In mobile radio-based navigation systems, depending on the method used, some functions for positioning are integrated into the Base Station Controller( BSC) or into the Mobile Switching Center( MSC), or are connected to them as independent components.
The Serving Mobile Location Center (SMLC) is such a functional unit supporting Location Services( LCS). The SMLC center determines and manages all position coordinates and schedules the services in the environment of the mobile station. The SMLC can manage some Location Measurement Units( LMU), which determines the time differences between the mobile and the base stations from the radio signals of the surrounding base stations. For some position determination methods, the distance determination is done with Timing Advance( TA), a distance-dependent radio signal.