‎"SHANNON, CLAUDE E.‎
‎Memory Requirements in a Telephone Exchange (Manuscript Received Dec. 7, 1949).‎

‎(New York), American Telephone and Telegraph Company, 1950. 8vo. Volume XXIX, July, No. 3, 1950 of ""The Bell System Technical Journal"". In the original printed blue wrappers. A bit of minor browning to extremities. Wrapper only attached to back hinge. Internally fine and clean. Pp. 343-359. [Entire issue: Pp. 295-468].‎

Reference : 43387

‎First edition of Shannon's influential paper on how to construct a telephone exchange network. ""The problem of designing a good rearrangeable network was (probably first) considered in a paper of C. E. Shannon investigating memory requirements in a telephone exchange. On the networks that he considered he imposed the realistic ""separate memory condition"" to the effect that in operation a separate part of the memory can be signed to each call on progress. This means that completion of a new call or termination of an old call will not disturb the state of memory elements associated with any call in progress. [...] Shannon's separate memory condition is actually met by modern connecting networks [...]. (Benes, Vaclav Edward. Mathematical Theory of Connecting Networks and Telephone Traffic: 017, 1965, p. 119.) Claude Shannon is widely regarded as being the father of information theory and cryptography. Origins of Cyberspace 883.The present issue also includes:1. Southworth, George C. Principles and Applications of Waveguide Transmission. Pp. 295-342.2. Hartley, R.V.L. Matter, A Mode of Motion. Pp. 350-368.3. Hartley, R.V.L. The Reflection of Diverging Waves by a Gyrostatic Medium. Pp. 369-389.4. Pierce, J.R. Traveling-Wave Tubes (Third Installment). Pp. 390-460.‎