Apparatus and method for locating mobile and portable radio terminals in a radio network
US5293645A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 1991 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Oct 4, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S5/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for locating a movable radio terminal within a cellular telephone network, or other radio network, which includes a plurality of base stations that transmit synchronized timing reference signals. A receiver in the network receives transmissions from the radio terminals to be located that include information compiled at the radio terminal indicating relative propagation delays in receipt of the timing reference signals from at least three base stations. A processor coupled with the receiver, processes the transmissions indicating relative propagation delays to identify a geographic location of the radio terminal. A complementary radio terminal receives the timing reference signals from base stations, including a designated base station and compiles information indicating propagation delays, relative to the propagation delay of the timing reference signal from the designated base station, from at least two additional base stations. The radio terminal transmits the information compiled so that a station receiving the transmission may locate the radio terminal in response to the information and the known locations of base stations in the network.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.