A transmission system develops a binary encoded data train having a message and a header preceding the message. The data train is applied to a carrier frequency to modulate the carrier using FSK techniques. The header includes synch signals, one or more address signals, a message length signal and control...http://www.google.com.tw/patents/US4383257?utm_source=gb-gplus-share專利 US4383257 - Message communication system with message storage
