Broadband over Power Lines
Hi-Speed Internet Access Through Your Power Plug!
It’s called BPL and it’s being tested right now. Is it coming soon to a power plug near you?
You plug your BPL modem into any power socket in your home and you’re instantly connected to a high speed broadband ISP. Sound too good to be true?
Maybe… maybe not.
BPL does seem to have more than its share of pros and cons.
Aside from the fact that nearly every home in the country is connected to the power grid, this exciting new technology offers several other advantages over current broadband Internet service connections.
First is the fact that no professional installation or additional wiring would be needed in your home. True ‘plug-and-play’ technology.
Another interesting aspect of BPL is that every electric device is connected to the electric distribution network. That means that BPL could let chips in every electric device talk to each other. Much simpler and more cost effective than putting a wireless chip in every appliance.
Imagine the possibilities if your alarm clock, light switch, water heater and coffee maker could talk each other! Or how about this scenario: You unpack and plug in your brand new flat-panel TV and it automatically connects to the cable box, DVD player, your Home Theater system and the Internet.
Even more than the communications aspect, electric utilities are interested in BPL because it could give them an intelligent electric grid that is both more secure and more reliable. That in turn could lead to less pollution and lower electric power costs.
The above-ground utility wires that carry BPL signals can also act as antennas and cause radio frequency interference with airplane radios, emergency, military and police radios, HAM radios and short-wave broadcasts. This possible interference is central to the debate over whether or not the FCC should allow BPL to exist.
How Broadband Over Power Lines Works
There are two different technologies under development: Access BPL and In-house BPL.
Access BPL combines the technological principles of radio, wireless networking, and modems. It uses medium voltage power lines carrying about 7,200 volts (the ones that you see at the top of electric utility poles) to carry broadband Internet traffic. It can send data over power lines and into homes at speeds between 500 kilobits and 3 megabits per second which is currently comparable to cable and DSL modem speeds.
But turning the power grid into a stable, high-speed system of data transmission is tricky.
Those medium voltage power lines lines are just one component of a power grid. In addition there are generators, high voltage lines, substations and transformers that help carry electricity from the power plant all the way to your plug. And all of them interfere with data transmission.
So first BPL bypasses high-voltage power lines using either fiber-optic or telephone lines to inject the data into the medium-voltage power grid downstream. However the data can only travel so far before it begins to degrade. So special devices (called repeaters) are installed on the lines to take in the data and amplify it for the next leg of the journey.
There is also no way to run a clean data signal through a transformer. To overcome this, one BPL model uses two other devices, a coupler and a bridge to distribute Internet traffic. These are attached at the power pole and allow the data to bypass the transformer and enter the low voltage lines attached to your home. There are also wireless systems that bypass the low voltage lines altogether.
From there Access BPL uses a special modem that is about the size of a common AC adapter. It simply plugs into a 110 volt wall socket and has an Ethernet cable that connects to your computer (wireless versions are also available). BPL modems use silicon chips specifically designed to send signals over medium voltage power lines and separate data from 110 volt electric current. These are available right now and several electric utility companies in over 26 states are quietly doing pilot programs.
In-house BPL networks machines within your home or office. In-house BPL products can easily comply with the radiated emissions limits listed in Part 15 of the FCC’s Rules, because they connect directly with the low voltage electric lines inside your home or office. This technology has little to do with actually connecting to the Internet and is available in stores right now.
Is BPL coming to your neighborhood soon?
Bottom line… Don’t count on it! At least not soon. The radio interference issue is serious enough that at least one utility company was forced to terminate its pilot program prematurely.
Is the idea going to die? Don’t count on that either. The concept has enough merits and profit potential that BPL developers and investors alike refuse to give up. And that attitude will most likely persist until the FCC finally says “no way”.