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Re: [Discuss-gnuradio] GNU Radio & wireless SmartMeters

From: Eric A. Cottrell
Subject: Re: [Discuss-gnuradio] GNU Radio & wireless SmartMeters
Date: Mon, 26 Nov 2007 19:54:41 -0500
User-agent: Thunderbird (X11/20070801)

Dave wrote:
> After years of development (involving close work with the EPRI, or
> Electric Power Research Institute, a power industry consortium of
> large utility corporations), PG&E has selected a new type of electric
> power meter from SmartSynch, Inc. [2] that can wirelessly transmit
> massive amounts of data about your building's electrical usage to a
> radio receiver nearby in your neighborhood. From those base stations,
> the data is sent over an "advanced communications network" (meaning
> fractional T1?). Although PG&E has "no plan to utilize the device's
> real-time capabilities", the feature is nevertheless fully present in
> the beta devices... it is "just not turned on", according to a
> semi-trained SmartMeter representative I spoke with, the feature is
> nevertheless fully present in the beta devices... it is "just not
> turned on". Of course, we all know how terribly trustworthy and
> super-civic-minded these power companies are, right?

A sizable utility like PG&E needs a good data network for their SCADA
system.  This is used for distributed metering and control at the
transmission line level and employs Microwave and/or Fiber.  The Fiber
is usually run along the transmission line right-of-way.  Utilites
usually own and maintain their communications networks.

Power Line Carrier is used for low speed data.  It is basically Low
Frequency Radio Waves coupled directly to the transmission line.  Older
systems used on-off keying while newer systems use PSK.

A brief search shows PG&E uses fiber and offers their excess capacity
for sale as some other utilities are doing.  Some utilities are also
looking into becoming ISPs by deploying a Broadband over power lines
(BPL) system,.

>From what I heard about SmartMeters they extend SCADA functions down to
the distribution level.  I could see utiliies having the wireless
receivers at substations and using their fiber to get it back to the
central servers.  I mainly deal with the Protective Relaying part of the
industry so I am more familiar with electric utility communications that
support the System Fault Protection part.  The few large utilities I
have talked to do take network security seriously.

The security threat posed to you in your home depends on what is meant
by real-time.  Typically the meter in a house measures the power you use
in watt-hours.  The real-time function may just be a direct reading of
the voltage and current on a per cycle basis much like a regular AC
Voltmeter and AC Ampmeter.  I would be more concerned if the device has
DFR (Digital Fault Recorder) functions that can sample many points on
the AC waveform and send it back over SCADA.  The sampling rates
generally go up to 200 KSPS.
I am not familiar with the sampling rates needed to reconstruct computer
monitor output.

A DFR is handy if a transmission line fault occurs and the fault
protection does not operate properly.  It is possible to playback the
fault recording from the DFR records and test the fault protection.

I work for a company that makes test equipment for the power industry. 
It is a private company in the process of being sold to the holding
company that owns DCSI.  DCSI is involved with SmartMeters.

73 Eric

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