They use different types of mesh networks to communicate. Both GE and Landis+Gyr use Silver Spring Networks networking equipment and transceivers. There are sometimes complaints because the user is generally paying a little for the electricity to operate the meters and broadcast all this, although I guess it's possible to separate that out - i.e. only check the current going into the house.Here is my smart meter story. Few months back I noticed some wonkiness with the electricity in the house. Intermittent light dimming once in awhile, nothing huge. I was out front working on the car when the AEP truck pulls up. He said he needed to ck my meter out because it had reported intermittent electrical outages for my address. He checked it and traced it to a bad transformer bus bar (corrosion) in the alley. No telling how long I would have put up with it without the meter dropping a dime on the problem. Another good thing, in the event of a power outage, AEP knows instantly when and where the power is out.
The city of Santa Clara, California operates its own electric utility. They Wi-Fi for transmission. The city owned Wi-Fi network is also available for free public internet service. I've tried using it though. Just getting to the OK screen can take forever, it's rather iffy signal, and even when it's working perfectly it's pretty slow. I read somewhere that individual devices are limited to 1 Mbit/sec, although when I ran speed tests I was sometimes getting speeds comparable to dial-up internet.