Abstract: A method of transmitting broadcast information by using multiple carriers is provided. The method includes: configuring a superframe for an operation of the multiple carriers; and transmitting the broadcast information through at least one primary carrier selected from the multiple carriers. Accordingly, the multiple carrier system can effectively manage respective carriers, and particularly can effectively use radio resources in transmission of broadcast information.

Abstract: A method of transmitting data for reducing interference in a hierarchical cell structure including a macro base station (BS) providing multi carriers and a femto BS providing a single carrier includes performing a channel scan within an interfered carrier to acquire channel state information and neighbor femto BS information if interference with the femto BS occurs; transmitting a channel measurement report including the channel state information and the neighbor femto BS information to the macro BS; and transmitting data through a carrier changed by receiving carrier change information from the macro BS.

Abstract: In a power saving operation management method in a mobile communication system, a base station receives a sleep mode entering request message from a mobile station desiring to enter the sleep mode, determines a sleep period type and a parameter by analyzing a combination of radio channels between the mobile station and the base station, and transmits a sleep mode entering response message including the sleep period type and the parameter.

Abstract: In an Automatic Repeat reQuest (ARQ) method for recovering ARQ data by a target base station when handover of a mobile terminal is performed from a serving base station to the target base station in a portable Internet system is provided. First ARQ data, which includes a first service data unit (SDU), a first ARQ block sequence number, and a first sub-ARQ block sequence number, that are buffered in the serving base station are received and second ARQ data, which includes a second SDU, are received from the serving base station. The received first SDU is divided into ARQ blocks and is transmitted to the mobile terminal; and the received second SDU is divided into the ARQ blocks and is transmitted to the mobile terminal.

Abstract: There is provided a method in which a base station transmits downlink data in a wireless access system supporting multi-carriers. The method comprising negotiating with a terminal about a sleep mode parameter including information on a sleep window and a listening window, if the terminal is operating in a sleep mode, transmitting information on a carrier used for data transmission among the multi-carriers to the terminal through at least one of a medium access control (MAC) header, a MAC control message, and a control channel and transmitting data to the terminal based on the information during the listening window. Accordingly, waste of radio resources can be prevented by making efficient use of the multi-carriers even though the terminal is operating in the sleep mode.

Abstract: There is provided a method for handover of a terminal in a wireless access system using multi-carrier operation. The method comprises: receiving a handover command message from a serving base station; and performing network reentry to a target base station based on the handover command message, wherein the handover command message includes information required for handover to the target base station and information on whether the target base station supports handover using multi-carriers. Accordingly, it is possible to efficiently perform the handover in the wireless access system supporting the multi-carriers.

Abstract: A terminal receives a map scheduling interval that is set to be greater than a multicast and broadcast service map transmission cycle by a base station from the base station, and receives a multicast and broadcast service map from the base station according to the received map scheduling interval.

Abstract: In a method of transmitting broadcasting information, the broadcasting information is classified into fixed broadcasting information for transmitting to a fixed position of a super-frame and variable broadcasting information to be variably transmitted in the form of a broadcasting message. The fixed broadcasting information may be classified into primary broadcasting information having a short cycle and secondary broadcasting information having a long cycle.

Abstract: The present invention relates to a device for performing a security function in a medium access control (MAC) layer in a wireless portable Internet system and an authentication method thereof. In the wireless portable Internet system including a physical layer and the MAC layer, a security sublayer (i.e., the device for performing the security function in the MAC layer) is provided on an MAC common part sublayer. The security sublayer includes a privacy key management (PKM) control management module, a traffic data encryption/authentication module, a control message processing module, a message authentication module, a Rivest Shamir Adleman (RSA)-based authentication module, an authentication control/security association (SA) control module, and an extensible authentication protocol (EAP) encapsulation/decapsulation module.

Abstract: A method for measuring a position includes: allocating a first ranging code and a first ranging region for a mobile station; receiving a second ranging code and allocation information on a second ranging region of the mobile station from a neighboring base station; transmitting the first ranging code and the second ranging code to the mobile station; receiving the first ranging code from the mobile station in the first ranging region; calculating a received timing adjustment value of the first ranging code; receiving a received timing adjustment value of the second ranging code from the neighboring base station; and measuring the position of the mobile station according to the received timing adjustment value of the first ranging code and the received timing adjustment value of the second ranging code. Therefore, the cost and efficiency can be improved by measuring the position of the mobile station by changing the ranging method used in the conventional system.

