Communication Without Internet
Order of what still works
- Text messages (SMS) — only need a minimal mobile network, often still work when calls/data already fail. Keep them short; sending is retried automatically once there is a network.
- Calls (mobile) — as long as the masts have backup power (minutes to a few hours after a blackout)
- Emergency number 112 (EU) — works via ANY available network, even if your own has no reception
- Analogue landline — rare nowadays; VoIP landlines (router!) fail immediately as well
- Radio (reception) — the most important source of information, see the frequency list in
00-notfall-uebersicht.md
Making your phone battery last
- Power-saving mode + minimum brightness + 2G/"calls only" if available
- Flight mode when there is no network (searching for a network drains the battery most) — check briefly every hour
- One device in the family active, the others switched off (reserve)
Radio communication (independent of any infrastructure)
| Technology | Range | Note |
|---|---|---|
| PMR446 walkie-talkies | 0.5–3 km (town), more with line of sight | Licence-free in Europe, cheap, ideal for family/neighbours. Agree on a channel beforehand: channel …… |
| CB radio | 5–30 km | Licence-free in Germany, for example; base station/mobile, active community |
| Amateur (ham) radio | regional to worldwide | Licence required; the backbone of emergency communication in a disaster |
Each country decides which radios may be used licence-free — check before buying, especially outside Europe.
Agree on a family plan now: If the network is down → switch on PMR channel …… for 5 minutes every hour on the hour (saves batteries).
Meeting-point plan (fill in!)
| Situation | Place |
|---|---|
| Home not accessible | Meeting point 1: …… |
| Neighbourhood cordoned off | Meeting point 2: …… |
| Contact person outside the region (phone number on paper!) | …… |
Be able to leave a note on the door ("I'm at X, time") — keep a pen + tape ready.
Offline communication on the local network (the LAN works without internet!)
Router with power = your own Wi-Fi keeps running, just without internet:
- Share files via a network share (see 08-pc-netzwerk-offline.md)
- Install LAN chat programs beforehand (e.g. a simple LAN messenger on all devices)
- Make local AI on the laptop accessible to everyone on the Wi-Fi (see 07-lokale-ki.md)
Receiving messages from the authorities
- Cell Broadcast: arrives automatically on any modern phone (Settings → keep emergency alerts enabled)
- Sirens (Germany): rising and falling tone for 1 min. = danger → turn on the radio. Other countries use other signals — see the warning systems in the region box at the top.
- Loudspeaker vans of the authorities in the event of a total outage
- Points of contact: during prolonged emergencies, many municipalities in Germany set up emergency information points ("Katastrophenschutz-Leuchttürme", often at fire stations or town halls) — they provide information and can pass on emergency calls. Ask your local council whether there is anything similar where you live.