A portion of the bits within an assigned Temporary Mobile Station Identification (TMSI) number are encoded based upon a subscriber's group classifications (i.e., classifications based on the user's characteristics, such as subscriber services and affiliation). When a mobile station user requests service in a visiting location, the user's service profile is accessed to determine the user's group classifications (if any). The mobile station is assigned a TMSI number according to the user's accessed service profile and a portion of bits associated with the TMSI number are encoded based on the identifiable user group classification. The length of the assigned TMSI number may be adjusted depending upon the particular application to maximize the number of TMSI numbers that may be transmitted in a single paging slot.