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Current Status of Restoration Following Tohoku – Pacific Ocean Earthquake

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by March 24, 2011 Technology

TOKYO, Mar. 24 /Kyodo JBN-AsiaNet/ —

As a result of NTT Group’s full-scale, round-the-clock recovery efforts, NTT Group companies have been steadily restoring services centered in the Tohoku region that were disrupted by the March 11, 2011 Tohoku – Pacific Ocean Earthquake in Japan. The efforts have included establishment of Disaster Countermeasures Office in accordance with disaster prevention operation plans based on the Basic Act on Disaster Control Measures. The current status of restoration for major services is as follows.

(1) Nippon Telegraph and Telephone East Corporation (“NTT East”)

The earthquake and tsunami disrupted commercial power supply and caused equipment failure in approximately 1,000 exchange offices. NTT East responded by deploying emergency batteries, emergency power generators and mobile power-supply vehicles to supply power. However, some exchange offices remained inoperable, resulting in the disruption of a total of approximately 1,470,000 circuits in telephone subscriber lines, ISDN and FLET’S Hikari (FTTH) services as of 6:00 a.m., March 13 (JST). NTT East, with the help of other NTT Group companies and construction companies, mobilized some 5,000 people in total to make an all-out effort to restore these services. By 1:00 p.m., March 23 (JST), approximately 90 percent of the exchange offices had been restored along with the recovery of commercial power supply, leaving 93 exchange offices and approximately 155,000 circuits waiting to be restored.

Unit: circuits
Service As of 1:00 p.m., March 23 As of 6:00 a.m., March 13
Telephone subscriber lines 115,900 879,500
ISDN 10,200 118,600
FLET’S Hikari 28,800 475,400
Total 154,900 1,473,500

Note: Figures exclude failures due to disruptions between customers and NTT East exchange offices.

The 93 exchange offices yet to be restored include those with physical damage, flooding or disruption of connection to backbone transmission lines in areas severely impacted by the earthquake and/or tsunami, and those located in the off-limits area surrounding the malfunctioning nuclear power plant. For these reasons, the recovery of most of these exchange offices is expected to require a significant amount of time.
To provide people affected by the earthquake and its aftermath with communication means, NTT East has installed 2,076 special public telephones in 615 locations available for use free of charge (as of noon, March 23 (JST)). Also, existing public telephones in the six prefectures located within the Tohoku region (Aomori, Iwate, Miyagi, Akita, Yamagata and Fukushima) as well as in Ibaraki Prefecture may be used free of charge.
Since the earthquake, NTT East has been providing safety confirmation services “Disaster Emergency Message Dial 171” and “Disaster Emergency Broadband Message Board (Web 171)” to be used by those affected by the earthquake. As of 1:00 p.m. on March 23 (JST), “Disaster Emergency Message Dial 171” had been accessed approximately 3,093,400 times cumulatively and “Disaster Emergency Broadband Message Board (Web 171)” approximately 236,400 times cumulatively.


Following the earthquake and tsunami, mobile services had been disrupted at approximately 6,720 base stations as of 5:00 p.m. on March 12 (JST). Recovery efforts had reduced the figure to approximately 840 as of 1:00 p.m. on March 23 (JST).

Unit: base stations
Region As of 1:00 p.m., March 23 As of 5:00 p.m., March 12
Tohoku 820 4,900
Kanto-Koshinetsu 17 1,820
Total 840 6,720

Note: Actual amounts are shown for figures equal to or less than 20. Figures more than 20 have been rounded to the nearest ten.
As of 1:00 p.m. on March 23 (JST), DOCOMO had taken the following measures to provide telecommunication access.
– Rental of satellite mobile phones (830 handsets)
– Rental of mobile phones (1,184 handsets)
– Deployment of mobile base station vehicles (30 vehicles)
– Deployment of mobile power-supply vehicles (30 vehicles)
– Deployment of mobile power generators (400 generators)
– Installation of free mobile-phone charging stations (100 locations)
Immediately after the earthquake, DOCOMO started providing “Disaster Message Board” service. The service had been accessed approximately 3,661,400 times cumulatively as of 00:00 a.m. on March 23 (JST).

(3) NTT Communications Corporation (“NTT Com”)

Some services were experiencing disruptions following the earthquake and/or tsunami, but have been recovered as follows, as of 5.00 p.m., March 22 (JST).

Unit: circuits
Service As of 5:00 p.m., March 22 As of 8:30 p.m., March 12
IP-VPN, e-VLAN, etc. 2,300 15,000

Submarine cables connecting Japan with the United States and other parts of Asia have been partially damaged, but NTT Com has been using other backup cable routes to maintain uninterrupted services to avoid any major impact on its overseas communication services. As for NTT Com’s data centers, no damage was confirmed.

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Source: Nippon Telegraph and Telephone Corporation

Tenmin Yoshiara
Public Relations Office
Nippon Telegraph and Telephone Corporation
Tel: +81-3-5205-5550
e-mail: ntt-cnr@—


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