WO2009132255A2 - Method and system for resolving inter-mbs-zone performance issues using mbs service groups - Google Patents

Abstract

A system for resolving inter-zone performance issues using Multicast Broadcast Service (MBS) groups is disclosed. The system includes a processing unit creating an MBS service group from a plurality of MBS zones, having common MBS service group information, where each MBS zone includes one or more base stations. The common MBS service group information is provided to one or more mobile stations, so that it can be determined whether a target base station is in the MBS service group, based on the common MBS service group information. Thereafter, service is obtained from the target base station if it is determined that the target base station is in the MBS service group.

Description

METHOD AND SYSTEM FOR RESOLVING INTER-MBS-ZONE PERFORMANCE ISSUES USING MBS SERVICE GROUPS

Cross-Reference to Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No.

61/047,704 filed on April 24, 2008, entitled "Resolving Inter-MBS-Zone Performance Issues Using MBS Service Groups", the contents of which are incorporated by reference herein in their entirety.

Field

[0002] The present invention relates generally to wireless communications, and more particularly to inter-zone Multicast Broadcast Service (MBS) performance.

Background

[0003] In the current IEEE 802.16R.ev2/D9 draft specification for Air Interface for

Broadband Wireless Access Systems that includes support for Multicast Broadcast Services (MBS) (incorporated herein by reference), support for seamless service continuity of MBS reception for mobile stations (MSs) as they move between Base Stations (BSs) within an MBS Zone leverages the daisy-chain mechanism provided by MBS_DATA_IE and the fact that the communications parameters associated with each MBS service flow are the required to be the same between BSs within the MBS Zone. An MBS Zone is comprised of one or more base stations (BSs) belonging to the same geographical region to which the BSs synchronize their downlink transmissions at least to the granularity of an air interface frame with the same data contents over the same or different frequencies to a set of target MSs or to any MS in that region. An MBS Zone is identified by an MBS Zone Identifier (MBS Zone ID) and an MBS service flow is associated with an Multicast Connection Identifier (MCID) that identifies the air interface connection over which the data of the MBS service flow are transmitted within a BS. Support for seamless service continuity between BSs in adjoining (or neighboring) MBS Zones has been included via the broadcasting of the mapping of MBS Zone ID and MCID from their values in the current MBS Zone to their corresponding values in the neighboring MBS Zone and any differences in the alignment of MBS data transmissions for the same MBS service flows between the neighboring MBS Zones.

[0004] Due to radio frequency (RF) deployment considerations, such as frequency reuse factors greater than one, latency of backbone network (NW) and complexity considerations of backbone synchronization (e.g., Macro Diversity Zone spanning over more than a single ASN coverage area), the coverage area of a single MBS Zone may be limited or the coverage areas of multiple MBS Zones may be interleaved. Therefore, multiple MBS Zones which are transmitting the same MBS contents may be required to support the Multi-BS MBS service. As a result, it is necessary for the MS to maintain MBS service continuity across multiple MBS Zones. It is important to point out that the different MBS Zones which are transmitting the same MBS contents may or may not be using the same frequency or the same carrier.

[0005] As the MBS Zone ID and multicast connection identifier (MCID) remain the same within an MBS Zone, the MS can refer to the same burst of the downlink (DL) subframes that are synchronously transmitted by the BSs which belong to the same MBS Zone to receive the MBS DL transmission. In addition, the MBS_DATA_IE which is part of the MBS_MAP message provides the support to daisy-chain the data transmissions of the given MBS service across multiple DL frames which are not immediately following each other consecutively. With the MBS_DATA_IE support, there is no need to search for the MBS_MAP_IE in every frame to locate the MBS burst for the given MBS Zone.

[0006] Not only does such a mechanism allow a more efficient MBS handover support for the MS without the need of an MCID update when the MS is moving from one BS to another BS compared to the unicast handover scenario; more importantly, such a mechanism also allows the MS to remain in a power saving mode (e.g., idle mode) without the need of reestablishing the MCID(s) in order to resume the reception of the MBS DL transmission from the new serving BS and while operating in the power saving mode to determine when it needs to be available to receive relevant MBS data content. [0007] The fundamental problem of the current IEEE 802.16Rev2/D9 draft specification for multi-BS MBS operation is that in order to support service continuity a potentially significant amount of MBS Zone ID and MCID remapping information between neighboring MBS Zones needs to be broadcasted within an MBS Zone so that the MS will have this information before it transitions to the neighboring MBS Zone and therefore, is prepared to immediately receive the next MBS transmissions for the particular MBS service after such transition. For each MBS uniquely identifiable service content, as determined by MBS Zone ID and MCID pair, there is remapping information required to all neighboring MBS Zones..

Summary

[0008] The presently disclosed embodiments are directed to solving one or more of the problems presented in the prior art, described above, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings.

[0009] One embodiment of the present disclosure is directed to a method of resolving inter-zone performance issues using Multicast Broadcast Service (MBS) groups. The method includes grouping a plurality of MBS zones into an MBS service group, having common MBS service group information, wherein each MBS zone includes one or more base stations; signaling the common MBS service group information to one or more mobile stations; determining whether a target base station is in the MBS service group, based on the common MBS service group information; and obtaining service from the target base station if it is determined that the target base station is in the MBS service group.

[0010] Another embodiment is directed to a system for resolving inter-zone performance issues using MBS groups. The system includes a memory module configured to store a plurality of MBS zones as an MBS service group, having common MBS service group information, wherein each MBS zone includes one or more base stations. The system further includes a transceiver configured to signal the common MBS service group information to one or more mobile stations; and a processor module configured to determine whether a target base station is in the MBS service group, based on the common MBS service group information. A network communication module is configured to provide service by the target base station if it is determined that the target base station is in the MBS service group.

[0011] Yet another embodiment is directed to a computer-readable medium storing instructions thereon for performing a method of resolving inter-zone performance issues using MBS groups. The method includes grouping a plurality of MBS zones into an MBS service group, having common MBS service group information, wherein each MBS zone includes one or more base stations; signaling the common MBS service group information to one or more mobile stations; determining whether a target base station is in the MBS service group, based on the common MBS service group information; and providing service from the target base station if it is determined that the target base station is in the MBS service group.

[0012] Further features and advantages of the present disclosure, as well as the structure and operation of various embodiments of the present disclosure, are described in detail below with reference to the accompanying drawings.

Brief Description of the Drawings

[0013] The present disclosure, in accordance with one or more various embodiments, is described in detail with reference to the following Figures. The drawings are provided for purposes of illustration only and merely depict exemplary embodiments of the disclosure. These drawings are provided to facilitate the reader's understanding of the disclosure and should not be considered limiting of the breadth, scope, or applicability of the disclosure. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.

[0014] Fig. 1 is an illustration of an exemplary mobile radio channel operating environment, according to an embodiment.

