantage of the bandwidth preserving feature of multicasting. [0032] In contrast, the system 100 exploits the multicast technology by avoiding unicasting within the data path. By way of example, the system 100 of FIG. 1 can be implemented using an exemplary architecture, as depicted in FIG. 2.

[§033] FIG. 2 is a diagram of a communication system having an architecture compatible with WiMAX, according to an embodiment of the invention. System 200, according to certain embodiments, provides efficient IP multicast support for mobile wireless host (e.g., mobile subscriber station (MSS) 201). A mechanism is introduced to optimize the IP multicast path with user mobility in the access network 200. This approach need not impose any changes in existing standards — e.g., Mobile IP, which is designed to allow mobile device users to move from one network to another while maintaining a permanent BP address. Mobile IP is detailed in Internet Engineering Task Force (IETF) Request for Comment (RFC) 3344, which is incorporated by reference in its entirety.

[0034] In an exemplary embodiment, the architecture employs multicasting via the IP- multicast (IP-M) protocol, wherein the feeds of multicast flows are delivered from an MC-Router located within the access network. IP-M together with other protocols - e.g., IGMP (Internet Group Management Protocol) /MLD (Multicast Listener Discovery) — is utilized, in one embodiment, for joining, leaving and routing MS traffic. Alternatively, hypertext transfer protocol (HTTP)-based protocols can be employed.

[0035] The system 200 can be explained by way of a Network Reference Model (NRM), which is a logical representation of the WiMAX network architecture. The NRM identifies functional entities and reference points over which interoperability is achieved between functional entities. The system 200 includes the following logical entities: mobile subscriber station (MSS) 201, access service network (ASN) 203, and connectivity service network (CSN) 205. The CSN 205 provides connectivity to a public data network, such as the Internet 207.

[0036] Each of the entities, MSS 201, ASN 203 and CSN 205, represents a grouping of functional entities, whereby each of these functions may be realized in a single physical device or may be distributed over multiple physical devices. The grouping and distribution of functions into physical devices within a functional entity, such as an Access Service Network (ASN), depends on the particular applications and services of the network. A manufacturer may choose any physical implementation of functions, either individually or in combination, as long as the implementation meets the functional and interoperability requirements.

[0037] According to certain embodiments, the Access Service Network (ASN) 203 is defined as a set of network functions needed to provide radio access to a WiMAX subscriber. The ASN 203, in an exemplary embodiment, provides the following functions of Table 1:

WiMAX Layer-2 _,(L2) connectivity with WiMAX MS

Transfer of Authentication Authorization and Accounting (AAA) messages to WiMAX subscriber's Home Network Service Provider (H-NSP) for authentication, authorization and session accounting for subscriber sessions

Network discovery and selection of an appropriate NSP that WiMAX subscriber accesses

WiMAX service(s) from

Relay functionality for establishing Layer-3 (L3) connectivity with a WiMAX MS (i.e.,

IP address allocation)

Radio Resource Management

ASN-CSN tunneling

In addition to the above functions, for a portable and mobile environment, an ASN can support the following functions:

- ASN anchor mobility

- CSN anchor mobility

- Paging and Location Management

Table 1

[0038] The ASN 203 comprises network elements such as one or more Base Station(s) 203a, and one or more ASN Gateway(s) 203b-203d: ASN GW (Serving), ASN GW (U-Anchor), and ASN GW (C-Anchor).

[0039] The ASN 203 may be shared by more than one Connectivity Service Networks (CSN) 205. CSN 205 can be defined as a set of network functions that provide IP connectivity services to the WiMAX subscriber(s). The CSN 205 may provide the following functions, as enumerated in Table 2:

MS IP address and endpoint parameter allocation for user sessions

Internet access

AAA proxy or server

Policy and Admission Control based on user subscription profiles

ASN-CSN tunneling support,

WiMAX subscriber billing and inter-operator settlement

Inter-CSN tunneling for roaming

Inter- ASN mobility

WiMAX services such as location based services, connectivity for peer-to-peer services, provisioning, authorization and/or connectivity to IP multimedia services and facilities to support, for example, lawful intercept services such as those compliant with

Communications Assistance Law Enforcement Act (GALEA) procedures.

Table 2

[0040] The CSN 205 may comprise network elements, such as Authentication Authorization and Accounting (AAA) proxy/servers 205a, home agent 205b, a multicast router 205c as well as user databases (not shown), inter-working gateway devices (not shown), other routers (not shown).

