A telephone system for reliably providing caller identification information to telephone call recipients such that they can choose whether or not to answer a telephone call. The telephone system includes a decoder module for receiving a toll-free telephone call and decoding automatic number identification...http://www.google.com.hk/patents/US20030156693?utm_source=gb-gplus-share專利 US20030156693 - Converting automatic number identification information to caller ID information
