Broadband Power Line communications & the amateur radio

Do ban BPL !

Since 2002, Internet trials using the electricity power cabling system are undertaken in the U.S.A. and Europe by private and national electricity companies. These trials are know as Power Line Transmissions (PLT), Power Line Communications (PLC) or Broadband Power Line telecommunications (BPL) aka "courants porteurs en ligne" in French (CPL).

BPL uses the low and medium-voltage power lines like the ones installed along our streets and displayed at right to distribute broadband services on frequencies between 2 and 80 MHz. The signal is broadband, meaning that it is spread over hundreds of kilohertz; in other words these companies are parasiting our amateurs bands ! 

Such trials are in violation of the european directive about the "electromagnetic compatibility" (ref. 92/31/EEC handling the famous logo) that states that "everybody may use frequencies at the condition to not disturb the other users". However, it appears that these private or national companies are far to respect this law. 

Today this issue impacts broadcasters too that request a special attention from ITU Radiocommunication Sector (ITU-R). Indeed Sub Working Group (SWG) 6E1 expressed the view that interference produced by systems employing BPL as well as by Industrial, Scientific and Medical (ISM) equipment and short-range devices, would compromise broadcast reception. BBC engineers for example described the interference as varying between "annoying" and "a level sufficient to make the broadcast completely unintelligible".

ITU's SWG 6E1 is of the opinion that "any increase in the amount of noise due to these systems is unacceptable," said a statement from the group's chairman to the chairman of Working Party 6E (WP 6E). "In particular, broadcast services should be protected from unwanted emissions from PLT systems," the panel asserted, "as these emissions are a byproduct of a system that is not itself a user of the radio spectrum." The panel recommended the formation of a group representing all users of the radio spectrum "to coordinate development of limits to be imposed on the radiation from these systems".

While some companies gave up their BPL tests due to interference they were unable to remove, other companies continue generating interference on HF. In Austria for example, the Linz Power Company's BPL pilot project created massive interference in the Red Cross service during a disaster response drill in May 2003. The Austrian Amateur Transmitter Federation (OVSV) asked the Government Ministry for Commerce to halt these radio interferences.

In the U.S.A., the Disaster Preparedness and Emergency Response Association (DERA) called on the FCC to require impartial PBL field testing as well as additional public comment and full and open public hearings. 

DERA concludes that "serious interference to and disruption of critical emergency communications systems [...] would almost certainly result from BPL implementation as currently proposed".

Meanwhile, the Amateur Radio Research and Development Corporation (AMRAD) filed additional test data with the FCC about interference caused by BPL systems. 

Their new data demonstrated that amateur operation in the test neighborhood would cause many homes to lose their Internet service. "At least an area out to a radius of 800m (0.51 miles) from the transmitting station could have their Internet connection interrupted", ARMAD said. "Closer-in homes would almost certainly have their Internet service interrupted".

For its experiment AMRAD used the Potomac Electric Power Company system test site, and a mid-1960s vintage home with unshielded interior electrical wiring and overhead power lines. It resulted that at a distance of 800m (0.51 miles), data transfer ceased in the face of a 100-W signal on 3980 kHz from a mobile transmitter. Adjacent to the test property, data transfer ceased in all but one instance at a transmitter power of just 4 W in the BPL operating band from 4 to 21 MHz.

Since 2004, the ARRL is conducting a complete and independent BPL engineering study as well. Its results as well the comments of BPL victims are regularly published in the columns of QST magazine.

To forge your own opinion about theses interferences, I suggest you to load the next video to get an idea of the noise level generating by BPL on amateurs bands. When BPL is activated you can no more work any station, neither local or DX. This is not acceptable ! You will also find a compilation of videos recording these interferences on the ARRL website.

What is the weight of amateurs in this balance ?

