A telecommunications terminal is provided that is compatible with, and capable of connecting to, a cellular switch. Also provided are a protocol engine programmed to convert signals used in the terminal to a protocol required by the cellular switch and a service element programmed to generate wireline...http://www.google.com.hk/patents/US6118772?utm_source=gb-gplus-share專利 US6118772 - Wireline telephony on a cellular switch