Abstract: The present invention relates to a handover method of a mobile station in a wireless communication system, and a base station and a mobile station for the same. A list of neighboring base stations that can accept a handover of a mobile station is shared by the mobile station and a serving base station before the mobile station performs the handover so as to reduce handover delay time in a high speed environment through addition, the active base station set managed by the mobile station and the serving base station can be managed with consideration of radio signal quality and resource state of each of the neighboring base stations included in the active base station set, and thus when the mobile station attempts a network re-entry process to a target base station that is not ready for the handover of the mobile station due to a loss of a handover control message, a handover failure due to a lack of radio resources can be prevented, thereby increasing a handover success rate.

Abstract: Upper level protocol message transmitting method and apparatus are provided based on a new management message to be used in a portable Internet system. When a base station receives the upper level protocol message to be broadcast, it includes the same in the management message and transmits the included message to all the mobile terminals of a cell, and thus, the total number of the transmissions is decreased, thereby increasing a wireless efficiency.

Abstract: The present invention relates to encryption and decryption apparatuses in a wireless portable Internet system, and a method thereof. In the wireless portable Internet system, a subscriber station and a base station share an encryption during key distribution, and a message is encrypted with the encryption key and transmitted. In this case, a first initial vector is generated for encryption based on information shared by the subscriber station and the base station in a wireless channel, and the message is encrypted with the first initial vector and the encryption key and is then transmitted. In addition, a second initial vector for decryption is generated based on information shared by the subscriber station and the base station in the wireless channel, and the encrypted message is decrypted with the second initial vector and the encryption key. Herein, the first initial vector corresponds to the second initial vector.

Abstract: Disclosed is a handover method in a wireless portable Internet system. When a mobile subscriber station is in a drop state, a ranging request message including an identifier of a previous base station and a string generated by encoding the ranging request message using an authentication key of the previous base station is sent to a target base station. The target base station requests the previous base station to execute handover of the mobile subscriber station using the identifier of the previous base station included in the ranging request message. The previous base station carries out message authentication using the encoded string received from the target base station, and when the authentication is successful, transmits information about the mobile subscriber station that is required for handover to the target base station. Accordingly, a ceaseless service session can be provided even in the drop state.

Abstract: Disclosed is a method for constituting a layered cell, which is for constituting a cell in an OFDMA (Orthogonal Frequency Division Multiple Access) mobile communication system. The method includes: (a) dividing L carriers having orthogonality into M sub-channels; (b) dividing the carriers into N groups each having the M sub-channels; (c) grouping the N groups by an arbitrary integer into K classes; and (d) constituting a plurality of layered cells corresponding to the K classes. According to the present invention, the conception of the independent classes is introduced for a plurality of carriers to facilitate the use of the carriers to a system requiring an independent wireless area, allowing design of sectors and cells at a single frequency.

Abstract: In an Automatic Repeat reQuest (ARQ) method for recovering ARQ data by a target base station when handover of a mobile terminal is performed from a serving base station to the target base station in a portable Internet system is provided. First ARQ data, which includes a first service data unit (SDU), a first ARQ block sequence number, and a first sub-ARQ block sequence number, that are buffered in the serving base station are received and second ARQ data, which includes a second SDU, are received from the serving base station. The received first SDU is divided into ARQ blocks and is transmitted to the mobile terminal; and the received second SDU is divided into the ARQ blocks and is transmitted to the mobile terminal.

Abstract: An apparatus for wavelength assignment in wavelength multiplexing optical ring networks includes: a node section receiving a connection setup request, the node section comprising a plurality of nodes; and a wavelength assignment controller connected to the node section for, when the connection setup request occurs, determining paths available between the nodes using sparse wavelength conversion and limited wavelength conversion, calculating the total number of gaps for each node available, and assigning wavelengths to a path having the smallest total number of gaps. The present invention assigns wavelengths in consideration of both sparse wavelength conversion and limited wavelength conversion to minimize the call-blocking probability, and uses the wavelength in adjacent partitions to calculate the number of gaps for each wavelength and the total number of gaps.