Patent ID: 7310518

Claim:
A method of providing service to mobile stations utilizing a wireless telecommunications network, each of said mobile stations provisioned with an identifier comprising a set of digits, each identifier being one of two types including a first type of identifier in which a subset of most significant digits of the identifier are correctly programmed so as to indicate a home country and home network for the mobile station and a second type of identifier in which the subset of most significant digits of the identifier are incorrectly programmed, said method comprising: (a) defining a study period; (b) obtaining the identifiers from mobile stations entering the wireless telecommunications network during the study period; (c) collecting the subsets of most significant digits from each identifier obtained during the study period; (d) compiling a list of digit patterns, each digit pattern in the list corresponding to one of the subsets of most significant digits collected in step (c); (e) after the study period has ended, receiving identifiers from mobile stations accessing the wireless telecommunications network; and, (f) comparing the subsets of most significant digits of the identifiers received in step (e) to the compiled list to determine which are the first type of identifier and which are the second type of identifier.