Abstract: A method for detecting coverage loss during a sleep mode of a mobile station and an apparatus for performing the same are disclosed. The method for detecting coverage loss of a mobile station, which is operated in a sleep mode, in a broadband wireless access system comprises the steps of awaking regardless of a sleep window of a sleep cycle at a first time when a super frame header (SFH) is transmitted from a serving base station; detecting the super frame header; and operating for the sleep window or listening window in accordance with the sleep cycle if the detected result is successful, and awaking until the super frame header is successfully detected if the detected result is failed.

Abstract: A method for receiving and transmitting a paging message is disclosed. A method for receiving a paging message in an idle mode of a mobile station comprises receiving a paging indicator channel included in a super frame header from a base station; if a paging message of the mobile station exists after identifying the paging indicator, identifying a wake-up time of the mobile station from mapping information of the paging indicator channel; and receiving the paging message from the base station by waking up at the wake-up time. According to the embodiments of the present invention, the paging indicator channel including information useful for the mobile station to receive the paging message is added to the IEEE 802.16m frame structure, whereby the power consumed to receive the paging message can be reduced.

Abstract: Various methods of transmitting paging information in a wireless access system are disclosed. A method of transmitting paging information from a base station belonging to at least one paging groups according to one embodiment of the present invention includes the steps of allocating a paging group offset (PGO) per one specific one of at least one paging groups, transmitting a message including one paging group offset (PGO) per one specific paging group, and transmitting a broadcast channel (BCH) including paging group formation on the specific paging group at a timing point indicated by the paging group offset.

Abstract: A method for efficiently updating system information of a base station at a relay station of a broadband wireless access system and an apparatus for performing the method are disclosed. The method for updating system information of an advanced base station (ABS) at an advanced relay station (ARS) of a broadband wireless access system comprises receiving a first message, which includes changed information of the system information of the base station, from the base station; transmitting a second message for acknowledgment of the first message to the base station; and performing application for the changed information.

Abstract: A broadband wireless access system and, more particularly, a method for a mobile station and a base station to perform an efficient ranging procedure considering a ranging purpose and a device for performing the same are disclosed herein. A method of a mobile station for performing ranging in a broadband wireless access system, the method includes the steps of transmitting a first ranging preamble code for requesting ranging to a base station through a first ranging opportunity of a first frame, and, when a first message is received from the base station before a timer indicating a limited time point is expired, wherein the first message including a response to the first ranging preamble code is transmitted during the limited time point, determining whether or not the ranging request is successfully made by using the first message.

Abstract: The present invention relates to a wireless access system, and more particularly, to a method of transmitting/receiving a paging message by minimizing power consumption of a mobile station. A method of performing paging for a mobile station in idle mode comprises receiving a deregistration command message including a paging cycle, a paging offset and a paging group identifier and if moving away into a different cell area, performing a location update with a target base station of the different cell area. Preferably, the location update is performed only if moving away into an initially different cell area but is not performed if moving into another different cell area.

Abstract: A method for efficiently updating system information of a base station at a relay station of a broadband wireless access system and an apparatus for performing the method are disclosed. The method for updating system information of an advanced base station (ABS) at an advanced relay station (ARS) of a broadband wireless access system comprises receiving a first message, which includes changed information of the system information of the base station, from the base station; transmitting a second message for acknowledgment of the first message to the base station; and performing application for the changed information.

Abstract: A method for a handover with consideration of load status of cells is disclosed. The method for intra handover with consideration of load status of cells by a mobile station in a wireless communication system includes receiving a neighbor advertisement (MOB-NBR-ADV) message including load status information of neighbor cells from a serving base station, and performing intra handover according to the load status information of neighbor cells if there is at least a neighbor cell of which channel quality is equal to or higher than a handover threshold for a time duration among neighbor cells in an intra network.

Abstract: A method for paging in a wireless access system is disclosed. A method for efficiently paging a mobile station of an idle mode comprises allocating an identifier of a large paging group and an identifier of a specific one of small paging groups included in the large paging group to a broadcast channel region and transmitting a header including the broadcast channel region to the terminal. Accordingly, the present invention enables efficient paging.

Abstract: A method of paging in a wireless communication system is disclosed. In the method, a base station generates a paging advertisement message that includes a paging group ID bitmap indicating whether there are any mobile stations that perform paging for each of paging groups that include the base station, and transmits the paging advertisement message to the mobile stations.

Abstract: An Inter-RAT handover method is disclosed. A method for supporting an Inter-RAT handover by an IEEE 802.16m MS includes performing, by the MS, pre-registration in an Inter-RAT target BS using a tunneling, if a channel quality of an Inter-RAT neighbor cell is higher than a pre-registration threshold, and transmitting a handover request message for a handover to the target BS to a serving BS, if a channel quality of the neighbor cell is equal to or higher than a handover threshold during a time duration in a scanning of the neighbor cell and a channel quality of the target BS is equal to or higher than that of the neighbor cell. This handover method reduces a time required for a handover from an IEEE 802.16m network to a Non-802.16m network, provides a seamless service, supports a rapid recovery in case of a radio link failure, and increases handover reliability.

Abstract: A method of an efficient low duty mode (LDM) operation for a femto base station is disclosed. The method of a low duty mode (LDM) operation for a femto base station comprises operating at an available interval of a first length according to a default LDM pattern; and operating at an unavailable interval of a second length according to the default LDM pattern, wherein the available interval begins with a frame including a first preamble, the first preamble including information of carrier configuration and system bandwidth.

Abstract: A method for inter RAT handover is disclosed. The method for inter RAT handover comprises measuring cell quality of WiMAX neighbor cells from a user equipment of E-UTRAN and transmitting the measured result to an origin base station; and if RRC message is received from the origin base station, the RRC message including WiMAX signal, pre-registering with a target WiMAX base station using tunneling based on second layer protocol. Therefore, the user equipment can continue to receive a service with maintaining current service quality even though the user equipment moves to a heterogeneous network. In addition, it is possible to reduce the time required for the user equipment to perform handover to the target base station. Moreover, if there is a failure of a radio link when the user equipment performs handover, it is possible to enable fast recovery.

Abstract: A sleep mode operating method in a wireless communication system is disclosed. In a sleep mode operating method in a wireless communication system according to one embodiment of the present invention, a user equipment receives a sleep response (MOB_SLP-RSP) message including a sleep cycle and a listening window from a base station. For the listening window, the user equipment receives a last PDU indication indicating whether a PDU (protocol data unit) transmitted from the base station is a last PDU. The user equipment terminates the listening window according to the last PDU indication.

Abstract: A method of establishing security association during handover between heterogeneous networks in a radio access system is disclosed. A method of establishing security association before handover with a target base station included in a heterogeneous radio access network is performed comprises transmitting a request message to a service base station, the request message requesting the service base station to transfer authentication related information of a mobile station to a target network authentication server; and receiving a response message from the service base station before the handover with the target base station is performed, the response message including security related information used in a target network.

Abstract: A packet reordering method and a packet transmission method to implement reliable data communication are disclosed. The method of transmitting packets at a serving base station in case of a mobile station performing handover include, receiving a series of packets from an upper layer entity, and transmitting the series of packets one after the other to a target base station, wherein a packet of the series of packets includes an information field which represents whether the packet is the last transmitted packet. When the mobile station performs the I-RAT handover, the target serving station pre-reorders PDU packets, and transmits the reordered PDU packets to the mobile station, such that the mobile station can quickly transmit data without reordering the packets.

Abstract: A method for supporting mobility of a mobile station and the mobile station which supports the mobility are disclosed.

Abstract: A method for performing band handover in a broadband wireless access system is provided. In this method, a terminal in a band AMC mode in which the terminal transmits and receives data through a band selected from among bands to which a modulation scheme and a coding rate are adaptively applied receives channel status information of each band of a neighboring base station. The terminal then performs handover to the neighboring base station while maintaining the band AMC mode if it is determined based on the received channel status information that a channel status of each band of the neighboring base station satisfies a predetermined condition. This band handover method enables handover to be performed for each specific frequency band of a mobile terminal.

Abstract: A method for receiving a preamble signal of another communication system and a method for adaptively changing a measurement gap to discover another communication system are disclosed. A method for receiving a preamble signal from a base station of a second communication system by a communicating mobile station in a first communication system includes receiving measurement gap scheduling information from a base station of the first communication system, if a preamble signal of the second communication system is not received during an assigned measurement gap, changing the measurement gap, and receiving the preamble signal of the second communication system during the changed measurement gap.

Abstract: A fast uplink data transmission method for a handover is disclosed. This method effectively uses a handover signal when there is data to be transmitted to an uplink during an Intra Radio Access Technology (I-RAT) handover, such that it quickly transmits and receives uplink data. The method of transmitting uplink data in a wireless access system includes, transmitting a message including an information bit to a target base station by a mobile station during a handover, wherein the information bit indicates whether the uplink data is present, and receiving a radio resource for transmitting the uplink data from the target base station, if the information bit indicates the uplink data is present, wherein the radio resource is allocated by the target base station. So, uplink user data can be quickly transmitted to a destination while the UE performs the handover.