Patent ID: 6901257

Claim:
A mobile communication system, comprising: one or more base stations disposed in each of service areas for performing radio communication with a mobile station positioned in any of said service areas; one or more base station controllers serving as a master station of said one or more base stations and having channel station data indicative of whether there is a channel between a mobile switching center as a master station thereof and another system mobile switching center in another system of different specifications, said one or more base station controllers having means for, when a mobile station enters the service area of the other system and then an inter-system hand-off control process is to be performed via said mobile switching center as the master station while communicating with said mobile station through said base station, determining whether or not, based on said channel station data, said mobile switching center as the master station has a channel connected to the other system mobile switching center, and, if said mobile switching center as the master station has a channel connected to the other system mobile switching center, requesting an inter-system hand-off control process as a process for switching communication channels between said mobile station and said other system mobile switching center to said mobile switching center as the master station, and, if said mobile switching center as the master station does not have a channel connected to the other system mobile switching center, requesting an intra-system hand-off control process between said mobile station and the mobile switching center in a home system; and one or more interconnected mobile switching centers serving as a master station of at least one of said one or more base station controllers, for performing said hand-off control process in a home system when the intra-system hand-off control process is requested, at least one of said one or more interconnected mobile switching centers having a communication channel connected to the other system mobile switching center, for performing a predetermined hand-off control process between itself and said other system mobile switching center when said inter-system hand-off control process is requested. wherein each said one or more mobile switching centers comprises means for, when said intra-system hand-off control process is requested, selecting a mobile switching center in the home system which has a communication channel connected to said other system mobile switching center, and performing a hand-off control process between itself and the selected mobile switching center.