Analysis: Japan’s telecoms infrastructure proves resilient in face of devastating earthquake

Analysis: Japan’s telecoms infrastructure proves resilient in face of devastating earthquake

Work is underway in Japan to repair the country’s telecommunications links following the 9.0 magnitude earthquake that struck the country on 11 March 2011.


 Japan's earthquake and Tsunami devastated
 the north east region

The earthquake – the most powerful in the country’s history – triggered a tsunami which caused widespread devastation in north east Japan, leaving an estimated 10,000 people dead. As the country continues its recovery efforts, Japan’s major telcos have been able to restore some of the fixed and mobile services in the worst affected areas of the country. The county’s telecommunication links were initially heavily affected by the power shortages which led to nationwide rolling black-outs, bringing down fixed broadband and VoIP services. Submarine cables were also damaged by the earthquake and tsunami, but many providers were able to reroute traffic to backup cables. This redundancy has appeared to be enough to keep Japan connected to the rest of the world.

The experiences of major Japanese telecoms service provider NTT Group provide a compelling reference point to the serious disruption that occurred to domestic and international telecoms operations. The group’s local fixed-line operations for east Japan, NTT East, experienced a disrupted commercial power supply and equipment failure in approximately 1,000 exchange offices, which resulted in the disruption of approximately 1.5 million circuits in telephone subscriber lines, ISN and FLET’s Hikari (FTTH) services.

By 23 March, however, 90% of exchange offices had been restored, with approximately 155,000 circuits still requiring repair at the time of going to press. Repair to these exchange offices is likely to be heavily delayed as they are located in the off-limits area surrounding the quake-hit Fukushima nuclear plant. NTT East has therefore installed 2,076 emergency public telephones in 615 locations available free of charge.

The group’s international arm, NTT Communications, experienced partial damage to a number of its submarine cables connecting Japan to the US and other parts of Asia. Services were maintained, however, by back-up cables. “On the first day of the earthquake there was significantly reduced connectivity to the US, but by the second and third day we had began to recover. At the moment, customers won’t experience any congestion,” said Nick Wakai, VP for IP business of global business division, NTT Communications.

“We are very well trained and prepared for this form of natural disaster, and have many power units and back-up generators for each project. But this earthquake was just too big for anyone to have predicted.”

Telecoms equipment manufacturers also played their role in supporting the recovery process, with Chinese giant Huawei sending a shipment of essential telecommunications equipment to Tokyo shortly after the earthquake struck. “As the earthquake has significantly damaged local telecommunications networks, we are also helping our customers in Japan to repair and restore the communications infrastructure by providing technical teams and any necessary equipment that will bring their systems back to normal as quickly as possible,” said a Huawei spokesperson.

The disaster had a surprisingly limited impact on the structure and routing of the region’s internet, a fact Renesys’ CTO Jim Cowie has labelled an “engineering triumph.” Out of roughly 6,000 Japanese network prefixes on the global routing table, only 100 were temporarily withdrawn from service following the earthquake. Internet traffic into and out of Japan has, however, dropped by roughly 10% which can be attributed to local power shortages.

“After the Taiwan earthquake in 2007, the impact on cables was abrupt and there was not a lot of redundancy available to draw on. The situation is apparently very different in Japan where they have enough redundancy to draw on and enough capacity to keep going around the problem,” said Cowie.

“Clearly the cables and landing systems were constructed in the right way; there’s simply no other way to explain the limited impact that the disaster has had on communications.”

Despite Japan’s reputation as being one of the best prepared countries in the world for handling natural disasters, the magnitude of the earthquake was such that rebuilding the country is estimated to cost approximately $309 billion. A lengthy restoration process will also face some of the country’s telcos.

“Restoring international submarine cables could take a month and a half,” said Wakai. “The area devastated by the tsunami will take much longer to repair. After the Kobe earthquake in 1995 it took three years for Japan to recover. This time the damage is more widespread, so will take longer.”

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