[0041] in an exemplary embodiment, the architecture of the system 200 is based on IP- multicast (IP-M), and thus, the feeds of multicast flows are delivered from a multicast router (MC-Router) (not shown). IP-M together with control protocol IGMP (Internet Group Management Protocol) / MLD (Multicast Listener Discovery) is utilized, in one embodiment, for joining, leaving and routing MC traffic. The Internet Group Management Protocol (IGMP) is a communications protocol used to manage the membership of Internet Protocol multicast groups. IGMP is used by D? hosts and adjacent multicast routers to establish multicast group (or channel) memberships. For example, IGMP can be used for online video and gaming, and allows more efficient use of resources when supporting these uses. It is contemplated that other equivalent protocols can be utilized as well - e.g., hypertext transfer protocol (HTTP)-based protocols.

[0042] As shown in FIG. 2, several interoperability reference points (RPs) are shown. A reference point is a conceptual point (or interface) between two groups of functions and resides in different functional entities on either side of it. These functions expose various protocols associated with the reference point. It is noted that all protocols associated with a RP may not always terminate in the same functional entity — i.e., two protocols associated with a RP may originate and terminate in different functional entities.

[0043] The normative reference points between the major functional entities are as follows: reference points R1-R5. Reference Point Rl includes the protocols and procedures between MSS 201 and ASN 203, according to the air interface (e.g., physical layer (PHY) and medium access control (MAC)) specifications (e.g., IEEE P802.16e-2005 and IEEE P802.16-2004, which are incorporated herein by reference in their entireties). Reference point Rl may include additional protocols related to the management plane. Reference Point R2 includes protocols and procedures between the MSS 201 and CSN 205 associated with Authentication, Services Authorization and D? Host configuration management. This reference point is logical in that it does not reflect a direct protocol interface between the MSS 201 and CSN 205. The authentication part of reference point R2 runs between the MSS 201 and the CSN 205 operated by the home network service provider (NSP); however, the MSS 201 and CSN 205 operated by the visited NSP may partially process the described procedures and mechanisms. [§044] Reference Point R3 includes the set of control plane protocols between the MSS 201 and the CSN 205 to support AAA, policy enforcement and mobility management capabilities. It also encompasses the bearer plane methods (e.g., tunnelling) to transfer user data between the ASN 203 and the CSN 205. Reference Point R4 provides control and bearer plane protocols originating/terminating in various functional entities of an ASN 203 that coordinate MS mobility between ASNs and ASN-GWs. R4 is the only interoperable RP between similar or heterogeneous ASNs.

[0045] Reference Point R5 provides the set of control plane and bearer plane protocols for internetworking between a CSN operated by the home NSP and that operated by a visited NSP. It is recognized that, traditionally, mapping existing IP multicast solution to WiMAX access network with mobility does not lead to an efficient solution with respect to user and control plane. [0046] It is recognized that the existing reference points Rl, R2, R3, R4 and R5 can be reused and extended with multicast broadcast service functionality. This reference point is, for example, crossed by IPv4 (Internet Protocol version 4)/IPv6 (Internet Protocol version 6) protocols and IGMP (for IPv4) and MLD (for IPv6). Multicast Listener Discovery is the protocol used in the IPv6 protocol suite by a router to discover listeners for a specific multicast group (or channel), much as IGMP is used in IPv4. The protocol is embedded in ICMPv6 instead of using a separate protocol. MLDvI is similar to IGMPv2 and MLDv2 similar to IGMPv3. The protocol is described in IETF RFC 3810, which is incorporated herein by reference in its entirety.

[0047] For the purposes of illustration, a number of assumptions can be made for the system 200. A multicast service zone refers to a set of base stations in a location defined for a multicast service. It is contemplated that multiple service zones can be configured. Also, BS 203a and serving ASN GW 203b within a service area maintain a multicast distribution tree for a particular MBS service.

[0048] Further, according to one embodiment, the ASN GW (e.g., GWs 203b-203d) is IP multicast capable. MSS 201 is connected to multicast capability U-Anchor ASN GW 203c or serving anchor ASN GW 203b. This GW 203b or 203c is capable of intercepting and executing IGMP join message originated from the MSS 201. Additionally, it is contemplated that a local multicast router (not shown) can be deployed in the network 200. In such a case, the serving ASN GW 203b joins the local multicast router (or multicast server), which in turn joins a multicast group (or channel) router to establish a MBS data path.

[0049] The MSS 201 supports multicast discovery, and thus, can send an IGMP Join message to HA 205b because it is the first IP address for a device visible (nearest multicast router) from both client MIP (CMEP) and proxy MIP (PMIP) terminals. Alternatively, MSS 201 can be provisioned/configured with any other address. The multicast router address can also be learned from the IGMP broadcast message, for instance.

[0050] The system 200 further provides multicast service authentication, wherein service authentication can be performed with multicast group router to fetch service group identifier (ID).

