Complex sentence: The term is only valid in the context of one call since any MSC may provide both the gateway function and the visited MSC function, however, some manufacturers design dedicated high capacity MSCs which do not have any base station subsystems (BSS) connected to them.
Split into simpler sentences: The term is only valid in the context of one call, since any MSC may provide both the gateway function and the visited MSC function. However, some manufacturers design dedicated high capacity MSCs which do not have any base station subsystems (BSS) connected to them.