By including the mobile units unique address in topology...http://www.google.es/patents/US5533026?utm_source=gb-gplus-sharePatente US5533026 - Communication system including method and apparatus for maintaining communications with a mobile terminal B???squeda avanzada de patentes N???mero de publicaci???nUS5533026 ATipo de publicaci???nConcesi???n N???mero de solicitudUS 08/398,717 Fecha de public