Important changes are taking place in the outside plant of the telephone operating companies. The cables that connect the customers telephone to the local central office are becoming larger and longer. Open wire, which has been typical of outside plant since the beginnings of telephony, is giving way to multiple line wire. There is a growing trend toward buried plant. New techniques pulse code modulation and remote line concentrators are coming into use to provide more efficient utilization of copper. Electronic computers are being used as engineering and administrative tools. This article discusses these and other major changes that have been taking place in outside plant during the last decade, and speculates on changes that may lie ahead.
Prepared for presentation at the Annual Wire and Cable Symposium (10th), Asbury Park, N. J., November 29 1961.