Technology Feb. 13, 2012 - 11:12AM JST ( 10 )

TOKYO —

KDDI Corp, the operator of au mobile phone services, said Sunday that data communication disruption which occurred Saturday night affected up to 6.15 million cell phones and smartphones.

A spokesperson said the company’s proprietary ezweb e-mail service was disrupted from around 8:35 p.m. Saturday until just before midnight. It is believed to have been the company’s largest data disruption since August 2003, when about 12.79 million of its cell phones were affected by a communications system problem, Fuji TV reported.

The latest trouble is believed to have been caused by an electricity supply failure to a batch of e-mail servers, but the company added that the incident had no impact on voice calls and Internet access. The company speculated that the failure may have resulted from an increase in smartphone data traffic.

Industry analysts say a similar incident affected up to 1.3 million users last Thursday, when some au smartphones were temporarily unable to access the Internet.

The infrastructure problems come shortly after the government cautioned KDDI’s competitor NTT Docomo Inc and urged it to implement countermeasures such as improving its facilities following a series of service disruptions since last year.

The Internal Affairs and Communications Ministry ordered the company to submit a report on the improvements by the end of March, Fuji reported.

Japan Today