A New Carrier System for Rural Service

Although carrier has been used successfully to provide trunks in the Bell System for more than 35 years, it has not been economically feasible, up to the present time, to apply carrier telephone techniques extensively to the rural telephone plant. The technical and economic problems associated with providing telephone service to customers in rural areas has long been one of the most difficult problems facing the telephone industry. The widely scattered locations of customers in rural areas have led to a large number of rural telephone routes with only a few customer lines-per route. This has precluded the use of large cables on any one route, which would be economically attractive in urban areas. The extensive use of carrier has not been feasible because the distances from the rural customers to the Central Office are in the 5- to 20-mile range in which carrier has not been generally economical in the past. The two lines of attack which were taken on this problem were to reduce the cost of telephone plant through less expensive small cables and open-wire plant, 1 and to provide an economically attractive carrier system designed to meet the particular needs of rural telephone service. This paper discusses the broad objectives for a rural customer carrier system, the major parameters of the PI system which was developed to meet those objectives, and its circuit, equipment, and power arrangements. It also covers the engineering and maintenance methods to be used by the Bell System Operating Companies to install and operate the system.