An apparatus and method of effecting hand-off of a mobile station in a first wireless communication system, which has a first mobile switching node operable with a first base station and a second mobile switching node operable with a second base station, and a second wireless communication system, is...http://www.google.com.tw/patents/US7499705?utm_source=gb-gplus-share專利 US7499705 - Handover in a hybrid communications network
