Abstract: A method for handover between heterogeneous radio access networks is disclosed. When a multi-mode mobile station performs Inter-RAT handover, pre-authentication is performed before implementing a link layer handover procedure with a target access point. The pre-authentication method has as little an effect on currently served quality of service as possible and the handover is efficiently performed using the pre-authentication method. The pre-authentication is performed through medium independent handover (MIH) and various MIH primitives for pre-authentication are provided.

Abstract: A method of protecting location privacy of a mobile station when the mobile station enters a network is disclosed. A method of supporting location privacy comprises the steps of transmitting a ranging code for performing initial ranging; and receiving a message including temporary station identifier after transmitting a ranging request message including MAC address of a mobile station. In this case, the temporary station identifier is used to provide security of a media access control (MAC) address or mapping information of the MAC address and station identifier, wherein the MAC address is to identify a mobile station within a base station.

Abstract: A method of performing random access in a broadband wireless access system is disclosed. The method includes performing first random access through at least one of a plurality of random access channels, receiving information about the number of access-failed channels among the plurality of random access channels from a base station, when the first random access fails, and performing second random access according to a probability value calculated based on the received information. The present invention increases utilization of random access channels and can effectively schedule an uplink bandwidth, thereby providing an efficient ranging method.

Abstract: The present invention relates to methods for sending and receiving security related information during handover on a wireless access system and methods for managing a traffic encoding key (TEK). In one example of the present invention, a security performance negotiation method for supporting the hand-over of mobile handsets comprises the steps of: carrying out, in advance, a security performance negotiation procedure with a first base station (T-ABS), prior to registration on the first base station; generating a traffic encoding key (TEK) by using security related information acquired by means of the security performance negotiation procedure; and carrying out a general performance exchange procedure encoded by means of the TEK and a zone switch with the first base station.

Abstract: A data transmission and reception method for ensuring privacy and security and a method for identifying a Mobile Station (MS), while ensuring the location privacy of the MS in a wireless access system are disclosed. The MS identification method includes transmitting a ranging request message including a hashed Medium Access Control (MAC) address to a Base Station (BS), for initial ranging, and receiving a ranging response message including a temporary station Identifier (ID) from the BS. The temporary station ID is used to provide security to a MAC address or station ID by which the BS uniquely identifies the MS.

Abstract: A method of protecting control signaling transceived between a mobile station and a base station in a wireless access system is disclosed. And, a method of encrypting control signals selectively is disclosed. The present invention defines new control signal encryption key (CSEK) and group control signal encryption key (GCSEK) for encrypting a control signal and discloses methods of protecting a control signal using the control signal encryption keys. Moreover, although the new control signal encryption key and the like are not used, the present invention efficiently protects control signaling by selectively encrypting control signals.

Abstract: A device, system and method for performing an uncontrolled handover in a mobile station, a ranging request message including an identifier of a serving base station and a first identifier used in the serving base station is transmitted to a first target base station to perform network (re)entry to the first target base station, and a ranging response message including security information and a second identifier for identifying the mobile station is received from the first target base station.

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 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.

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 of establishing security association between heterogeneous networks is disclosed. The method comprises a first step of receiving information of heterogeneous networks near a mobile station; a second step of transmitting a request message requesting authentication related information transfer to a target heterogeneous network where the mobile station intends to perform handover, among the heterogeneous networks near the mobile station; and a third step of receiving authentication related information and key related information of the target heterogeneous network. At this time, the first step, the second step, and the third step are preferable performed before handover is performed between heterogeneous networks.

Abstract: A method of performing random access in a broadband wireless access system is disclosed. The method includes performing first random access through at least one of a plurality of random access channels, receiving information about the number of access-failed channels among the plurality of random access channels from a base station, when the first random access fails, and performing second random access according to a probability value calculated based on the received information. The present invention increases utilization of random access channels and can effectively schedule an uplink bandwidth, thereby providing an efficient ranging method.

Abstract: A method of performing initial ranging in a wireless communication system includes transmitting a ranging request message and receiving a ranging response message including a temporary identifier for a mobile station which transmits the ranging request message. By using the temporary identifier which identifies the mobile station before establishing authentication, it is possible to prevent the MAC address from being exposed to a malicious attacker through a wireless interface and to secure location privacy.

Abstract: A method of enabling a mobile station to perform initialization to a base station in a wireless communication system is provided. The method includes synchronizing with the base station, obtaining an uplink parameter based on the synchronization, performing initial ranging by using the uplink parameter and establishing security association between the mobile station and the base station while performing the initial ranging. During the initial ranging, a mobile station's unique identifier or control signaling can securely be transmitted.

Abstract: A method for handover between heterogeneous radio access networks is disclosed. When a multi-mode mobile station performs Inter-RAT handover, pre-authentication is performed before implementing a link layer handover procedure with a target access point. The pre-authentication method has as little an effect on currently served quality of service as possible and the handover is efficiently performed using the pre-authentication method. The pre-authentication is performed through medium independent handover (MIH) and various MIH primitives for pre-authentication are provided.

Abstract: Various methods and apparatus for encrypting signals in a wireless access system are disclosed. A method for selectively encrypting a management message in an MS includes steps of generating a Medium Access Control Protocol Data Unit (MAC PDU) including the selectively encrypted management message and an Fragmentation Extended Header (FEH) and transmitting the MAC PDU to the BS. The FEH includes indication information indicating whether the management message was encrypted.

Abstract: A method for performing a handover between MBS zones of a mobile station receiving multicast and broadcast service (MBS) data in a wireless access system is disclosed. The method for performing the handover between first and second MBS zones of the mobile station in a wireless access system includes receiving the MBS from a first base station belonging to the first MBS zone which uses a first MBS zone identifier (ID), requesting the handover between the first and second MBS zones, receiving parameter information including a second MBS zone identifier (ID), from the first base station, and receiving the MBS from a second base station belonging to the second MBS zone, using the parameter information, wherein the second MBS zone uses the second MBS zone identifier (ID) which is needed to receive the MBS.

Abstract: A method of protecting location privacy of a mobile station when the mobile station enters a network is disclosed. A method of supporting location privacy comprises the steps of transmitting a ranging code for performing initial ranging; and receiving a message including temporary station identifier after transmitting a ranging request message including MAC address of a mobile station. In this case, the temporary station identifier is used to provide security of a media access control (MAC) address or mapping information of the MAC address and station identifier, wherein the MAC address is to identify a mobile station within a base station.

Abstract: A method of providing location privacy of a mobile station in a wireless access system is disclosed. The method of providing location privacy of a mobile station comprises the steps of transmitting a deregistration request message to a serving base station, the deregistration message requesting entry to an idle mode; and receiving a deregistration command message from the serving base station, the deregistration command message including a temporary identifier allocated to the mobile station. In this case, the temporary identifier is an identifier for uniquely identifying the mobile station from a paging group to which the serving base station belongs.