In the event of mains grid power failure it is very easy to lose all forms of communication.

Many mobile phone cells don't have battery backup, our internet and TV depend on mains power, landline phone technology is being phased out and many houses don't have it any longer.

I realised recently that I no longer have a battery powered domestic radio, so I bought one, then further realised I didn't know what stations were the official emergency broadcast stations.

BBC Radio 2 and BBC Radio 4 on FM are the official emergency broadcast stations. It is probably worth making a note of the frequencies and strengths of those stations at your home.

For two way communication you can buy PMR radios but these have a very small number of RF channels and would soon be overwhelmed with too many users.

If you are at risk and need a landline service, your telephone provider is obliged to provide equipment with a one hour backup provision - although this is not very re-assuring if you wake up in the morning and find out the power went off 6 hours ago.

A mobile phone service service will continue but it will have less cells and outbound calls from non-emergency personnel would probably be blocked to prevent it being overwhelmed, and it will permit broadcast calls to your phone. This might not be comprehensive in all locations. However all mobile phone services will be joined together to increase the chance of more people having a signal.

Most of the above applies to extensive long periods of power failure, localised or short periods are less likely to kick into emergency status.

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