Abstract: A hard handoff method between asynchronous CDMA (code division multiple access) system and synchronous CDMA system is provided. A hard handoff method between asynchronous CDMA (code division multiple access) system and synchronous CDMA system in accordance with an embodiment of the present invention includes following steps. First step is to transmit asynchronous CDMA channels from synchronous CDMA base stations with a purpose of synchronizing handoff time at synchronous CDMA base station and code used at synchronous CDMA base station. The transmission is done by a mobile terminal that is in communication with an asynchronous CDMA base station. The transmission is a part of handoff process and the mobile terminal performs hard handoff to synchronous CDMA base station. Second step is to report measured result to the asynchronous CDMA base station on the basis of intensity of asynchronous CDMA pilot channel received from an adjacent synchronous CDMA base station. The reporting is done by the mobile terminal.

Abstract: There is provided a method for performing an inter-packet data service node (PDSN) hard handoff. The method is implemented by setting up a channel link passing through a target base station controller (T-BSC), a source base station controller (S-BSC), a source packet control function (S-PCF) and a source-PDSN (S-PDSN) by establishing a channel link between the S-BSC and the T-BSC via a mobile station center (MSC) in an active packet session mode, performing the hard handoff between the S-BSC, the T-BSC and a mobile station (MS) and transmitting or receiving user packet data exchanged between the MS and the T-BSC through the established channel link to or from the S-PDSN in case the hard handoff is completed.

Abstract: There is provided a method for performing an intra-packet data service node (PDSN) hard handoff. The method is implemented by setting up a channel passing through a target base station controller (T-BSC), a source base station controller (S-BSC), a source packet control function (S-PCF) and a PDSN by establishing a channel link between the S-BSC and the T-BSC via a mobile station center (MSC) in an active packet session mode, performing the hard handoff between the S-BSC, the T-BSC and a mobile station (MS) and transmitting or receiving user packet data exchanged between the MS and the T-BSC through the established channel link to or from the PDSN in case the hard handoff is completed.