Disaster prevention measures of NTT for telecommunications network systems

In Japan, earthquakes and other natural disasters such as typhoons and heavy rains occur frequently. Developing measures to prevent communication interruptions caused by natural disasters, especially earthquakes, is a major priority of telecommunication service companies. Recent disaster damage in Japan is outlined, and preventive measures being taken by Nippon Telegraph and Telephone (NTT) are described. NTT´s design guidelines are based on three fundamental principles: improving network reliability, whereby facilities are physically reinforced and strengthened; preventing isolation, ensuring that communication with disaster-stricken districts is constant; and rapidly restoring services. Each of these principles and the methods used for their implementation are discussed.<>