| 摘要 |
PURPOSE: A handoff method in an up-link synchronous transmission system is provided to separately consider only a hard handoff owing to an increase in a cell occupancy region as well as a performance and an accommodation capacity by allowing a base station to select a timing to be hard handoff to a base station which a mobile station takes as a reference timing and transmitting a control bit to the base station. CONSTITUTION: When a mobile station advances into a handoff region(301), the mobile station measures strengths of pilots of the current base station and a target base station(302) and determines whether the measured pilot strength of the target base station is sufficient(303). If the pilot strength of the target base station, the target base station receives a handoff instruction message from a base station controller and performs a handoff(304,305). The mobile station forms a link between the current base station and the target base station, and the base station controller measures/compares a quality of the mobile station signal of both links to determine whether a timing adjustment and a reconfiguration are required the state of the target base station and determine whether to perform handoff(307). If the adjustment and reconfiguration are required with the synchronous timing of the target base station, a timing hard handoff message is transmitted for synchronization in the target base station and timing adjustment and reconfiguration are re-set to perform a synchronous timing hard handoff(308). The current base station resets codes by the handoff message from the base station controller and communicates with the codes used in the target base station(309). The mobile station measures a strength of a pilot 'A' of the current base station to determine whether the measured value is sufficient(311). When the measure time reaches a handoff banishing timer limit value, the mobile station transmits a pilot strength measurement message and receives a handoff instruction from the base station controller(312). The mobile station excludes the pilot 'A' from an actual call list and transmits a handoff completion message, thereby completing a handoff process(313).
|
