Re: {2 Meter WSPR} Utility Smart Meters Illegally Hamper Weak SignalStudies in 902-928 MHz Amateur Band

[n6...@sonic.net]

On Wed 20/03/13 9:25 AM , KP4MD <kp...@cfmilazzo.com> wrote:

In this video at http://www.youtube.com/watch?v=yy6C6-xn5vs my Newsky TV301U RTL-SDR recorded one minute of a 3 MHz segment centered on 915 MHz of these strong radio bursts transmitted throughout the 902-928 MHz amateur band by Landis & Gyr E350 AXR-SD Smart Meters that Sacramento Metropolitan Utility District (SMUD) installed on all homes in my neighborhood.  

I'm a bit confused by your characterization of these signals as 'strong'. You don't indicate your SDR calibration but it appears that the signals are only a few ten's of dB above your noise floor. In a 3 MHz bandwidth this wouldn't seem to be terribly large at 20' distance.

The signals in this video match the characteristics of the FCC test reports for the Landis & Gyr Focus AXR-SD Smart Meters (FCC ID OWS-NIC514).  See https://picasaweb.google.com/114032640816757126398/SmartMeterInterferenceOn902928MHzBand  

The signals were received quite strongly on a 4 inch flexible antenna in a ground floor window about 20 feet from a nearby smart meter, with many other neighbors' meters not far away.  The signals vary in strength, as expected from meters at varying distances. They also resemble the signals in W6DTW's "Spectrum Analysis of a Smart Meter" http://www.youtube.com/watch?v=gQM1OpGyAqg and as described by VE3NCQ and in other references.

SMUD claims that "Smart meters transmit radio signals once every four hours... average meters communicate for approximately 60 seconds every 24 hours..." https://www.smud.org/en/residential/customer-service/smart-meters/common-questions.htm 

This may be true for one solitary Smart Meter, HOWEVER, as seen in this video, the device frequently emits "about 1 watt" RF transmissions throughout the 902-928 MHz 33 cm amateur band throughout the day, not only sending its own data, but constantly receiving and repeating neighbor's data when part of a peer-to-peer MESH network of hundreds of Smart Meters.  

As explained on http://www.arrl.org/smart-meters these Smart Meters are NOT ISM devices--they are unlicensed FCC Part 15 devices.  As such, they have no protection from interference from licensed users of 902-928 MHz and must NOT cause interference to licensed spectrum users, that is, to either primary ISM or to the secondary amateur radio service.  According to FCC Part 15 regulations, it is the responsibility of the user (SMUD) to mitigate harmful interference caused by these unlicensed devices to amateur stations and other licensed users of these frequencies.

With about 200 homes in my 90,000 sq. meter housing development, the smart meters in my neighborhood generate over 200 watts total RF power on 902-928 MHz. Considering that SMUD has installed over 600,000 of these meters in the Sacramento metropolitan area, we are surrounded by over half a megawatt of random unlicensed transmitters causing interference throughout the 33 cm amateur radio band.  

https://www.smud.org/en/about-smud/news-media/news-releases/2012-04-16.htm

Again, I think this might be a little misleading. *Average* power is greatly less than the half megawatt you suggest and it is spread over a very large geographic area.  By the same reckoning the sun, at roughly 1 kW/yard^2 could be considered to be dumping a couple of hundred *billion* watts into an area the size of Sacramento (100 sq miles) - and that is *average* power on a sunny day. That's far more than a million times as much!

I'm not supporting the utilities' use of the spectrum this way but I think we need to keep things in perspective in order to remain credible.

In years past, during the early 1990's, I built up radios and several of us created a wide area amateur 900 MHz TCP/IP network running at about 250 kbps in Northern California. During that time the utilites and others - notably Metricomm and Utilicomm, were using this spectrum for mesh networking and remote meter reading. At that time a number of hams were involved with Metricomm, including George Flammer who is now with Silver Springs Networks the provider of the Smart Meter PG&E presently has on my house.  These radios were similar in power to the one you are reporting here.

As it turned out, there wasn't a great deal of interference with our 900 MHz TCP/IP radios, even though those radios were simple FM and about 1 MHz wide. Bob, WA6M, examined and used a couple of versions of the Metricomm radios and may remember more than I do.

