On Mon, 28 Mar 2011 16:53 -0400, "Carl Denk" wrote: > A couple of questions: > 2: Do the Smart Meters have wireless transmitter(s) that are part of a=20 > network that relays meter to meter across some distance to get the data=20 > to some receiving node on the network that could be many maximum signal=20 > range distances from the originator. 915 MHz and 2405 MHz have been=20 > mentioned Hi Carl, In the urban and suburban areas of California the meters form a mesh network within a neighborhood and then there are concentrators that connect them to the internet and back to the power company. In rural areas the meters mesh into groups as best they can but aren't in contact with a concentrator. The information is stored and when the meter reader drives nearby one of the meters the data is downloaded for all meters in that isolated group. So even if you are fairly isolated you don't need a person to see your meter to read it. This info is all from the PG&E website and careful Googling. But it is constantly evolving as the firmware is still developing and eventually enough concentrators will be in place so all meters everywhere will be in constant contact. Even without constant contact, it will still allow them to better audit the power and catch meter bypassers etc. They probably have some clever pricing plans to roll out once the meters are everywhere. And neat hardware to go along with it, so you can get a discount if you have your thermostat linked to it that can pop into a different temperature profile if there is a power grid alert. And charge more for all other customers during that same alert. After all, they aren't putting all this effort in to save us money. I think most people have figured that part out already :) Gas meters are short range 35 mW 2.4 GHz. Electric meters are 0.5-1.0 watt ~900 Mhz. So the range could be very good under the right conditions, maybe a mile. But it's radio. You can get a mile with 1 milliwatt if everything's perfect. Or barely 20 feet if it isn't. Most power meters are at head height and outdoors. That's better than being a foot off the ground and indoors, although it still allows for a lot of things that hurt the signal. But figure how well a walkie-talkie does. Probably comparable. > 1: Do the Smart Meters send a signal over the power lines to get the=20 > data back to the power supplier? I don't think there is any use of data over power lines. Phone wires for DSL are usually close enough and the price of hardware is a lot better. Think about what it takes to connect data to a 12 KV line. And they are prepared to wait a while for complete coverage. Until then, the trucks can drive by and scan. But that is just speculation on my part. > 3: Is Google part of the software chain? What would Google have to do with it? > It would be nice if someone could dissect the more popular meters and=20 > publish what the find. As far as I know, the meters are not available for purchase. Bob --=20 http://www.fastmail.fm - The way an email service should be --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .