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: Disclosed are a system and a method for selecting a new serving base station when a drop occurs in a mobile subscriber station in a broadband wireless access communication system including the mobile subscriber station, a serving base station communicating with the mobile subscriber station, and a plurality of neighbor base stations, different from the serving base station. The mobile subscriber station receives information related to the neighbor base stations from the serving base station communicating with the mobile subscriber station. The mobile subscriber station monitors the frequency bands of the neighbor base stations included in the information related to the neighbor base stations if the drop is detected in order to detect target base stations capable of serving as a new serving base station for communicating with the mobile subscriber station when the drop occurs in the mobile subscriber station according to a monitoring result for the frequency bands of the neighbor base stations.

Abstract: Disclosed is a method for enabling a mobile station existing in a serving cell area to perform a handover procedure in a broadband mobile communication system including the mobile station, a serving base station providing a service to the mobile station, and one or more target base stations containing at least one target cell area overlapping with the serving cell area occupied by the serving base station. The method includes transmitting a handover request message from the mobile station to the serving base station when it is detected that a performance of a handover is necessary; and transmitting a handover indication message containing handover cancel information to the serving base station when the mobile station determines a cancel of the handover while the mobile station is being handed over to one or more target base stations by the serving base station.

Abstract: A call processing method and apparatus for effective QoS (Quality of Service) control in a mobile communication system is provided. In one embodiment of the present invention, a base station checks available resources upon receipt of a call set-up request from a mobile station. If the resources are not enough to satisfy the QoS of the requested call, the base station suspends a call in progress with a lower service level than that of the requested call. Later, if available resources are secured, the base station resumes the suspended call.

Abstract: A method of releasing a supplemental channel in a CDMA mobile communication system. Upon request of releasing the supplemental channel, a base station determines whether to transition from the current state to another state, generates a first message indicating release of the SCH and a next state to transit to, transmits the first message to a mobile station. Upon receipt of a second message in response to the first message from the mobile station, the base station releases the SCH, and transits to the next state.

Abstract: Dynamically allocating a frame cell (FC)/subchannel in a mobile communication system by an access point that receives channel quality information (CQIs) fed back from access terminals, determines a modulation and coding scheme (MCS) to be applied to the access terminals based on the CQIs, and if access terminals whose FCs/subchannels must be changed are detected from the access terminals, sends an FC/subchannel change request to an access router. The access router allocates an FC/subchannel set by selecting a number of FCs/subchannels according to the FC/subchannel change request, and transmits information on the allocated FC/subchannel set to the access point. The access point selects and allocates a particular FC/subchannel from among FCs/subchannels in the FC/subchannel set information to the access terminals whose FCs/subchannels must be changed, based on CQIs last received from the access terminals.

Abstract: A method and apparatus for transmitting a DL-WUCH for a mode transition in a sleeping state in a broadband wireless communication system are provided. In the broadband wireless communication system, a base station (BS) transmits control information to a plurality of subscriber stations (SSs) on a common control channel. To demodulate a control channel signal received from the BS, an SS receives a wakeup channel signal which indicates whether the control channel signal includes control information for the SS, reads a wakeup channel indicator at a predetermined position assigned to the SS of the wakeup channel signal, and determines whether to demodulate the control channel signal according to the wakeup channel indicator.

Abstract: A system and method for dynamically allocating channels in a wireless communication system including multiple sub-channels and multiple frame cells, each of the sub-channels being an assembly including a preset number of sub-frequency bands divided from an overall frequency band, the frame cells using each of the sub-channels as a basic transmission unit and having a frequency domain and a time domain occupied by the sub-channels. A mobile station transmits channel quality information of frame cells to an access point. An access router transmits channel allocation information about the multiple frame cells and sub-channels determined according to the received channel quality information to the access point, and the access point receives the channel allocation information about the multiple frame cells and sub-channels, compares the channel allocation information with newest channel quality information, and allocates a sub-channel of a frame cell selected according to the comparison to the mobile station.

Abstract: A method for mode transition of a subscriber station between a sleep mode and an awake mode in a broadband wireless access communication system including a base station and at least the subscriber station, the subscriber station having data to transmit in the awake mode and not having data to transmit in the sleep mode is disclosed. The method includes receiving a dedicated orthogonal code from the base station and transiting into the sleep mode in the awake mode, the dedicated orthogonal code being allocated exclusively to the subscriber station; and in the sleep mode, transmitting a message to the base station by means of the dedicated orthogonal code in order to transit into the awake mode.

Abstract: Disclosed is an efficient random access method which enables a subscriber station to gain access to an uplink in broadband mobile communication system including the subscriber station and a base station. The method enables a subscriber station to perform re-access to a base station at a high speed in the mobile communication system, in which an access channel is allocated so that the subscriber station and the base station can transmit a message to each other using a code within a predetermined period of time, wherein, the method includes the steps of: the subscriber station receiving a request rejection message including a dedicated code in response to a request message transmitted from the subscriber station to the base station through the access channel; and the subscriber station checking the received request rejection message, and re-transmitting the request message in a contention-free method corresponding to the dedicated code which is included in the request rejection message.

