Damaged caused to telecommunications networks in Japan by the March 11 earthquake will take months to fully repair.
The earthquake caused massive disruption to the country's telephone network mainly from damage to infrastructure or overloading. The latter has now eased but a lot of work remains until base stations are repaired or replaced in the affected area.
NTT DoCoMo, Japan's largest cellular carrier, said two thirds of its 10,000 base stations in northern Japan were out of action immediately following the earthquake but the network has rapidly recovered. As of 1 pm Thursday, the carrier still had 810 base stations out of action, said Naoko Minobe, a spokeswoman for the company.
Recovering in some areas could take several months. In the meantime it has 30 mobile base stations in the region serving towns that would otherwise not have service, but the base stations only reach a few hundred meters. Beyond that, many areas remain with no cell phone service from the carrier or Japan's other cellular operators.
Immediately after the earthquake, cellular traffic spiked and carriers implemented restrictions across east Japan including in Tokyo. At one point, NTT DoCoMo was only connecting one in ten calls from handsets, but the restrictions were lifted a day after the quake. A surge in calls is still seen after strong aftershocks and restrictions have sometimes been reintroduced to avoid clogging the network.
NTT East, the fixed-line carrier for the region, lost 1.5 million phone, ISDN and fiber optic Internet lines when the quake hit. It has restored most, but 155,000 lines remain without service because telephone exchanges were too badly damaged or have lost their connection to NTT's backbone network.
To help people stay connected, NTT is offering free calls from all public phones in six quake-hit prefectures in northern Japan. It has also installed 2,076 additional public phones in 615 locations.