The AAA server 205a can perform user subscription and policy check with respect to the MSS

201. For instance, such request can be initiated by IGMP message intercepting node.

[0051] To appreciate the approach for providing multicast service according to the various embodiments, it is instructive to examine traditional IP multicasting systems (shown in FIGs. 3-

5).

[0052] FIG. 3 is a diagram of an exemplary communication system providing Internet Protocol (IP) multicast with home agent routing. By this method, multicast reception on Mobile Hosts (MH) 301 is handled by HA 303. Routing is performed by executing IGMP and delivering multicast to its MH 301 as if the MHs 301 are in the home network. When MH 301 is not in home network, datagrams are delivered by tunnelling through foreign agent/access router (FAJAR) 305; with IGMP membership reports from the MH 301 being unicast to HA 303. [0053] Use of MIP multicast resource utilization (e.g., as specified RFC 3344) is inefficient due to mandated unicast routing. Namely, datagram is unicast separately to each MS 307, separate tunnel from separate HA are used to deliver the same group to a wireless network leading to a tunnel convergence problem.

[0054] In such a WiMAX network, the concept of serving ASN GW 309 increases one more layer in hierarchy - i.e., the serving ASN GW will receive unicast datagram from other foreign agent also. The consequences of multicast support in RFC 3344 are that multicast becomes unicast in the home agent. As a result, only unicast is used across the interfaces that are most resource limited (e.g., Radio Rl, Last hop transport R6). One approach would be to modify Mobile IP. [0(155] With modified MEP, HA 303 and FA/ AR 305 will transport multicast packets. The ownership of this flow will be to the first MD? MS 307 that has requested it. Multiple users 307 can then join the multicast tree at FA/ AR. If Multicast R3 is merged for multiple users, the ownership of the communication leg belongs to one user and is deleted when the user moves away (e.g., mobile EP handover or deregisters). This process results in service interruption due to mobility of the user that owns the R3 multicast tunnel and reestablishment of the tunnel with another user.

[0056] Another way of modifying Mobile EP involves foreign agent routing, as shown in FIG. 4.

[§057] FIG. 4 is a diagram of an exemplary communication system providing Internet Protocol (EP) multicast with foreign agent routing. Foreign Agent (FA) routing can provide better resource utilization for multicast datagram compared to home agent routing mechanism (of FIG. 3). FA/ AR 305 hides the home address of MH 301 and enforces local administrative policies for multicast. With WiMAX, the serving ASN GW can receive unicast datagram from other foreign agents as well. One approach is to discard the datagram from the other foreign agents or notify them to stop forwarding the datagram. A roaming MS 307 can set up a tunnel from its home network to receive multicast. Alternatively, the MS 307 that enters the network with ongoing multicast session will still use home network (in this case, MS does not send IGMP join which can be intercepted by FA/ AR).

[0058] FIG. 5 is a diagram of an exemplary communication system providing Internet Protocol (EP) multicast with combined home agent and foreign agent routing. The FA/ AR 305 executes IGMP locally and sets up unique tunnel on demand for all required groups originating at the HA 303 of the first MH 301 that joins each group. A HA 303 whose MH 301 have all left the foreign network will tear down the tunnel and inform the FA/ AR 305, which sets up a new tunnel after a new membership report arrives or immediately if a join/leave message is used. The HA 303 can be a multicast router and can notify the FA/ AR 305 before tearing down a tunnel; otherwise, an inactive tunnel cannot be distinguished from a disconnected one. In a WiMAX network, the serving ASN GW 309 receives unicast datagrams from other foreign agents as well. As with the system of FIG. 3, service interruption can occur because of a user (owning R3 multicast tunnel) leaves the group. [0059] FIG. 6 is a flowchart of a multicast join procedure, according to an embodiment of the invention. This multicast join procedure is described with respect to system 200 of FIG. 2. In step 601, the MSS 201 sends a request (e.g., IGMP/MLD Join message) to the HA 205b to join the multicast service or group. The HA 205b, in an exemplary embodiment, is the nearest multicast router that is visible to device from both client MIP and proxy MDP terminal. Alternatively, MSS 201 can be provisioned / configured with any other address. For instance, the multicast router address can be learned from an IGMP broadcast message. Next, the request is intercepted by a node (step 603); e.g., IGMP Join Interception/ Execution can be executed at either Serving ASN GW 203b or user anchor ASN GW 203c or Home Agent 205b. [0060] In step 605, the intercepting node requests the AAA server 205a to authenticate user's multicast subscription and policies for the requested multicast service. Optionally, the intercepting node performs, as in step 605, multicast broadcast service (MBS) authentication and authorization with the multicast router. It is noted that MS multicast client/server authentication can achieve the same function, according to one embodiment.