Abstract: Disclosed is a method for controlling an operational state of a medium access control layer in a broadband wireless access communication system. The method includes the steps of performing an uplink access of a contention-based scheme to an access point using resources required to perform the uplink access according to the contention-based scheme when data to be transmitted in an access state is detected, and being allocated resources required to perform an uplink access of a contention-free scheme from the access point in a case of failing in the uplink access of the contention-based scheme; and performing a state transition from the access state into the traffic state in a case of having been allocated the resource required for the contention-free scheme, and performing the uplink access of the contention-free scheme to the access point using the allocated resource in the traffic state.

Abstract: A common packet channel assignment method and device in a CDMA (Code Division Multiple Access) communication system is disclosed. The method comprises transmitting an access preamble signal having channel information which is used to access a base station, and then receiving an; access preamble acquisition indicator signal from the base station in response to the access preamble signal. A collision detection preamble for detecting a collision is transmitted in response to the received access preamble acquisition indicator signal. A first signal indicating acquisition of the collision detection preamble and a second signal indicating channel assignment are received, both of which the base station has transmitted in response to the collision acquisition signal. Upon receipt of the first signal, a common packet channel is assigned according to information designated by the second signal.

Abstract: A device for generating a block sequence number in a communication system for transmitting frames comprised of a block sequence number and a succeeding data field. The block sequence number is assigned to every block unit corresponding to a multiple of the byte to transmit the increased number of data bits, so that the data bits in at least one of the frames can be verified in byte unit at a receiving side. A difference D is calculated between a first byte sequence number A of m bits indicating a first byte of transmission data and a second byte sequence number B of m bits indicating data of the first byte in a second block succeeding a first block to which the transmission data belongs. The first byte sequence number A is converted to a block sequence number of n bits smaller in number than m bits using difference D.

Abstract: A system for transmitting a message for generating an Internet Protocol version 6 (IPv6) address is provided. The system includes at least one access terminal, an access point, and a router. The access terminal transmits a first medium access control (MAC) layer connection message including its own MAC address and a fast address setup indication field to the access point. The access point receives the first MAC layer connection message from the access terminal, and determines whether a duplicate MAC address of the MAC address of the access terminal exists in the same sub-network.

Abstract: A channel assigning device and method in a CDMA communication system is described. According to one aspect of the present invention, in a channel assigning method for a base station, the base station establishes a first dedicated channel and communicates with a mobile station on the established dedicated channel. Then, the base station determines the type of a second dedicated channel and channel spreading code information upon request for additional assignment of a second dedicated channel while in the conversation state, assigns the second dedicated channel, and generates a channel assignment message including the determined channel assignment mode and channel spreading code information to assign the second dedicated control channel. The base station transmits the channel assignment message to the mobile station on the first dedicated channel.

Abstract: A broadband wireless access communication system having a sleep mode in which there is no data to be transmitted or received to/from a base station by a subscriber station, and an awake mode in which there is data to be transmitted or received to/from the base station by the subscriber station. The subscriber station sets a next sleep mode after a sleep interval between a start time of the sleep mode and a start time of the awake mode has reached a given maximum window value. The subscriber station receives a traffic indication message indicating absence of data to be transmitted from the base station after the start time of the awake mode; transmits a sleep request message to the base station; receives a response message to the sleep request message from the base station; and then operates in the next sleep mode.

Abstract: A system and method for controlling data rates of a reverse packet data in mobile communication system for transmitting reverse packet data from a mobile station to a base station over a reverse packet data channel at a plurality of data rates. The present invention provides an apparatus and method for improving throughput of an entire system by enabling a base station's scheduler to rapidly assign reverse resource for a mobile station that has completed its data transmission to other mobile stations.

Abstract: A broadband wireless access communication system having a sleep and an awake mode. A subscriber station controls the sleep mode upon receiving a denial response of a base station to a sleep request from the subscriber station to the base station. If the denial response from the base station is received, the subscriber station retransmits a sleep request to the base station after a lapse of waiting duration. If the denial response from the base station is received, the subscriber station holds retransmission of a sleep request to the base station until an unsolicited response to the sleep request is received from the base station.

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.

Abstract: There is provided a data transmitting method in a CDMA system. In the CDMA system, a control hold state and an active state are set for data transmission between a mobile station and a base station. The control hold state is entered to transmit a control signal on a dedicated control channel and the active state is divided into a low rate transmission substate for transmitting a small amount of data on the dedicated control channel or/and a fundamental channel and a high rate transmission substate for transmitting a large amount of data on a supplemental channel and on at least one of the dedicated control channel and the fundamental channel.