[0015] Fig. 2 is an illustration of an exemplary communication system, according to an embodiment. [0016] Fig. 3 is an illustration of an exemplary radio channel operating environment with a plurality of MBS zones grouped into MBS service groups, according to an embodiment.

[0017] Fig. 4 is a flowchart illustrating a method of resolving inter-zone performance issues using MBS groups, according to an embodiment.

Detailed Description of Exemplary Embodiments

[0018] The following description is presented to enable a person of ordinary skill in the art to make and use the invention. Descriptions of specific devices, techniques, and applications are provided only as examples. Various modifications to the examples described herein will be readily apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the examples described herein and shown, but is to be accorded the scope consistent with the claims.

[0019] The word "exemplary" is used herein to mean "serving as an example or illustration." Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs.

[0020] Reference will now be made in detail to aspects of the subject technology, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

[0021] It should be understood that the specific order or hierarchy of steps in the processes disclosed herein is an example of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[0022] Embodiments disclosed herein describe a wireless cellular communication system where the transmission direction from a base station to mobile station is called downlink, while the opposite direction is called uplink. On both downlink and uplink, the radio signal transmissions over the time are divided into periodic frames (or subframes, slots, etc). Each radio frame contains multiple time symbols that include data symbols (DS) and reference symbols (RS). Data symbols carry the data information, while the reference symbols are known at both transmitter and receiver, and are used for channel estimation purposes. Note that the functions described in the present disclosure may be performed by either a base station or a mobile station. A mobile station may be any user device such as a mobile phone, and a mobile station may also be referred to as user equipment (UE) or subscriber station (SS).

[0023] Embodiments of the invention are described herein in the context of one practical application, namely, communication between a base station and a plurality of mobile devices. In this context, the exemplary s ystem is applicable to provide data communications between base station(s) and a plurality of mobile devices. Embodiments of the disclosure, however, are not limited to such base station and mobile device communication applications, and the methods described herein may also be utilized in other applications such as mobile-to-mobile communications, or wireless local loop communications. As would be apparent to one of ordinary skill in the art after reading this description, these are merely examples and the invention is not limited to operating in accordance with these examples. Assignment of resources within a frame to the data being carried can be applied to any digital communications system with data transmissions organized within a frame structure and where the full set of such resources within a frame can be flexibly divided according to portions of different sizes to the data being carried.

[0024] According to one embodiment, providing service continuity across multicast broadcast service (MBS) zones for mobile stations (MSs) in Idle mode can be done by allowing the current daisy-chaining of MBS bursts that exist within MBS Zones to operate in the entire service area where certain similar or the same MBS content is being delivered. Supporting this operation requires that MSs are aware of the content association between MBS Zones at the time the MS performs a handover or, in the case of Idle Mode, a preferred base station (BS) reselection. Therefore, this kind of neighbor cell MBS Zone association information needs to be provided to the current serving BS so that the MS has the information at the time of BS reselection. [0025] According to an embodiment, such neighbor cell MBS Zone association information is provided in such a way that meets one or more of the following requirements:

1. Additional signaling overhead can be minimized in providing such association information over the breadth of the various MBS Zone deployment scenarios, such as with macro-diversity enabled and without, with scenarios where MBS Zone crossing may be more frequent (such as with sparse macro-diversity MBS Zones for higher order frequency reuse deployments in which MBS Zones may be defined on a carrier frequency basis with macro-diversity enabled), or less frequent (such as in single frequency macro-diversity deployments);

2. No impact to critical signaling (e.g., IEEE 802.16 MAPs); and/or

3. MBS zone transition is supported shortly after joining the service (e.g., information available either with an active MBS connection or not).

[0026] According to an embodiment, MBS service flows which may have the same geographic extent by virtue of being associated with a common set of MBS Zones and may require seamless service continuity across all MBS Zones within which the MBS service flows are made available, may be associated with a common MBS Service Group identified by an MBS Service Group Identifier (MBS Service Group ID). The association of MBS Service Group to MBS Zone can be defined by attaching the MBS Service Group ID to the appropriate MBS Zone identifier when the MBS Zone identifiers are made known to the MS via the data carrier detect (DCD) and neighbor advertisements, for example. If an MS has obtained the neighboring BS's MBS Zone identifier information, and thereby the associated MBS Service Group IDs, it may then know, before performing a handover, the MBS Zone identifiers that will allow the MBS content (that it is currently receiving) to be continued at the target BS by searching for MBS Zone identifiers that are associated with the MBS Service Groups that it is actively receiving.

[0027] MBSs provide an efficient method for concurrent transport of data common to a group of users using a common multicast content identifier (MCID). MBS service may be offered in the downlink only and may be coordinated and optionally synchronized among a group of BSs to allow macro-diversity. The service flows associated with MBS have certain QoS parameters and may require encryption performed using a globally defined sequence of Traffic Encryption Keys (TEKs). Since a multicast connection is associated with a service flow, it is associated with the QoS and traffic parameters for that service flow. All service flows that transmit similar MBS contents (e.g., multiple channels of video), created on any MS 104, may have the same service flow management encodings for QoS parameter set.

[0028] Service flows to carry MBS data are instantiated on individual MSs participating in the service while in Normal Operation. During such instantiation the MS learns the parameters that identify the service and associated service flows. Each BS capable of providing MBS service belongs to a certain MBS Zone, which is a set of BSs where the same MCID and same security association (SA) is used for transmitting the content of certain service flow(s), according to an embodiment. One or more MBS service flows may belong to the same MBS Service Group. One or more MBS Service Groups may be served via an MBS Zone. Within the MBS Zones comprising the geographic service area of the MBS Service Group, the same MBS contents may be transmitted over the same MCID and SA, and if applicable, the same logical channels for each MBS service flow belonging to the MBS Service Group. Seamless service continuity for MBS service flows within an MBS Service Group is provided within its geographic service area.

