HK1097679B - Method and system for signaling in broadcast communication system - Google Patents

Description

Method and system for signaling in a broadcast communication system

Claiming priority in accordance with 35U.S.C. § 119

This patent application claims priority from U.S. patent application No. 60/502,504, entitled "method System for Signaling in Broadcast Communication System," filed on 9/11/2003, assigned to the assignee of the present invention and incorporated herein by reference.

Background

Technical Field

The present invention relates to broadcast communications, also known as point-to-multipoint communications, in a wired or wireless communication system, and more particularly to a system and method for signaling in such a broadcast communication system.

Background

Communication systems have been developed to enable the transmission of information signals from an origination station to a destination station at a different physical location. When an information signal is transmitted from an origination station over a communication channel, the information signal is first converted into a form suitable for efficient transmission over the communication channel. The conversion or modulation of the information signal involves varying a parameter of the carrier wave in accordance with the information signal in such a way that the frequency spectrum of the resulting modulated carrier wave is confined within the communication channel bandwidth. At the destination station, the original information signal is replicated from the modulated carrier wave received over the communication channel. This replication is typically accomplished by using the inverse of the modulation process employed by the origination station.

Modulation also facilitates multiple access, i.e., simultaneous transmission and/or reception, of several signals over a common communication channel. Multiple-access communication systems typically include a plurality of subscriber units that require intermittent service of several relatively short durations rather than continuous access to a common communication channel. Several multiple access techniques are known in the art, such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA) and amplitude modulation multiple Access (AM). Another type of multiple access technique IS Code Division Multiple Access (CDMA) Spread Spectrum systems that conform to the standard "TIA/EIA/IS-95 Mobile Station-Base Station compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System", hereinafter referred to as the IS-95 standard. The use of CDMA techniques IN MULTIPLE access communication SYSTEMs is disclosed IN U.S. patent nos. 4,901,307 and 5,103,459, entitled "forward speech MULTIPLE-access communication SYSTEM USING SATELLITE OR tertiary reporting SYSTEMs," and entitled "SYSTEM AND METHOD FOR generating new communications IN a CDMA CELLULAR TELEPHONE SYSTEM," both assigned to the assignee of the present invention.

Multiple-access communication systems may be wireless or wired and may communicate voice and/or data. An example of a communication system that communicates both voice and data IS a system that conforms to the IS-95 standard and provides for the transmission of both voice and data over a communication channel. A METHOD FOR transmitting DATA in the form OF fixed-size code channel frames is described in detail in U.S. patent No. 5,504,773, entitled "METHOD AND APPARATUS FOR FORMATTING OF DATA FOR TRANSMISSION," assigned to the assignee OF the present invention. According to the IS-95 standard, data or speech IS divided into 20 millisecond wide coded channel frames with data rates as high as 14.4 Kbps. Other examples of communication systems that communicate both voice and data are communication systems that comply with the following standards: "third generation partnership project" (3GPP), which is included in a group of documents including document numbers 3G TS25.211, 3G TS 25.212, 3G TS 25.213, and 3G TS 25.214(W-CDMA standard); or "TR-45.5 Physical Layer Standard for cdma2000Spread Spectrum Systems" (IS-2000 Standard).

In a multiple access wireless communication system, communication between users is conducted through one or more base stations. A first user on a wireless subscriber station communicates with a second user on a second wireless subscriber station by transmitting data on a reverse link to the base station. The base station receives the data and can route the data to another base station. Data is sent on the forward link of the same or other base station to the second subscriber station. The forward link refers to transmission from a base station to a wireless subscriber station and the reverse link refers to transmission from a wireless subscriber station to a base station. Likewise, communication may be conducted between a first user on a wireless subscriber station and a second user on a terrestrial station. The base station receives data from a first user on a wireless subscriber station on a reverse link and routes the data through a Public Switched Telephone Network (PSTN) to a second user on a land station. In many communication systems, such as IS-95, W-CDMA, IS-2000, the forward link and reverse link are assigned separate frequencies.

The above-described wireless communication system is an example of a point-to-point communication service. In contrast, the broadcast service provides a central station to multipoint communication service. The basic model of a broadcast system consists of a network of broadcast subscribers served by one or more central stations that transmit information to the subscribers with specific content (e.g., news, movies, sports events, etc.). Each broadcast network user's subscriber station monitors a common broadcast forward link signal. Since the central station fixedly determines the content, the user generally no longer transmits back. Common examples of broadcast service communication systems are TV broadcasts, radio broadcasts, etc. Such communication systems are typically specially constructed communication systems. With the recent development of wireless cellular telephone systems, there has been a growing interest in using existing infrastructure for broadcast systems, primarily the infrastructure of point-to-point cellular telephone systems. (As used herein, the term "cellular" system encompasses communication systems using both cellular and PCS frequencies.)

The introduction of a common broadcast forward link into a cellular telephone system requires the integration of broadcast services with the services provided by the cellular telephone system. The subscriber station needs to be able to support such functions: the subscriber station is enabled to operate in both a broadcast mode and a communication mode. Accordingly, there is a need in the art for a method and system for signaling in a cellular telephone system that provides a broadcast service to enable a subscriber station to perform both services.

Disclosure of Invention

Embodiments disclosed herein address the above stated needs by providing a method for subscriber station registration in a broadcast communication system, the method comprising: receiving an HSBS channel modulating a first frequency; monitoring a timer status of the HSBS channel; and effectuating a broadcast service registration to the sector transmitting the HSBS channel if the timer status expires; setting a timer state of an HSBS channel to enabled; and starting a timer for the HSBS channel. A base station receiving a broadcast service registration from a subscriber station at a sector; adding a paging identifier to a paging set of the subscriber station; and starting a timer for the paging identifier.

According to another aspect, the base station sends a paging message to the subscriber station in accordance with the state of the paging set.

In accordance with another aspect, the above-described need is addressed by providing a method for paging a subscriber station in a broadcast communication system without requiring the subscriber station to register.

Drawings

FIG. 1 illustrates a conceptual block diagram of a high speed broadcast service communication system;

fig. 2 illustrates the concept of physical and logical channels of the HSBS; and

fig. 3 illustrates paging set maintenance in accordance with an embodiment.

Detailed Description

Definition of

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The term "point-to-point communication" is used herein to mean communication between two subscriber stations over a dedicated communication channel.

The term "group service, point-to-multipoint communication, push-to-talk, or distribution service" is used herein to mean a communication in which multiple subscriber stations typically receive communications from one subscriber station.

The term "packet" is used herein to mean a group of bits arranged into a particular format, including data (payload) and control elements. Control elements include, for example, preambles, quality metrics, and other elements known to those skilled in the art. Quality metrics include, for example, Cyclic Redundancy Check (CRC), parity bits, and other metrics known to those skilled in the art.

The term "access network" is used herein to mean a Base Station (BS) and a set of one or more base station controllers. The access physics transports data packets between multiple subscriber stations. The access network may be further connected to other networks outside the access network, such as a corporate intranet or the internet, and may transport data packets between individual access terminals and terminals outside the network.

The term "base station" is used herein to mean the hardware with which a subscriber station communicates. A cell refers to either hardware or a geographic coverage area, depending on the environment in which the term is used. A sector is a portion of a cell. The principles described with cells can be easily extended to sectors since sectors have the characteristics of cells.

The term "subscriber station" is used herein to mean the hardware with which an access network communicates. A subscriber station may be mobile or stationary. A subscriber station may be any data device that communicates through a wireless channel or through a wired channel, such as fiber optic or coaxial cables. A subscriber station may also be any of a variety of devices including, but not limited to: PC card, flash memory, external or internal modem, or wireless or wireline phone. A subscriber station that is in the process of establishing an active traffic channel connection with a base station is said to be in a connection setup state. A subscriber station that has established an active traffic channel connection with a base station is referred to as an active subscriber station and is said to be in a traffic state.

The term "physical channel" is used herein to mean a communication route over which a signal propagates, which is described in terms of modulation characteristics and coding.

The term "logical channel" is used herein to mean a communication route within the protocol layer of a base station or subscriber station.

The term "communication channel/link" is used herein to mean a physical channel or a logical channel depending on the environment.

The term "reverse channel/link" is used herein to mean a communication channel/link through which a subscriber station sends signals to a base station.

The term "forward channel/link" is used herein to mean a communication channel/link through which a base station sends signals to a subscriber station.

The term "soft handoff" is used herein to mean communication between a subscriber station and two or more sectors, where each sector belongs to a different cell. Reverse link communications are received by two sectors and forward link communications are simultaneously effectuated upon the forward links of the two or more sectors.

The term "softer handoff" is used herein to mean communication between a subscriber station and two or more sectors, where each sector belongs to the same cell. Reverse link communications are received by two sectors and forward link communications are simultaneously effectuated upon a forward link of one of the two or more sectors.

The term "erasure" is used herein to mean the failure to identify a message.

Detailed Description

As mentioned above, the basic model of a broadcast system comprises a network of broadcast subscribers served by one or more central stations that transmit information to the subscribers with specific content (e.g., news, movies, sports events, etc.). Each broadcast network user's subscriber station monitors a common broadcast forward link signal. Fig. 1 illustrates a conceptual block diagram of a communication system 100 capable of performing High Speed Broadcast Service (HSBS) in accordance with various embodiments of the invention.

The broadcast content originates from a Content Server (CS) 102. The content server may be located within a carrier network (not shown) or outside the Internet (IP) 104. The content is delivered in packets to a Broadcast Packet Data Serving Node (BPDSN) 106. The term BPDSN is used because: although the BPDSN may be physically co-located or identical to a conventional PDSN (not shown), the BPDSN is logically different from the conventional PDSN. The BPDSN 106 delivers packets to a Packet Control Function (PCF)108 according to their destination. For HSBS, the PCF is a control entity controlling the functions of the base station 110, since the base station controller is used for regular voice and data services. To illustrate the connection of the high-level concept of HSBS to the physical access network, fig. 1 shows a PCF that is physically co-located or even identical to a Base Station Controller (BSC), but logically different from the BSC. Those of ordinary skill in the art will appreciate that this is for illustrative purposes only. The BSC/PCF 108 provides the packets to the base station 110.

Communication system 100 allows High Speed Broadcast Services (HSBS) by introducing a forward broadcast shared channel (F-BSCH)112 that can operate at high data rates that are received by a large number of subscriber stations 114. The term "forward broadcast shared channel" is used herein to mean a single forward link physical channel that carries broadcast traffic. A single F-BSCH may carry one or more HSBS channels multiplexed in a TDM manner within the single F-BSCH. The term "HSBS channel" is used herein to mean a single logical HSBS broadcast session defined by the broadcast content of the session. Each session is defined by a broadcast content that may vary as follows: e.g., 7 am-news, 8 am-weather, 9 am-movie, etc. Fig. 2 illustrates the physical and logical channel concepts discussed for the HSBS.

As shown in fig. 2, the HSBS is transmitted on two F-BSCHs 202, each F-BSCH 202 being transmitted on a separate frequency fx, fy. Thus, for example, in the IS-2000 communication system described above, this physical channel would include, for example: a forward supplemental channel (F-SCH), a forward broadcast control channel (F-BCCH), a forward common control channel (F-CCCH), other common and dedicated channels, and combinations of channels. The use of public and private channels in the broadcast of information is disclosed in U.S. provisional patent application No. 60/279,970 entitled "METHOD and apparatus FOR GROUP channels USING DEDICATED AND common channels IN WIRELESS NETWORKS", filed on 28/3 of 2001 and assigned to the assignee of the present invention. Those skilled in the art will appreciate other communication systems that use channels that perform similar functions and therefore the principles of the present invention may be applied to other communication systems. The F-BSCH 202 transmits broadcast traffic, which includes one or more broadcast sessions. F-BSCH 202b carries an HSBS channel 204 c; two HSBS channels 204a, 204b are multiplexed onto the F-BCCH 202 a. The contents of the HSBS channel are formatted into packets, which include a payload 206 and a header 208.

Those of ordinary skill in the art will recognize that the HSBS broadcast service deployment shown in fig. 2 is merely illustrative. Thus, within a given sector, HSBS broadcast services may be deployed in a variety of ways depending on the features supported by the implementation of a particular communication system. The implementation features include: the number of HSBS sessions supported, the number of frequency allocations, the number of broadcast physical channels supported, and other implementation features known to those skilled in the art. Thus, for example, more than two frequencies and F-BSCHs may be employed within a sector. Also, more than two HSBS channels may be multiplexed onto one F-BSCH. Also, a single HSBS channel may be multiplexed onto one broadcast channel within a sector, serving subscribers residing in those frequencies on different frequencies.

Since one or more different HSBS channels can be multiplexed onto the same F-BSCH physical channel, the different HSBS channels must be distinguished. Thus, the base station assigns a broadcast service reference identifier (bsrid) to each packet of a particular HSBS channel, which can distinguish between the individual HSBS channels. Based on the value of bsrid within the received packet, the demultiplexer at the subscriber station separately communicates which packets are to be transmitted to the decoder for the monitored HSBS channel. Thus, the bsrid has an importance over the air (i.e., between the subscriber station and the BS).

