You encode the location information in the actual broadcast message: https://en.wikipedia.org/wiki/Specific_Area_Message_Encoding https://en.wikipedia.org/wiki

You encode the location information in the actual broadcast message: https://en.wikipedia.org/wiki/Specific_Area_Message_Encoding https://en.wikipedia.org/wiki/Specific_Area_Message_Encoding This is a solved problem: weather radios have been doing this for years.