The paper proposes and analyzes a combined framing and error control scheme for the DS3 format in which the primary framing bits are replaced with parity check bits of a rate 0.9912 extended and shortened Hamming code. A fast syndrome computation scheme is developed for the code to facilitate faster reframe times. The proposed scheme has better overall reframing performance than conventional framing, and reduces the output BER to approximately 1360P/sub e//sup 2/. This is effective against error-rate floors or "dribble error" phenomena in fiber optical transmission. Primary applications are in advanced in-service performance monitoring and for throughput enhancement in ATM networking applications using leased DS3 carrier signals.>

It is known that the combination of uniform quantization and entropy coding performs optimally at asymptotically high rates. However, due to synchronization problems resulting from the use of variable length codes, this is true only in the absence of transmission errors. Thus, the performance over noisy channels can be improved by using either fixed length codes and Lloyd-Max quantization or by adding end-of-line symbols. Computer simulations are used to compare the above two schemes for a variety of error rates, line lengths and amounts of error protection. It is found that the "uniform" scheme gives the best SNR for a given rate in the case of memoryless Gaussian and Laplacian sources, provided that its parameters are chosen sensibly. It is expected that these results will generalize to other sources.>