[0029] Fig. 1 illustrates a mobile radio channel operating environment 100, according to one embodiment of the present invention. The mobile radio channel operating environment 100 may include a base station (BS) 102, a mobile station (MS) 104, various obstacles 106/108/110, and a cluster of notional hexagonal MBS zones 126/130/132/134/136/138/140 overlaying a geographical area 101. Each MBS zone 126/130/132/134/136/138/140 may include any number of base stations operating at allocated bandwidths to provide adequate radio coverage to its intended users. For example, the base station 102 may operate at an allocated channel transmission bandwidth to provide adequate coverage to the mobile station 104. The exemplary mobile station 104 in Fig. 1 is an automobile; however mobile station 104 may be any user device such as a mobile phone. Alternately, mobile station 104 may be a personal digital assistant (PDA) such as a Blackberry device, MP3 player or other similar portable device. According to some embodiments, mobile station 104 may be a personal wireless computer such as a wireless notebook computer, a wireless palmtop computer, or other mobile computer devices. [0030] The base station 102 and the mobile station 104 may communicate via a downlink radio frame 118, and an uplink radio frame 124 respectively. Each radio frame 118/124 may be further divided into sub-frames 120/126 which may include data symbols 122/124. In this mobile radio channel operating environment 100, a signal transmitted from a base station 102 may suffer from the operating conditions mentioned above. For example, multipath signal components 112 may occur as a consequence of reflections, scattering, and diffraction of the transmitted signal by natural and/or man-made objects 106/108/110. At the receiver antenna 114, a multitude of signals may arrive from many different directions with different delays, attenuations, and phases. Generally, the time difference between the arrival moment of the first received multipath component 116 (typically the line of sight component), and the last received multipath component (possibly any of the multipath signal components 112) is called delay spread. The combination of signals with various delays, attenuations, and phases may create distortions such as ISI and ICI in the received signal. The distortion may complicate reception and conversion of the received signal into useful information. For example, delay spread may cause ISI in the useful information (data symbols) contained in the radio frame 124.

[0031] Fig. 2 shows an exemplary wireless communication system 200 for transmitting and receiving signals, in accordance with one embodiment of the present invention. The system 200 may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In the exemplary embodiment, system 200 can be used to transmit and receive data symbols in a wireless communication environment such as the wireless communication environment 100 (Fig. 1). System 200 generally comprises a BS 102 with a BS transceiver module 202, a BS antenna 206, a BS processor module 216 and a BS memory module 218. System 200 generally comprises an MS 104 with an MS transceiver module 208, an MS antenna 212, an MS memory module 220, an MS processor module 222, and a network communication module 226. Of course both BS 102 and MS 104 may include additional or alternative modules without departing from the scope of the present disclosure.

[0032] Furthermore, these and other elements of system 200 may be interconnected together using a data communication bus (e.g., 228, 230), or any suitable interconnection arrangement. Such interconnection facilitates communication between the various elements of wireless system 200. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein may be implemented in hardware, computer- readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[0033] In the exemplary system 200, the BS transceiver 202 and the MS transceiver 208 each comprise a transmitter module and a receiver module (not shown). Additionally, although not shown in this figure, those skilled in the art will recognize that a transmitter may transmit to more than one receiver, and that multiple transmitters may transmit to the same receiver.

[0034] In the particular example system depicted in Figure 2, an "uplink" transceiver 208 includes a transmitter that shares an antenna with an uplink receiver. A duplex switch may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion. Similarly, a "downlink" transceiver 202 includes a receiver which shares a downlink antenna with a downlink transmitter. A downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna in time duplex fashion.

[0035] The mobile station transceiver 208 and the base station transceiver 202 are configured to communicate via a wireless data communication link 214. The mobile station transceiver 208 and the base station transceiver 202 cooperate with a suitably configured RF antenna arrangement 206/212 that can support a particular wireless communication protocol and modulation scheme. In the exemplary embodiment, the mobile station transceiver 208 and the base station transceiver 202 are configured to support industry standards such as the Third Generation Partnership Project Long Term Evolution (3GPP LTE), Third Generation Partnership Project 2 Ultra Mobile Broadband (3Gpp2 UMB), Time Division-Synchronous Code Division Multiple Access (TD- SCDMA), and Wireless Interoperability for Microwave Access (WiMAX), and the like. The mobile station transceiver 208 and the base station transceiver 202 may be configured to support alternate, or additional, wireless data communication protocols, including future variations of IEEE 802.16, such as 802.16e, 802.16m, and so on.

[0036] According to certain embodiments, the BS 102 controls the radio resource allocations and assignments, and the MS 104 is configured to decode and interpret the allocation protocol. For example, such embodiments may be employed in systems where multiple MSs 104 share the same radio channel which is controlled by one BS 102. However, in alternative embodiments, the MS 104 controls allocation of radio resources for a particular link, and could implement the role of radio resource controller or allocator, as described herein.

[0037] Processor modules 216/222 may be implemented, or realized, with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this manner, a processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, or the like. A processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration. Processor modules 216/222 comprise processing logic that is configured to carry out the functions, techniques, and processing tasks associated with the operation of system 200. In practical embodiments the processing logic may be resident in the BS 102 and/or may be part of a network architecture that communicates with the BS transceiver 202.

[0038] The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by processor modules 216/222, or in any practical combination thereof. A software module may reside in memory modules 218/220, which may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, memory modules 218/220 may be coupled to the processor modules 218/222 respectively such that the processors modules 216/220 can read information from, and write information to, memory modules 618/620. As an example, processor module 216, and memory modules 218, processor module 222, and memory module 220 may reside in their respective ASICs. The memory modules 218/220 may also be integrated into the processor modules 216/220. In an embodiment, the memory module 218/220 may include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules 216/222. Memory modules 218/220 may also include non- volatile memory for storing instructions to be executed by the processor modules 216/220.

[0039] Memory modules 218/220 may include a frame structure database (not shown) in accordance with an exemplary embodiment of the invention. Frame structure parameter databases may be configured to store, maintain, and provide data as needed to support the functionality of system 200 in the manner described below. Moreover, a frame structure database may be a local database coupled to the processors 216/222, or may be a remote database, for example, a central network database, and the like. A frame structure database may be configured to maintain, without limitation, frame structure parameters as explained below. In this manner, a frame structure database may include a lookup table for purposes of storing frame structure parameters.

[0040] The network communication module 226 generally represents the hardware, software, firmware, processing logic, and/or other components of system 200 that enable bi-directional communication between base station transceiver 202, and network components to which the base station transceiver 202 is connected. For example, network communication module 226 may be configured to support internet or WiMAX traffic. In a typical deployment, without limitation, network communication module 226 provides an 802.3 Ethernet interface such that base station transceiver 202 can communicate with a conventional Ethernet based computer network. In this manner, the network communication module 226 may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC)).

[0041] Fig. 3 is an illustration of an exemplary radio channel operating environment with a plurality of MBS zones grouped into MBS service groups (or MBS service areas), according to an embodiment. Fig. 3 depicts various MBS zones 302/304/306/308/310/312 grouped into MBS service groups 300 (or MBS service areas) (shown as 300(a) and 300(b)). For exemplary purposes, only two MBS service groups 300(a) and 300(b) are depicted; however, any number of MBS service groups may be available. MBS zones 302/304/306/308/310/312 can include any number of BSs 102 and MSs 104.

[0042] As shown in Fig. 3, MBS service group 300(a) includes MBS zones 302,

304 and 306, while MBS service group 300(b) includes MBS zones 306, 308, 310 and 312. According to the depicted embodiment, an MBS zone (e.g., 306) may be included in multiple MBS service groups 300(a) and 300(b). Of course in an MBS service group 300, the included MBS zones may be disjointed, and are not required to be in any particular type of cluster. MBS zones may be any shape and are depicted as hexagons for exemplary purposes.