[0061] Thereafter, the AAA server 205a performs the requested authentication and notifies, per step 607, the control anchor ASN GW 203d to join multicast group on behalf of MSS 201. If the FA/AR is the serving ASN GW 203b (as determined in step 609), the control anchor ASN GW 203d then notifies Serving ASN GW 203b to join the multicast group (step 611). [0062] The process, in step 613, determines whether the serving ASN GW 203b is already a member of the multicast group. If the serving ASN GW 203b is not a member of multicast group, the GW 203b joins the multicast router, per step 615, assuming there exists a local multicast router in network (such as site multicast router); i.e., the serving ASN GW 203b joins the local router which in turn joins the multicast group router. Subsequently, the serving ASN GW 203b notifies the MSS 201 and adds the MSS 201 to its distribution list (step 617). For ongoing multicast session, it establishes radio resource setup with BS 203a. [0063] According to certain embodiments, the procedures shown in FIGs. 7-12 illustrate where the intercepting node can reside to provide IGMP Join interception and execution: (1) IGMP Join Execution in HA; (2) IGMP Join Execution in U-Anchor ASN GW (FA/AR); and (3) IGMP Join Execution in Serving ASN GW. [0064] FIG. 7 is a diagram of a communication system providing multicast support in WiMAX access in which join execution is performed in a home agent, according to an embodiment of the invention. System 700 includes a serving ASN GW 701 that serves base stations 703 within two MBS zones, for example. Additionally, the system 700 utilizes a control anchor ASN GW 705 and a user anchor (U-anchor) ASN GW (FA/RA) 707, as well as an AAA server 709. CSN HA 711 communicates with a multicast router 713, which, as shown, can interface with one or more content providers 715, 717.

[0(165] The system 700 provides reference point MBS CP between IGMP intercepting node (HA) and Multicast group router 713, which is used for multicast service to fetch service group JJD. Reference Point MBS DP+CP exists between the Serving ASN GW 701 and the local/group multicast router 713, which provides multicast data delivery, and control signaling (e.g., session start/stop, establishment of data path and user mobility).

[0066] FIG. 8 is a diagram of a message flow providing join execution in the home agent of the system of FIG. 7, according to an embodiment of the invention. In step 801, an MSS (e.g., MSS 201) sends an IGMP (IPv4) or MLD (IPv6) Join message to signal its interest in receiving a particular multicast services identified by an IP multicast address. The IGMP Join Interception/ Execution occurs at the Home Agent 711, which performs authentication of the user subscription and retrieves policies associated with the user's subscription (step 803) with the AAA server 709. Optionally, the HA 711, as the intercepting node, can perform MBS service authentication and authorization with the multicast router 713 (e.g., 3GPP/3GPP2), as in step 805. [Θ067] Next, the AAA server 709 performs the required authentication, and notifies the control anchor ASN GW 705 to join the multicast group on behalf of the MSS 201 by submitting a MBS notification request message (step 807). Subsequently, in step 809, the control anchor ASN GW 705 notifies the serving ASN GW 701 to join the multicast group by relaying the MBS notification request message. The serving ASN GW 701 then acknowledges the support of the multicast service (step 811) with a MBS notification response. To support multicast services, the serving ASN GW 701 has to be within the multicast services area.

[0068] In step 813, the serving ASN GW 701 sends a MBS registration request to the multicast router 713, which responds with a MBS registration response to indicate that the multicast router 713 has added the serving ASN GW 701 to its distribution list (per step 815). The response message may include multicast service details such as the service start time, quality of service, accounting details etc.

[0069] In step 817, the serving ASN GW 701 notifies (with service start time, quality of service, accounting details) the MSS 201 that the MSS's request has been accepted. [0070] FIG. 9 is a diagram of a communication system providing multicast support in WiMAX access in which join execution is performed in a foreign agent (e.g., U-anchor access service network (ASN) gateway), according to an embodiment of the invention. Under this scenario, a reference point MBS CP is utilized between IGMP/MLD intercepting node (F A/ AR) 707 and the multicast group router 713 for the multicast service to fetch a service group ID, for example. The operation of the FA/ AR 707 is detailed below with respect to FIG. 10. [0071] FIG. 10 is a diagram of a message flow providing join execution in the U-anchor access service network (ASN) gateway of the system of FIG. 9, according to an embodiment of the invention. In step 1001, the MSS 201 sends a join message (e.g., an IGMP (IPv4) or MLD (IPv6) Join message) to signal its interest in receiving a particular multicast services identified, for example, by a certain IP multicast address. The join message is intercepted by the ASN GW FA/AR 707, per step 1003. In step 1005, the ASN GW FA/AR 707 consults with the AAA server 709 on the user subscription of the multicast service, and applies any policies associated with the user subscription. Next, the ASN GW FA/AR 707 communicates with the multicast router 713 to perform multicast service authentication (step 1007).

