1982/83 End Office Connection Study: Analog Voice and Voiceband Data Transmission Performance Characterization of the Public Switched Network

A comprehensive systemwide field study, referred to as the 1982/83 End Office Connection Study (EOCS), was undertaken by Bell Laboratories from October 1982 through January 1983 to characterize the transmission performance of the predivestiture Bell System public switched telecommunications network. Analog voice and voiceband data transmission parameters were measured on about 6500 direct-distance-dialing connections among 20 end office buildings located throughout the continental United States. The analog parameters measured on the connections included loss; noise; frequency response; envelope delay distortion; intermodulation distortion; phase jitter; amplitude jitter; peak-to-average ratio; frequency shift; propagation delay; transient phenomena such as impulse noise, gain hits, phase hits, and dropouts; and error rates of 1200-b/s full-duplex and 4800-b/s half-duplex data sets. This paper presents the results of the EOCS data analysis; a companion paper describes the measurement equipment and the sampling plan. The performance characterization information presented in this paper updates the similar information provided by a survey conducted in 1969/70. The results represent the last predivestiture Bell System network performance characterization and may serve as a benchmark for the end-to-end performance in the post-divestiture environment.