In joining the amateur radio community, broadcasters and emergency services help us to fight against these "BPL" companies. But it is still too early to say if this is a good or a bad news for our hobby. Too much financial interests are in balance and to save their economy (and gain votes) political already demonstrated that they do not hesitate to hack FCC commissioners who have no concept of the technology they are supposed to be regulating. We all hope that the WP 6E's report will be in favor of spectrum users without modifying our rights to use amateur bands as we already observed in 432 MHz, 1.2 and 2.4 GHz some times ago that were partly reassigned.

I remind you that amateur radio is more than an activity or a simple hobby, it is defined as a service that we pay yearly. As such, if we can not take advantage of this radiocommunication service, in some countries we have the right to require an exploitation loss or at least to request the suppression of these interferences at the responsible's charge.

Unfortunately, until now neither our national representative ham associations (ARRL, RSGB, ARC, RSGB, UBA, REF, etc) or the concerned IARU delegation can oppose to this criminal practice.

Amateur radio  associations have discussed about this problem in the offices of the European Commission at Brussels in 2003, but without to get the slightest action or result up to day, on the contrary... The European Commission and well as FCC encourage the deployment of BPL networks (without to forget Trans horizon radars interfering in amateur bands, see this link) !

As Sun Tzu wrote in his Art of War, "Know the enemy, know yourself; in a thousand battles, a thousand victories". The most active ham association fighting against this problem is actually ARRL on behalf of the League's 155000 members who has gathered over 5000 complaints and comments from the amateur radio community. We all hope that this action will convince one day ITU to prohibite BPL.

Confronted to such laxities and to lobbies that are standing by, early 2003 Hilary, alias G4JKS, representing the UK Anti-BPL group gave up his fight against administrations. Hopefully Peter Cochrane has resumed the fight and wrote an article about BPL that his author ask us to publish as often as possible on the Internet. Thanks to his fight and the new ITU decision, the future of ham radio looks less noisy.

The right technology for the right job

This document is a reprint from a short article published on Silicon website in which Peter Cochrane reminded how can be hard the fight against administrations even when hams rights are derided. Here are his commentaries.

For a decade now business plans have arrived on my desk, in increasing numbers each year, but only a small percentage find their way to commercial success. Remarkably I see very little correlation between plans.

There is, however, a major exception where the same plan seems to arrive on my desk every year. Each time it is presented as revolutionary and ground-breaking. But it is always the same technology and it is always as flawed and as misconceived as the original I first saw a decade ago.

News reports often included to amplify the case are along the following lines : XYZ Company is proud to report broadband internet trials are underway using a ground-breaking technology that will revolutionise radio, TV, cable TV, internet and data services to the home. Existing electricity power cable can supply all of your digital services at speeds up to 50 Mbits. Extensive laboratory trials have proven this technology, and testing with customers is at an early stage. If fully successful a commercial rollout is planned within the next three months. 

It is then customary to include a CEO interview that says something along the lines of : "All the obstacles have been overcome. The technology is now proven, stable and economically viable, and we are in a position to revolutionise the last mile. We also predict this technology will see the demise of the telco in the next decade..."

Partner companies usually keep their names secret in anticipation of further announcements to be made later that year and the technical press always seem convinced it is all true. But about 6-12 months after the announcements the companies involved quietly say they are ceasing trials and development because some alternative technology has been discovered. It then goes very quiet and nothing more is heard.

I wouldn't find this so upsetting if it only happened once but to my knowledge there have been dozens of false dawns. If only the people involved would visit my office I could save them a small fortune. At a modest estimate, over $200m has been expended to date and no one has been successful in transmitting significant amounts of data over power cables to the home.

I can guarantee no one will get this technology to work as advertised. It might be appealing and economically attractive but I'm afraid the basic laws of physics cannot be sidelined. For anyone contemplating the waste of another $5-30m here is my 'don't do it' shortlist :

- Power cables employ low-grade plastic that is unfriendly to high-frequency signals as the absorption per unit length is very high. This alone precludes transmission of high-speed data over significant distances.