[0072] Steps 1009-1019 are similar to the join procedure of FIG. 8. Namely, the AAA server, as in step 1009, submits a MBS notification request message to the control anchor ASN GW 705 regarding joining of the multicast group by the MSS 201. In turn, the control Anchor ASN GW 705 instructs the serving ASN GW 701 to join multicast group by relaying the notification request (step 1011). The serving ASN GW 701, per step 1013, acknowledges with a response message to indicate support for the multicast service. At this point, the serving ASN GW 701 communicates with the multicast router 713 to perform a registration process for the MBS, per steps 1015, 1017. The multicast router 713 includes the serving ASN GW 701 to its multicast distribution list. Thereafter, the serving ASN GW 701 generates a MBS join accepted message and transmits the message to the MSS 201, thereby completing the multicast join procedure. [§073] FIG. 11 is a diagram of a communication system providing multicast support in WiMAX access in which join execution is performed in the serving node, according to an embodiment of the invention. In this configuration, unlike the system 700 and system 900, the multicast router 713 of system 1100 is without a MBS CP interface to either the ASN GW FA/ AR 707 or the CSN HA 711. Reference Point MBS DP+CP between the serving ASN GW 701 and the local/group multicast router 713 provides the following functions: multicast data delivery, and control signaling (e.g., session start/stop, establishment of data path, user mobility and fetching of service group DD). With this arrangement, the intercepting node is the serving ASN GW 701.

[0074] FIG. 12 is a diagram of a message flow providing IGMP join execution in a serving ASN gateway, according to an embodiment of the invention. As with the other join procedures of FIGs. 8 and 10, the MSS 201 initiates the multicast join procedure by generating an appropriate message, e.g., IGMP (IPv4) or MLD (IPv6) Join message, to receive a particular multicast (as identified by an IP multicast address, for example), per step 1201. In this example, the serving ASN GW 701, as the intercepting node, provides the IGMP Join Interception/ Execution. Steps 1205-1219 are similar to those of FIG. 10, with the exception that steps 1205- 1207 are executed by the serving ASN GW 701, as opposed to FA/ AR 707. [0075 J FIG. 13 is a diagram of a message flow of an IP multicast session start procedure, according to an embodiment of the invention. The multicast router 713 sends, as in step 1301, a Session Start Request to the serving ASN GW 701. Upon receiving the request, the serving ASN GW 701 informs the base station with a MBS Session Start Response to setup the radio resource for the MBS (steps 1303 and 1305). If the MSS 201 is in Idle/sleep/power-save mode, paging can be performed. In step 1307, the multicast router 713 sends a MBS DP established message to the serving GW ASGN 701, the BS 203b, and ultimately to the MSS 201. [0076] The above arrangements providing multicast joining procedures, according to certain embodiments, permits use of existing protocols. For example, the systems and processes of FIGs. 8-13 permit use of IPv4 using IGMP and IPv6 using MLD, and do not entail changes for Mobile IPv4/v6. Consequently, these systems can be quickly adopted.

[Θ077] One of ordinary skill in the art would recognize that the processes for providing a multicast-broadcast service may be implemented via software, hardware (e.g., general processor, Digital Signal Processing (DSP) chip, an Application Specific Integrated Circuit (ASIC), Field Programmable Gate Arrays (FPGAs), etc.), firmware, or a combination thereof. Such exemplary hardware for performing the described functions is detailed below with respect to FIG. 14.

[0078J FIG. 14 illustrates exemplary hardware upon which various embodiments of the invention can be implemented. A computing system 1400 includes a bus 1401 or other communication mechanism for communicating information and a processor 1403 coupled to the bus 1401 for processing information. The computing system 1400 also includes main memory 1405, such as a random access memory (RAM) or other dynamic storage device, coupled to the bus 1401 for storing information and instructions to be executed by the processor 1403. Main memory 1405 can also be used for storing temporary variables or other intermediate information during execution of instructions by the processor 1403. The computing system 1400 may further include a read only memory (ROM) 1407 or other static storage device coupled to the bus 1401 for storing static information and instructions for the processor 1403. A storage device 1409, such as a magnetic disk or optical disk, is coupled to the bus 1401 for persistently storing information and instructions.

