Patent ID: 7194268
Filing Date: 2007-03-20
Classification: H04M,H04W

Abstract:
1. A method of call forwarding a call originally placed to a mobile telephone number of a mobile telephone to a landline telephone number of a landline telephone, wherein the call is routed through a telephone network by a service provider, the method comprising: (a) receiving from the landline telephone a set-up telephone call directed to a predetermined number while the mobile telephone is at a forwarding location and is powered on; (b) upon receiving the set-up telephone call, determining the forwarding location using a mobile location technology capable of locating the mobile telephone using service provider equipment; (c) determining a current mobile telephone location of the mobile telephone by the mobile location technology; (d) determining whether the call to the mobile telephone number is being made to the mobile telephone when the current mobile telephone location is approximately at the forwarding location; and (e) forwarding the call to the mobile telephone number to the landline telephone number using the service provider equipment when the current mobile telephone location is approximately at the forwarding location; wherein the mobile location technology is a time difference of arrival method having the steps of: (i) receiving a signal of the mobile telephone at a first antenna site having a first receiver, a second antenna site having a second receiver and a third antenna site having a third receiver; (ii) synchronizing the receivers by using a precision standard clock; (iii) determining a first time of arrival (TOA) when the signal reaches the first receiver, a second TOA when the signal reaches the second receiver and a third TOA when the signal reaches the third receiver; (iv) calculating a first time difference between the first TOA and the second TOA, a second time difference between the second TOA and the third TOA, and a third time difference between the third TOA and the first TOA; and (v) generating the current mobile telephone location expressed in longitude and latitude by using a geographic location algorithm, said geographic location algorithm being a function of a known transmission speed of the signal of the mobile telephone, the first, second and third time differences and geographic locations of the first, second and third antenna sites.