As described above, an HSBS channel refers to a single logical HSBS broadcast session defined by the broadcast content of the HSBS channel. Thus, while the BSR _ ID enables the subscriber station to separate the physical broadcast transmissions of the HSBS channels, identifiers of the various logical HSBS channels are required to enable the subscriber station to map the content of the HSBS channels to the physical broadcast transmissions of the HSBS channels, i.e., the subscriber station must distinguish between, for example, movie HSBS and news HSBS. Thus, each HSBS channel has a unique identifier (HSBS _ ID) that connects the HSBS content/service to which the subscriber station has subscribed with the corresponding physical broadcast transmission. Thus, the HSBS _ ID has end-to-end significance (i.e., between the subscriber station and the content server). The value of HSBS _ ID is learned by external means; that is, when the subscriber station user subscribes to a broadcast content/service, the subscriber station user needs to obtain the HSBS _ ID corresponding to the HSBS channel. For example, for a particular sporting event, the entire schedule of the event is known in advance and announced, such as by mass media, service provider operations, and the like. Alternatively, news is broadcast on a periodic schedule. Alternatively, the external means may include, for example: e-mail, Short Message System (SMS) broadcast, and other means known to those of ordinary skill in the art. In one embodiment, the schedule is provided within an HSBS broadcast session.

Finally, since the HSBS channel is multiplexed onto a F-BSCH physical channel and there are multiple possibilities for the HSBS channel to transmit on the F-BSCH, the subscriber station needs to go up to which HSBS channel (hsbsjd/bsrid) is transmitted on which F-BSCH (fbschjd). This information is specified by a logical to physical mapping. In the above embodiments, the logical-to-physical mapping is completely specified by the set { HSBS _ ID, BSR _ ID, FBSCH _ ID }.

Broadcast service parameter signaling

Since the base station implements logical-to-physical mapping, this logical-to-physical mapping information needs to be signaled over the air to the subscriber station so that a subscriber station desiring to monitor a given HSBS channel can determine which F-BSCH channel it should monitor. Thus, the broadcast physical channel parameters, broadcast logical channel parameters, and logical-to-physical mapping need to be signaled to the subscriber station over the air interface.

In an embodiment, the broadcast service parameters are signaled in an existing overhead message on a channel provided by the communication system for the overhead message. However, since all subscriber stations must monitor the overhead message, even subscriber stations that are not subscribed or capable of HSBS receive the message and need to decode at least the header of the message. In one embodiment, the header provides information, such as a sequence number that informs the subscriber station whether the message content has changed. If only the message content related to the overhead parameters changes, all subscriber stations must decode the rest of the message.

Thus, in another embodiment, the broadcast service parameters are signaled in an overhead message specific to the Broadcast Service (BSPM). Only subscriber stations subscribing/interested in the HSBS service need to monitor the message. Since the subscriber station may start monitoring the HSBS channel at any time, the broadcast service parameter message needs to be sent continuously by each sector that has configured one or more broadcast channels in any sector frequency. According to one embodiment, the broadcast service parameter message is transmitted on a channel provided by the communication system for overhead messages. In a communication system conforming to the IS-2000 standard, the channels provided by such a communication system for overhead messages may include, for example: a forward paging channel (F-PCH), a forward broadcast control channel (F-BCCH), and other channels provided by the communication system for overhead messages as known to those of ordinary skill in the art. Those of ordinary skill in the art will appreciate other communication systems that use channels that perform similar functions; thus, the principles of the present invention may be applied to other communication systems.

However, the subscriber station can monitor the channel provided by the communication system for overhead messages only while in the idle state. Thus, the subscriber station cannot access the broadcast service parameter message while the subscriber station monitors the F-BSCH while participating in another call, i.e., while in the dedicated mode. Thus, in an embodiment, the broadcast service parameters are signaled to the subscriber station in dedicated mode through existing messages on one or more dedicated channels. However, since this embodiment requires that the message be sent once using a dedicated channel rather than on the channel provided by the communication system for overhead messages, the message must be sent separately to each subscriber station. Thus, in an alternative embodiment, the subscriber station continues to use the parameters received in the broadcast service parameters message while confirming that these parameters may have expired.

One of ordinary skill in the art will recognize that broadcast service parameter messages may be used for signaling other broadcast-related information. For example, the broadcast service parameters message may also include, for each physical channel, a list of neighbors that are sending the same information, thereby enabling the subscriber station to perform a handoff. The handover METHOD and SYSTEM are described IN detail IN co-pending U.S. patent application No. 09/933,607 entitled "METHOD and SYSTEM FOR a hand off IN a BROADCAST COMMUNICATION SYSTEM", filed on 8/20/2001. In addition, the broadcast service parameter message may include a message related to broadcast service registration, as described below. Also, the broadcast service parameters message may include HSBS scheduling signaling, as described in detail below.

HSBS scheduling signaling

The subscriber station user needs to be up to the start time of the HSBS session in order to be able to monitor the HSBS session. The user also needs the duration or end time up to the HSBS session. Typically, the signaling of HSBS channel content schedules is beyond the scope of the air interface/communication system because, as described above, users subscribed to HSBS services may know the schedule of HSBS broadcast sessions. However, the user may need convenience independent of external means and be able to retrieve the HSBS schedule using the subscriber station.

Thus, in one embodiment, the base station informs the subscriber station about the start of the HSBS session by signaling a message on the paging channel. This may be implemented in the form of a broadcast paging message or a broadcast Short Message System (SMS). The message indicates the start time of the HSBS session. All subscriber stations monitoring the paging channel receive the message and only subscriber stations configured to respond to the message notify the subscriber station of the user. If the subscriber station user selects to monitor the HSBS session, the subscriber station tunes to the appropriate frequency to monitor the F-BSCH. However, the subscriber station may not prompt the user to begin monitoring the F-BSCH if it is so programmed.

Since the subscriber station user may decide to monitor the HSBS session at a time later than the session start time, it is not sufficient for the base station to send the message to the subscriber station only once before the session start, since the subscriber station monitoring the paging channel will not receive the message at this time. The subscriber station is unable to monitor the paging channel for various reasons, such as being turned off, in a fade, in a voice call, and for other reasons known to those of ordinary skill in the art. Therefore, the message needs to be repeated for the entire duration of the HSBS session. The more frequent the message repetition, the lower the average delay for a given subscriber station to join an ongoing session.

In another embodiment, the base station informs the subscriber about the start of the HSBS session by signaling a message, such as a broadcast service parameters message, on a channel provided for overhead messages by the communication channel. The information transmitted is the same as that sent on the paging channel, in particular the start time and duration or end time. However, since the overhead message is repeated, the information is continuously transmitted. To prevent the subscriber from repeatedly reading the same message (no change in content), a sequence number is added to the overhead message. The subscriber station ignores messages containing the same sequence number. Such use of serial numbers is well known to those of ordinary skill in the art. In this embodiment, by using a broadcast service parameter message, the sequence number of the broadcast service parameter message is incremented only when any of its contents changes, such as when a session is first started and when the session is ended.

The end of the HSBS session to the subscriber currently monitoring the F-BSCH is indicated by a special end message sent on the F-BSCH. This requires the multiplex sublayer to know which frames correspond to broadcast data and which frames correspond to signaling data (end message). In one embodiment, the value of bsrid, e.g., bsrid 000, indicates that the packet carries signaling data. In another embodiment, where a special message is not necessary, the base station sends a NULL (NULL) frame on the F-BSCH. In yet another embodiment, the base station turns off the F-BSCH. The subscriber station detects that no energy is being sent on the F-BSCH and concludes that the HSBS session is over.

Alternatively, the various embodiments described above representing the start of a session may be used to indicate the end of a session. In one embodiment, the message content indicating the start of the session includes information about the duration or end of the session. In another embodiment, an explicit message may be sent to indicate the end of the HSBS session.

Since subscriber stations participating in another call may also desire to monitor the F-BSCH simultaneously, the start of the HSBS session must also be signaled to the subscriber station in dedicated mode. The signaling method according to the above embodiments is also applicable.

Call model

A basic requirement of the broadcast service is that a subscriber station in the common channel mode (i.e., not participating in another call) can monitor the HSBS service. Also, the subscriber station should be able to receive/make a call while receiving the broadcast service. Thus, while the subscriber station monitors the F-BSCH, the subscriber station is able to receive paging notifications, send call originations, and perform registrations.

To enable the operating mode, the subscriber station must be able to simultaneously monitor the F-BSCH and the channel provided for overhead information. Such channels include, for example: a forward common control channel (F-CCCH) and a forward paging channel (F-PCH) in an IS-2000 compliant communication system. Those of ordinary skill in the art will appreciate that reference to IS-2000 IS for illustrative purposes only and that other communication standards provide channels that provide similar functionality. Furthermore, the subscriber must be able to monitor the F-BSCH and the channel provided for overhead information simultaneously. Such channels include, for example: a forward common control channel (F-CCCH) and a forward paging channel (F-PCH) in an IS-2000 compliant communication system, with or without a forward quick paging channel (F-QPCH). Furthermore, the subscriber station must be able to respond to pages, perform call origination, perform registration, respond to MS-directed messages, and perform other functions known to those skilled in the art while monitoring the F-BSCH. Accordingly, an Is-2000 compliant communication system may use, for example, a reverse access channel (R-ACH), a reverse enhanced access channel (R-EACH), and a reverse common control channel (R-CCCH). The above channels must be available on the same frequency as modulated by the F-BSCH.

One possible enhancement to the call model introduced above is that the subscriber station can simultaneously listen to the HSBS channel and participate in another call (such as a voice call). Thus, the F-BSCH and the dedicated traffic channel (the channel allocated for voice calls, etc.) are, for example, at the same frequency, because the current model of the subscriber station cannot monitor multiple frequencies simultaneously. The subscriber station can monitor the HSBS channel in either the common channel mode or the dedicated channel mode. In addition, the subscriber station must be able to simultaneously monitor the F-BSCH and channels for traffic and/or signaling traffic associated with other calls. Such channels include, for example: forward fundamental channel (F-FCH), forward dedicated control channel (F-DCCH) in IS-2000 compliant communication systems. Finally, the subscriber station must be able to transmit one or more channels for traffic and/or signaling traffic associated with other calls while monitoring the F-BSCH. Such channels include, for example: reverse fundamental channel (R-FCH), reverse dedicated control channel (R-DCCH) in IS-2000 compliant communication systems.

When the subscriber station desires to originate another call while monitoring the HSBS channel, the subscriber station stops monitoring the HSBS channel or continues origination if simultaneous participation in the HSBS and another call is supported.

When the subscriber station receives a page while monitoring the HSBS channel, the subscriber station rejects accepting the incoming call and continues to monitor the HSBS channel. According to one embodiment, the subscriber station sends a message to the paging base station indicating that the subscriber station is not interested in the incoming call, potentially indicating the service option that the subscriber station is not interested in. In accordance with another embodiment, the subscriber station sends a page response message with a special service option to indicate that the subscriber station is not interested in the incoming call. Alternatively, the subscriber station transitions to dedicated mode, accepts caller identification, and decides whether to accept the call while continuing to monitor the HSBS channel or while temporarily interrupting HSBS monitoring.

According to another embodiment, when a subscriber station receives a page while monitoring the HSBS channel, the subscriber station channel accepts the incoming call and stops monitoring the HSBS channel. Alternatively, if simultaneous participation in the HSBS and another call is supported, the incoming call is accepted while continuing to monitor the HSBS channel.

In an embodiment, a subscriber station that is not transmitting on the traffic channel monitors the HSBS channel in common channel mode, even though the subscriber station can monitor the HSBS channel in dedicated channel mode, because monitoring the HSBS channel in dedicated channel mode requires more system resources. Thus, when a subscriber station simultaneously monitors the HSBS, communicates on the traffic channel, and the communication ends, the subscriber station releases the dedicated channel and transitions to the common channel mode.

Frequency hashing and paging

When the base station receives a request to communicate with the subscriber station, the base station generates a paging message for the subscriber station. The base station then determines a paging channel monitored by the subscriber station and sends a paging message on the paging channel. Since a base station of a communication system may support multiple paging channels per frequency and/or multiple frequencies, a method of determining the frequency and paging channel monitored by a subscriber station at the base station and the subscriber station has been developed. A method based on the IS-2000 standard IS described. Those of ordinary skill in the art will appreciate that the IS-2000 standard was chosen for illustrative purposes and any method of ensuring consistency between base stations and subscriber stations could be readily substituted.

Upon power-up, the subscriber station enters a system determination substate in which the system on which the acquisition attempt is to be performed is selected. In one embodiment, after a system is selected for system determination, the subscriber station transitions to a pilot acquisition substate wherein the subscriber station attempts to demodulate a pilot signal based on acquisition parameters retrieved in the system determination substate. The subscriber station attempts to acquire a CDMA pilot signal in accordance with the acquisition parameters. When the subscriber station detects a pilot signal having an energy above a predetermined threshold, the subscriber station transitions to a synchronization channel acquisition substate and attempts to acquire a synchronization channel. Generally, the synchronization channel broadcast by the base station includes basic system information such as System Identification (SID) and Network Identification (NID), but most importantly provides timing information to the subscriber station. The subscriber station adjusts the timing of the subscriber station in accordance with the synchronization channel information and enters the subscriber station idle state. The subscriber station begins an idle state by receiving an overhead channel identified in a synchronization channel message, and if the base station acquired by the subscriber station supports multiple frequencies, both the subscriber station and the base station use a hashing function to determine which frequency to use for communication. The subscriber station and the base station then use a hash function to determine the paging channel monitored by the subscriber station. In one embodiment, the hash function accepts multiple entities for hashing, such as frequency, paging channel, etc., and international subscriber station identity (IMSI), and outputs one entity.

The above method (hereinafter referred to as the current hashing method) works well in a point-to-point communication system. However, the current hashing method cannot be directly used for a broadcast service, as described with reference to fig. 3. FIG. 3 illustrates at frequency f_xTwo HSBS channels 302a, 302b multiplexed on an F-BSCH channel 304a for uplink transmission and at frequency F_yOne HSBS channel 302c multiplexed on the F-BSCH channel 304b transmitted. At frequency f_zThere is no HSBS channel. Paging channels 306a, 306b, and 306c are on respective frequencies f_x、f_yAnd f_zIs sent. Although fig. 3 shows only one paging channel per frequency, one of ordinary skill in the art will recognize that this is for illustration purposes only, as the mapping of the subscriber station on a particular paging channel is determined by a hashing function. If the subscriber station subscribes to all three HSBS channels 302, it is free to change reception from one HSBS channel 302 to another HSBS channel 302. This is achieved byThe term "subscription" is used herein to mean allowing a subscriber station to receive a particular HSBS channel.

Without loss of generality, assume at time t₁The subscriber station powers up. The subscriber station tunes to frequency f using, for example, the hashing method described above_zRegisters with the base station and begins monitoring the paging channel 306 c. The base station performs the same hashing method to determine that the subscriber station is at frequency f_zThe paging channel 306c is monitored. At time t₂The subscriber station decides to monitor an HSBS channel 302 a. As described above, a subscriber station desiring to receive an HSBS channel must monitor the frequency containing the F-BSCH channel, modulated by the HSBS channel. Thus, the subscriber station tunes to the frequency f_xAnd begins receiving HSBS channel 302 a. Because of the limitations at the subscriber station, which enables the subscriber station to be tuned to only one frequency, the subscriber station monitors the paging channel 306a on frequency fx. Since the subscriber station is required to be able to receive paging messages while receiving the HSBS channel, the paging message to the subscriber station must be at frequency f_xIs transmitted on the paging channel. However, the current hashing method does not make up for a situation where the subscriber station may change frequency. Thus, at a frequency f_zThe base station hashing the subscriber station on the paging channel 306c is unaware of the re-tuning of the subscriber station. Thus, the base station operates at frequency f_zThe paging message sent on paging channel 306c may fail. Therefore, there is a need for a method and system to evaluate the frequency at which a base station pages a subscriber station. One of ordinary skill in the art recognizes that once the frequency is determined, the current paging channel determination method may be used.

Thus, in accordance with an embodiment of the present invention, a subscriber station registers with a base station the identity of the various HSBS channels that the subscriber station has subscribed to and is interested in monitoring. Since each HSBS channel modulates a corresponding F-BSCH on a particular frequency, the base station knows which set of frequencies the subscriber station can be found on and therefore successfully pages the subscriber station. Registration of the HSBS channel is used during handover. The purpose of the handoff is to transfer the subscriber station from an HSBS channel originated by a first base station to an HSBS channel originated by a second base station. However, the HSBS channel may be modulated with different frequencies at the first and second base stations, whereas the HSBS has the same unique identifier HSBS _ ID; since each base station knows the frequency on which a given HSBS _ ID is transmitted (via logical to physical mapping), the base station can successfully page the subscriber station. Thus, registration of individual HSBS channel identities facilitates handover. According to another embodiment, a subscriber station registers with a base station the frequencies modulated by the HSBS channel that the subscriber station has subscribed to and is interested in monitoring. Registration is performed periodically according to the timer status of a particular HSBS channel.

To allow this registration, the subscriber station maintains a TIMER STATUS (HSBS _ TIMER _ STATUS) for each HSBS channel that it has subscribed to and is interested in monitoring. The HSBS channel is identified by a unique identifier (HSBS _ ID). The HSBS _ TIMER _ STATUS of each TIMER is either "enabled" (i.e., the TIMER is running) or "expired" (i.e., the TIMER is not running). The subscriber station also maintains a counter, i.e., a broadcast service registration Timer (THSBS), for each HSBS channel that it is interested in monitoring. The counter is incremented at the determined time interval. When the counter reaches a predetermined value (HSBS _ REG _ TIMER), the subscriber station indicates that the TIMER has expired and sets HSBS _ TIMER _ STATUS to "expired".

After power-up, the subscriber station initializes the HSBS _ TIMER _ STATUS to "expired" for all channels. The subscriber station then tunes to a frequency in accordance with the current hashing method and registers with the base station that transmitted the frequency. If HSBS _ TIMER _ STATUS when the subscriber station tunes to the frequency of HSBS channel modulation identified by HSBS _ ID ═ i_S[i]Set to "expired", the subscriber station performs a broadcast service registration for the HSBS channel with the base station, setting HSBS _ TIMER _ STATUS_S[i]Set to "enable" and start a counter T_HSBS[I]. Counter T while subscriber station is still monitoring HSBS channel i_HSBS[I]Upon expiration, the subscriber station again performs broadcast service registration for HSBS channel i with the base station, setting HSBS _ TIMER _ STATUS_S[i]Set to "Enable" and start counter T_HSBS[I]. When a subscriber station tunes to a particular frequency (either due to an initial power-up registration process or due to monitoring of HSBS channel i) and desires to monitor HSBS information on the same frequencyOn way j, if HSBS _ TIMER _ STATUS_S[j]Set to "expired", the subscriber station performs a broadcast service registration for the HSBS channel j with the base station, setting HSBS _ TIMER _ STATUS_S[j]Set to "Enable" and start counter T_HSBS[j]。

Each base station maintains a paging SET (PAGE _ SET) for each subscriber station. Page _ SET for subscriber station after receiving power-up registration from ith subscriber station_jInitialized to contain the frequency to which the subscriber station is tuned according to the current hashing method, i.e., Page _ SET_j＝{f_power-up}. When a base station receives a broadcast service registration from a subscriber station for an HSBS channel identified by HSBS _ ID ═ i, the base station PAGEs a _ SET to a paging SET_j＝{f_power-upI adds the HSBS channel identifier and starts a counter T_HSBS[I]. If the counter T corresponding to HSBS channel i of the subscriber station_HSBS[I]Upon expiration, the base station deletes the HSBS _ ID i from the paging set. When the subscriber station has an incoming call, the base station uses a logical-to-physical mapping to determine frequencies corresponding to all HSBS channels whose identifiers are in the paging set. The base station then sends a paging message to the subscriber station on all of these frequencies. Thus, the timer at the subscriber station and the timer at the base station must be synchronized, or the timer at the base station must expire before the timer at the subscriber station expires. If the timer at the base station expires before the timer at the subscriber station expires, the base station deletes the HSBS _ ID i from the paging set while the subscriber station is still on the HSBS channel.

As described above, in the counter T_HSBS[I]Registration is performed periodically when a value determined by the value HSBS _ REG _ TIMER, which is a configurable parameter sent by the base station to the subscriber station, is reached. The value HSBS _ REG _ TIMER is determined as an optimum value between the signaling load resulting from the subscriber station broadcast service registration and the signaling load resulting from the uncertainty about the frequency with which the subscriber station needs to be paged. To reduce the signaling load, the broadcast service registration must be combined with another type of registration, such as time-based registration, distance-based registration, area-based registration, and common in the artOther registration types are known to the skilled person. For example, in time-based registration, a base station configures a subscriber station to register at predetermined time intervals. If the subscriber station performs a broadcast service registration, the subscriber station need not perform a time-based registration for that time period because the base station determined the location of the subscriber station from the broadcast service registration.

Referring back to fig. 3, the method performed by the subscriber station and the base station according to the above-described embodiment of the present invention is illustrated. At time t₁The subscriber station powers up and tunes to the frequency f using the current procedure_zHSBS _ TIMER _ STATUS is transmitted for all HSBS channels_SSet to "expired" and register. Base station initializes paging set of subscriber station to frequency f_z。(PAGE_SET_iAnd { fz }. ) (subscript i identifies the subscriber station)

At time t₂The subscriber station desires to monitor the HSBS channel 302 a. (HSBS ID ═ 1). Subscriber station tuning to frequency f_xSending a broadcast service registration for HSBS channel 302a, HSBS _ TIMER _ STATUS_S[1]Set to "Enable" and start counter T_HSBS[1]. Base station PAGE _ SET_i＝{1，fz}。

At time t₃The subscriber station is no longer interested in monitoring the HSBS channel 302a, but instead wishes to monitor the HSBS channel 302 b. The subscriber station sends a broadcast service registration for the HSBS channel 302b, sending an HSBS _ TIMER _ STATUS_S[2]Set to "Enable" and start counter T_HSBS[2]. Base station PAGE _ SET_i＝{2，1，fz}。

At time t₄The subscriber station is no longer interested in monitoring the HSBS channel 302b, but instead wishes to monitor the HSBS channel 302 c. The subscriber station tunes to frequency fy, sends a broadcast service registration for the HSBS channel 302c, and sends HSBSTIMER _ STATUS_S[3]Set to "Enable" and start counter T_HSBS[3]. Base station PAGE _ SET_i＝{3，2，1，fz}。

At time t₅Counter T_HSBS[1]Due, the subscriber station sends HSBS _ TIMER_STATUS_S[1]Set to "due". Since the subscriber station is no longer monitoring the HSBS channel 302a, the subscriber station need not send a broadcast service registration for the HSBS channel 302a, and thus the base station deletes the HSBS _ ID1 from the paging set. Thus, Page _ SET_i＝{3，2，fz}。

At time t₆Counter T_HSBS[2]Due, the subscriber station sends HSBS _ TIMER _ STATUS_S[2]Set to "due". Since the subscriber station is no longer monitoring the HSBS channel 302b, the subscriber station need not send a broadcast service registration for the HSBS channel 302b, and thus the base station deletes the HSBS _ ID2 from the paging set. Thus, Page _ SET_i＝{3，fz}。

At time t₇Counter T_HSBS[3]Due, the subscriber station sends HSBS _ TIMER _ STATUS_S[3]Set to "due". Since the subscriber station monitors the HSBS channel 302c, the subscriber station sends a broadcast service registration for the HSBS channel 302c, setting the HSBS _ TIMER _ STATUS_S[3]Set to "enable" and restart the counter T_HSBS[3]. Base station maintains Page _ SET_i＝{3，fz}。

At time t₈The subscriber station is no longer interested in any HSBS channel. In an embodiment, the subscriber station tunes to fz and enters an idle state. Paging SET does not change PAGE _ SET {3, fz }. In another embodiment, the subscriber station remains on frequency fy.

At time t₉Counter T_HSBS[3]And (4) expiration. According to the following embodiment, wherein the subscriber station tunes to fz and enters the idle state, the subscriber station sets the HSBS _ TIMER _ STATUS_S[3]Set to "due". Since the subscriber station is no longer monitoring the HSBS channel 302c, the subscriber station need not send a broadcast service registration for the HSBS channel 302c, and thus the base station deletes the HSBS _ ID3 from the paging set. Thus, Page _ SET_iAnd { fz }. According to the following embodiment, where the subscriber station remains at fy and enters the idle state, the subscriber station sends a broadcast service registration for the HSBS channel 302c, sending the HSBS _ TIMER _ STATUS_S[3]Set to "enable" and restart the counter T_HSBS[3]. Base station maintains Page _ SET_i＝{3，fz}。

In an alternative embodiment, registration is not required. In one embodiment, the HSBS channel is transmitted on all frequencies of a sector. Thus the current hashing method can be used. In certain circumstances, embodiments may not be practical because the resource allocation to deploy the F-BSCH on all frequencies may be overburdened. Also, the F-BSCH modulated by the HSBS channel is a high power channel; it acts as a source of interference.

Thus, in another embodiment, the base station transmits the paging message on a paging channel having a frequency of: the frequency to which the subscriber station initially tunes according to the current hashing method, and all frequencies modulated by the HSBS channel. This embodiment takes the current hashing approach in exchange for easy paging decisions and does not require knowledge of subscriber station HSBS subscription details with respect to multiple frequencies and at multiple paging channels.

According to another embodiment, in order to reduce the paging load, subscriber stations are divided into two categories. The first category includes subscriber stations that are not subscribed or not capable of HSBS service, and the second category includes subscriber stations that are subscribed to HSBS service. The base station is provided with subscription information for the subscriber station to be paged. The subscription information is provided, for example, from a Home Location Register (HLR), an HSBS content server, or similar entity in the communication system. If no HSBS session is in progress, all subscriber stations tune to multiple frequencies according to the current hashing method. Thus, the base station pages the subscriber station at the appropriate frequency and at a paging channel. When HSBS service starts, subscriber stations belonging to the second class, which are interested in HSBS sessions, tune to the appropriate HSBS channel. The base station pages subscriber stations belonging to the first class according to the current paging method. The base station knows whether the HSBS session is on or off and knows the subscriber profile of each subscriber station belonging to the second class. Therefore, the base station transmits a paging message to subscriber stations belonging to the second class on the following paging channels: a paging channel on a frequency to which the subscriber station is initially tuned, a paging channel on a frequency modulated by an HSBS channel to which the subscriber station is subscribed. This embodiment achieves low paging load without modifying the current hashing method with respect to the need to learn subscriber station subscription information.

