Towards large-capacity, energy-efficient, and sustainable communication networks

− 30 − Synthesiology English edition Vol.7 No.1 pp.30-43 (Jun. 2014) bound routes), and switching to one route if the other is disrupted. However, in a major disaster such as the 2011 Off the Pacific Coast of Tohoku Earthquake (Great East Japan Earthquake), failure recovery doesn’t work well since failures may occur in a wide region at many locations, and both routes can be disrupted. In that disaster, agile and wide-scale reconfiguration of the network was necessary. Moreover, to continue the network service without being affected by the instability of power supply due to the disaster, the importance of low power-consuming network operation in ordinary times has been recognized.