Juicy broadband faces hurdles

The recent article by Hook reporter Lisa Provence [July 1: "Electric change, Nelson makes net history"], presents an overly optimistic and somewhat incomplete picture of the status of Broadband over Powerline (BPL).

Most significant is the fact that BPL is not a done deal. All BPL services are in the testing phase allowed by the Federal Communications Commission.

The city of Manassas, which had one of the earliest BPL trials, has subsequently terminated the experiment because of interference it caused to licensed radio services. The trial in Cedar Rapids, Iowa, by Alliant Energy is now the subject of a formal complaint to the FCC for alleged "ongoing harmful and willful interference to one or more licensed radio stations." Austria is reported to have curtailed a BPL field trial because of interference.

The basic flaw with this politically and commercially attractive concept is that power lines designed to conduct low frequency current are being used to transmit high frequency signals.

The broadband signal by definition is not confined to a single frequency, such as a radio or television station. The power lines are in effect turned into a giant radio transmission antenna. Think of tuning in your favorite TV or radio station and receiving a hundred or so other programs superimposed.

You can find a small sticker on most PCs and VCRs stating that the device is allowed to operate as long as the device does not cause harmful interference to other devices and must itself accept any interference.

This is the hurdle that the BPL providers must deal with and is the basis for the field test phase of the technology.

Charles G. Battig