The Nippon Signal Co., Ltd.

Yuhei Otsuka

Toshihito Shirai

Terufumi Yamaguchi

Masahide Takahashi

Hideyuki Kato

Hiroshi Ogihara

Hiroki Saito

A wireless communication network system including: mobile radios mounted on a moving body moving along a predetermined route; and a plurality of immobile radios arranged along the route, adjacent immobile radios wirelessly communicating with each other, to transmit information from a transmission source to a terminal by relaying the information. The mobile radios and the immobile radios communicate with each other by a time division multiple access method, in which time synchronization is performed to allow each of the mobile radios and the immobile radios to communicate in an allocated time slot. The mobile radios are disposed on front and rear parts of the moving body and are capable of communicating with each other. When the moving body is between the immobile radios arranged to be capable of wirelessly communicating with each other, the two mobile radios is capable of relaying information propagation between the immobile radios.

Wireless communication network system

Mobile radio sets are installed on front and rear parts of a mobile body, one of fixed radio sets is set as a synchronization base station, and the other radio sets including the mobile radio sets are set as synchronization packet relay stations. Each of the relay stations in a synchronization acquiring mode makes a transition to a ground synchronization maintaining mode higher in synchronization accuracy when receiving a synchronization packet without the intervention of the mobile radio sets, or makes a transition to an on-vehicle synchronization maintaining mode lower in synchronization accuracy when receiving a synchronization packet with the intervention of the mobile radio sets, and the relay station in the on-vehicle synchronization maintaining mode makes a transition to the ground synchronization maintaining mode when receiving a synchronization packet from a relay station in the ground synchronization maintaining mode.

Wireless communication network system synchronization method

Growing community of inventors

Kuki, Japan

Yuhei Otsuka