Method and system for determining the position of mobile radio terminals

US5952969A · kind A · utility

Assignee

• Telefonaktiebolaget LM Ericsson (Publ) · SE

Inventors

• Bo Hagerman · Stockholm, SE
• Sara Mazur · Bromma, SE
• Walter Ghisler · Upplands Väsby, SE

Key dates

• Filing date: Aug 18, 1997
• Grant date: Sep 14, 1999
• Expiry date: Aug 18, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S5/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The disclosure describes a novel Time Difference of Arrival (TDOA) method and system for determining the position of a mobile radio terminal within an associated mobile radio system, which is based on Time of Arrival (TOA) measurements, including a plurality of radio base stations, measuring devices, network controller, and service node. The measuring devices are synchronized in otherwise unsynchronized radio base stations. The measuring devices measure TOA on demand and (optionally) Direction of Arrival (DOA), on a digital uplink time slot or on digital information on an analog uplink traffic channel in one or more radio base stations. The TOA and DOA information and the traffic channel number are reported to a Mobile Services Switching Center, which obtains the mobile terminal's identity from the traffic channel number and sends the terminal identity and TOA and DOA measurement information to a Service Node. The Service Node calculates the position of the mobile radio terminal using the TOA information (supplemented by the DOA information when available).