Abstract: A method and system for transmitting/receiving a signal in a wireless communication system are provided, in which an mobile station determines a sequence number of a first protocol data unit being a last received protocol data unit, transmits the SN of the first protocol data unit to a serving base station, and allocates a virtual SDU sequence number to a service data unit including a second protocol data unit following the first protocol data unit.

Abstract: A handover method of a Mobile Station (MS) and a wireless mobile communication system are provided. The handover method includes sending a handover request message to a Serving Base Station (BS), receiving a handover response message including handover Target BS information and an entire Cipher-based Message Authentication Code (CMAC) value corresponding to a first number of bits, from the Serving BS in response to the handover request message, storing a partial CMAC value corresponding to a second number of Most Significant Bit (MSB) bits in the entire CMAC value, sending to the Serving BS a handover indication message including the entire CMAC value and information on a Target BS to which the MS has determined to handover, selecting a ranging code using the partial CMAC value, and sending the selected ranging code to the Target BS.

Abstract: A system and method for periodic ranging in sleep mode in a communication system are provided, in which an MS is allocated an uplink burst from a BS and transmits a first message in the allocated uplink burst to the BS, the first message indicating that the MS is alive during sleep mode.

Abstract: A method and apparatus for transmitting and receiving control information in a wireless communication system are provided. The apparatus includes a DownLink/UpLink (DL/UL) indicator for indicating whether a connection associated with control information to be transmitted is a DL connection or a UL connection and a flow Identification (ID) that identifies the connection are generated and control information including the DL/UL indicator and the flow ID is transmitted to another party to the connection.

Abstract: Provided are an apparatus and method for negotiating a frame offset between a Base Station (BS) and a Relay Station (RS) in a wireless communication system using a multi-hop relay scheme. A communication method of a superordinate station includes, upon detecting an initial access of an relay station, determining an offset value between a frame number used in the superordinate station and a frame number to be used in the relay station; generating a message including RS frame offset information corresponding to the offset value; and transmitting the generated message to the relay station. Accordingly, since the base station and the relay station share the frame offset, the base station can transmit a specific broadcast message in advance to the relay station by considering the frame offset, and the relay station can transmit data, which has to be transmitted in synchronization with the base station at the same time point or at the same frame number, to a Mobile Station (MS) at an exact time point.

Abstract: A method for performing fast base station switching in an mobile station capable of using multiple frequency assignments in a wireless communication system are provided, in which initial network entry to a base station managing at least two frequency assignments is performed in one of the at least two frequency assignments, overlay mode support information and FA information about the at least two frequency assignments are acquired by the initial network entry, the overlay mode support information indicating whether the base station supports multiple frequency assignments, the base station is notified that the mobile station will operate in an overlay mode using multiple frequency assignments based on the acquired information, and signals are transmitted and received to and from the base station in the at least two frequency assignments.

Abstract: A method for managing flow information of a mobile station by a target base station in a communication system is provided. The method includes receiving a ranging request message, which includes a flow identifier for each of flows between a serving base station and the mobile station and a change count indicating the number of times of an addition/change/deletion operation of a corresponding flow for each of flow identifiers, from the mobile station; and transmitting a ranging response message, which includes a validity indicator indicating whether the change count of each of the flow identifiers is valid or not, to the mobile station, wherein, when the validity indicator indicates that at least one change count among change counts for each of the flow identifiers is not valid, the ranging response message includes a list including the at least one change count that is not valid.

Abstract: A method and apparatus of a base station (BS) perform uplink (UL) random access in a wireless communication system. Random access channel information is determined on each of a plurality of frames constituting a superframe, and a control message comprising the random access channel information is broadcasted. A method and apparatus of a mobile station (MS) perform UL random access in a wireless communication system. A control message comprising random access channel information is received. A frame for minimizing a collision during a contention-based random access is selected based on the random access channel information. For data to be transmitted using the selected frame, it is determined whether the information to be transmitted is an access class with equal or higher priority to a received access class comprised in the random access channel information. A contention-based random access bandwidth request is transmitted to the BS for the data to be transmitted.

Abstract: Provided is a method for receiving a notification indicating a completion of a network re-entry procedure by a Base Station (BS) in a communication system. The method includes transmitting, to a Mobile Station (MS), a RaNGing ReSPonse (RNG-RSP) message including information indicating whether to omit any of processes or transmission of messages for performing a network re-entry procedure with the BS; and receiving, from the MS, a notification indicating the completion of the network re-entry procedure.

Abstract: A method and a Mobile Station (MS), for use in a wireless communication network comprising a plurality of Base Stations (BSs) capable of communicating with a plurality of MSs, wherein at least some of the BSs are Femtocell BSs (FBSs) and at least some of the BSs are Macrocell BSs (MBSs), for identifying the BSs at the MS, are provided. The method includes receiving at least one of a globally unique BS ID and an Operator ID from an FBS via a Broadcast CHannel (BCH), deriving a Closed Subscriber Group IDentifier (CSG ID) from the received at least one of the globally unique BS ID and the Operator ID, and determining, based on the derived CSG ID, if the FBS is a CSG FBS to which the MS is subscribed.

