Telephone-traffic techniques

Given well designed and reliable equipment, the efficiency of a telecommunication system depends on having sufficient equipment to meet requirements for normal service, with a reasonable margin for peak traffic. At the same time, the cost of the network must be low enough to permit the provision of an efficient service to the subscriber on acceptable terms. The determination of the amount and arrangement of equipment, so as to achieve an optimum balance between service and cost, is one of the most important aspects of telecommunication-system design, which has attracted the attention of engineers and mathematicians since the early days of telephony. Modern technical developments, including the application of electronic switching and control techniques, have posed many new traffic problems. This review deals with the general principles of telecommunication traffic, and their application to exchange and network engineering.