To prevent uneven distribution of the subscriber station among frequencies due to the subscriber station tuning to different frequencies modulated by the HSBS channel, the above embodiment may be modified by: for subscriber stations belonging to the first class, the modification is made by inputting only frequencies that are not modulated by the HSBS into the hash function. Also, if the HSBS session is in progress, only the frequency modulated by the HSBS is input to the hash function for the subscriber stations belonging to the second class. One of ordinary skill in the art recognizes that other combinations of frequencies may be used depending on the access network usage pattern.

Thus, in another embodiment, the subscriber station notifies the base station after starting or ending monitoring of the HSBS channel. Thus, the subscriber station initially tunes to a frequency according to the current hashing method. When the subscriber station desires to monitor an HSBS channel, the subscriber station sends a notification message to the base station indicating that monitoring of the HSBS channel is desired and tunes to the frequency modulated by the HSBS channel. When the subscriber station is no longer interested in HSBS channel reception, the subscriber station sends a notification message indicating a desire to stop monitoring the HSBS channel and tune back to the original frequency. This embodiment assumes a trust relationship between the subscriber station and the access network. If such a relationship has not been established, the base station confirms that the subscriber station subscribes to the requested HSBS channel, or grants or denies the request, upon receipt of the notification message. Only upon receiving the access grant is the subscriber station tuned to the frequency modulated by the HSBS channel. The base station can successfully page the subscriber station because it is explicitly informed about the current frequency to which the subscriber station is tuned. This embodiment enables easy paging decisions without modifying the current hashing method and without knowing the subscriber station's subscription, e.g., at the beginning and end of a popular program, relative to a large reverse link signaling load (which may be bursty).

In another embodiment, to reduce the reverse link signaling load, the subscriber station notifies the base station only when it changes frequency. Thus, the subscriber station first tunes to a frequency according to the current hashing method. When the subscriber station desires to monitor an HSBS channel that is modulated at a different frequency than the frequency monitored by the subscriber station, the subscriber station sends a notification message to the base station indicating that monitoring of the HSBS channel is desired and tunes to the frequency modulated by the HSBS channel. The subscriber station discontinues HSBS monitoring when the subscriber station is no longer interested in HSBS channel reception. The subscriber station does not need to do anything because the subscriber station does not change frequency. Since the base station explicitly informs about the current frequency to which the subscriber station is tuned, it can successfully page the subscriber station. As in the above-described embodiment, a request response may be required if a trust relationship is not established between the subscriber station and the access network. This embodiment enables easy paging decisions without modifying the current hashing method and without learning the subscriber station's subscription, e.g., at the beginning and end of a popular program, relative to a large reverse link signaling load (which may be bursty).

Those skilled in the art will appreciate that although the flow diagrams are drawn in an order that facilitates understanding, in actual implementations, certain steps may be implemented in parallel.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. The skilled person will recognize the interactivity of the hardware and software in these cases and how best to implement the described functionality for each particular application. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The implementation or execution of the various illustrative logical blocks, modules, and algorithm steps described in connection with the embodiments described herein may be implemented or performed with: a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the patent and trademark office patent files or records, but otherwise reserves all rights whatsoever.

There is also a need for a flexible method of deploying broadcast service parameter messages in a sector.

In idle state BCMCS design, a mobile station may enter its hash (hash-to) frequency in idle state as specified in the current cdma2000 standard. Similarly, at a hashed frequency, the mobile station monitors the hashed paging channel. This ensures that all mobile stations (whether they support BCMCS or not) follow the same procedure for system determination, idle state frequency selection, and idle state paging channel selection. Once the mobile station enters the hash frequency in the idle state, if the user requests BCMCS FLOW IDx, the mobile station reads BSPM (broadcast service parameter message) on that frequency (i.e., the hash frequency and hash paging channel of the mobile station) to determine whether BCMCS FLOW IDx is available in that sector. If BCMCS FLOW IDx is available in the sector, the mobile station determines from the BSPM all necessary information to monitor the service (such as the frequency it is transmitted, configuration parameters for the F-BSCH, etc.). The mobile station then tunes to the appropriate frequency (if different from the hash frequency) and monitors the F-BSCH.

The above design means that the BSPM must be signaled in each paging channel on the various frequencies of the sector, since the mobile stations interested in BCMCS may be on either frequency and on either paging channel. For the same reason, each of these BSPMs must transmit information about the BCMCS FLOW ID available on all frequencies on that sector. This is desirable from the mobile station's perspective because it minimizes the delay for the mobile station to begin monitoring the desired BCMCS content. But if the number of BCMCS FLOW IDs sent within a sector is large, this scheme is ineffective from a network point of view due to a large amount of overhead (i.e., BSPM) required to provide BCMCS services. This is illustrated below and in table 1.

TABLE 1

BSPM1	All information of BCMCS _ FLOW _ ID1 all information of BCMCS _ FLOW _ ID2 all information of BCMCS _ FLOW _ ID3
		BSPM2	All information of BCMCS _ FLOW _ ID1 all information of BCMCS _ FLOW _ ID2 all information of BCMCS _ FLOW _ ID3
BSPM3	All information of BCMCS _ FLOW _ ID1 all information of BCMCS _ FLOW _ ID2 all information of BCMCS _ FLOW _ ID3
		BSPM4	All information of BCMCS _ FLOW _ ID1 all information of BCMCS _ FLOW _ ID2 all information of BCMCS _ FLOW _ ID3

To provide operators with the flexibility to trade off between the amount of BSPM overhead and the delay to start monitoring BCMCS in their BCMCS deployment, a flexible mechanism is assumed for BSPM deployment as described below.

On each paging channel on each frequency, information regarding BCMCS availability in the sector is provided via one of four possible methods:

1. indicating that BCMCS is not available in that sector

2. Indicating that BCMCS is available in the sector and pointing to the frequency and paging channel where the MS can determine information about BCMCS FLOW ID available in the sector

3. Provide a list of available BCMCS FLOW IDs in the sector and point to the frequency and paging channel where information about that particular BCMCS FLOW ID can be obtained

4. Provide a list of available bcmcsflowids in the sector and provide all necessary information needed for the mobile station to monitor that particular bcmcsflowid

The above four methods of signaling BCMCS information are implemented by the following combination of system parameter message/MC-RR parameter message and BSPM sum:

● in the system parameters message/MC-RR parameters message, a 2-bit flag (BCMCS _ IND) is added, set as follows:

● BCMCS _ IND ═ 00 → BCMCS service is not available in the sector

As long as the MS resides in the sector, the user cannot receive any BCMCS service, and the BSPM is not transmitted in the sector

● BCMCS _ IND ═ 01 → BCMCS service is available in the sector, but go to BCMCS _ FREQ/BCMCS _ page to collect all necessary information

The BSPM is not transmitted on the paging channel on this frequency, noting that BCMCS _ FREQ may be this frequency, with only the paging channel being different. This enables the BS to transmit the BSPM only at the frequency in which the F-BSCH is deployed, thus reducing BSPM overhead. A mobile station interested in BCMCS knows where to get information when needed.