[0079] The computing system 1400 may be coupled via the bus 1401 to a display 1411, such as a liquid crystal display, or active matrix display, for displaying information to a user. An input device 1413, such as a keyboard including alphanumeric and other keys, may be coupled to the bus 1401 for communicating information and command selections to the processor 1403. The input device 1413 can include a cursor control, such as a mouse, a trackball, or cursor direction keys, for communicating direction information and command selections to the processor 1403 and for controlling cursor movement on the display 1411.

10080] According to various embodiments of the invention, the processes described herein can be provided by the computing system 1400 in response to the processor 1403 executing an arrangement of instructions contained in main memory 1405. Such instructions can be read into main memory 1405 from another computer-readable medium, such as the storage device 1409. Execution of the arrangement of instructions contained in main memory 1405 causes the processor 1403 to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the instructions contained in main memory 1405. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the embodiment of the invention. In another example, reconfigurable hardware such as Field Programmable Gate Arrays (FPGAs) can be used, in which the functionality and connection topology of its logic gates are customizable at run-time, typically by programming memory look up tables. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.

[0081] The computing system 1400 also includes at least one communication interface 1415 coupled to bus 1401. The communication interface 1415 provides a two-way data communication coupling to a network link (not shown). The communication interface 1415 sends and receives electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information. Further, the communication interface 1415 can include peripheral interface devices, such as a Universal Serial Bus (USB) interface, a PCMCIA (Personal Computer Memory Card International Association) interface, etc.

[0082] The processor 1403 may execute the transmitted code while being received and/or store the code in the storage device 1409, or other non-volatile storage for later execution. In this manner, the computing system 1400 may obtain application code in the form of a carrier wave.

[0083] The term "computer-readable medium" as used herein refers to any medium that participates in providing instructions to the processor 1403 for execution. Such a medium may take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as the storage device 1409. Volatile media include dynamic memory, such as main memory 1405. Transmission media include coaxial cables, copper wire and fiber optics, including the wires that comprise the bus 1401. Transmission media can also take the form of acoustic, optical, or electromagnetic waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, CDRW, DVD, any other optical medium, punch cards, paper tape, optical mark sheets, any other physical medium with patterns of holes or other optically recognizable indicia, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave, or any other medium from which a computer can rea^ [0084] Various forms of computer-readable media may be involved in providing instructions to a processor for execution. For example, the instructions for carrying out at least part of the invention may initially be borne on a magnetic disk of a remote computer. In such a scenario, the remote computer loads the instructions into main memory and sends the instructions over a telephone line using a modem. A modem of a local system receives the data on the telephone line and uses an infrared transmitter to convert the data to an infrared signal and transmit the infrared signal to a portable computing device, such as a personal digital assistant (PDA) or a laptop. An infrared detector on the portable computing device receives the information and instructions borne by the infrared signal and places the data on a bus. The bus conveys the data to main memory, from which a processor retrieves and executes the instructions. The instructions received by main memory can optionally be stored on storage device either before or after execution by processor.

[0085] FIG. 15 is a diagram of exemplary components of a mobile station capable of operating in the system of FIG. 1, according to an embodiment of the invention. Generally, a radio receiver is often defined in terms of front-end and back-end characteristics. The front-end of the receiver encompasses all of the Radio Frequency (RF) circuitry whereas the back-end encompasses all of the base-band processing circuitry. Pertinent internal components of the telephone include a Main Control Unit (MCU) 1503, a Digital Signal Processor (DSP) 1505, and a receiver/transmitter unit including a microphone gain control unit and a speaker gain control unit. A main display unit 1507 provides a display to the user in support of various applications and mobile station functions. An audio function circuitry 1509 includes a microphone 1511 and microphone amplifier that amplifies the speech signal output from the microphone 1511. The amplified speech signal output from the microphone 1511 is fed to a coder/decoder (CODEC) 1513.

[0086] A radio section 1515 amplifies power and converts frequency in order to communicate with a base station, which is included in a mobile communication system (e.g., systems of FIG. 15A or 15B), via antenna 1517. The power amplifier (PA) 1519 and the transmitter/modulation circuitry are operationally responsive to the MCU 1503, with an output from the PA 1519 coupled to the duplexer 1521 or circulator or antenna switch, as known in the art. The PA 1519 also couples to a battery interface and power control unit 1520. [0087] In use, a user of mobile station 1501 speaks into the microphone 1511 and his or her voice along with any detected background noise is converted into an analog voltage. The analog voltage is then converted into a digital signal through the Analog to Digital Converter (ADC) 1523. The control unit 1503 routes the digital signal into the DSP 1505 for processing therein, such as speech encoding, channel encoding, encrypting, and interleaving. In the exemplary embodiment, the processed voice signals are encoded, by units not separately shown, using the cellular transmission protocol of Code Division Multiple Access (CDMA), as described in detail in the Telecommunication Industry Association's TIA/EIA/IS-95-A Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System; which is incorporated herein by reference in its entirety.

