Patent ID: 8971873
Filing Date: 2015-03-03
Classification: H04W

Abstract:
1. A method of selecting a wireless carrier system using a vehicle telematics unit, comprising the steps of: (a) detecting that a forward link of a wireless connection from a vehicle telematics unit to a currently-used base station of a wireless carrier system is operational; (b) determining that a reverse link of the wireless connection from the currently-used base station of the wireless carrier system to the vehicle telematics unit is not operational using a dragged timer; (c) altering the duration of the dragged timer based on the speed of a vehicle carrying the vehicle telematics unit; (d) identifying one or more base stations neighboring the vehicle telematics unit for communications in response to the detections in steps (a)-(b); (e) comparing a system identification number (SID) of the identified neighboring base station and a SID of the currently-used base station with a preferred roaming list; (f) determining that the SID of the neighboring base station is less preferred than the SID of the currently-used base station using the preferred roaming list; (g) overriding a preference of the vehicle telematics unit to maintain a registration with the currently-used base station based on the determination in step (f); and; (h) registering the vehicle telematics unit with the neighboring base station.