Patent ID: 8300622
Filing Date: 2012-10-30
Classification: H04W

Abstract:
1. A method for improving quality, by eliminating speed gaps, during tandem free operation (TFO) signal transmission over a network comprising a first transcoder rate adapter unit and a second transcoder rate adapter unit, the method comprising the steps of: eliminate the time period of speech gaps that occur as a result of oscillation of transcoder rate adapter units between different functional states, transmitting a plurality of tandem free operation frames from the first transcoder rate adapter unit to the second transcoder rate adapter unit; detecting a state change of the first transcoder rate adapter unit from an operation state to a synchronization lost state; in response to detecting the state change, transmitting from the first transcoder rate adapter unit to the second transcoder rate adapter a synchronization lost (SYL) message embedded in a number of tandem free operation frames sufficient to embed the synchronization lost message; detecting a plurality of subsequent state changes of the first transcoder rate adapter unit from the operation state to the synchronization lost state; in response to a first state change, sending a discontinue transmission message in the TX queue followed by four regular tandem free operation synchronization lost (TFO SYL) messages; and responsive to a second state change, embedding a first TFO_SYL message, followed by three regular TFO_SYL messages, and following each of the plurality of subsequent state changes, sending one more embedded TFO_SYL message and one fewer regular TFO_SYL messages is sent until a time gap caused by the oscillations is completely filled.