Patent ID: 8428628

Claim:
A communication method comprising the steps of: managing the communication area by dividing the communication area into a plurality of first areas applied in a first mobile communication system and a plurality of second areas applied in a second mobile communication system distinct from the first mobile communication system; transmitting, at a radio base station device, broadcast information for notifying the first area and the second area under control of the radio base station device; transmitting, from a first mobile terminal incapable of registering a location thereof with the second areas to the radio base station device, a first location registration request signal for the first area included in the broadcast information, when the first area is not identical to a first area stored as a current location registration area; and transmitting, from a second mobile terminal capable of registering a location thereof with the second areas to the radio base station device, a second location registration request signal for the second area included in the broadcast information, when the second area is not included in a second area group stored as a current location registration area, wherein the first mobile terminal is configured to perform existing location registration processing and ignore the plurality of second areas when the second areas are included in broadcast information transmitted from the radio base station device, and wherein the second mobile terminal is configured to perform existing location registration processing in an area when the plurality of second areas are not included in broadcast information transmitted from the radio base station device.