Patent ID: 6134242
Filing Date: 2000-10-17
Classification: H04J,H04W

Abstract:
A method of switching from a non-tandem operating mode in which information is communicated in a single-encoded frame format to a tandem operating mode in which information is communicated in a double-encoded frame format in a communication system comprising a plurality of transcoders, the method comprising the steps of:at a first transcoder:switching to the tandem operating mode; andinverting bits of the double-encoded frame format that correspond to synchronisation bits in the single-encoded frame format, the synchronisation bits interspersed throughout a frame;at a second transcoder initially operating in the non-tandem operating mode and coupled to the first transcoder:perceiving the reception of the double-encoded frame format as a single-encoded frame format;detecting a plurality of errors in the synchronisation bits of the single-encoded frame format as a consequence of the corresponding bits in the double-encoded frame format being inverted; andswitching to the tandem operating mode in response to detecting the plurality of errors in the synchronisation bits.