Abstract: A method of requesting and allocating an upstream bandwidth in an RS in a multi-hop relay BWA communication system is provided. The RS receives an upstream bandwidth request message including an upstream bandwidth from at least one MS for a predetermined time period, detects the requested upstream bandwidth from the upstream bandwidth request message, calculates a total requested upstream bandwidth by summing the requested upstream bandwidth from the at least one MS, generates a new upstream bandwidth request message including the total requested upstream bandwidth, and sends the new upstream bandwidth request message to a BS.

Abstract: An apparatus and method for implementing a vertical handoff between a WLAN and a broadband wireless communication network are provided. The vertical handoff apparatus includes a base station (BS) of the broadband wireless network and at least one access point (AP) of the WLAN within the cell coverage area of the BS, and a switch for forwarding packets between the BS and the at least one AP and processing a handoff between the BS and the at least one AP.

Abstract: Disclosed is a system and a method for controlling a handover of a mobile subscriber station in a broadband wireless access communication system. When serving base station determines to perform a handover of the mobile subscriber station, neighbor base stations to which the mobile subscriber station can be handed over, from among neighbor base stations of the mobile subscriber station, are determined based on a service quality level of service being currently provided to the mobile subscriber station. A handover request signal containing information related to the determined neighbor base station to which the mobile subscriber station can be handed over is transmitted to the mobile subscriber station.

Abstract: A method is provided for allocating resources by a Base Station (BS) in a wireless communication system. The method includes persistently allocating one or more resource slots among a plurality of resource slots, the persistently allocated one or more resource slots being allocated to corresponding one or more Mobile Stations (MSs), de-allocating at least one persistently allocated resource slot of the one or more persistently allocated resource slots, determining whether a hole is created due to the de-allocation among the one or more persistently allocated resource slots not de-allocated, and shifting a location of at least one of the one or more non-de-allocated persistently allocated resource slots when it is determined that the hole is created due to the de-allocation.

Abstract: A Mobile Subscriber Station (MSS) and an active Base Station (BS) for measuring/reporting a channel quality in a broadband wireless access communication system. The MSS includes a receiver for receiving, from an active BS, channel quality measurement information for the MSS to measure channel qualities of the active BS and a plurality of neighbor BSs, and channel quality report information defining a report mode for the MSS to report measured channel qualities of the active BS and the plurality of neighbor BSs, a processor for measuring the channel qualities of the active BS and the plurality of neighbor BSs according to the channel quality measurement information, and a transmitter for reporting the measured channel qualities of the active BS and the plurality of neighbor BSs to the active BS according to the channel quality report information.

Abstract: An apparatus and method for handover of a Mobile Station (MS) in a wireless communication system are provided. The method includes, if a ranging request signal is received from the MS attempting access through a handover, determining if the BS and a serving BS of the MS are the same BS based on the ranging request signal, and, if the BS and the serving BS are the same BS, determining the effectiveness of a Cipher-based Message Authentication Code (CMAC) included in the ranging request signal using previous authentication information of the MS. The serving BS denotes a BS from which the MS has been serviced before the handover. The previous authentication information of the MS denotes authentication information that the serving BS has used for authenticating the MS.

Abstract: A method for controlling a sleep mode operation by a mobile station (MS) in a communication system. In the sleep mode operation control method, after entering a sleep mode, the MS transitions to an awake state in a listening interval. When there is data to transmit or receive to/from a base station (BS) in the awake state, the MS causes a neutral interval following the listening interval to transition to the awake state, and transmits or receives the data. The neutral interval is an interval where transition to the awake state and sleep state is available according to the data transmission/reception of the MS operating in the sleep mode.

Abstract: A decoding method in a communication system using a Low Density Parity Check (LDPC) code. The method includes determining whether an LDPC codeword to be decoded is a general LDPC codeword to which a puncturing scheme is not applied or a punctured LDPC codeword to which the puncturing scheme is applied; if the LDPC codeword to be decoded is the punctured LDPC codeword, generating a child parity check matrix according to a mother parity check matrix indicative of a parity check matrix of the general LDPC codeword, and a puncturing pattern applied to the punctured LDPC codeword; and decoding the punctured LDPC codeword according to the child parity check matrix.

Abstract: An apparatus and method of controlling an action change gap interval in a multi-hop relay cellular network, includes constructing a first symbol included in a first frame as a first interval for a first action change and a second interval for exchanging data; and constructing a last symbol included in the first frame as a first interval for exchanging data and a second interval for a second action change. Accordingly, the system capacity and the system efficiency can be raised by reducing the overhead due to the action change gap in the cellular network.

Abstract: A method for measuring/reporting a channel quality in a broadband wireless access communication system. The method for reporting channel qualities of active BS and neighbor BSs measured by an MSS to the active BS when the MSS exists in a specific area covered by the active BS and neighbor BSs in a communication system includes the steps of: a) receiving channel quality report information indicative of channel periods of the channel qualities from the active BS, and receiving channel quality measurement information associated with individual channel qualities of the neighbor BSs and the active BS from the active BS; b) measuring SINRs of the neighbor BSs and the active BS according to the channel quality measurement information; and c) reporting the measured SINRs of the neighbor BSs and the active BS to the active BS.