November 26, 2021 Appropriate Response of NTT Docomo Inc. to Telecommunications Accident (Administrative Guidance)

Today, the Ministry of Internal Affairs and Communications (MIC) issued a stern warning to NTT Docomo Inc. (headed by II Motoyuki, President and CEO) regarding an accident on October 14, 2021, to prevent the occurrence of similar accidents. In addition, MIC instructed NTT Docomo Inc. to make thorough preparations for the switchover work in advance, improve the internal and external coordination system and the content of the information provided to users and share the lessons learned with other carriers throughout the telecommunications industry.

1. Background

On October 14, 2021, NTT Docomo Inc. experienced a communication failure that affected approximately one million users for two hours and 20 minutes. On November 10 of the same year, MIC received a serious accident report from the company on the failure in accordance with Article 28 of the Telecommunications Business Act (Act No. 86 of 1984).
MIC examined the contents of the said report. In addition to the fact that the accident was related to a voice transmission service that handles emergency calls, MIC thinks that the social impact of the accident was extremely significant, given that mobile phone services are part of important infrastructure for people’s lives. It is considered necessary to take sufficient measures to prevent similar accidents.

2. Content of administrative guidance

Such a serious accident is a major disruption to users’ interests. Therefore, MIC today issued a stern warning to the company to prevent similar accidents from occurring. From the perspective of preventing recurrence, MIC requested the following measures: Thorough preparation for switchover work, improvements in the internal and external coordination system, improvements in the content of the information provided to users, and sharing lessons learned with other carriers throughout the telecommunications industry. MIC instructed them to report the details of the specific measures they have taken.