Patent ID: 7151756
Filing Date: 2006-12-19
Classification: H04B,H04W

Abstract:
1. A hard handoff method from an asynchronous CDMA base station to a synchronous CDMA base station, comprising: a first step of, at the synchronous CDMA base station, transmitting asynchronous CDMA channels including an asynchronous CDMA synchronization channel and an asynchronous CDMA common pilot channel to a mobile terminal communicated with the asynchronous CDMA base station for synchronizing a handoff time at the synchronous CDMA base station, wherein the synchronous CDMA base station further transmits synchronous CDMA channels to another mobile terminal; a second step of, at the mobile terminal, measuring each intensity of the asynchronous CDMA common pilot channels outputted from the synchronous CDMA base station and the asynchronous CDMA base station to report the measured result to the asynchronous CDMA base station; a third step of, at the asynchronous CDMA base station, transmitting a handoff request message to the synchronous CDMA base station on the basis of the result reported from the mobile terminal; a fourth step of, at the synchronous CDMA base station which receives the handoff request message, transmitting an information to the asynchronous CDMA base station, wherein the information is necessary to perform the hard handoff; and a fifth step of, at the mobile terminal, performing the hard handoff from the asynchronous CDMA base station to the synchronous CDMA base station in response to the information received from the asynchronous CDMA base station through a traffic channel.