Technical Topics, September 2005
BPL: Some Good News?
Over the past couple of years this column has reported on NASWA’s effort to head off interference from Broadband over Power Line (BPL) technology to shortwave reception. NASWA filed comments with the FCC pointing out the danger that this technology posed for the shortwave broadcast listener. Most of NASWA’s recommendations to the FCC were ignored as the Commission charged ahead with its preconceived conclusion that BPL was the answer to increasing competition in the broadband access universe.
Over those same years many observers have pointed out the financial risks faced by the BPL start-up companies. The technical faults associated with BPL, especially its likelihood of causing interference to licensed services and its susceptibility to interference from nearby transmitters, have been used by wishful thinkers in predicting that BPL will fall flat on its face and never become a real threat to the shortwave listener.
Just when these wishful thinkers were gathering a following of true believers, reality has reared its ugly head. Google, Goldman Sachs, and Hearst are jointly investing $100 million in privately owned Current Technologies. On the surface such an investment by sophisticated investors might be seen as bad news, a sign that BPL is here to stay. But there is a silver lining to this dark cloud.
Current is one of the primary manufacturers of BPL equipment and a charter member of the HomePlug alliance. HomePlug is a standard defining the architecture of home networks communicating between rooms by using the home’s power wiring. Current is also has a design for using the medium voltage power distribution network for longer distance transmission of BPL signals. The potentially good news is that Current Technologies uses the 30–50 MHz range (as NASWA recommended in its comments to the FCC) for this service so their technology is not a serious threat to shortwave broadcasting.
Current is providing the hardware for the BPL pilot program in Cincinnati, Ohio. ARRL reports in the August issue of QST that the Cincinnati system is progressing without significant reported interference problems.
The fact that these deep-pocket investors chose to back Current is actually good news for shortwave listeners. They could have invested in other companies whose technology has been demonstrated in several failed field trials to cause severe interference to shortwave reception and amateur radio operations. But they did not.
Did these deep-pocket investors assess the weaknesses of the other manufacturers and decide that Current had the best chance of success? I would like to think so. As Wall Street grows to appreciate the financial risks associated with backing a technology that not only causes interference but is likely to be disrupted by nearby ham radio and CB transmissions, an enlightened Wall Street will likely opt to take the lower risk approach afforded by companies that address these weaknesses and that design systems with both ingress and egress immunity.
More good news–on May 23, 2005 Motorola announced a new BPL system architecture called Powerline LV (Low Voltage). Motorola entirely avoids using the medium voltage power distribution network. Instead they employ their Canopy wireless broadband technology to link between the power pole outside the customer’s home and a central node. Between the pole and the customer, Motorola uses a modified HomePlug standard. Motorola has decided to add additional filtering to protect amateur radio frequencies and has indicated they will handle individual cases of interference to shortwave broadcasting by using a wireless link from the pole to the house when necessary according to an editorial in the August 2005 edition of ARRL’s magazine, QST.
So now we have at least two BPL equipment providers who have recognized the risk associated with the interference issue. More importantly we now see investors gravitating to these companies. Somebody has received the message that many BPL systems cause interference or are susceptible to interference from nearby shortwave transmitters and are risky investments.
When the FCC announced their rules for BPL, they ignored the NASWA input that you cannot expect non-technical shortwave listeners to be aware of complex FCC procedures to notify and work with BPL providers to eliminate interference according to a negotiated schedule. It is much more probable that shortwave listeners will simply wonder why they can no longer receive their favorite stations, chalk it up to atmospherics or sunspots, and click their radios off.
That situation is only likely to worsen when DRM-equipped (Digital Radio Mondiale) radios hit the market next year. These radios will, if successfully marketed, bring a whole new population into the shortwave listening world. The sound is advertised as equivalent to monaural FM radio. That will make shortwave easy listening for a whole new class of listener.
Why you ask? DRM has the potential to eliminate many of the objections people have to analog shortwave transmission. Almost every woman I know is revolted by heterodynes, fading distortion, static, and interference that most NASWA members consider part of the shortwave listening experience. (Some have attributed this heightened sensitivity to the fact that women have generally better high frequency hearing capability than men. Anthropologists have theorized this heightened sensitivity allows women to better hear the cries of their babies.
My own theory is that women are generally less exposed to the loud noises of hot-rod engines, gunfire, and jackhammers than men. Such loud noises have been proven to be the cause of thickening eardrums as we age. Thick eardrums do not vibrate as easily or as rapidly as thin ones. Thus men have a reduced sensitivity to high frequencies and a greater tolerance to broadband noise, static, harmonic distortion, and heterodynes.
Similarly, younger people, raised on FM radio and CD quality music, are often turned off by analog shortwave broadcasts with all the nasty noises and distortions previously mentioned.
So half the adult population (the women) and almost all the young folks can’t stand to listen to analog shortwave broadcasts. Certainly DRM holds the promise that these potential listeners can be induced to buy new $300 radios. That is a big market. Will the manufacturers of such mass-market radios sit on their hands while BPL destroys their potential market? I think not.
Manufacturers of analog radios did sit on their hands with few exceptions during the FCC rule-making process. But many of those manufacturers were already convinced that shortwave radios were not a serious market. Since then several analog radio manufacturers have abandoned the shortwave receiver market as some international broadcasters did the same.
The advent of DRM and its potential market base could give rise to the necessary financial muscle to force the FCC to clean up the BPL mess. As often happens, the marketplace may do what government does not have the courage to do. Until next time, stay tuned.