Public demand exists for expanded new uses of the telephone to provide information and entertainment. Hearing a recorded announcement over a telephone is increasing in popularity.
Provision of the mass announcement capability on the No.
High-quality service requires the proper planning for the quantities of central office and trunking equipment and the effective utilization of this equipment in the operational environment.
The No. 4 ESS is a digital time-division toll and tandem switching system first placed in service in Chicago.
Electronic switching systems, in modern terminology, are composed of two parts, the central processing unit and the peripheral system. In No.
A large development undertaking like No.
Prologue By A. E. SPENCER, Jr. (Manuscript received February 23, 1977) No.
July-August 1981 Copyright © 1981 American Telephone and Telegraph Company. Printed in U.S.A. Number 6 No. 4 ESS: Prologue By K. E.
The No. 4 Electronic Switching System (No. 4 ESS), a stored program switching system, has most of its required control, administrative, and maintenance functions provided via program.