[0088] The encoded signals are then routed to an equalizer 1525 for compensation of any frequency-dependent impairments that occur during transmission though the air such as phase and amplitude distortion. After equalizing the bit stream, the modulator 1527 combines the signal with a RF signal generated in the RF interface 1529. The modulator 1527 generates a sine wave by way of frequency or phase modulation. In order to prepare the signal for transmission, an up-converter 1531 combines the sine wave output from the modulator 1527 with another sine wave generated by a synthesizer 1533 to achieve the desired frequency of transmission. The signal is then sent through a PA 1519 to increase the signal to an appropriate power level. In practical systems, the PA 1519 acts as a variable gain amplifier whose gain is controlled by the DSP 1505 from information received from a network base station. The signal is then filtered within the duplexer 1521 and optionally sent to an antenna coupler 1535 to match impedances to provide maximum power transfer. Finally, the signal is transmitted via antenna 1517 to a local base station. An automatic gain control (AGC) can be supplied to control the gain of the final stages of the receiver. The signals may be forwarded from there to a remote telephone which may be another cellular telephone, other mobile phone or a land-line connected to a Public Switched Telephone Network (PSTN), or other telephony networks.

[0089] Voice signals transmitted to the mobile station 1501 are received via antenna 1517 and immediately amplified by a low noise amplifier (LNA) 1537. A down-converter 1539 lowers the carrier frequency while the demodulator 1541 strips away the RF leaving only a digital bit stream. The signal then goes through the equalizer 1525 and is processed by the DSP 1505. A Digital to Analog Converter (DAC) 1543 converts the signal and the resulting output is transmitted to the user through the speaker 1545, all under control of a Main Control Unit (MCU) 1503-which can be implemented as a Central Processing Unit (CPU) (not shown).

[0090] The MCU 1503 receives various signals including input signals from the keyboard 1547. The MCU 1503 delivers a display command and a switch command to the display 1507 and to the speech output switching controller, respectively. Further, the MCU 1503 exchanges information with the DSP 1505 and can access an optionally incorporated SIM card 1549 and a memory 1551. In addition, the MCU 1503 executes various control functions required of the station. The DSP 1505 may, depending upon the implementation, perform any of a variety of conventional digital processing functions on the voice signals. Additionally, DSP 1505 determines the background noise level of the local environment from the signals detected by microphone 1511 and sets the gain of microphone 1511 to a level selected to compensate for the natural tendency of the user of the mobile station 1501.

10091] The CODEC 1513 includes the ADC 1523 and DAC 1543. The memory 1551 stores various data including call incoming tone data and is capable of storing other data including music data received via, e.g., the global Internet. The software module could reside in RAM memory, flash memory, registers, or any other form of writable storage medium known in the art. The memory device 1551 may be, but not limited to, a single memory, CD, DVD, ROM, RAM, EEPROM, optical storage, or any other non-volatile storage medium capable of storing digital data.

[0092] An optionally incorporated SIM card 1549 carries, for instance, important information, such as the cellular phone number, the carrier supplying service, subscription details, and security information. The SIM card 1549 serves primarily to identify the mobile station 1501 on a radio network. The card 1549 also contains a memory for storing a personal telephone number registry, text messages, and user specific mobile station settings.

[0093] While the invention has been described in connection with a number of embodiments and implementations, the invention is not so limited but covers various obvious modifications and equivalent arrangements, which fall within the purview of the appended claims. Although features of the invention are expressed in certain combinations among the claims, it is contemplated that these features can be arranged in any combination and order.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method comprising: intercepting a join message originated from a mobile host for joining a multicast group associated with a multicast service; and requesting authentication of a user subscription and associated policy for the multicast service, wherein a serving gateway of the mobile host joins the multicast group in response to the authentication, and the mobile host is added to a multicast distribution list of the serving gateway.

2. A method according to claim 1, wherein the join message is intercepted by an intercepting node, the method further comprising: performing, by the intercepting node, authentication and authorization of the multicast service with a multicast router that is a part of the multicast group.

3. A method according to claim 1, wherein the authentication is executed by an authentication server that is configured to notify a control gateway to join the multicast group, the control gateway being configured to notify the serving gateway to join the multicast group.

4. A method according to claim 3, wherein the serving gateway is part of an access service network (ASN) that includes the control gateway, the authentication server and a foreign agent gateway, the foreign agent gateway being configured to communicate with a home agent that provides transport of data to the mobile host.