[0043] Fig. 4 is a flowchart illustrating a method of resolving inter-zone performance issues using MBS groups, according to an embodiment. Referring to Fig. 4, at operation 400, MBS zones 302/304/306/308/310/312 are grouped into MBS service groups 300(a) and 300(b) for example. MBS zones may be grouped, for example, dependant upon their relative geographic locations, as well as common data transmitted from BSs 102 therein.

[0044] As noted above, according to an embodiment, MBS service flows which may have the same geographic extent by virtue of being associated with a common set of MBS Zones and may require seamless service continuity across all MBS Zones within which the MBS service flows are made available, may be associated with a common MBS Service Group identified by an MBS Service Group Identifier (MBS Service Group ID). The association of MBS Service Group to MBS Zone can be defined by attaching the MBS Service Group ID to the appropriate MBS Zone identifier when the MBS Zone identifiers are made known to the MS/SS via the DCD and neighbor advertisements. If an MS has obtained the neighboring BS's MBS Zone identifier information, and thereby the associated MBS Service Group IDs, it may then know, before performing handover, the MBS Zone identifiers that will allow the MBS content (that it is currently receiving) to be continued at the target BS by searching for MBS Zone identifiers that are associated with the MBS Service Groups that it is actively receiving. [0045] From operation 400, the process continues to operation 410, where common MBS service group 300(a), 300(b) information is indicated to one or more MS 104. Such information may include the MBS service group ID(s), MBS zone ID(s) and/or MCID(s). Similarly, according to another embodiment, an MS 104 in idle mode may, if it has stored neighbor information for a new preferred BS 102, for example, use the MBS Service Group ID info to obtain the associated MBS Zone identifiers that may allow service continuity for the MBS content that it is actively receiving. The MS may determine that the particular MBS content that it is currently receiving is not available at a particular BS 102, if the MS 104 does not find the MBS Service Group ID associated with the content to be attached to any MBS Zone identifier supported by the BS 102. If the MS 104 does not have applicable neighbor information stored, the MS can obtain such information from the Preferred BSs 102 DCD (since the MS 104 has to receive such information from the Preferred BS before it can begin reception from the BS 102).

[0046] In one embodiment, the MS 104 can be provided the MBS Service Group

ID associated with a particular MBS content (or set of contents) when it establishes an MBS connection to receive that content if such content is associated with an MBS Service Group. If an MBS service flow is not associated with an MBS Service Group, an MBS Service Group ID is not provided during establishment of the MBS connection for the service flow. In this manner, the MS 104 knows that the MCID for the service flow is not guaranteed to remain the same to any neighboring MBS Zones and therefore, MBS MAP message chaining mechanism does not continue to any neighboring MBS Zones for this MBS service flow unless MCID and MBS Zone ID remapping information is provided by other means, such as is currently possible in IEEE 802.16 via the broadcasting of such remapping information. In another embodiment, the MS 104 may not know a-priori whether or not the MBS content is available at a BS 102 without performing an MBS update request via location update when the MS 104 is in Idle Mode or on not receiving a CID update after handover.

[0047] In one embodiment, an MBS Zone may have one or more MBS Service

Groups associated with it and may also include MBS service flows that are not associated with an MBS Service Group. Accordingly, one or more MBS Service Groups and also MBS service flows, not belonging to an MBS Service Group, are flexibly allowed to be provided via a particular MBS Zone. This allows independence in the configuration for macro-diversity coverage and radio resource allocation considerations (as governed by the MBS Zone) from the configuration of the service coverage area and seamlessness of the service continuity requirements across the service coverage area (as governed by the MBS Service Group).

[0048] Since providing the same MBS content generally requires the same values of service flow parameters, such as QoS to be set, and there is generally no need to reorganize the bundling of content to service flows or even within service flows (such as the mapping of MBS content to logical channels if this is enabled), there should be no loss of MBS service support by requiring the service flow parameters to remain unchanged for service flows within an MBS Service Group over the entire geographic area for which the MBS Service Group is available. In one embodiment, the service flow parameters, including MCID assignments and logical channel mappings, remain the same throughout the entire geographic area for which an MBS Service Group is available. In this manner, signaling overhead is greatly simplified and reduced (since updating of these parameters is not required on MBS Zone transitions) to achieve service continuity across MBS Zones that provide the same content.

[0049] The additional overhead to add to the MBS Service Group ID information to support one or more embodiments of this invention is minimal. With the MBS Service Group ID being defined as typically one byte, there can be only one byte of additional information for each MBS Service Group that is associated with an MBS Zone identifier that is active for a BS. According to an embodiment of the invention, this information is included in the DCD and in the neighbor list (MOB_NBR-ADV). In the neighbor list, the amount of overhead may depend on how many BSs in the neighboring area have different sets of MBS Zones with different MBS Service Group associations since the neighbor list was designed to eliminate the replication of DCD TLV information which is identical between neighboring BSs included in the list. In one embodiment, this can also be one additional byte for each MBS Service Group that is associated with an MBS Zone identifier per neighboring BS, but generally, the additional overhead due to support for MBS Service Groups will be significantly less than this.

[0050] From operation 410, the process continues to operation 420, where it is determined whether a target or preferred BS 102 is within a desirable MBS service group 300 (e.g., an MBS service group 300 transmitting appropriate content data). A MS 104 can make this determination based on the content information of the MBS service group 300 within which the preferred BS 102 resides, as described above.

[0051] From operation 420, the process continues to operation 430, where the MS

104 obtains service from the target (or preferred) BS 102 in the target BS 102 is in the MBS service group 300.

RNG-REQ (ranging request) message:

[0052] According to an embodiment, the Type Length Value (TLV) parameter can be included in the RNG-REQ message when the MS 104 is attempting to perform a location update due to an MBS update. The MBS update indicates the MS 104 is currently attempting to perform a location update due to a need to update service flow management encodings for MBS flows.

REG-RSP (registration response) message:

[0053] According to another embodiment, for MSs 104, when the information is available to create CID update TLV, the target BS 102 may include the CID update (as explained below) and SAID_update TLVs in the REG-RSP for an MS 104 recognized by the target BS 102 as performing handoff, or network reentry from idle mode, or location update for an MBS update. BS 102 may include a compressed CID update TLV (as explained below) instead of the CID_update TLV in REG-RSP message, if the CID update procedure is required. The target BS 102 recognizes an MS 104 performing network reentry from idle mode by the presence of a serving BSID or paging controller ID and ranging purpose indication with Bit # 0 set to one in the RNG-REQ message. The target BS 102 recognizes an MS 104 performing location update for MBS zone update by the presence of a paging controller ID, ranging purpose indication with Bit # 1 set to one, and an MBS update in the RNG-REQ.

