1969-70 Connection Survey: Analog Transmission Performance on the Switched Telecommunications Network

Information related to transmission performance of toll connections is essential to the evaluation of toll service quality, necessary for assessing the adequacy of present administrative and maintenance procedures, and important in establishing objectives for new transmission systems and equipment. Bell Telephone Laboratories has conducted a number of system-wide transmission surveys since 1959. Surveys made in 1959, 1962, and 1966 1-3 concentrated on the transmission performance of toll connections. Other surveys have examined the performance of specific equipments or portions of the telephone network. 4-0 This survey is based on a probability sample of telephone traffic. The use of probability sampling permits estimation of transmission performance parameters for the population of all toll calls and permits quantitative measure of the possible error in these estimates. The 1969-70 survey differs from previous surveys by including more measures of the transmission performance of the connection. 1311