This paper presents a physical theory of impulse noise in telephone networks based on the assumption that impulsive disturbances can reverberate through a network for very long periods of time. A mechanism of regeneration and propagation of disturbances through signaling circuits is proposed, and the resulting reverberation is modeled as a random walk in one dimension. Theoretical results agree surprisingly well with empirical probability distributions of inter-error intervals in data transmission. However, direct experimental evidence is lacking to substantiate (or disprove) the physical mechanism on which the theory is based.

This is another in a series of invited tutorial, status and survey papers that are being regularly solicited by the PTGIT Committee on Special Papers. We invited Profess01 Fano to commit to paprr his elegant but, unelaborate explanation of the principles of sequential decoding, a scheme which is currently contending for a position as the most practical implementation to dale of Shannon’s theory of noisy communication channels. -&e&l Pcqwrs Committw.