COMBINED FRAMING AND ERROR-CORRECTION CODING FOR THE DS3 SIGNAL FORMAT

This paper proposes and analyzes a combined framing and error control scheme for the DS3 format in which the primary framing bits are replac ed with parity check bits of a rate 0.9912 extended and shortened Hamm ing code. A fast syndrome computation scheme is developed for the code to facilitate faster reframe times. The proposed scheme has better ov erall reframing performance than conventional framing, and reduces the output BER to approximately 1360P(c)(2). This is effective against er ror-rate floors or ''dribble error'' phenomena in fiber optical transm ission. Primary applications are in advanced inservice performance mon itoring and for throughput enhancement in ATM networking applications using leased DS3 carrier signals.