5. A method according to claim 4, wherein the join message is intercepted by an intercepting node that is either the serving gateway, the foreign agent gateway, or the home agent.

6. A method according to claim 1, wherein the mobile host and the serving gateway are each configured to operate in a wireless access network including a Worldwide Interoperability for Microwave Access (WiMAX) network.

7. A method according to claim 1, wherein membership of the multicast group is provided through an Internet Group Management Protocol (IGMP) protocol or a Multicast Listener Discovery (MLD) protocol.

8. An apparatus comprising: logic configured to intercept a join message originated from a mobile host for joining a multicast group associated with a multicast service, wherein the logic is further configured to request authentication of a user subscription and associated policy for the multicast service, wherein a serving gateway of the mobile host joins the multicast group in response to the authentication, and the mobile host is added to a multicast distribution list of the serving gateway.

9. An apparatus according to claim 8, further comprising: authentication logic configured to authenticate and authorize the multicast service with a multicast router that is a part of the multicast group.

10. An apparatus according to claim 8, wherein the authentication of the user subscription and the associated policy is executed by an authentication server that is configured to notify a control gateway to join the multicast group, the control gateway being configured to notify the serving gateway to join the multicast group.

11. An apparatus according to claim 10, wherein the serving gateway is part of an access service network (ASN) that includes the control gateway, the authentication server and a foreign agent gateway, the foreign agent gateway being configured to communicate with a home agent that provides transport of data to the mobile host.

12. An apparatus according to claim 11, wherein the intercepting node is either the serving gateway, the foreign agent gateway, or the home agent.

13. An apparatus according to claim 8, wherein the mobile host and the serving gateway are each configured to operate in a wireless access network including a Worldwide Interoperability for Microwave Access (WiMAX) network.

14. An apparatus according to claim 8, wherein membership of the multicast group is provided through an Internet Group Management Protocol (IGMP) protocol or a Multicast Listener Discovery (MLD) protocol.

15. A method comprising: generating a join message for joining a multicast group associated with a multicast service; transmitting the join message to an access network according to a multicast address, wherein the access network includes an intercept node configured to intercept the join message and to request authentication of a user subscription and associated policy for the multicast service; and receiving a join acceptance message in response the join message to indicate addition to a multicast distribution list if the user subscription and the associated policy are authenticated.

16. A method according to claim 15, wherein the intercepting node is further configured to perform authentication and authorization of the multicast service with a multicast router that is a part of the multicast group.

17. A method according to claim 15, wherein the authentication is executed by an authentication server that is configured to notify a control gateway to join the multicast group, the control gateway being configured to notify a serving gateway to join the multicast group.

18. A method according to claim 17, wherein the serving gateway is part of an access service network (ASN) that includes the control gateway, the authentication server and a foreign agent gateway, the foreign agent gateway being configured to communicate with a home agent that provides transport of data.

19. A method according to claim 18, wherein the intercepting node that is either the serving gateway, the foreign agent gateway, or the home agent.

20. A method according to claim 15, wherein the access network includes a Worldwide Interoperability for Microwave Access (WiMAX) network.

21. A method according to claim 15, wherein membership of the multicast group is provided through an Internet Group Management Protocol (IGMP) protocol or a Multicast Listener Discovery (MLD) protocol.

22. An apparatus comprising: a processor configured to generate a join message for joining a multicast group associated with a multicast service; and a transceiver coupled to the processor and configured to transmit the join message to an access network according to a multicast address, wherein the access network includes an intercept node configured to intercept the join message and to request authentication of a user subscription and associated policy for the multicast service, wherein the transceiver is further configured to receive a join acceptance message in response the join message to indicate addition to a multicast distribution list if the user subscription and the associated policy are authenticated.

23. An apparatus according to claim 22, wherein the intercepting node is further configured to perform authentication and authorization of the multicast service with a multicast router that is a part of the multicast group.

24. An apparatus according to claim 22, wherein the authentication is executed by an authentication server that is configured to notify a control gateway to join the multicast group, the control gateway being configured to notify a serving gateway to join the multicast group.

25. An apparatus according to claim 24, wherein the serving gateway is part of an access service network (ASN) that includes the control gateway, the authentication server and a foreign agent gateway, the foreign agent gateway being configured to communicate with a home agent that provides transport of data.

26. An apparatus according to claim 25, wherein the intercepting node that is either the serving gateway, the foreign agent gateway, or the home agent.

27. An apparatus according to claim 22, wherein the access network includes a Worldwide Interoperability for Microwave Access (WiMAX) network.

28. An apparatus according to claim 22, wherein membership of the multicast group is provided through an Internet Group Management Protocol (IGMP) protocol or a Multicast Listener Discovery (MLD) protocol.