Abstract: A system and method for allocating a safety channel in a broadband wireless access (BWA) communication system including a serving base station (BS) for providing a service to a mobile station (MS) and neighbor BSs. Upon receiving a request for allocation of the safety channel from the MS, the serving BS sends a request for allocation of the safety channel to a target BS having the best channel condition among the neighbor BSs. Upon receiving information indicating possibility of allocating the safety channel from the target BS, the serving BS controls the MS such that the MS performs communication through the allocated safety channel. Upon detecting a need for receiving a safety channel, the MS sends, to the serving BS, information indicating that the MS should be allocated the safety channel, and receives a safety channel allocated according to a control signal from the serving BS.

Abstract: A method for supporting handover in a BWA communication system is provided. The system includes an MS, a serving BS, and a plurality of neighbor BSs. The coverage area of each of the BSs is divided into sectors using different subcarrier bands. The MS collects information broadcast from the serving BS on the serving BS and the neighbor BS, measures a signal level for each of the sectors of the serving BS and the neighbor BSs according to the collected information, and sends a handover request based on the measured signal level for each of the sectors. The serving BS broadcasts information on the serving BS and the neighbor BS to the MS, determines if the MS can perform a soft handover from its current sector to another sector upon receiving the handover request from the MS, and permits the MS to perform the soft handover if possible.

Abstract: An information frame of a new format transmitted according to a radio link protocol (RLP), and a device and method for transmitting and receiving the information frame in a mobile communication system. The information frame is comprised of a plurality of consecutive multiplex frames each having a given length. The multiplex frames each are comprised of a header and a succeeding RLP frame, and the RLP frame includes transmission data. At least one of the multiplex frames is comprised of a plurality of sub-multiplex frames, and each sub-multiplex frame is comprised of a header including an RLP service identifier field and a length indication field for indicating a length of the transmission data, and a data block associated to the succeeding RLP frame.

Abstract: In a broadband wireless access communication system which includes a mobile station, a serving base station and neighbor base stations located adjacent to the serving base station, the serving base station collects the information of the neighbor base stations, determines if the collected information of the neighbor base stations matches the information of the serving base station, sets up predetermined groups by classifying the neighbor base stations according to a result of the determination, and broadcasts a predetermined message including information of the setup groups, and the mobile station receives the predetermined message broadcasted, confirms the information of the neighbor base stations included in the received message, and performs location information update in accordance with the confirmed information.

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: Disclosed is a method and a system for performing a handover capable of minimizing a service delay in a broadband wireless access communication system including a mobile station (MS), a serving base station (BS) providing services to the MS, and a target BS to which the MS hands over. The method comprises the steps of detecting that the handover from the serving BS to the target BS is necessary; and transmitting a request to the serving BS in order to perform portions of a handover process prior to the handover to the target BS.

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 method for broadcasting channel information, available channel and data rate of a base station in a CDMA communication system. The base station receives information indicating that a mobile station has data to transmit, over an access preamble channel. The base station transmits use status information of physical channels and maximum available data rate information on a status indicator channel. The mobile station receives the use status information of physical channels and the maximum available data rate information through the status indicator channel from a base station. The mobile station transmits to the base station an access preamble for requesting allocation of a given physical channel determined depending on the use status information and the maximum available data rate information.

Abstract: A method for transmitting data in a mobile communication system. The method comprising segmenting a data stream into at least one consecutive frame having a variable data length, the data stream being segmented into a plurality of consecutive blocks having a variable data length, each said consecutive block being segmented into a plurality of sub-consecutive blocks having a byte length; attaching, at each head of the consecutive frames, a header including a first set of bits indicating the sequence number of a consecutive block corresponding to the head and a second set of bits indicating the sequence number of a sub-consecutive block corresponding to the head; and transmitting the header-attached consecutive frames.

Abstract: Disclosed is a method for allocating a safety channel in a wireless communication system which 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 subbands, each of which is a set of a predetermined number of contiguous subcarriers, where the subchannels include a safety subchannel allocated to particular subscriber stations (SSs), which is unused in a neighbor base station. The method comprises the steps of: transmitting, by the SS, its channel quality information to the base station (BS) when a channel quality of a subchannel allocated to the SS is less than to predetermined reference channel quality; and allocating a safety subchannel to the SS, by the BS upon receiving the channel quality information indicating that the channel quality of the subchannel is less than to the reference channel quality.

