Ntt Mobile Communications Network, Inc.

Takaaki Satoh

Motoshi Tamura

Tomoyuki Ohtani

Hiroki Morikawa

Fumiaki Ishino

Akiko Nakashima

Hisashi Shimizu

H B-412 Ntt Koigakubo-Ryo Shimizu

M 12 Ntt Shinomiya-Shataku Tamura

A 1-208 Hill House La Queste Nakashima

Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor) stores transmission delay characteristics corresponding to services which are available to the mobile station. Furthermore, a communication timing setting means (diversity handover trunk) determines the timing of communication for the base stations according to the transmission delay characteristic selected according to the service.

Frame synchronization circuit

Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor ) stores transmission delay characteristics corresponding to services which are available to the mobile station. Furthermore, a communication timing setting means (diversity handover trunk ) determines the timing of communication for the base stations according to the transmission delay characteristic selected according to the service.

Method for handover

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Yokohama, Japan

Takaaki Satoh