US 7,321,575 B2
Node position measuring system
Kenichi Mizugaki, Kokubunji (Japan); and Ryosuke Fujiwara, Kokubunji (Japan)
Assigned to Hitachi, Ltd., Tokyo (Japan)
Filed on Dec. 05, 2005, as Appl. No. 11/293,215.
Claims priority of application No. 2004-365939 (JP), filed on Dec. 17, 2004.
Prior Publication US 2006/0133271 A1, Jun. 22, 2006
Int. Cl. H04Q 7/00 (2006.01)
U.S. Cl. 370—328  [370/338; 370/342; 370/222; 370/401; 455/456.1; 455/404.2; 455/67.11; 455/67.13; 342/357.01; 342/463] 14 Claims
OG exemplary drawing
 
1. A node position measuring system, comprising:
a node that transmits a positioning signal;
a reference station that transmits a reference signal;
a plurality of base stations that receive the positioning signal and the reference signal;
a server that calculates a position of the node; and
a network that interconnects the base stations and the server, wherein:
the reference station comprises:
a positioning signal reception module that receives the positioning signal; and
a reference signal generation module that transmits the reference signal after the positioning signal reception module receives the positioning signal;
each of the base stations comprises:
a signal reception module that receives the positioning signal and the reference signal;
a reception time measuring module that detects specific patterns from the positioning signal and the reference signal received by the signal reception module to measure a detection time; and
a communication module that transmits time information to the server, the time information being generated from the detection time measured by the reception time measuring module; and
the server comprises a position calculation module that calculates the position of the node based on the time information transmitted from the base station.