Abstract: Disclosed is a method for enabling a mobile station existing in a serving cell area to perform a handover procedure in a broadband mobile communication system including the mobile station, a serving base station providing a service to the mobile station, and one or more target base stations containing at least one target cell area overlapping with the serving cell area occupied by the serving base station. The method includes transmitting a handover request message from the mobile station to the serving base station when it is detected that a performance of a handover is necessary; and transmitting a handover indication message containing handover cancel information to the serving base station when the mobile station determines a cancel of the handover while the mobile station is being handed over to one or more target base stations by the serving base station.

Abstract: Provided is a method for transmitting/receiving data in a communication system providing Multicast/Broadcast Service (MBS). The method includes, generating transmission data to be transmitted to a receiver; allocating the transmission data to a frame; setting a MAP message that includes information on a frame offset related to the frame; and transmitting to the receiver the MAP message.

Abstract: A method for allocating a band Adaptive Modulation and Coding (AMC) channel in a wireless communication system that divides a full frequency band into a plurality of subcarrier bands and includes subchannels, each of which is a set of a predetermined number of neighbor subcarrier bands. Upon recognizing a need for a band AMC channel, a subscriber station (SS) sends a request for allocation of the band AMC channel to a base station (BS). Upon receiving the band AMC channel allocation request, the BS determines if it can allocate the band AMC channel requested by the SS, considering a resource situation of the BS, and transmits information on the determination to the SS.

Abstract: A system and method for transmitting a traffic indication message in a Broadband Wireless Access communication system. A base station (BS) transmits the traffic indication message to mobile subscriber stations (MSSs). The traffic indication message includes information on a number of MSS groups and information on a number of traffic indication indexes, each of the MSS groups includes a predetermined number of MSSs, and each of the traffic indication indexes is assigned to each of the MSS groups, and includes a bitmap including a predetermined number of bits. The predetermined number of bits is identical to the number of the MSSs included in each of the MSS groups, each of the predetermined number of the bits is assigned to each of the MSSs included in each of the MSS groups, and represents operation instruction information for each of the MSSs.

Abstract: Disclosed is a method for recognizing by a Mobile Subscriber Station (MSS) whether a serving Base Station (BS) retains connection information in a mobile communication system including the serving BS for providing a service to the MSS and a target BS adjacent to the serving BS. The method includes the steps of receiving a handover request message from the serving BS, the handover request message including a resource remain type field representing whether the connection information having been set with the serving BS is retained, and a resource retain time field representing a connection information-retaining time by the serving BS, and recognizing that the serving BS retains the connection information during a time determined by a value of the resource retain time field.

Abstract: A method for transmitting a traffic indication message for directing a mobile subscriber station (MSS) in a sleep mode to transition to an awake mode in a Broadband Wireless Access communication system supporting the sleep mode and the awake mode. This method includes the steps of individually allocating, to MSSs belonging to a corresponding base station, corresponding areas indicating traffic instructions for the MSSs in a traffic indication field in the traffic indication message, and indicating state transition instructions in the areas allocated to the MSSs, before transmitting the traffic indication message to the MSSs.

Abstract: A method for controlling an idle mode in a broadband wireless access (BWA) communication system. A mobile station (MS) transmits to a base station (BS) a de-registration request (DREG-REQ) indicating a state transition request to the idle mode. The BS transmits to the MS a de-registration command (DREG-CMD) for commanding state transition to the idle mode. The MS transmits to the BS a de-registration acknowledgement (DREG-ACK) in response to the DREG-CMD.

Abstract: Disclosed are a system and a method for selecting a new serving base station when a drop occurs in a mobile subscriber station in a broadband wireless access communication system including the mobile subscriber station, a serving base station communicating with the mobile subscriber station, and a plurality of neighbor base stations, different from the serving base station. The mobile subscriber station receives information related to the neighbor base stations from the serving base station communicating with the mobile subscriber station. The mobile subscriber station monitors the frequency bands of the neighbor base stations included in the information related to the neighbor base stations if the drop is detected in order to detect target base stations capable of serving as a new serving base station for communicating with the mobile subscriber station when the drop occurs in the mobile subscriber station according to a monitoring result for the frequency bands of the neighbor base stations.

Abstract: A method for providing an interactive data service between a base station and a mobile station in a mobile communication system including at least one mobile station, the base station communicating with the mobile station, and a server connected to the base station. The base station simultaneously transmits data transmitted from the server, to one or more mobile stations over a forward common channel. A particular mobile station receiving a service through the common channel transmits reverse transmission data over a dedicated channel.

