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Disaster Preparedness

Japan experiences earthquakes, typhoons, heavy rain, and landslides regularly. When these events happen, cell networks often go down or become overloaded. Meshtastic can provide a local communication layer that works independently of infrastructure.

When cell networks fail​

After a major earthquake or typhoon, cell towers may lose power or be physically damaged. Even when towers are intact, network congestion can make calls and messages impossible for hours. This creates immediate problems:

  • Families cannot confirm each other's safety
  • Neighborhood coordinators cannot check on elderly residents
  • Information about road closures, water supply, and evacuation routes cannot be shared
  • Local emergency response teams lose coordination

What Meshtastic can do​

Meshtastic devices create a local mesh network that works without any infrastructure:

  • Send text messages between devices within range (typically 1-5 km in urban/suburban areas, more with elevation)
  • Share GPS positions so team members can see each other's locations
  • Relay messages through intermediate devices, extending range across a neighborhood
  • Work for days on a single battery charge

This makes Meshtastic useful for:

  • Welfare checks — neighborhood volunteers checking on residents
  • Information sharing — passing along updates about water, power, and road conditions
  • Coordination — organizing local response efforts when phone networks are down

What Meshtastic cannot do​

It is important to be clear about limitations:

  • Meshtastic cannot call emergency services (110, 119). It is not a replacement for a phone.
  • Meshtastic does not connect to the internet. Messages stay within the local mesh network.
  • Meshtastic is not a rescue beacon. For personal emergency signaling, use a PLB (Personal Locator Beacon) or satellite messenger.
  • Range is limited to the local area. It is a neighborhood tool, not a city-wide system.

How to prepare​

For individuals and families​

  1. Buy two or more devices. Meshtastic only works if there are at least two devices. Keep one at home and carry one with you, or distribute them to family members.
  2. Set up a family channel. Create a private channel and share it with family members before an emergency happens. See Channels and Groups.
  3. Test your devices. Send messages between home and your workplace or a neighbor's house to understand your range.
  4. Keep devices charged. Include Meshtastic devices in your disaster kit alongside batteries and power banks.

For neighborhood groups (自治会・町内会)​

  1. Distribute devices to block coordinators and welfare check volunteers.
  2. Create a shared channel for the neighborhood network.
  3. Place a relay node at a high point (a rooftop or upper floor) to extend range across the neighborhood.
  4. Practice regularly. Include Meshtastic in disaster drills (防災訓練).
  5. Document the setup. Write down channel names, device assignments, and basic instructions so anyone can use the system.

Integration with existing disaster preparedness​

Meshtastic works alongside Japan's existing disaster infrastructure:

LayerToolPurpose
National alertsJ-Alert, NHKEarthquake early warning, tsunami alerts
Emergency callsPhone (110, 119)Police, fire, ambulance
Family safetyPhone, MeshtasticConfirm safety, coordinate meetup
Neighborhood coordinationMeshtasticWelfare checks, local information sharing
Personal rescuePLB, satellite messengerSignal for rescue when unreachable

Meshtastic fills the "neighborhood coordination" layer. It does not replace any of the other layers.

Practical tips​

  • Start small. Two or three devices in a family or small group is enough to get started.
  • Elevation helps range. A device on the second or third floor of a building reaches much further than one at ground level.
  • Keep a power bank in your disaster kit. A 10,000 mAh power bank can keep a Meshtastic device running for a week or more.
  • Use simple device names. In an emergency, names like "Tanaka-Home" and "Tanaka-Work" are easier to understand than codes.

Further reading​