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Ensure Reliable Communications / items coveredCSR Priority Activity
Ensuring Stable and Reliable Communications Services

Management Approach

Why This is a CSR Priority Activity for NTT Group

It is critical that communications are secured as they are important in saving people’s lives, such as the communications necessary for maintaining public order and for rescue and restoration operations at times of disasters, and for emergency communications, such as 110, 118, and 119. Japan is a country prone to natural disasters such as earthquakes and typhoons.
The importance of telecommunications networks was reaffirmed by the devastating Great East Japan Earthquake.

Facing the possibility of an earthquake directly underneath Tokyo or the Nankai Trough off Japan’s southern coastline, there is a pressing need for society to prepare for such potential disasters while ensuring the stability and reliability of its telecommunications infrastructure.

Management Approach and System

NTT Group has defined three key themes for disaster countermeasures: securing critical communications, prompt restoration of services, and improving network reliability. We have been strengthening efforts based on these themes since the Great East Japan Earthquake.

Specifically, we are taking measures to improve the reliability of our telecommunications infrastructure. To ensure that our communications services operate without interruption at all times, we employ transmission trunk line multirouting, have enacted blackout countermeasures for communications buildings and base stations, and are making communications buildings more quake-proof. In addition, we are expanding the assortment of power supply vehicles and other disaster response equipment that we have positioned throughout Japan, and are repeatedly conducting trainings to prepare for major natural disasters. We are making a daily effort to guarantee that, in the event of a disaster, we are able to immediately set up a Disaster Countermeasures Office and other emergency structures and make the necessary emergency and critical communications as designated public institutions prescribed in the Basic Act on Disaster Control Measures.

In fiscal 2017, two major accidents occurred at the four telecommunications businesses (NTT East, NTT WEST, NTT Communications and NTT DOCOMO), and service stability was 99.99%.

The NTT Group’s Basic Policy on Disaster Countermeasures

The NTT Group’s basic policy on disaster countermeasures

Quantitative Indicator

  • Number of major accidents*1Number of major accidents
  • Service stability*2Service stability
  • *1 Number of accidents that led to a suspension of telecommunications services or a decline in communications quality that meet the following criteria regarding duration and number of people affected:
    Up to March 2015
    • At least two continuous hours affecting at least 30,000 users
    April 2015 onward
    • Emergency call services (110, 119, etc.): at least 1 hour affecting at least 30,000 users
    • Voice services other than emergency calls: at least 2 hours affecting at least 30,000 users, or at least 1 hour affecting at least 100,000 users
    • Internet-related services (free of charge): at least 12 hours affecting at least 1 million users, or at least 24 hours affecting at least 100,000 users
    • Other services: more than 2 hours affecting 30,000 users, or more than one hour affecting 1million users
  • *2 [1 – total hours under the impact of major accidents (number of affected users × hours of major accidents) / total hours of major service provision (number of users × 24 hours ×
    365 days)] × 100%

Major Reports

  • NTT Group CSR
You can watch introduction videos here.
  • NTT Group Environmental Activities
  • NTT Annual Report 2017

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