Accession Number : AD0914030

Title :   A Methodology for Autovon Access Line Engineering.

Corporate Author : COMPUTER SCIENCES CORP FALLS CHURCH VA

Report Date : MAR 1973

Pagination or Media Count : 26

Abstract : Directional access lines and trunks may be used to enhance reliability, improve service in a preferred direction, or reduce certain costs. The probability of loss (blocking) is the measure of performance most frequently used in circuit switched systems. Poisson and Erlang B tables have been conventionally used to evaluate this blocking. However, in some cases there are significant errors in these estimates because the peakedness of the traffic offered to the common group is neglected. In recent years equivalent random techniques developed by Wilkinson and Bretschneider have been used to provide better estimates of blocking, but these techniques have limited application. In this study, the error in blocking estimates associated with the Bretschneider technique has been evaluated for a specific type of directional configuration. Directional grades of service were computed using the Bretschneider technique and compared with the results of a series of event-by-event simulations. The Bretschneider technique provides good estimates of blocking if the degree of imbalance between incoming and outgoing components is not severe and if the proportion of directionalized circuits is nominal. A program was written to automate the Bretschneider technique in both a design and a performance mode. (Author)

Descriptors :   *SWITCHING CIRCUITS), (*TELEPHONE SYSTEMS, CONTROL SYSTEMS, COSTS, TRAFFIC, SIMULATION, DIRECTION FINDING, COMMUNICATION EQUIPMENT, SYSTEMS ENGINEERING.

Subject Categories : Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE