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Utility Cuts Short BPL Trial
fatboy writes "The ARRL is reporting that Alliant Energy has called an early end to its broadband over power line (BPL) pilot project in Cedar Rapids, Iowa. The "evaluation system" went live March 30, and plans were for it to remain active until August or September. Alliant shut it down June 25. Ongoing, unresolved HF interference from the system to retired engineer Jim Spencer, W0SR, and other amateurs prompted the ARRL to file a complaint to the FCC on Spencer's behalf demanding it be shut down."
- Put up power lines - = huge aerial system
- Inject wideband RF into huge aerial system
- Interference!
In fact the whole idea of RF over power lines, though attractive at first sight, is a triumph of will over physics. A system designed to take kilovolts at around 50-60Hz, with mechanical switches all over the network and a mixture of capacitors and inductors to adjust power factor, is not a benign environment for RF. But people keep trying to do it. There have been attempts at LANs over household wiring - but wireless networking has just about killed that with a combination of speed, convenience and safety.You can adapt a car to travel on water, but the result is expensive and technically poor. In the same way, I feel broadband over AC power is a cross-model step too far.
Panurge has posted for the last time. Thanks for the positive moderations.
They already tried. They already failed for much the same reasons, except i believe it was also interfering with LW and AM radio signals.
You dont mess with the BBC's signal in the UK. The phase "Ton of bricks" does not give justice to what will happen
The big problem with BPL, as was stated by a poster in a previous article, is the wire. Unshielded transmission line will create signals that interfere with radio service. Unshielded wire will also act like a big antenna and pick up noise, thus limiting the bandwidth of the data the line can carry. Replace the wire with something better, and well, you don't have broadband over power lines any more. You will, however, have a workable system without the interference problems.
The problem is twofold.
First of all on HF spectrum there are not only amateur radio operators: ships, aircrafts, military, private services, broadcasting stations and so on.
If there is an harmful interference to an amateur radio station it could be as well exist an harmful interference to an international airport or a coast guard station. And they can't hear an airplane or a boat distress call.
Using wires made for 50/60 power to transmit data
at high speed is a bad idea because the infrastructure was made to transmit power: the impedance is low and variable, cables aren't paired or shielded, and there is a lot of noise.
Power utilities have a right of way, so to have another competitor they have only to pull optical fibers along with power lines and put a WiFi/UMTS
base station on the poles (or a 10BaseFL/100BaseFX/1000BaseSX switch and pull fiber to the homes).
Better badwidth for users, no interferences to and from other services and appliances, and a working technology.
These hobbyists, who use a very small portion of the frequencies in question, include a large number of people who are active in public service sectors for emergencies and for the public welfare in general (for free and providing their own equipment), such as providing free phone patch services for the military in remote areas to call home. In emergencies when the local utilities go out, getting traffic into unaffected areas is very important and if that receiving area has BPL interference than life and limb could be in jeopordy.
BPL is supposed to conform to the existing rules and regulations in place stating that no service is allowed to interfere with another. Period. All these other services have to conform and just because a few people want to make money off the BPL for a few people at the expense of all others does not give them the right to use an unsound technology to do it. If they can come up with good technology that doesn't cause problems than by all means go ahead. And BTW, what are you going to do if you have a transmitter of any service located nearby that continuously knocks out your BPL link? Nothing. BPL is a Type 15 service that has no legal recourse when it is interferred with. BPL as current technology is broken and most likely cannot be cleaned up without massive expense (guess who pays) and investment in a much different type of equipment than is proposed. The power companies want to use the current equipment for BPL because it is cheap. If they have to build a different technology than it is no longer going to be cheap.
Plus what will happen should BPL go through is that the power companies will lease the grid to the existing ISPs and your fees will likely remain within a few percentage points of existing services over POTS and cable anyway. The idea is to make highspeed internet available to all, not to keep your price down.
Too lazy to create a sig...
Sending data over power cables is the first thing that strikes us when we think of broad-band. As someone involved with broad-band initiatives in india, as a veteran slashdotter and as an ex-ham, i think this needs a few pieces of missing information.
Why power lines? because they are there. More importantly, because you cannot touch any other copper lines (like ma'bell) nor lay them afresh without being billg hisself. now guess who demands this money? the very FCC!
It is often a cheaper and a simpler solution to just run a shielded cable. In India, where such zoning and municipal laws are lax, I have a 100 mbps ethernet drop into my home office. The electic poles are tapped for feeding the hubs on the way as well as providing the physical support for the cable high above the reach of straying cows, buffalos, kids on bikes and cable thieves.
The cable operators pay the electricity folks a fixed low per-pole charge. In the case of BPL, i think it is more of FCC trying to save the phone companies than creating a new last mile solution.
Why can't we lay more cable in anycase? it is a cheaper option.
The point often missed about HF is that like ozone layer, it really affects the entire world. I have a 5 watt transceiver that regularly goes around the world (www.phonestack.com/farhan) using just a 10 meter stretch of wire for an antenna. the noise that BPL will generate can easily disrupt global HF communications that form the backbone for many countries even today. Imagine the interference BPL would create by contributing megawatts of power radiating over millions of miles of wires all over the country.
blaming amateurs is really a shame. especially at slashdot. from the early open source tcp/ip (the KA9Q) to Alan cox. Amateurs have frontlined development of Internet. the very idea of personal science (as something that individuals pursue for pure satisfaction) that propels towards free and open softwares finds its foundations in amateur radio.
Amateur radio is really the only open source communication technology. Everywhere else, you still pay per use. It is also the classic peer to peer technology, it requires no 'service providers' at all just you and a couple of transistors connected to a clothline. The entire communication stack (read morse code decoder) is in your head. how's that for a setup?
The purpose of all philosophers was to impress women