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: 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: 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: 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: A method of a base station transmitting Multicast Broadcast Service (hereinafter referred to as MBS) includes transmitting MBS configuration information, including information about an MBS region which is a resource region to which MBS-related information is allocated and information about an MBS MAP, to a terminal and transmitting MBS data to the terminal through the MBS region. The information about the MBS region includes location information and a transmission parameter of the MBS region. The MBS MAP includes an MBS configuration information change indication which indicates whether the MBS configuration information is expected to change from first MBS configuration information to second MBS configuration information. MBS is effectively and persistently managed in a mobile wireless communication system supporting MBS.

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: 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.