Communication when networks fail

A phone call needs a whole chain: your device, a mast or router, cables and switching equipment – and every link needs power. Many installations have backup power from batteries or generators, but it usually lasts only for a limited time. If one link fails, the chain breaks. Also, every network is built only for a certain number of simultaneous calls. In a crisis, very many people suddenly want to phone, and the network is overloaded even if it is still technically running.

Broadcasting is a one-way street: a transmitter sends, and every radio within range receives, no matter how many there are. That is why authorities use radio to inform people in emergencies. A battery, crank or solar radio therefore stays useful long after the internet and mobile networks have gone silent.

Short text messages need far less network capacity than calls and are often delivered as soon as there is a brief connection. Agree simple standard messages in the family, such as “Safe, at home”. Keep calls short so emergency calls can get through.

An out-of-area contact is a clever trick. Calls to another region often get through more easily than connections within the affected area. Everyone checks in with this person, who passes on who is where. Add an agreed meeting point in case nobody can be reached.

Write the most important numbers and addresses on a card for your wallet and go bag. Also note the frequencies of your regional radio stations. Save your phone battery: power-saving mode, lower brightness, close unnecessary apps and switch the phone off at times when there is no network anyway.

The emergency call always takes priority. Try it even when the network is poor. If it does not work, go to neighbours, the nearest fire or police station, or a contact point the municipality may set up during longer outages. Find out beforehand whether there is such a place near you and where.

In a crisis, rumours spread quickly. Do not pass on anything that does not come from a reliable source, such as the radio or official bodies. False reports can put people in danger or frighten them unnecessarily.

Radio transceivers are subject to different rules and sometimes licensing requirements depending on the country. Check local rules before you buy or use one.

Find out how your region issues warnings: sirens, radio, warning apps, alerts sent directly to phones (cell broadcast where available) or loudspeaker vans. Set up warning apps while the network is working. Many regions have regular warning test days – a good opportunity to check whether the warning reaches you.

Hold a small family test once: everyone sends the agreed standard message to the contact person, and you check whether everyone has the numbers on paper and knows the meeting point. Also switch on your radio and find the regional station – without searching online.

The BBK and Ready.gov both recommend a battery or crank radio as part of emergency equipment. Ready.gov also advises text messages instead of calls and an out-of-area contact.

In longer outages, the neighbourhood is often the fastest help. A notice in the stairwell with the latest information from the radio, or knowing who in the building lives alone, sometimes replaces many phone calls.