Final Report Chapter 5 Mid-Term Development Plan replace them to IP10Gbps+STM64 (1Gbps). It should be noted that along the highway, there are buried the 96-core fiber optic cables are buried. The backbone circuits normally use the fiber optic cables for the main circuits, whereas in case of the failures occurred in the fiber-optic cables, the cables are switched over to the microwave links. In case of the failures occurred in the fiber-optic cables, though the available band-width to be used for the backbone becomes narrower, they try to keep circuits connecting the mobile telephone switches (MSC) and public switched telephone networks (PSTN). As mentioned above, the backbone circuits are provided, however, the transmission equipment for the 96-core fiber optic cables have never been sufficiently enough, and the microwave radio circuits, as a whole, too much aged. Also, to be noted is the switching over to the back-up circuits is made not automatically, but manually. In other words, it is not sufficient, in the capability, nor in the qualities. And it is predicted that in the future, there should be a big shortage in quantitatively, 5-4