Fundamental transmission planning of telephone networks

Problems arising from new C.C.I.F. recommendations regarding losses in national systems for an international connection having been considered [Abstract 1939B02422], some of the steps necessary to meet them are now discussed. It is desirable to maintain transmission within the 10-25 db. range, and the economic problem is to keep as near to this as is consistent with acceptable charges. A compromise long-distance standard of 30-35 db. subscriber-to-subscriber loss has been set up by most European Administrations. While the exact allocation of this loss between individual units is impracticable, suitable groupings of plant may be studied as individual units. These are the local or exchange area network, the junction plant and the long-distance network. Considerations show that, with decrease in permissible loss, the cost of the first increases rapidly, that of the second less rapidly, while with new technique that of the third remains almost stationary. The author discusses in general terms the best loss allocations to allow both local and national standards to be met most economically, reference being made to the Roumanian Telephone Co.'s system.