- Power cables are not physically symmetrical and are therefore very effective antennas. They radiate energy from high-speed data signals which becomes a source of interference for wireless services including broadcast radio as well as emergency, maritime, aeronautical, military and navigation services. By reciprocity they also suck in energy from every local radio source which further degrades data signals.

- As signals propagate along cables they become weaker but the switching transients from washings machines, refrigerators, vacuum cleaners, electric drills, light switches and other appliances are huge, do not decay at the same rate and swamp data signals

- Switching transients on power grids with generators going on and off line, dynamic load sharing, fault and maintenance work, all induces massive transients that also swamp data signals.

- Cable joints, transformers, power meters, the on/off nature of electrical appliances and the topology of power grids create large load changes and multiple signal reflection points. This creates a dynamic echo environment where the transmitted signal is further corrupted

- Real time communications of any kind - whether by telephone, radio or TV - are taken out by the huge voltage transients inherent to power lines and ultimately the data rates achievable for non-real time are also very low.

- Transformers and power meters require a workaround as they present an absolute block to any high frequency signals.

This is a short disaster list that says this technology will not work. And the real nail in the coffin ? Telephone and cables were designed to carry far higher frequencies than 50 Hz power cables and in every aspect offer superior performance for all data applications. And more recently wireless technology is becoming so low cost and so high performance that signal processing requirements for data over power cables, even if it were possible, would be prohibitively expensive in comparison.

In many locations the power companies have installed optical fibre along their power lines for telemetry related to the control of power distribution. Because their data requirements are so meagre huge amounts of bandwidth are available. So it does make sense for wireless technology to be used at that end point, in a distribution mode to attack the last mile.

Despite all of this there are more than 20 power companies currently active across Europe planning or conducting trials. The reported field performance results are very poor, as expected! Installation costs are higher than the telcos and cablecos. Yet they still seem determined to become the biggest source of radio interference on the planet.

And the ultimate decider ? It looks as though the politicians will be asked to decide between the power and wireless lobbies on the legality of the interference levels.

Contrary to a widely held belief, all the technology necessary to transform the local loop is to hand, and sporadic solutions such as data over powerline are a bit of an economically driven red herring. 

So please, will the next candidate thinking of sending me another business plan with a revolutionary technology that will exploit power cables please employ someone who understands Maxwell's equations, data transmission and holistic economics.

This column was compiled in a hotel lobby between meetings and despatched via a Wi-Fi link that appeared without identification - thanks to whoever decided to provide this charitable service.

And you ?

What can you do ? In the U.S.A. you can make a donation to ARRL to preserve your rights. In other countries do preserve our bands in becoming member of your national radio association. Do continue working in HF bands too and complain to the police (with statement) and to your national ham association each time that you observe a BPL trial in violation of amateur rights. A passive attitude is in favour of BPL companies and in this case do not be surprised if one day our bands disappear, reassigned to other services.

In addition, each time that you read an article about BPL in a magazine and that it forgot to speak about interference generated by these trials, write to the editor, explaining what are the side effects of these transmissions on HF bands and specially on radio amateurs activities, emergency services, broadcast listenings and army transmissions.

Take action now ! Publish as often as possible this page on the Internet and discuss about BPL with all concerned actors. All the amateur and broadcaster community will thank you.

And now ? At the end, we lost the fight against BPL ! Indeed, in all supporting countries, BPL networks are now fully in line with the regulatory framework. Do they continue to generate RFI ? Yes, they do... :-(

For more information

ITU-R Working Party 6E

PLC measurement in Europe, CE-Mag

GoBPL, by AB3AX

Broadcasters join Anti-BPL Chorus, ARRL

BPL is a Pandora's Box, ARRL

BPL and Amateur Radio, ARRL

Impact of RFI caused by BPL, ARRL

Broadband Powerline Communications Systems, ACA (PDF)

RF Field Strength Meter (in kit)

In French

Comment ça marche (CPL)

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