I bring these points up because I think it important that we be accurate and level-headed in considering QRM from unlicensed users.  My experience is that *actual interference* on VHF/UHF between services is a lot rarer than common wisdom might lead one to believe. The reality is that attenuation over real-world paths is far greater than most people realize. It's essentially the reason that even with cell sites only a few miles apart and running 20+ watts of power to each sector antenna, many of us experience dropped calls - never mind loss of ability for data communications.

Glenn n6gn

VE3NCQ has posted an excellent description of the smart meter interference problem in Canada, and how the energy industry has in effect illegally appropriated the 902-928 MHz band with no regard for rendering it useless for licensed amateur radio operations in metropolitan areas. http://www.ve3ncq.ca/wordpress/?page_id=10

Description from Landis & Gyr Product Specification Sheet:

"The module transmits and receives data through a robust, peer-to-peer mesh network utilizing the 902 to 928 MHz unlicensed frequency. The single-phase digital endpoint prioritizes messages based upon application, operates in a broad-based, multi-purpose network with millions of endpoints, and provide control through a user-friendly interface for network and data management.

In addition to kWh and kW readings, the RF modules report load profile, time-of-use periods (AX only) and up to 5-minute interval data for billing, engineering and customer service applications. RF modules offer high-power output -- up to 425 miliwatts (sic) -- to enable optimal transmission without added infrastructure..."

The FCC ID Label inside this Smart Meter reads:

GE PN 123S123456 

SSN Catalog 340-040304 

FCC ID: OWS-NIC514                 IC: 5975A-NIC514 

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.            

                                                          996-000015A 

This FCC ID Information is at http://transition.fcc.gov/oet/ea/fccid/

Grantee Code: OWS

Product Code: -NIC514

Landis & Gyr RF Specification Sheet

http://www.landisgyr.com/na/files/pdf1/FOCUS_AX_Universal_RF_Sell_Sheet1.pdf

Gridstream RF Video: http://www.youtube.com/watch?v=X3SjWubt5Lo

--
You received this message because you are subscribed to the Google Groups "2 Meter WSPR" group.
To unsubscribe from this group and stop receiving emails from it, send an email to 2-meter-wspr...@googlegroups.com.
To post to this group, send email to 2-mete...@googlegroups.com.
Visit this group at http://groups.google.com/group/2-meter-wspr?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.
 
 

[KP4MD]

I call the Smart Meter signals "strong" because they approach the saturation level of this receiver and will certainly swamp out the sub-noise floor signals such as we use in VHF-UHF propagation studies and other weak signal modes.  The signals are probably much stronger than 30 dB above the true noise floor as this RTL-SDR receiver has a typical noise figure of 7 dB (see http://www.sm5bsz.com/linuxdsp/hware/rtlsdr/rtlsdr.htm) and the antenna was a helically shortened 4 inch stubby whip inside a window.

FCC Part 15 rules were intended to allow sporadic operation of individual low power transmitters without causing interference.  The blanketing of metropolitan areas with networks of autonomous Part 15 transmitters creates an uncontrollable source of constant intereference to licensed users that violates the terms and spirit of Part 15 rules.  Although your 902 MHz network may have fared well in the early 1990's, over the past few years these unlicensed 33 cm transmitters continue to proliferate at a rate that surpasses anything previously there by several orders of magnitude.  

I don't suppose that the broadcast industry would complacently accept the installation of unlicensed Part 15 transmitters on all our homes if they were to constantly frequency hop through all channels on the AM and FM broadcast bands.  Likewise, the amateur radio community should speak up to protect its frequencies from the increasing number of intruders that adversely affect their usefulness.

Carol, KP4MD/W6

Centered on 915 MHz my Newsky TV301U RTL-SDR recorded one minute of a 3 MHz segment of these strong radio bursts transmitted throughout the 902-928 MHz amateur band by Landis & Gyr E350 AXR-SD Smart Meters.  The display shows 200 kHz signal bandwidth and waterfall shows the 300 kHz frequency hopping pattern, same as the following pictures from the FCC Emissions Test report for this smart meter.  SMUD claims that "Smart meters transmit radio signals once every four hours... average meters communicate for approximately 60 seconds every 24 hours..." https://www.smud.org/en/residential/customer-service/smart-meters/common-questions.htm HOWEVER, as seen in this video http://www.youtube.com/watch?v=yy6C6-xn5vs , the device frequently emits "about 1 watt" RF transmissions throughout the 902-928 MHz 33 cm amateur band throughout the day, not only sending its own data, but constantly receiving and repeating neighbor's data as part of a peer-to-peer RF MESH network.