[0054] The CID update is a compound TLV value that provides a shorthand method for replacing the active connections used by the MS 104 in its previous serving BS 102. Each CID_update TLV specifies a CID in the target BS 102 that may replace a CID used in the previous serving BS 102. Multiple instances of CID_update may occur in the REG-RSP to facilitate recreating and reassigning admitted or active service flows for the MS 104 from its previous serving BS 102. If any of the service flow parameters change (including target SAID, see below), then those service flow parameter encoding TLVs that have changed may be added. If the BS 102 cannot reestablish a particular service flow, it may not include an instance of CID_update for that service flow. These TLVs enable the target BS 102 to renew connections used in the previous serving BS 102, but with different service flow management encodings settings.

[0055] The Compressed CID update TLV also provides for replacing the active connections used by the MS 104 in its previous serving BS 102 as the CID update TLV. It can diminish the length of REG-RSP message, according to various embodiments.

MBS_MAP (multicast and broadcast service map) message:

[0056] According to an embodiment, the BS can send an MBS_MAP message on the Broadcast CID to specify the location and size of multi-BS MBS data bursts which are located in frames that are from two to five frames in the future from the frame containing the MBS MAP message. If present, an MBS MAP message can be located at the first symbol and the first subchannel in the MBS. The MBS_MAP message format is presented below. This message includes the MBS_DATA_IE,

Extended_MBS_DATA_IE and MBS_DATA_Time_Diversity_IE, which define the access information for the MBS burst. (See Tables below).

Establishment of multicast connections

[0057] The BS 102 may establish a DL MBS by creating a multicast connection with each MS 104 to be associated with the service. Any available traffic CID value may be used for the service (i.e., there may be no dedicated CIDs for multicast transport connections). To ensure proper multicast operation, the CID used for the service is the same for all MSs 104 on the same channel that participate in the connection. The MSs 104 need not be aware that the connection is a multicast connection; however, for MBSs which utilize MBS specific features, the multicast connection may be established using a multicast CID.

[0058] The data transmitted on the connection with the given CID may be received and processed by the MAC of each involved MS 104. Thus, each multicast or broadcast SDU may be transmitted only once per BS 102 channel. Since a multicast connection is associated with a service flow, it is associated with the QoS and traffic parameters for that service flow. Automatic Repeat Request (ARQ) is not applicable to multicast connections. If a DL multicast connection is to be encrypted, each MS 104 participating in the connection may have an additional security association (SA), allowing that connection to be encrypted using keys that are independent of those used for other encrypted transmissions between the MSs 104 and the BS 102.

Service flows n static context

[0059] When service flow parameters at the target BS 102 are different than the serving BS 102, the target BS 102 may use CID update and or SAID_update as part of REG-RSP encodings TLV in RNG-RSP, or DSC-REQ messages upon HO completion, to change the configuration of the connections, as required.

[0060] In one embodiment, ARQ and Hybrid ARQ (HARQ) are not applicable to multicast connections as there is no feedback from the MS 104 at layer one or layer two. However MBS may be used with time-diversity enabled allowing a HARQ like behavior, where some HARQ parameters are used for MBS bursts to allow proper sequencing and time diversity combining when MBS bursts are retransmitted, without requiring any layer one or layer two acknowledgements from the MS 104.

[0061] In one embodiment, Logical Channel IDs, which pairs with MCID in the

Extended MBS DATA IE, is allocated to each MBS Contents ID value in the order that it is included in the MBS Contents IDs TL. In this manner, an MS 104 can receive multiple MBS messages for an MBS connection with different MBS contents distinguished by Logical Channel ID belonging to a MCID. The BS 102 may allocate MBS service data units (SDUs) in the order defined in the Extended MBS DATA IE.

[0062] In one embodiment, if a DL multicast connection is to be encrypted, each MS

104 participating in the connection may have an additional security association (SA) allowing that connection to be encrypted using keys that are independent of those used for other encrypted transmissions between the MS 104 and the BS 102.

[0063] In one embodiment, MBS flows may be encrypted at the application layer or

MAC or both. Upper layer encryption may be employed to prevent non-authorized access to multicast and broadcast content. MBS may provide access control against theft of service by enforcing data encryption based on advanced encryption standard with counter mode encryption (AES-CTR) defined in NIST Special Publication 800-38A and FIPS 197. Details of MBS security are defined in the tables below. [0064] In one embodiment, for all BSs 102 that belong to the same MBS Zone and if applicable, that support the same MBS Service Group 300, the following coordination can be provided:

[0065] Mapping of SDUs into the MBS Bursts should be identical, and the same

SDU's may be transmitted in the same frame in all BS in the same MBS Zone.

[0066] Packets of the MBS content may be classified and mapped to SDUs identically at each BS 102 within the MBS Zone.

[0067] SDU fragment sequence number and fragmentation size across frame transmissions must be identical, according to an embodiment.

[0068] Coordination in the MBS Zone and, if applicable, between all MBS Zones for an MBS Service Group 300 can provide a means for the MS 104 to continue to receive MBS transmissions from any BS 102 that is part of the MBS Zone and that supports the same MBS Service Group 300, respectively, regardless of the MS 104 operating mode (e.g., Normal Operation, Idle Mode) without need for the MS 104 to register to the BS 102 from which it receives the transmission.

[0069] In one embodiment, in addition to coordination, MBS transmissions may optionally be synchronized across all BSs 102 within an MBS Zone. This option enables an MS 104 to receive the multicast or broadcast transmission from multiple BSs 102 using macro-diversity, and thereby improves the reliability of reception. When Macro-diversity is enabled, an additional parameter may also be required to be the same across the BSs 102 if macro-diversity is used as explained below.

[0070] In one embodiment, a BS 102 may provide the MS 104 with MBS content locally within its coverage and independently of other BSs 102. The single BS 102 provision of MBS can therefore include a configuration where an MBS Zone is configured to consist of one BS 102. This configuration may be provided as one of the possible cases of multi-BS MBS. In this case, the BS 102 may use any MCID value for providing the MBS service, independently of other BSs 102. In single-BS-MBS access, the MS 104 receives the MBS data from its serving BS 102, and the MS 104 should not expect the service flow for this MBS connection to continue should the MS 104 leave the serving BS 102. [0071] In one embodiment, when the MS 014 registers at the BS 102 for receiving multicast and broadcast services, the BS 102 or MS 104 may initiate the Dynamic Service Addition (DSA) procedure with respect to multicast and broadcast connections. Such knowledge may be used to initiate bi-directional upper layers communication between the MS 104 and the network for the purpose of configuration of MBS. After successful configuration, the MS 104 can reuse the same configuration when it moves to another BS 102 without re-configuration.

