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:
Jun. 25, 2013
Filed:
Jun. 12, 2006
Robert Willem Rowe, Cambridge, GB;
Peter James Duffett-smith, Cambridge, GB;
Robert Willem Rowe, Cambridge, GB;
Peter James Duffett-Smith, Cambridge, GB;
Cambridge Positioning Systems Limited, Cambridge, GB;
Abstract
To determine whether a mobile terminal of a communications system has moved outside a locale, the terminal measures relative time offsets of signals received by the terminal from transmitters of the network, relative to each other or a reference. At a first time when the terminal is within a given locale, the time of receipt of signals received by the terminal from a plurality of the transmitters relative to a reference or each other are measured to create a first set of receive time offsets. At a second time, a second set of receive time offsets is measured. Change(s) in receive time offsets is/are calculated, and change(s) between the first and second times in transmission time offsets of the signals transmitted by at least one transmitter is/are obtained to determine movement indicators that are compared with threshold valuets to determine whether the mobile terminal has moved outside the locale.