Patent ID: 8706110

Claim:
A method for operating a cellular telephone in a cellular network having second generation (2G) and third generation (3G) cells, comprising: while wirelessly connected to a 2G cell, obtaining a primary scrambling code list broadcast by the cellular network using the cellular telephone, wherein the primary scrambling code list includes primary scrambling codes corresponding to 3G cells in the cellular network that are potentially available to wirelessly communicate with the cellular telephone and includes less than all possible primary scrambling codes; performing an evaluation of primary scrambling code pilot signal strengths for each of the primary scrambling codes in the primary scrambling code list by using the cellular telephone to compare the primary scrambling code pilot signal strengths for each of the primary scrambling codes in the primary scrambling code list to a threshold signal strength; determining whether a prior full primary scrambling code pilot signal strength scan associated with the evaluation of the primary scrambling code pilot signal strengths for each of the primary scrambling codes in the primary scrambling code list and for at least one primary scrambling code not included in the primary scrambling code list has failed within a predetermined time interval before a current time; in response to determining that at least one of the primary scrambling code pilot signal strengths exceeds the threshold signal strength, establishing wireless communications between the cellular telephone and a 3G cell corresponding to one of the primary scrambling code pilot signal strengths that exceeds the threshold signal strength without performing a full primary scrambling code pilot signal strength scan; in response to determining that none of the primary scrambling code pilot signal strengths exceeds the threshold signal strength and that no prior full primary scrambling code pilot signal strength scans have failed within the predetermined time interval, performing a full primary scrambling code pilot signal strength scan; and in response to determining that none of the primary scrambling code pilot signal strengths exceeds the threshold signal strength and that at least one full primary scrambling code pilot signal strength scan has failed within the predetermined time interval, inhibiting performance of a subsequent full primary scrambling code pilot signal strength scan.