Abstract: A method for allocating a channel quality information channel (CQICH) in a communication system is disclosed. After fast switching from a serving anchor base station (BS) to a target anchor BS, a mobile station (MS) detects absence of a CQICH allocated from the target anchor BS. Upon detecting the absence of the allocated CQICH, the MS sends a request for allocating the CQICH to the target anchor BS. Upon receiving the CQICH allocation request, the target anchor BS detects a need to allocate a CQICH to the MS.

Abstract: A method for requesting allocation of a Channel Quality Information Channel (CQICH) by a Mobile Station (MS) in a communication system. The method includes switching, by the MS, from a serving anchor Base Station (BS) to a target anchor BS, detecting an absence of a CQICH allocated from the target anchor BS, and transmitting, from the MS to the target anchor BS, a CQICH allocation request. The CQICH allocation request includes a CQICH allocation request header including a basic Connection IDentifier (CID) of the MS and a Header Check Sequence (HCS) for the CQICH allocation request header.

Abstract: Disclosed is a method for enabling a mobile station existing in a serving cell area to perform a handover procedure in a broadband mobile communication system including the mobile station, a serving base station providing a service to the mobile station, and one or more target base stations containing at least one target cell area overlapping with the serving cell area occupied by the serving base station. The method includes transmitting a handover request message from the mobile station to the serving base station when it is detected that a performance of a handover is necessary; and transmitting a handover indication message containing handover cancel information to the serving base station when the mobile station determines a cancel of the handover while the mobile station is being handed over to one or more target base stations by the serving base station.

Abstract: A system and method for updating a sleep identifier (SLPID) of a mobile station (MS) in a broadband wireless access (BWA) communication system having a sleep mode in which there is no transmission data and an awake mode in which there is transmission data. Upon recognizing a need to update an SLPID allocated to an MS in the sleep mode in the initial phase of the sleep mode, a base station (BS) reallocates a new SLPID to be allocated to the MS and transmits SLPID update information to the MS. Upon receiving the SLPID update information for its current SLPID during the sleep mode, the MS updates its current SLPID with the reallocated SLPID according to the received update information.

Abstract: An apparatus and method for controlling a reverse data rate in a mobile station. The method includes determining whether the mobile station has sufficient power to transmit at an increased data rate compared to a current data rate, and transmitting a determination result to a base station.

Abstract: A broadband wireless access (BWA) communication system includes a mobile subscriber station (MSS), a serving base station (BS) with which the MSS performs communication, and a plurality of neighbor BSs. The serving BS transmits, to the MSS, a handover request message including information on at least one recommended BS to which the MSS can perform a handover, among the neighbor BSs, and indication information indicating a fast handover, and transmits, to each of the recommended BSs, a handover confirm message indicating that the MSS will perform the fast handover.

Abstract: Disclosed is a method for recognizing by a Mobile Subscriber Station (MSS) whether a serving Base Station (BS) retains connection information in a mobile communication system including the serving BS for providing a service to the MSS and a target BS adjacent to the serving BS. The method includes the steps of receiving a handover request message from the serving BS, the handover request message including a resource remain type field representing whether the connection information having been set with the serving BS is retained, and a resource retain time field representing a connection information-retaining time by the serving BS, and recognizing that the serving BS retains the connection information during a time determined by a value of the resource retain time field.

Abstract: A reverse transmission controlling method in a mobile communication system. After receiving forward information commanding a reverse data rate change on a forward channel from a base station, a mobile station increases its reverse data rate to a data rate equal to or lower than a maximum data rate if the forward information commands a reverse data rate increase, determines whether the increased data rate can be further increased for the next frame, and transmits the determination result with information representing the increased data rate to the base station.

Abstract: A system for a periodic ranging in a BWA communication system. In the system, a receiver in a sleep mode of a wireless communication system receives a sleep mode transition message, which including first information relating to a timing point at which the periodic ranging is performed, from a transmitter, transits to the sleep mode, and performs the periodic ranging at a timing point corresponding to the first information. Accordingly, the periodic ranging of the receiver in the sleep mode can be performed.

Abstract: A broadband wireless access (BWA) communication system includes a mobile subscriber station (MSS), a serving base station (BS) with which the MSS performs communication, and a plurality of neighbor BSs. The serving BS transmits, to the MSS, a handover request message including information on at least one recommended BS to which the MSS can perform a handover, among the neighbor BSs, and indication information indicating a fast handover, and transmits, to each of the recommended BSs, a handover confirm message indicating that the MSS will perform the fast handover.

Abstract: A broadband wireless access communication system including a serving BS which broadcasts a MOB_NBR-ADV message to an MS is provided. A method for configuring the MOB_NBR-ADV message is also provided, and includes adding a specific field, which represents whether at least one information field constituting the MOB_NBR-ADV message exists, to the MOB_NBR-ADV message, determining if at least one information field is included in the MOB_NBR-ADV message, and determining a bit value of the specific field according to whether at least one information field is included in the MOB_NBR-ADV message.