We have them here and they still have the meter reader walking house to house so what ever they do is not very strong of a signal. The reader puts her "instrument" (no hidden meaning for the word instrument, mods) very close to the meter sender.@shortbus each meter can have the same frequency. The reading is taken by proximity Each report can have the number of gallons used and the serial number of the meter - which is then correlated to your account and not mine.
OR they may be connected via cell tower data. Truth is - I don't know how they do it. It's probably a fairly closely guarded secret. Not intended for general population. But there's probably more information out there than I can imagine.
There still would need to be either a code or something to signify one meter from another. Never meant that they used different frequencies for each house. But probably each meter maker uses a different one.