Free from interference: FCC adopts powerline rules
By Matthew Miller, Special Projects Editor -- EDN, October 26, 2004
The FCC has given its formal blessing to broadband-over-powerline (BPL) technology—the delivery of broadband to homes and businesses via the electrical grid. While adopting rules designed to ensure that BPL services won't interfere with other technologies, FCC officials also asserted that BPL itself should be protected from a different kind of harmful interference: that caused by the government.
On the technical side, the FCC's ruling aims to protect users of existing services—including the Coast Guard, aircraft, and amateur-radio operators—from interference generated by data-carrying power lines. Specifically, the ruling flags some frequency bands as entirely off limits and establishes geographical "exclusion zones," such as in the vicinity of radio-astronomy facilities, where BPL services would have to avoid operating in certain frequencies. In addition, the rules define a formal process of consultation and conflict resolution, including a public database for identifying offending BPL deployments.
In announcing the rules, FCC officials waxed positively poetic about BPL's prospects. "We have both had the opportunity to witness BPL services firsthand, and we believe that this new technology holds great promise as a low-cost broadband competitor," wrote chairman Michael Powell and commissioner Kathleen Abernathy. The fact that the utility grid extends to almost every home in the nation makes BPL especially promising and worthy of a hands-off regulatory approach, they argued: "The benefits and advantages of BPL are just beginning to be recognized. That is why it is important for regulators to exercise restraint and avoid heavy-handed regulations."
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BPL radiates broadband RF interference. It is basic physics and cannot be changed. The only way to mitigate this effect is to notch out frequencies, which reduces the speed of the connection BPL provides. (This does not solve intermodulation effects either.)
The frequency range that BPL operates on is in use by other services. If harmful interference were to be truly dealt with it would require BPL being notched over its entire range of frequencies. This is not practical and if the FCC is a proponent of BPL then it will not happen. The only reasons to push for BPL are political (elected officials can point to it and say they are enabling broadband access for all) and economic (big utility companies have lots of lobbying money to throw around to help them move into a side business).
From a technical standpoint BPL is a poor substitute for wireless systems that can provide faster service at a lower cost and with no harmful interference. By the time any signifigant BPL rollout can occur, WiMAX will be rolling out and will provide a better solution.
All BPL will accomplish is to increase the RF noise floor and cause hostility between utility companies, end users of the service, and users of the spectrum that will be affected.
Wyatt Foard - 2004-29-10 07:02:00 PDT -
Bad Idea! Nobody wants broadband more than I. I live in the back woods of Oregon, 26k is my speed and I’m stuck with it. But I use 15 FM intercoms on 5 acres and also X10 devices that use the power lines as communication wires. I also have very weak AM, FM & TV signals, I also use FRS radios and 433Mhz remote controls. Digital signals create unlimited harmonics. (BPL) technology will create unlimited interference on me and render my investments totally useless. BPL has failed in other countries and it will fail here too. Just wait until your garage door wont open because the receiver is being jammed by BPL. I had to replace a power supply in one of my computers because it was creating constant static on ALL FM intercoms. Hackers will be able to read the neighbors email that aren’t smart enough to protect themselves.
Jeff Smith - 2004-27-10 22:47:00 PDT
