NTT Docomo said on November 5 that a nationwide mobile service outage that began around 11:18 a.m. that day affects only subscribers to its 5G SA (Standalone) option. The cause is under investigation, and the company has not said when service will be restored.
Customers on the option are finding voice calls, data communication and SMS hard to use. Docomo said they may be able to get service back by selecting 4G in their network settings and then restarting the phone or toggling airplane mode on and off.
5G SA is an add-on that connects only over 5G-dedicated equipment. Docomo advertises it as staying unaffected when 4G networks are congested, allowing smoother communication.
MVNO correction
Users of 5G and 4G services outside the 5G SA option are not affected. Docomo initially said MVNOs — mobile virtual network operators, which lease capacity on its network and sell it under their own brands — would also be hit, then corrected that to say they would not. Emergency calls are unaffected.
The disruption is confined to the newest slice of Docomo's network, leaving the older 4G layer and standard 5G service running. Docomo has not said how many subscribers are on the 5G SA option.