Patent ID: 8676199

Claim:
A connection method for use by a vehicle telematics unit to establish a wireless telephone connection between the telematics unit and a call center over a GSM cellular system, comprising the steps of: (a) determining that a call attempted using a primary connection strategy and a secondary connection strategy has failed; (b) detecting that the call attempted using the primary strategy and secondary strategy is permitted to revert to a voice-only call when a modem data connection cannot be established, and if so, then: (c) selecting an available PLMN using a manual network selection mode supported by the GSM cellular system; (d) selecting a base station within the selected PLMN; (e) attempting to attach to the selected base station; (f) attempting origination of a voice channel cellular connection if the telematics unit is attached to a base station; and (g) iteratively repeating steps (c) through (f) for each available PLMN that has been recently used to place a call.