NTT DoCoMo has developed the i-mode® Disaster Message Board service, allowing i-mode users to send SMS to a special site in the event of major calamities, when the network is too busy to process the sharp increase of traffic.
Voice calls and data packet transmissions would be treated separately, so that texts posted at the Disaster Message Board have better chance to arrive safely.

In a further effort to reduce traffic, subscribers calling during major disasters will hear a message advising them to resort to the i-mode Disaster Message Board service instead of directly calling their relatives or friends.