NTT DoCoMo Inc., Japan’s biggest wireless carrier, said it restored mobile-phone services in central Tokyo after an interruption that lasted more than four hours, the fourth disruption in the past two months.
As many as 2.52 million users experienced glitches in voice and data communication from 8:26 a.m. to 1:08 p.m., the Tokyo-based company said in a statement today. A surge in wireless traffic on DoCoMo’s switching equipment caused the problem, the carrier said.
The disruption may have been aggravated after East Japan Railway Co. stopped some train services for about 50 minutes from 9:05 a.m., prompting a surge of passengers to make calls or send text messages, Takuya Ori, a spokesman for DoCoMo, said by phone. He said he wasn’t immediately able to comment on improvement plans.
DoCoMo, which halted its messaging service for smartphones on Dec. 20, Jan. 1 and Jan. 2, is expanding its data capacity in response to an increase in the number of smartphone users.
The train service halt, which affected about 110,000 people, was triggered after smoke was noticed on the track on the Yamanote Line, which circles Tokyo’s center, Toshihide Watanabe, a spokesman for the railway, said by telephone.