Constitution of wide area telephone network using optical fiber communication

With recent, remarkable development of optical fiber technology optical fibers are replacing conventional coaxial cables and microwave systems in the toll telephone network. This paper optimizes a telecommunication network configuration which uses large‐capacity transmission systems such as optical fibers. In a hypothetical Japanese toll telephone network, the required numbers of circuits and systems are calculated and compared for five types of network models (i.e., mesh, lattice, ring, ring‐mesh composite and star‐mesh composite types). As a result of these calculations, the 400–Mb/s system and 1.6–Gb/s system are shown to be applicable to most of the toll transmission sections. The required amounts of circuits increase in the order of lattice type, ring‐mesh composite type, star‐mesh composite type, mesh type and ring type. When the total toll originating traffic becomes about 5 × 106 erl (it is about 106 erl at present), the differences in required numbers of circuits among four types except the ring type are within several percent.