Nec Corporation

Nippon Telephone and Telegraph Corporation

Nippon Telegraph and Telephone Corporation

Kenji Shitara

Yoshitoshi Murata

Akio Sasaki

In a wide area cordless telephone system, a wide service area is divided into a plurality of local service areas identified respectively by unique codes. Each local area has home position portable cordless telephones to which telephone numbers are permanently assigned and can accommodate roaming non-home position telephones belonging to other local areas. Each telephone receives a pre-registration polling signal from one of access units located at key points and returns a pre-registration response signal if a unique code contained in the received polling signal mismatches a stored area code. A controller in each local area assigns a reserved telephone number, if available, to a roaming telephone in response to such a response signal and registers this cordless telephone in memory. The controller then transmits an acknowledgement signal indicating the completion of a registration. The registered telephone responds to it by returning a post-registration signal which is monitored by the controller. The registration of this telephone is cancelled if the controller fails to receive the post-registration signal for a prescribed time interval.

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Tokyo, Japan

Kenji Shitara