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:
Mar. 13, 2001
Filed:
Nov. 17, 1997
British Telecommunications Public Limited Company, London, GB;
Abstract
The location of mobile unit cellular radio system is determined by determining the differences in timing of a characteristic feature of the transmission of the control channel of each of a plurality of base stations as measured at the mobile unit. The characteristic feature may, for example, be the training signal already used by the mobile unit in a cellular system to measure signal strength in handover operations. By determining the differences between time of arrival of transmissions from four base stations, location in two dimensions can be derived without prior knowledge of the actual distance to any of the base stations. A fifth base station allows location in three dimensions to be determined.