1486 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1957 



the one channel affected to be dropped, and the others to be worked 

 entirely free from this interference. This of course reduces the total bit 

 rate. 



To summarize the discussion in a general philosophical way, it can be 

 said that there is advantage in multiplexing the signal in the manner 

 that makes it as different as possible from the type of noise to which it 

 is expected to be the most exposed. If the predominant noise is in short 

 duration pulses, the most advantageous signal is in long duration pulses 

 with frequency discrimination multiplex. If the noise is in longer dura- 

 tion single frequencies, the most advantageous signal is in very short 

 pulses with time discrimination multiplex. 



VI. REFERENCES 



1. J. V. Harrington, P. Rosen, D A. Spaeth, Some Results on the Transmission 



of Pulses Over Lines, Sytnposium on Information Networks, III, pp. 115-130, 

 Polythechnic Institute of Brooklyn, April, 1954. 



2. F. W' Reynolds, A New Telephotograph System, B.S.T.J., 15, pp. 549-475, 



October, 1936. 



3. A. W. Horton and H. E. Vaughan, Transmission of Digital Information Over 



Telephone Circuits, B. S.T.J. , 34, pp. 511-528, May, 1955. 



4. C. A. Lovell, J. H. McGuigan and O. J. Murphv, An Experimental Polytonic 



Signaling System, B.S.T.J., 34, pp. 783-806, July, 1955. 



5. A. L. Matte, Advances in Carrier Telegraph Transmission, B.S.T.J., 19, pp. 



161-208, April, 1940; J. R. Davey and A. L. Matte, Frequency Shift Teleg- 

 raphy — Radio and Wire Applications, B.S.T.J., 27, pp. 265-304, April 

 1948. 



6. R. S. Caruthers, The Type Nl Carrier Telephone System; Objectives and 



Transmission Features, B.S.T.J., 30, pp. 1-32, January, 1951. 



7. P. Mertz, Transmission Line Characteristics and Effects on Pulse Transmis- 



sion, Symposiwn on Information Networks, III, pp. 115-130, Polytechnic 

 Institute of Brooklj-n, April, 1954. 



8. S. I. Corv, Telegraph Transmission Coefficients, Bell Laboratories Record, 



33, pp. '11-15, January, 1955. 



9. T. A. Jones and K. W. Pfleger, Performance Characteristics of Various Carrier 



Telegraph Methods, B.S.J .T., 25, pp. 483-531, July, 1946. 



10. C. A. Dahlbom, A. W. Horton, and D. L. Moody, Application of Multifre- 



quency Pulsing in Switching, Trans. A.I.E.E., 68, pp. 392-396, 1949. 



11. E. D. Sunde, Theoretical Fundamentals on Pulse Transmission, B.S.T.J., 33, 



pp. 721-788 and 987-1010, May and July, 1954. 



12. I. E. Lattimer, The Use of Telephone Circuits for Picture and Facismile 



Service, Long Lines Department, 1948. 



13. H. Nyquist, Certain Topics in Telegraph Transmission Theory, Trans. 



A.I.E.E., 47, pp. 617-644, April, 1928. 



14. B. M. Oliver, J. R. Pierce and C. E. Shannon, The Philosophy of PCM, Proc. 



I.R.E., 36, pp. 1324-1331, November, 1948. 



15. R. E. Crane, J. T. Dixon, and G. H. Huber, Frequency Division Techniques 



for a Coaxial Cable Network, Trans. A.I.E.E., 66, pp. 1451-1459, 1947. 



16. J. T. O'Leary, E. C. Blessing and J. W. Beyer, An Improved Three-Channel 



Carrier Telephone System, B.S.T.J., 17, pp. 162-183, January, 1938. 



17. C. W. Carter, U. S. Patent No. 2,390,869. 



