Oh Alistair, your post made me smile re 3 G being switched off shortly. Quite interesting that your presumably externally mounted meters., cant communicate with control..
We live in a house with 4 feet thick basement walls all round and solid concrete basement floor/raft, the basement ceiling is 6'6 high. They knew how to build them back then, with a very dense Accrington red brick almost equivalent to a blue engineering brick.
Unfortunately there appears to be no easy answer the meter placement issue.
