Guidance on repeated serious communication problems of Ministry of Internal Affairs and Communications, SoftBank Mobile

Based on the fact that SOFTBANK MOBILE has repeated serious communication failure accidents today, the Ministry of Internal Affairs and Communications provided guidance to ensure thorough management of telecommunications facilities.

Although it is said that there are serious accidents repeatedly, what kind of communication trouble was occurring?

Details are as follows.
(PDF file)Guidance for SOFTBANK MOBILE Corp. regarding thorough management of telecommunications facilities

According to this release, the Ministry of Internal Affairs and Communications received a report on service interruption corresponding to "serious accident" occurred three times in one month after April 9, 2008, and both accidents are measures to improve the reliability of the system And measures to minimize obstacles were not adequate and appropriate measures were taken for facility management, we strictly warned SOFTBANK MOBILE that these accidents will not reoccur, He told me that he asked for improvements so that he could investigate measures to prevent recurrence of accidents and check spare facilities.

By the way, the relevant requirements of "serious accident" is to satisfy the following two.

1. The number of users affected by suspension of service provision or deterioration in quality is more than 30,000
2. Suspension of service or degradation of quality over 2 hours

There are three "serious accidents" of SOFTBANK MOBILE, which are said to have occurred three times on April 9, as follows.

1.
Date and time of occurrence:Wednesday, April 9, 2008 18: 09 - 23: 41 (5 hours 32 minutes)
Affected services:No 3G mobile phone voice calls can be received / received
Influence range etc.:Approximately 870 thousand users nationwide
Cause:Both system faults in the visitor location register unit power supply section

2.
Date and time of occurrence:May 5, 2008 (Monday) 3: 37 - 6: 45 (3 hours 08 minutes)
Affected services:All services of 2nd generation mobile phone can not be used
Influence range etc.:Approximately 44,000 users in all parts of Akita prefecture, Aomori prefecture, Fukushima prefecture and Miyagi prefecture
Cause:Both systems fault of mobile communication exchange

3.
Date and time of occurrence:6: 29 - 11: 13 (4 hours 44 minutes) on May 6, 2008 (Tuesday)
Affected services:Packet communication service of 3G mobile phone can not be used
Influence range etc.:Approximately 640,000 users in some parts of eastern Tokyo, western Chiba and southern Saitama
Cause:Both system fault of packet switchboard

And the Ministry of Internal Affairs and Communications ask SoftBank Mobile to report recurrence prevention measures and preventive measures and report it by Friday, June 13.