| 摘要 |
PURPOSE: A hand-off method of a CDMA communication system is provided to make a packet data service possible after a hand-off to a PZ_ID(Packet Zone Identifier) changing area by transmitting an information message as to PZ_ID, which is supposed to be changed, to a mobile station having an activated voice call as a traffic channel. CONSTITUTION: A source base station decides a hand-off to a target base station based on a PSMM(Pilot Strength Measurement Message) from a mobile station which decided that a pilot signal intensity of a target base station is satisfied with a hand-off generation condition, and transmits a hand-off required message to a mobile switching center(S10). The switching center transmits a hand-off required message to a target base station for requesting a wireless resource allocation of the target base station(S11). The target base station allocates a wireless resource necessary for a hard hand-off and transmits a null forward traffic channel frame to the mobile station(S12), and transmits a Hand off Request Ack message to the mobile switching center(S13). The mobile switching center prepares a call switch from a source base station to a target base station, and transmits a hand-off command from the target base station to a source base station(S14). The source base station transmits a hand-off direction message to the mobile station for instructing a hand-off to the mobile station(S15). The mobile station transmits an MS Ack Order message to the source base station(S16). The source base station transmits a hand-off commenced message to the mobile switching center(S17). The mobile base station transmits a reverse traffic channel frame or a preamble to the target base station(S18). The mobile station transmits a hand-off completion message to the target base station(S19). The target base station transmits a BS Ack Order message to the mobile station(S20). The target base station transmits an in-traffic system parameter message including a PZ_ID of the target base station to the mobile station(S21). The mobile station transmits the MS Ack Order to the target base station(S22). The mobile station transmits a Clear Command message to the source base station(S24). The source base station transmits a message for reporting a call resource releasing completion(S25).
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