Abstract: A system is provided for performing location update in a wireless mobile communication system that uses an Internet protocol (IP) address and is classified as at least one paging group. A serving base station (BS) sends a message including an identifier of a paging group where the serving BS is located, determines whether there is a change in IP subnet of a mobile station (MS) upon receipt of a location update request from the MS, and upon recognizing a change in IP subnet of the MS, stores information on a new IP subnet and notifies the change in the IP subnet to the MS. Upon detecting a need for location update, the MS sends a request for location update to a serving BS, and receives a location update success notification and an allocated temporary IP address from the serving BS.

Abstract: A system and method for performing handover in a wireless mobile communication system are provided. In a Mobile Station (MS)-initiated scanning method of an (MS) in a wireless mobile communication system having at least two frequency bands with different central frequencies, the MS receives from a serving Base Station (BS) a mobile neighbor advertisement message including information about available radio resources of the neighbor BSs, transmits a new scanning request message to the serving BS, if the MS determines to measure Carrier-to-Interference and Noise Ratios (CINRs) of pilot signals from the serving BS and the neighbor BS, receives from the serving BS a response message for the scanning request message, including information about a BS which has reserved radio resources for a predetermined one of the at least two frequency bands, and measures the CINRs of the pilot signals in the predetermined frequency band.

Abstract: A method for determining a handoff of a mobile station (MS) in a mobile communication system. In the method, a serving base station (BS) measures a level of a first uplink signal by monitoring an uplink to the MS. The serving BS receives a level of a second uplink signal, measured and reported by at least one neighbor BS. The serving BS determines a handoff for the MS considering the level of the first uplink signal and the level of the second uplink signal.

Abstract: Disclosed is a method for transmitting an uplink data during handoff. A method for transmitting uplink data in a soft handoff system, in which a mobile station is simultaneously connected with at least two base transceiver systems under a control of a base station controller, includes selecting one of the base transceiver systems as a main base transceiver system, transmitting uplink signals to the main base transceiver system and sub-base transceiver systems, and transmitting by the sub-base transceiver systems received uplink signals to the main base transceiver system. Through the method, a main BTS for diversity combining and decoding soft bit strings is established among BTSs connected to a mobile station, so that it is possible to distribute a data processing amount centralized on a BSC to a BTS.

Abstract: Disclosed is a handoff method connected with resource allocation in order to prevent QoS degradation, which may occur during or before/after a handoff on account of channel state change resulting from the mobility of a radio communication apparatus. To this end, a serving base station currently-connected to the radio communication apparatus and a target base station to be connected after a handoff periodically or non-periodically measure uplink/downlink channel states in relation to the radio communication apparatus, and the target base station allocates resources (e.g., time slot, specific subcarrier, or specific frequency band) most suitable for the service requested from the radio communication apparatus during a handoff, thereby preventing QoS degradation due to the handoff.

Abstract: A mobile node (MN) connected to a first radio network transmits location information of a correspondent node (CN) to a base station (BS) constituting a second radio network. The BS determines whether it can establish a data transmission path to the CN, using network contract information of the second radio network and the location information of the CN. If the BS can establish the data transmission path, it determines a data transmission path to the CN using the network contract information of the second radio network and the location information of the CN, and transmits an identifier (ID) of the second radio network and service connection possibility/impossibility information to the MN. The MN establishes a connection to the second radio network, and communicates with the CN via the data transmission path.

Abstract: A method for determining an execution time of a VHO between base stations having different wireless interfaces in handoff among IP-based wireless access networks. The method includes: computing an execution time period of the VHO using identification information of the base stations, types of handoff protocols, a method for transferring data among the base stations, and transmission/reception mode information of an MT; computing first RSS information using the computed time period, the first RSS information representing an RSS threshold value of a home base station based on which the handoff must be performed before a link from the MT to the home base station is down; and determining the execution time of the handoff, including an initialization process for determining to perform the handoff using the first RSS information and RSS information values of the base stations.

Abstract: A handoff method in a mobile communication system using frequency hopping-orthogonal frequency division multiplexing (FH-OFDM). A mobile host predicts a handoff according to strength of transmission power of a currently serving base station, reserves a physical channel required for the handoff associated with at least one candidate base station, selects a handoff target base station from the at least one candidate base station, releases a channel with the serving base station, and performs data communication with the target base station through the reserved physical channel.

Abstract: A handoff method in a communication system where BSs providing different radio access interfaces to an MS are connected to an IP-based network through routers. A handoff from a first BS to a second BS is decided for an MS that receives IP service data from the first BS and an L2 connection is established between the MS and the second BS. During the L2 connection establishment, movement of the MS in the IP network is detected. Handoff negotiations are conducted between the first and second BSs by IP signaling. If the handoff is available according to the negotiations, mobility management control is performed considering movement of the MS. The IP service data is transmitted to the MS in a network path reset to the second BS by the mobility management control and an L2 connection is released between the MS and the first BS.

Abstract: A method quickly resuming a downlink service in a hard handover in a cellular mobile communication system. To provide the fast downlink service to an MS during a hard handover from an OBS to an NBS, the NBS receives handover user information from the OBS, and generates an MS temporary ID using the handover user information to identify the MS. If user data is generated for the MS before a connection is established for traffic transmission between the MS and the NBS, the NBS transmits the user data to the MS on an HCCH using the MS temporary ID.