Photo/Illutration The KDDI Corp. logo (Asahi Shimbun file photo)

Major mobile carrier KDDI Corp. is apologizing for its network failing a second time in as many months, after an estimated 83,000 users across 16 prefectures in eastern Japan could not place calls.

The outage on Aug. 24 occurred only weeks after KDDI pledged to do its utmost to prevent a similar communications services disruption from happening again.

But this time, the outage was not as bad, and the company was not alone in the spotlight.

Nippon Telegraph and Telephone West Corp., part of the telecommunications giant NTT group, also experienced network disruptions the following day, on Aug. 25, which hampered internet services.

According to KDDI, a system glitch disrupted its mobile phone services for about 45 minutes from around 9:13 p.m. on Aug. 24, preventing users in Tokyo, Hokkaido, Niigata and 13 other prefectures from making calls, including to emergency services.

KDDI officials resolved the network failure at 9:58 p.m. that day by disconnecting the malfunctioning equipment from its network.

The glitch affected individual users of KDDI’s au brand, UQ Mobile services, and “povo” plan subscribers, as well as businesses that use KDDI’s lines.

KDDI’s data communications services were not affected by the latest system failure, the company said.

Meanwhile, NTT West announced on Aug. 25 that its optical fiber internet connection services were disrupted from around 9 a.m., affecting five prefectures in the Kansai region, except for Osaka Prefecture, and seven prefectures in the Tokai and Hokuriku regions.

The company said it fixed the glitch by 2:44 p.m. that day.

KDDI’s last service outage, which struck on July 2 and lasted until July 4, upward of 61 hours, had affected more than 30.91 million users.

It was among the largest telecommunications network failures in Japan’s history, prompting the government to recognize it as a serious incident under the telecommunications business law.

The telecommunications ministry issued a rare administrative guidance rebuking KDDI on Aug. 3. It ordered the carrier to take countermeasures to prevent a recurrence.

This latest glitch will not likely be recognized as a serious incident, though, since disruptions to the mobile phone services, including those for emergency calls, lasted less than an hour and did not affect as nearly as many users.

(This article was compiled from reports by Yoshikatsu Nakajima, Kenta Nakamura and Takashi Yoshida.)