Why on earth do they need a Comms connection – surely just for a card reader.
Card reader requires a connection to clear the transaction, same as paying for petrol, or in a supermarket, the difference is that some of these chargers are in village hall car parks on the NW coast of Scotland & use a mobile phone connection when it works. Another favourite is to put the charger in an underground car park (that’s you BP in the Waitrose underground car park in Horsham) and wonder why there’s no reliable mobile signal.