Abstract: A method for performing a handoff in an ALL-IP network. The Mobile Station (MS) transmits measurement information to a new Base Transceiver System (BTS) and the Radio Network Controller (RNC) to start a handoff, the RNC requests the new BTS to set up a radio link with the MS. When the radio link is set up between the MS and the new BTS, the RNC requests to delete header information of the MS stored in an old BTS. The MS transmits a message including traffic header information to the new BTS, the new BTS transmits a binding update message to the MS. Then the MS transmits only the voice frame excluding the traffic header information to the new BTS.

Abstract: A system and method for handing over a terminal from a first base station to a second base station in a mobile communication system while the terminal is in communication with the first base station. Upon determining that the terminal must hand over to the second base station while communicating with the first base station in a first communication mode, a first base station controller controls the terminal such that it performs an initialization operation based on a second communication mode with the second base station. The first base station controller then notifies a first mobile switching center that the terminal has completed the initialization operation. The first mobile switching center notifies a second mobile switching center via a roaming gateway that the terminal must hand over to the second base station. The second mobile switching center controls a second base station controller such that it pages the terminal.

Abstract: A method for transmitting voice traffic in an ALL-IP-based mobile communication system. A mobile terminal first transmits header information using a signaling frame, and then separately transmits only a voice frame. A Node B detects the header information from the signaling frame received, stores the detected header information, and upon receipt of the voice frame, adds the header information to the voice frame and transmits the header-added voice frame to a core network.

Abstract: A handoff system and method using an MPTY (multiparty) service in a mobile communication system. When a terminal senses that it is located at the boundary of a WCDMA during a WCDMA communication service, it transitions to a first state. In the first state, the terminal requests an MPTY service to a BS in a CDMA network. If the strength of a first current WCDMA signal is less than a predetermined first threshold, the terminal transitions to a second state. In the second state, the terminal requests an available MPTY call to be maintained. If the strength of a second current WCDMA signal is less than a predetermined second threshold, the terminal transitions to a third state. Then the terminal establishes a CDMA call using the maintained MPTY call in the third state. If the strength of a third current WCDMA signal is less than a predetermined third threshold, the terminal ends the WCDAM call.

Abstract: A system and method for handing over a terminal from a first base station to a second base station in a mobile communication system while the terminal is in communication with the first base station. Upon determining that the terminal must hand over to the second base station while communicating with the first base station in a first communication mode, a first base station controller controls the terminal such that it performs an initialization operation based on a second communication mode with the second base station. The first base station controller then notifies a first mobile switching center that the terminal has completed the initialization operation. The first mobile switching center notifies a second mobile switching center via a roaming gateway that the terminal must hand over to the second base station. The second mobile switching center controls a second base station controller such that it pages the terminal.

Abstract: A soft handover apparatus and method in a CDMA mobile communication system are disclosed. According to the present invention, the step of comparing a predetermined threshold with the signal strength of a source Node B is further performed. If the signal strength is greater than the threshold and thus a handover required state is set, an assigned offset time is increased. No matter how strong signal is received from a target Node B, a soft handover procedure is performed only if the handover required state is maintained for the increased offset time.

Abstract: A handoff system and method using an MPTY (multiparty) service in a mobile communication system. When a terminal senses that it is located at the boundary of a WCDMA during a WCDMA communication service, it transitions to a first state. In the first state, the terminal requests an MPTY service to a BS in a CDMA network. If the strength of a first current WCDMA signal is less than a predetermined first threshold, the terminal transitions to a second state. In the second state, the terminal requests an available MPTY call to be maintained. If the strength of a second current WCDMA signal is less than a predetermined second threshold, the terminal transitions to a third state. Then the terminal establishes a CDMA call using the maintained MPTY call in the third state. If the strength of a third current WCDMA signal is less than a predetermined third threshold, the terminal ends the WCDAM call.

Abstract: A method for performing a handoff in an ALL-IP network including at least one MS (Mobile Station) for transmitting a signaling frame having a header and a voice frame to an old BTS (Base Transceiver System), which includes a header information storage for storing overhead information for the MS in association with a unique code of the MS, and an RNC (Radio Network Controller). The MS transmits measurement information to a new BTS and the RNC to start a handoff. Upon receipt of the measurement information, the RNC requests the new BTS to set up a radio link with the MS that has transmitted the measurement information. When the radio link is set up between the MS and the new BTS, the RNC deletes header information for the MS, stored in the header information storage of the old BTS. The MS transmits a message including traffic overhead information to the new BTS. Upon receipt of the message including the traffic header information, the new BTS transmits a binding update message to the MS.

Abstract: A method for controlling a mobile telephone in which user information and an automatic call number are previously registered in the mobile telephone. Upon receiving a user information check request and an automatic call request in a locked mode, the mobile telephone outputs the registered user information and connects a call to the registered automatic call number.

Abstract: A method for transmitting voice traffic in an ALL-IP-based mobile communication system. A mobile terminal first transmits header information using a signaling frame, and then separately transmits only a voice frame. A Node B detects the header information from the signaling frame received, stores the detected header information, and upon receipt of the voice frame, adds the header information to the voice frame and transmits the header-added voice frame to a core network.