improved arrangements were scheduled for application as circum- 

 stances warranted to the regional centers and primary outlets. At 

 the present time they have been applied to all of the regional centers 

 and about half of the primary outlets and about 95 per cent of the 

 switched connections requiring gain at the switching centers make 

 use entirely of this improved method. 



As the Bell System is a living and growing organism, the (ieneral 

 Toll Switching Plan is continuously under review and frequently 

 revised in detail. For example, while there are now four primary 

 outlets in the territory of the New England Telephone and Telegraph 

 Company, it seems probable that future developments in concentration 

 of circuits on cable routes will result in reducing these in number. 



The transmission requirements applied to the different classifications 

 of circuit for best results vary with the availability of further technical 

 developments. For example, in the future the improved high-speed 

 circuits made possible by the application of carrier to cables will 

 result in modifications of the General Toll Switching Plan, resulting 

 in improvements of transmission over all switched connections and in 

 economies in circuit design through liberalizing the transmission 

 requirements for certain routes, particularly the circuits between toll 

 centers and primary outlets. 



The General Toll Switching Plan is an important instrument in 

 systematizing plans for the design of plant extensions, for the applica- 

 tion of technical and operating improvements, and for realizing in fact 

 the ideal of universal service between any two telephones in the 

 country. 



The Joint Occupancy Of Plant 



The Bell System organizations involved directly in the giving of 

 telephone service include regional companies (known as the Associate 

 Companies), operating in various areas throughout the United States, 

 who are responsible for the exchange service and for toll service within 

 their areas,* and the American Telephone and Telegraph Company, 

 responsible for the long distance toll service between points in the 

 areas of different regional companies. 



As a result, it is a common situation to have inter-area toll plant 

 of one company terminating in towns and cities where the exchange 

 plant is ow'ned and operated by another company, and sometimes 

 extending for considerable distances along the same general routes as 

 the intra-area toll plant of that company. In a great many cases 



* There are a few companies in which certain interstate items of traffic within the 

 company area are handled by the American Telephone and Telegraph Company. 



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