EP0544447

This invention relates to apparatus and methods for providing cellular mobile telecommunication service in accordance with the requirements of the Global Systems for Mobile Communications (GSM) standard. A modular switching system is provided which performs the functions of the mobile switching center (210) plus those of a home location register (212), authentication center (216), visitor location register (214), and equipment identity register (218). The latter functions are advantageously spread among the modules of the switching system, thus avoiding the getting started cost of expensive dedicated data bases. A wireless global switching module advantageously switches mobile communications control messages among the modules of the system and between the modules and the base station systems (204), and terminates signaling links between the mobile switching center and the base station systems.