Engineering Traffic Networks for More Then One Busy Hour

January 1977 Telephone and Telegraph Company. Printed in Number 1 U.S.A. Engineering Traffic Networks for More Than One Busy Hour By M. EISENBERG (Manuscript received July 6, 1976) A procedure is described that is used to engineer traffic networks for more than one hour of point-to-point load data. The procedure differs significantly from existing methods, which are based upon the concept of "economic load on the last trunk" (ECCS). (When the peak-load hours on most routes coincide, however, the procedure reduces to the ECCS method.) This "multihour" procedure has been implemented in a computer program used in design studies of three end offices in the Los Angeles local network. For the cases examined, the multihour technique produced networks whose costs averaged approximately 7 percent below those achieved with the presently used single-hour methods. Thus, the multihour technique appears to promise considerable cost benefits in future network designs. I. INTRODUCTION In this paper, we describe a procedure used to engineer networks for more than one hour of point-to-point traffic data. Specifically, for a given routing structure, set of switching and transmission costs, and pointto-point offered load between each pair of offices for each of several hours, this method produces a (nearly) least-cost network that satisfies the constraint that the blocking probabilities on all final groups be below 1 a predetermined value (the "grade of service") for all hours. This multihour procedure is a major departure from currently used single-hour methods based upon the concept of "economic load on the last trunk" 1 ( E C C S ) .