Abstract :
This paper is an attempt to place before engineers general information in regard to automatic telephone switching. The subscriber´s requirements are independent of the means used to satisfy them. Automatic switching is uniformly fast and involves reduced mental stress to the user because the passing of the number is positive and waiting time is reduced to the minimum. Viewed by the owner the apparatus has longer life, the service is very acceptable to the public, and but a tithe of the female employees are used. Automatic switching apparatus has increased greatly in margin of safety. Much progress has been made toward standardization of form and toward best methods of maintenance. A few changes in structure are described and data given to show margins of safety in operation. Present practise regarding party lines and measured service (cash and credit) is stated briefly. The durability of automatic equipment is illustrated by the fact that plants have not yet worn out. Maintenance routines are essential to successful operation. Girls do routing testing with marked success. Rural telephone lines present problems which have been solved in several ways, influenced by the greater number of telephones per line, the conditions of signalling subscribers, and the inferior insulation often encountered. Code ringing can be retained. Rural automatic service is only a little inferior to city automatic service. The community automatic exchange serves a small group of subscribers, either isolated or part of a telephone network. The rotary line switch is used because it is simple, reliable, quick-acting, and provides 25 trunks. Eight variable factors in exchange design are presented with a discussion of each. Toll switching in an automatic exchange gives the toll operator direct dialing to the subscriber, complete control over his line, and periodic ringing. The toll network has also been improved by applying automatic switches to intermediate points, so that the originating toll- operator can set up the complete connection herself. The experience of the past twelve years shows that this increases the business-carrying capacity of toll lines at least 50 per cent to 100 per cent. A variety of schemes are available. The automatic switching of telephone lines is adaptable to all classes of telephone service and offers a flexible means of solving problems.
