Communication systems having single switching center configurations (100) or multiple switching center configurations (200) detect the occurrence of a mobile-to-mobile call using control messages. When it is determined that the call is mobile-to-mobile, a switching center (101) in the single switching...http://www.google.de/patents/US5608779?utm_source=gb-gplus-sharePatent US5608779 - Method for communications between mobile units using single and multiple switching center configurations