● BCMCS _ IND ═ 10 → BCMCS service is available in the sector and reads BSPM on the frequency and the paging channel to collect all necessary information. The BSPM provides additional flexibility.

When BCMCS _ IND is 00 or 01, the BSPM is not transmitted at the current frequency on the current paging channel. When BCMCS _ IND ═ 10, the BSPM is sent on the current paging channel at the current frequency, which provides the following flexibility via the BSPM _ BCMCS _ IND flag:

● BSPM _ BCMCS _ IND ═ 1 → all BCMCS _ FLOW _ IDs available in the sector are listed in the BPSM.

● BSPM _ BCMCS _ IND ═ 0 → not all BCMCS _ FLOW _ IDs available in the sector are listed in the BSPM, providing information about the frequency and paging channel in which the mobile station can obtain information.

● for either case of BSPM _ BCMCS _ IND, there are two ways to provide information for each BCMCS _ FLOW _ ID listed in BSPM:

only to the frequency and paging channel where the MS can collect all necessary information related to the BCMCS FLOW ID; no additional information is given and all necessary information (e.g., F-BSCH Walsh code, BSR _ ID, etc.) is included to enable the MS to monitor a given bcmcsflow _ ID.

From the mobile station perspective, the above design results in one of the following six results for the hash frequency and the hash paging channel at the mobile station for a given BCMCS FLOW ID in a given sector:

1. system parameter message/MC-RR parameter message signal BCMCS _ IND ═ 00 → BCMCS _ FLOW _ IDx cannot be monitored in the sector

2. System parameter message/MC-RR parameter message contains BCMCS _ IND ═ 01 → MS needs to tune to BCMCS _ FREQ/BCMCS _ page to determine if BCMCS _ FLOW _ IDx is available in the sector

3. The system parameter message/MC-RR parameter message contains BCMCS _ IND ═ 10; the MS reads the BSPM at the frequency; BSPM signal BSPM _ BCMCS _ IND ═ 0; BSPM unlisted BCMCS FLOW IDx → MS needs to tune to BCMCS _ FREQ/BCMCS _ page to determine if BCMCS FLOW IDx is available in the sector

4. The system parameter message/MC-RR parameter message contains BCMCS _ IND ═ 10; the MS reads the BSPM at the frequency; BSPM signal BSPM _ BCMCS _ IND ═ 1; BSPM does not list BCMCS _ FLOW _ IDx → BCMCS _ FLOW _ IDx cannot be monitored in that sector

5. The system parameter message/MC-RR parameter message contains BCMCS _ IND ═ 10; the MS reads the BSPM at the frequency; BSPM lists BCMCS FLOW IDx but only points to BCMCS _ FREQ → BCMCS FLOW IDx where information about BCMCS FLOW IDx can be collected can be monitored in that sector, but the MS must tune to BCMCS _ FREQ to determine where/how to monitor BCMCS FLOW IDx

6. The system parameter message/MC-RR parameter message contains BCMCS _ IND ═ 10; the MS reads the BSPM at the frequency; BSPM lists BCMCS FLOW IDx and provides all information → BCMCS FLOW IDx can be monitored in that sector, and the MS has all information to determine where/how to monitor BCMCS FLOW IDx

From the network perspective, the following flexible options are available:

1. the BSPM sent on each frequency channel on each frequency contains information about the BCMCS FLOW ID available on all frequencies of the sector

2. The BSPM sent on each frequency contains a list of bcmcsflow IDs available on all frequencies of the sector and points to the frequency where information necessary to monitor the bcmcsflow ID can be collected

3. Only one frequency sends a BSPM containing all necessary information about available bcmcflowid in other frequencies (see NOTE _ 1); other frequencies merely direct the mobile station to that frequency to gather the necessary information

4. Various combinations of the above 3 options are made according to the deployment requirements and types of BCMCS services. These options are shown below for some example uses of the above scenario,

TABLE 2

ESPM1BCMCS_IND＝10	BSPM1	All information BCMCS _ FLOW _ ID3 of all information BCMCS _ FLOW _ ID2 of BSPM _ BCMCS _ IND _ 1BCMCS _ FLOW _ ID1 of fy _ FLOW _ ID2 of fb _ BCMCS _ FLOW _ ID
			ESPM2BCMCS_IND＝10	BSPM2	All information BCMCS _ FLOW _ ID1 of BSPM _ BCMCS _ IND _ 1BCMCS _ FLOW _ ID3 fxBCMCS _ FLOW _ ID2 fx
ESPM3BCMCS_IND＝10	BSPM3	All information BCMCS _ FLOW _ ID1 of BSPM _ BCMCS _ IND _ 1BCMCS _ FLOW _ ID3 fxBCMCS _ FLOW _ ID2 fx
			ESPM4		Is not limited toTransmitting BSPM

BCMCS _ IND ═ 01 and fx

TABLE 3

ESPM1BCMCS_IND＝10	BSPM1	All information BCMCS _ FLOW _ ID3 of all information BCMCS _ FLOW _ ID2 of BSPM _ BCMCS _ IND _ 1BCMCS _ FLOW _ ID1 ry
			ESPM2BCMCS_IND＝10	BSPM2	All information BSPM _ BCMCS _ IND ═ 0BCMCS _ FLOW _ ID3 other BCMCS ═ fx
ESPM3BCMCS_IND＝10	BSPM3	All information BSPM _ BCMCS _ IND ═ 0BCMCS _ FLOW _ ID3 other BCMCS ═ fx
			ESPM4BCMCS _ IND ═ 01 and fx		Not transmitting BSPM

Note 1: when a BCMCS FLOW IDx is sent at frequency x, the BSPM at that frequency must list all information about that BCMCS FLOW IDx. This is used to avoid interruption of MS BCMCS reception if the MS needs to stay tuned to another frequency to get BSPM updates (worst case, the MS does not know at all the time to send BSPM on another frequency).

Note 2: none of the above constraints apply to the case where autonomous BCMCS requests are allowed (i.e., the MS is allowed to require a BCMCS FLOW ID that is not listed in the overhead). It already has its flag bit in BSPM; a similar flag bit (actually one value using bcmcsind) needs to be added in the system parameter message/MC-RR parameter message.

Claims (1)

1. A method for a communication system, comprising:

transmitting information on broadcast/multicast service BCMCS availability in a sector on each paging channel on each frequency by indicating at least one of:

a list of available broadcast/multicast service FLOW identifiers, BCMCS _ FLOW _ IDs, in the sector and to a frequency and paging channel from which information relating to a particular BCMCS _ FLOW _ ID is obtained;

a list of available BCMCS FLOW IDs in the sector and provides information that enables the mobile station to monitor a particular BCMCS FLOW ID.