[0072] According to an embodiment, during registration for reception of an MBS service flow at a BS 102, the MBS Zone as identified by its MBS_Zone ID, and if applicable, the MBS Service Group 300 as identified by its MBS Service Group ID for the MBS service flow are provided to the MS 104 during the DSA procedure. The MS 104 may continue to receive MBS transmissions from any BS 102 that is part of the MBS Zone and if applicable, that is part of any MBS Zone serving an MBS Service Group 300, regardless of the MS 104 operating mode (e.g., Normal Operation, Idle Mode) without need for update to any service flow management encoding for the MBS flow.

[0073] Should the MS 104 transit to a new MBS Zone while in Normal Operation, and provided that MS 104 MBS service flow management encodings have not otherwise been updated using the method explained above, as part of the handover the BS 102 may include CIDJLJpdate in REG-RSP encoding TLV in the RNG-RSP to provide updated service flow management encodings for any affected MBS flow.

[0074] In one embodiment, when an MS 104 in idle mode migrates to a BS 102 advertising another MBS_Zone and the MS 104 has one or more MBS service flows which are not part of MBS Service Groups 300 in the MBS Zone that changed, the MS 104 can be expected to have the MBS service flow management encodings updated at that BS 102, to acquire update on one or more of multicast CID Target SAID parameter, Packet Classification Rule parameter(s), MBS Zone Identifier Assignment parameter, and MBS contents IDs, to provide for further reception of MBS content for those MBS service flows. If the MS 104 has not received such information from the serving MBS_Zone as described above, the MS 104 may conduct location update to acquire updated MBS service flow management encodings, or may conduct re-entry from Idle mode. The BS 102 may include CIDJUpdate in REG-RSP encoding TLV in the RNG-RSP to provide updated service flow management encodings for any affected MBS flow. [0075] During a Dynamic Service Addition procedure, the BS 102 may include the

MBS contents IDs TLV in the DSA-REQ or DSA-RSP message to establish an MBS service flow for multiple MBS contents. The BS 102 may include MBS Contents Identifier TLV in DSA-REQ/RSP to establish an MBS connection with multiple MBS contents. The MS 104 may not include the MBS_Zone ID or MBS contents IDs in a DSA-REQ message.

Inter-MBS Zone transition

[0076] According to an embodiment, to allow seamless transition from one MBS

Zone to another without any interruption of MBS data service and operation, the MS 104 may apply MBS service flow management encodings for service in the new MBS Zone in one of the following ways:

[0077] In one embodiment, if the new MBS Zone provides support for one or more of the same MBS Service Groups 300 as the previous MBS Zone, then for the MBS service flows that belong to these MBS Service Groups 300, except for the MBS Zone ID, the MS 104 may continue to use the same MBS service flow management encodings, including MCID, Target SAID parameter, Packet Classification Rule parameter(s), and MBS Content IDs, that applied to these MBS service flows in the previous MBS Zone. However, if the new MBS Zone does not support one or more of the MBS Service Groups that were present in the previous MBS Zone, the MS 104 may deem the MBS service flows associated with these MBS Service Groups to be not available (i.e. have no continuity) in the new MBS Zone. Otherwise, the MS 104 may update MBS service flow management encodings including MCID, Target SAID parameter, Packet Classification Rule parameter(s), MBS Zone Identifier Assignment parameter, and MBS contents IDs.

[0078] In one embodiment, if the MS 104 has no MCID information regarding the new MBS Zone, then the MS 104 may be required to acquire MCID context through the other procedures, e.g., location-update, handover, or network-entry. However, if the MS 104 has an indication that the MCID has no continuity in the target MBS zone then the MS 104 may delete the MCID and MBS Zone Identifier Assignment related to the MCID, while the corresponding MBS service flows become provisioned but not active. If the MS 104 holds provisioned MBS service-flows and it moves to another MBS Zone in which one or more MCIDs of these service flows may change, then the MS 104 may perform MCID update procedure only for the provisioned service-flows for which the assigned MCID may change.

Performance enhancement with macro diversity

[0079] Multiple BSs 102 participating in the same multi-BS-MBS service may be time and frequency synchronized in the transmissions of common MBS data to allow macro diversity gain at the MS 104. When macro-diversity is enabled the MBS bursts positions and dimensions as well as PHY parameters may be the same across all BSs 102 within the same MBS Zone. In addition to the coordination parameters identified above, macro-diversity synchronization requires that all BSs 102 within the same MBS Zone may use the same as indicated below, according to an embodiment:

• DUIC parameters associated with each MBS Burst including FEC Type, Modulation Type, and Repetition Coding;

• Mapping of SDUs to PDU (order of the SDUs and fragments) including Sub Headers;

• Mapping of PDUs to bursts;

• Order of bursts in the zone/region; and/or

• MAP construction

Power saving operation

[0080] In one embodiment, to facilitate power efficient reception of MBS data, an

MBS MAP IE may be placed in the DL-MAP to point to the location of a dedicated MBS region allocation in the DL subframe. The purpose of this IE is to do the initial direction of the MS 104 to the MBS allocation, and to redirect any MS 104 that has lost synchronization with MBS allocations back to the next MBS allocation.

Multicast and broadcast zone (MBS_Zone) and MBS Service Group

[0081] In one embodiment, different CIDs or different SAs may be used in different service areas for the same MBS flow. A multicast and broadcast zone identifier (MBS_ZONE_ID) is used to indicate a service area through which a CID and SA for a broadcast and multicast service flow are valid. In addition, an MBS Service Group Identifier (MBS Service Group ID) is used to indicate a larger geographic service area consisting of two or more MBS Zones through which the same multicast and broadcast service and content is available and across which seamless service continuity is provided. A BS 102 that supports Multi-BS Access MBS may include the MBS zone identifier(s) and if applicable on a per-MBS-zone-identifier basis, an associated list of MBS Service Group IDs as a MBS zone identifier list and MBS Service Group IDs Per MBS Zone list in the DCD message, respectively. The MBS zone identifier may not be '0'.

[0082] When the MBS zone identifier list appears in DCD settings TLV in

MOB_NBR-ADV message with only one value of¹O', then the neighbor BS 102 is not affiliated with any MBS zone.

[0083] In one embodiment, in case BS 102 sends DSA for establishment of connection for MBS, MBS ZONE and if applicable, an MBS Service Group ID may be encoded in the DSA message. If an MS 104 in Idle mode moves into BSs 102 in the same MBS zone or other MBS zone providing support for the same MBS Service Groups, the MS 104 does not have to re-enter the network to re-establish a connection or a connection defined by MBS Contents Identifier to monitor the multicast and broadcast service flow. However, except when the previous and new MBS Zones associated with MBS service flows support the same MBS Service Groups, if an MS 104 moves into a different MBS zone, the MS 104 may need to update service flow management encodings for the MBS flow. One BS 102 may have multiple MBS zone IDs for different MBS services.

