Fundamental Plans for Toll 

 Telephone Plant 



By J. J. PILLIOD 



(Manuscript received Maj' 15, 1952) 



This paper covers the general switching plan and fundamental plant layout 

 proposed for handling telephone toll messages throughout the United States 

 and Canada using aidomatic toll switching. 



There has been rapid growth in the number of telephones and in the 

 volume of toll traffic, particularly long haul. Toll facilities are provided 

 under fundamental plans, an essential part of which is a toll switching 

 plan for setting up connections quickly between any two telephones. The 

 introduction of mechanical operation and the general improvement in the 

 transmission performance of the communication plant over a period of 

 years make the introduction of certain modifications in the fundamental 

 plans possible and advantageous at this time. The important new features 

 and the service improvements which are provided by the proposed plans are 

 outlined in this paper. The principal types and characteristics of circuit 

 facilities available for use in the intertoll network are also described. 



GENERAL ASPECTS OF TOLL SWITCHIXG PROBLEMS 



Switching plans providing for the systematic routing of toll telephone 

 traffic have been employed b}- the communication industiy for many 

 3^ears. These plans have contributed directly to the high c^ualit}' of long 

 distance telephone service enjoyed by the public in the United States 

 and Canada. This generally excellent service is the result of the coopera- 

 tive work of many organizations including the Bell Operating Companies, 

 many independent connecting Companies and others in the United 

 States as well as in adjoining countries. The techniques employed today 

 reflect a great amount of research and engineering and improvements in 

 manufacturing skill and in construction, maintenance and operating 

 methods developed over a period of many years. 



Throughout the United States and Canada there are approximate^ 

 20,000 different places - cities, towns, and villages - that serve as toll 



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