Abstract: A method supporting a Hybrid Automatic Repeat Request (HARQ) between a subscriber station and a base station in a broadband wireless access communication system including. The method includes the steps of: transmitting at least one H-ARQ enabled uplink burst from the subscriber station to the base station; generating ACK/NACK information according to the received HARQ enabled uplink burst at the base station; mapping the generated ACK/NACK information to a bitmap at the base station; transmitting the bitmap through a downlink information from the base station to the subscriber station.

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 method and a system for periodic ranging in a sleep mode of a broadband wireless access communication system having an awake mode in which data to be transmitted between a mobile subscriber station (MSS) and a base station (BS) exists and the sleep mode in which data to be transmitted between the MS and the BS does not exist, the sleep mode having a sleep interval and a listening interval, the MSS being capable and incapable of receiving data in the listening interval and in the sleep interval, respectively. The BS reports to the MSS in a listening interval before the sleep interval that the MSS must perform the periodic ranging in the sleep interval when the BS detects that it is necessary for the MSS in the sleep mode to perform the periodic ranging at a particular time point in the sleep interval.

Abstract: In a BWA communication system, an MSS changes its connection from the serving BS to the target BS, and sends the target BS a report indicating that the MSS will change its connection upon detecting occurrence of a pingpong effect in a process of performing a network re-entry operation with the target BS. The target BS sends the serving BS a notification indicating that the MSS will change its connection. Upon receiving from the MSS a report indicating that it will change its connection to the serving BS, the serving BS allocates a contention-free-based ranging resource to the MSS so that the MSS connects a communication service with the serving BS using the contention-free-based ranging resource, minimizing a service delay.

Abstract: A scheduling method for providing multimedia service and packet data service efficiently. The scheduling is a Round-Robin scheduling in an MQC (Multiple Quality Control) protocol structure. A transmitter in a base station transmits or retransmits TUs from different streams in a PLP using priority queues by the scheduling.

Abstract: A method for transmitting a plurality of data frames in a mobile telecommunications system is disclosed. Each data frame has a frame sequence number and a data block. The method comprises the steps of segmenting a data frame into a plurality of data segments for retransmission, assigning the frame sequence number to each of said data segment, and assigning respective sequence numbers to the data bytes of each data segment to distinguish the first and last bytes of said data segment.

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 and apparatus for defining at least one subcarrier as a subchannel, dividing a total frequency band into a plurality of subchannels, and allocating the subchannels to at least one mobile station in an OFDMA mobile communication system. The method includes receiving channel state information; comparing the received channel state information with a predetermined threshold, calculating an average occurrence length of a case in which the received channel state information is greater than the threshold, calculating a state hold prediction value, calculating an estimation value, sorting the calculated estimation values according to subchannels in order of their levels, and allocating subchannels according to the at least one mobile station in the sorted order.

Abstract: A system and method for dynamically allocating a frame cell (FC) and subchannel (FC/subchannel) is disclosed. An access point receives channel quality information (CQIs) which is fed back from a plurality of access terminals on an FC-by-FC basis, and determines a modulation and coding scheme (MCS) to be applied to each of the access terminals. If access terminals whose FCs/subchannels must be changed are detected from the plurality of the access terminals, the access point sends an FC/subchannel change request for the detected access terminals to an access router. The access router generates weights for all FCs, allocates an FC/subchannel set by selecting a predetermined number of FCs/subchannels considering the weights of the FCs for the access terminals corresponding to the received FC/subchannel change request, and transmits information on the allocated FC/subchannel set to the access point.

Abstract: Disclosed are an apparatus and a method for retransmitting a failing RLP frame assigned with a new unique identifier agreed to between the transmitting and receiving RLP processors instead of the original sequence number. The receiving RLP processor requests the transmitting RLP processor to retransmit a failing RLP frame assigned with a new identifier determined by the receiving RLP processor. Responding to the request, the transmitting RLP processor retransmits the failing RLP frame assigned with the requested new identifier instead of the original sequence number.