Location update conditions

[0084] In one embodiment, an MS 104 in idle mode can perform a location update process operation, if any location update condition is met. There are five location update evaluation conditions: paging group update, timer update, power down update, MAC hash skip threshold update, and MBS update. MS may also perform location update processes at will. One of skill in the art would realize that various location update processes may be implemented within the scope of the present disclosure.

MBS update

[0085] According to an embodiment, an MS 104 in idle mode can perform a location update process when the MS 104 with multi-BS-MBS flows detects a change of MBS Zone requiring MBS update. The MS 104 may detect the change of MBS Zone requiring MBS update by monitoring the MBS zone identifier list which is transmitted by the Preferred BS 102 in the DCD message. If the MBS zone identifier list detected does not include the MBS zone identifiers for all multi-BS-MBS flows to which the MS 104 belongs and if at least one of the MBS Zones which have changed has one or more MBS service flows that do not belong to an MBS Service Group, the MS 104 may determine that a change of MBS Zone requiring MBS update has occurred.

Secure location update process

[0086] According to an embodiment, if the MS 104 shares a valid security context with the target BS 102 so that the MS 104 may include a valid Hash-based Message Authentication Code/Cipher-based Message Authentication code HMAC/CMAC Tuple in the RNG-REQ, then the MS 104 may conduct initial ranging with the target BS 102 by sending a RNG-REQ including Ranging Purpose Indication TLV with Bit # one set to one, Location Update Request and Paging Controller ID TLVs and HMAC/CMAC Tuple. If a change of MBS Zone requiring MBS update has been detected, then the MS 104 may include MBS update TLV in RNG-REQ. If the target BS 102 evaluates the HMAC/CMAC Tuple as valid and can supply a corresponding authenticating HMAC/CMAC Tuple, then the target BS 102 may reply with a RNG-RSP including the Location Update Response TLV and HMAC/CMAC Tuple completing the location update process. If the paging group has changed, then target BS 102 may include Paging Group ID TLV in the RNG-RSP. If the target BS 102 responds with a successful Location Update Response = 0x00 (Success of Location Update), the target BS 102 can notify the paging controller via the backbone network of the MS 104 new location information, the MS 104 can assume the Paging Group ID of the target BS 102, and the paging controller may send a message over the backbone network to inform the BS 102 at which the MS 104 entered idle mode that the MS 104 has transitioned to a different Paging Group. If the MBS Zone has changed, then the BS 102 may include CIDJUpdate TLV in RNG-RSP and may include at least the SFID, Multicast CID, MBS Zone Identifier Assignment parameter, and may include MBS contents IDs, for any multi-BS-MBS service flow for which the MBS Zone has changed. If the target BS 102 evaluates the HMAC/CMAC Tuple as invalid, cannot supply a corresponding authenticating HMAC/CMAC Tuple, or otherwise elects to direct the MS 104 to use unsecure location update, then the target BS 102 can instruct the MS 104 to continue network reentry using the unsecure location update process by inclusion of Location Update Response TLV in RNG-RSP with a value of 0x01 (Failure of Location Update). [0087] Table 1 below is an exemplary row to be added to the existing table in the

IEEE 802.16 standard that defines Type values for TLVs for a DCD message. Variable "xx" is used as Type value, and any various values may be included (similar to Table 2, as well).

Table 1

Table 2

[0088] In one embodiment, the MBS Capabilities Supported parameter contains a bit map specifying whether particular enhanced MBS capabilities are supported or not. A bit value of T means the particular capability is supported whereas a bit value of '0' means the particular capability is not supported. (See Table 3). Type "yy" is used as a variable, which one of skill in the art would realize could be assigned different values.

Type Length Value Scope

yy 1 Bit #0: MBS Service Group REG-REQ, supported

Bit #l-#7: reserved

REG-RSP

Table 3

MBS Service Group ID Assignment parameter

[0089] According to an embodiment, the DSA-REQ/RSP message may contain the value of this parameter to specify an MBS Service Group ID that identifies an MBS Service Group to which the MBS service flow is associated. The MBS Service Group is bound to the MBS Zone as identified by the MBS Zone identifier that may be specified for an MBS connection via the inclusion of the 'MBS Zone Identifier Assignment parameter' TLV as explained above. If this TLV has not been included in any DSA-REQ/RSP or DSC-REQ/RSP for the MBS connection or this TLV has been included but the MBS Service Group ID is an 8-bit long value of 0, this may indicate that the MBS connection is not associated with an MBS Service Group. (See Table 4 below).

[0090] According to an embodiment, if the MBS connection had previously not been associated with an MBS Service Group, the inclusion of this 'MBS Service Group ID Assignment parameter' TLV containing an 8-bit MBS Service Group ID that is non-zero or containing a valid 16-bit MBS Service Group ID in a DSC-REQ/RSP may associate the MBS connection with the identified MBS Service Group, and in addition, bind the MBS Service Group to the MBS Zone that has been assigned to the MBS connection. Conversely, if the MBS connection had previously been associated with an MBS Service Group, the inclusion of this 'MBS Service Group ID Assignment parameter' TLV containing an 8-bit MBS Service Group ID of value 0 may delete the MBS Service Group association from this MBS connection.

[0091] The inclusion of this 'MBS Service Group ID Assignment parameter' TLV is only valid for an MBS connection, "zz" is used in the "Type" as a variable, which one of skill in the art would realize could be assigned different values.

Table 4

[0092] To ensure proper multicast operation on networks of BSs 102 employing

MBS, the MCIDs used for common MBS content and service may be the same for all BSs 102 within the same MBS-Zone, and if the MBS service flow belongs to an MBS Service Group, may be the same for all MBS Zones comprising the geographic service area of the MBS Service Group. This allows the MS 104 which has already registered with a service to be seamlessly synchronized with MBS transmissions within an MBS Zone and to maintain service continuity across MBS Zones for an MBS Service Group without communicating in the UL or re-registering with other BS 102 within that MBS-Zone and within the entire geographic service area of an MBS Service Group, respectively. The MBS_Zone ID's may not be reused across any two adjacent MBS zones. [0093] While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or other configuration for the disclosure, which is done to aid in understanding the features and functionality that can be included in the disclosure. The disclosure is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, although the disclosure is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described. They instead can be applied alone or in some combination, to one or more of the other embodiments of the disclosure, whether or not such embodiments are described, and whether or not such features are presented as being a part of a described embodiment. Thus the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

[0094] In this document, the term "module" as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules; however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the invention.

[0095] In this document, the terms "computer program product", "computer- readable medium", and the like, may be used generally to refer to media such as, memory storage devices, or storage unit. These, and other forms of computer-readable media, may be involved in storing one or more instructions for use by processor to cause the processor to perform specified operations. Such instructions, generally referred to as "computer program code" (which may be grouped in the form of computer programs or other groupings), when executed, enable the computing system.

[0096] It will be appreciated that, for clarity purposes, the above description has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processors or domains may be used without detracting from the invention. For example, functionality illustrated to be performed by separate processors or controllers may be performed by the same processor or controller. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0097] Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term "including" should be read as meaning "including, without limitation" or the like; the term "example" is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; and adjectives such as "conventional," "traditional," "normal," "standard," "known", and terms of similar meaning, should not be construed as limiting the item described to a given time period, or to an item available as of a given time. But instead these terms should be read to encompass conventional, traditional, normal, or standard technologies that may be available, known now, or at any time in the future. Likewise, a group of items linked with the conjunction "and" should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as "and/or" unless expressly stated otherwise. Similarly, a group of items linked with the conjunction "or" should not be read as requiring mutual exclusivity among that group, but rather should also be read as "and/or" unless expressly stated otherwise. Furthermore, although items, elements or components of the disclosure may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. The presence of broadening words and phrases such as "one or more," "at least," "but not limited to", or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.

[0098] Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the invention. It will be appreciated that, for clarity purposes, the above description has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the invention. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0099] Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by, for example, a single unit or processing logic element. Additionally, although individual features may be included in different claims, these may possibly be advantageously combined. The inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Also, the inclusion of a feature in one category of claims does not imply a limitation to this category, but rather the feature may be equally applicable to other claim categories, as appropriate.

Claims

WHAT IS CLAIMED IS:

1. A method of resolving inter-zone performance issues using Multicast Broadcast Service (MBS) groups, comprising: grouping a plurality of MBS zones into an MBS service group, having common MBS service group information, wherein each MBS zone includes one or more base stations; signaling the common MBS service group information to one or more mobile stations; determining whether a target base station is in the MBS service group, based on the common MBS service group information; and obtaining service from the target base station if it is determined that the target base station is in the MBS service group.

2. The method of claim 1 , wherein the plurality of MBS zones in the MBS service group transmit at least some substantially similar content.

3. The method of claim 1, wherein the common MBS service group information includes at least one MBS zone identifier (ID).

4. The method of claim 1, wherein the common MBS service group information includes at least MBS service group identifier (ID).

5. The method of claim 4, wherein the MBS service group ID is one byte or one byte that is extensible to 2 bytes.

6. The method of claim 1 , wherein the common MBS service group information includes an MBS service flow parameter value, applicable for all MBS service flows belonging to the MBS service group, in all base stations belonging to the plurality of MBS zones of the MBS service group.

7. The method of claim 1 , wherein the common MBS service group information includes at least one multicast connection identifier (MCID).

8. The method of claim 1 , wherein the plurality of MBS zones are within a predetermined geographic area.

9. The method of claim 1, the determining comprises: determining whether the target base station is in the MBS service group based on an MBS Service Group ID supported by the target base station; determining that a neighboring base station does not support continuity of the same MBS service content by the absence of the association of the MBS service group with that base station; and determining whether an MBS service flow belongs to the MBS service group by association of the MBS Service Group ID to an MBS connection over which data of the MBS service flow is transmitted.

10. The method of claim 1, wherein the signaling of MBS service group information regarding associated with the target base station is performed using a downlink channel descriptor (DCD) message transmitted from the target base station.

11. The method of claim 1, wherein the signaling of MBS service group information regarding association with the target base station is performed using DCD information included in neighbor base station advertisements (MOB_NBR-ADV) messages.

12. The method of claim 1, wherein an association of MBS service group to MBS service flow is performed during MBS connection addition or change.

13. The method of claim 1 , wherein a mobile station uses a presence or absence of MBS service group support at a neighboring base station for handover and Idle Mode preferred base station selection decisions.

14. The method of claim 1, wherein at least one of the plurality of MBS zones is associated with at least one other MBS service group.

15. A system for resolving inter-zone performance issues using Multicast Broadcast Service (MBS) groups, comprising: a memory module configured to store a plurality of MBS zones as an MBS service group, having common MBS service group information, wherein each MBS zone includes one or more base stations; a transceiver configured to signal the common MBS service group information to one or more mobile stations; a processor module configured to determine whether a target base station is in the MBS service group, based on the common MBS service group information; and a network communication module configured to provide service by the target base station if it is determined that the target base station is in the MBS service group.

16. The system of claim 15, wherein the plurality of MBS zones in the MBS service group transmit at least some substantially similar content.

17. The system of claim 15, wherein the common MBS service group information includes at least one MBS zone identifier (ID).

18. The system of claim 15, wherein the common MBS service group information includes at least MBS service group identifier (ID).

19. The system of claim 18, wherein the MBS service group ID is one byte or one byte that is extensible to 2 bytes.

20. The system of claim 15, wherein the common MBS service group information includes an MBS service flow parameter value, applicable for all MBS service flows belonging to the MBS service group, in all base stations belonging to the plurality of MBS zones of the MBS service group.

21. The system of claim 15, wherein the common MBS service group information includes at least one multicast connection identifier (MCID).

22. The system of claim 15, wherein the plurality of MBS zones are within a predetermined geographic area.

23. The system of claim 15, the processor module is further configured to: determine whether the target base station is in the MBS service group based on an

MBS Service Group ID supported by the target base station; determine that a neighboring base station does not support continuity of the same MBS service content by the absence of the association of the MBS service group with that base station; and determine whether an MBS service flow belongs to the MBS service group by association of the MBS Service Group ID to an MBS connection over which data of the MBS service flow is transmitted.

24. The system of claim 15, wherein the transceiver is further configured to signal MBS service group information regarding associated with the target base station using a downlink channel descriptor (DCD) message transmitted from the target base station.

25. The method of claim 15, wherein the transceiver is further configured to signal MBS service group information regarding association with the target base station using DCD information included in neighbor base station advertisements (MOB_NBR- ADV) messages.

26. The method of claim 15, wherein an association of MBS service group to MBS service flow is performed during MBS connection addition or change.

27. The method of claim 15, wherein a mobile station uses a presence or absence of MBS service group support at a neighboring base station for handover and Idle Mode preferred base station selection decisions.

28. The method of claim 15, wherein at least one of the plurality of MBS zones is associated with at least one other MBS service group.

29. A computer-readable medium storing instructions thereon for performing a method of resolving inter-zone performance issues using Multicast Broadcast Service (MBS) groups, the method comprising: grouping a plurality of MBS zones into an MBS service group, having common MBS service group information, wherein each MBS zone includes one or more base stations; signaling the common MBS service group information to one or more mobile stations; determining whether a target base station is in the MBS service group, based on the common MBS service group information; and providing service from the target base station if it is determined that the target base station is in the MBS service group.