A wireless communication system facilitates communication with subscribing units within a respective service area that supports at least one communication protocol revision. The system communicates with a subscribing unit operating within a respective service area to determine the communication protocol revisions supported by the subscribing unit. Subsequently, the subscribing unit and base station communicate according to a supported communication protocol revision. The base station and subscribing unit further communicate to indicate extended services supported by the subscribing unit and the methods of delivering the extended services to the subscribing unit. The extended services include caller line ID, message waiting indications and short message services among other extended services. In addition to a base station, the wireless communication system may include a mobile switching center that is in communication with the base station. The mobile switching center includes a visitor location register that records communication protocol revisions of the subscribing unit.