A wireless communication system facilitates communication within subscribing units within a respective service area, 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 may 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 may 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 may include a visitor location register that records communication protocol revisions supported by the subscribing unit. In such construction, the visitor location register may also include records that indicate which extended services are supported by the subscribing unit as well as the protocols supported by the subscribing unit for delivery of the extended services. The base station may include a protocol capability indication unit while the subscribing unit may include an identification unit that, together, facilitate determining correct operation. A method of operation allows the base station and subscribing unit to communicate and operate according to common protocol revisions and to correctly deliver extended services to the subscribing unit.