System and method for supporting higher-layer protocol messaging in an in-band modem

摘要

Detecting an acknowledgment signal sent from a destination terminal at a source terminal in an in-band communication system is disclosed. A first synchronization sequence followed by a low layer acknowledgement message and a second synchronization sequence followed by a high layer acknowledgement message is detected.

主权项

1. A method of controlling source terminal transmissions from a source terminal in an in-band communication system, the method comprising:
detecting a request signal to transmit a user data message at the source terminal; storing a message identifier at the source terminal; transmitting a synchronization signal from the source terminal upon detection of the request signal; transmitting the user data message from the source terminal; discontinuing transmission of the user data message upon detection of either an in-band low layer acknowledgement (LLACK) signal or an in-band high layer application (HLMSG) signal, wherein the LLACK signal is comprised of a first synchronization sequence followed by a LLACK message, wherein the HLMSG signal is comprised of a second synchronization sequence followed by a transformed HLMSG message, and wherein the second synchronization sequence is different than the first synchronization sequence sufficient to distinguish the LLACK message from the transformed HLMSG message without acknowledgement identifier bits.