This will be interesting if anyone from AGL replies here re this.
I believe smart meter readings are transmitted from the home or business to a wide area network, made up of mobile phone or radio masts, so there might be some sort of national system of wireless, but not sure just how elaborate this might need to be in our more remote areas.
It is a 2 way communication so a network service provider can disconnect or reconnect power to a specific site, throttle or turn solar off completely, etc, if the network requires it for bushfire risk, grid oversupply, etc.
There is scant information about this online.
I did read somewhere that where digital meters that are unable to communicate are installed (or type 4a option of having the comms turned off), a consumer may upload readings just like older analogue meters.