The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 02, 2003
Filed:
Sep. 29, 2000
Byron Hua Chen, Whippany, NJ (US);
Robert Ellis Richton, Madison, NJ (US);
Ibrahim Tekin, Summit, NJ (US);
Giovanni Vannucci, Township of Middletown, Monmouth County, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A method and apparatus for estimating the location of a mobile terminal. The method estimates the locations by: a) using at least one forward-link geo-location technique without using any reverse-link geo-location techniques, this being performed when there are enough base stations visible to the mobile terminal to be able to use the forward-link geo-location technique without using any reverse-link geo-location techniques to estimate the location, and b) using at least one reverse-link geo-location technique when there are not enough base stations visible to the mobile terminal to be able to use the forward-link geo-location technique without also concurrently using any reverse-link geo-location techniques to estimate the location. The forward-link geo-location techniques can be used either alone or in combination with each other, and include such known geo-location techniques as a time-difference-of-arrival technique and angle-difference-of-arrival technique. Illustratively, when the predetermined number, for example three, base stations are visible to the mobile terminal, the location of the mobile terminal is estimated using time-difference-of-arrival. When fewer than three base stations are visible to the mobile terminal, the location of the mobile terminal is estimated using round trip delay. Estimating the location of a mobile terminal by using only forward-link geo-location techniques when there are enough base stations visible to the mobile terminals to be able to use forward-link geo-location techniques, produces a more accurate estimation of the mobile terminal's location. It also allows wireless assisted GPS (AGPS) systems to more quickly estimate a more precise location of the mobile terminal.