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rf_engineer
join:2003-08-04
USA
| reply to Fox McCloud
Re: FCC Official Anouncement
said by Fox McCloud  :while BPL can cause interference, if properly set up, it will not. Have any of you read any of the information about low-voltage BPL? I might also at that the ARRL has BPL set up at their HQ in Connecticut, and has not experienced any problems. Still, I'm not praising or damning this technology just yet...there needs to be many more tests run with the low-voltage BPL. The system at ARRL HQ notches out the ham bands and uses hardware filters rather than just software filters like all the other manufacturers. They also only use the low voltage part of the power lines (after the transformer), and not the overhead lines like all the other systems. The low voltage system there is good for ham radio, though it doesn't do anything for the other 90% of services on the bands, just like the notching you see on other systems, so it's not a silver bullet. And the majority of systems in the field aren't like the system operating at ARRL HQ. I do think BPL on overhead high voltage lines is a losing battle, though, and a low voltage system has more potential. But don't expect it to blow the doors off of FIOS or even cable and DSL anytime soon. | |
drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs:
| ""don't expect it to blow the doors off of FIOS or even cable and DSL anytime soon.""
Which I totally agree with, and think most people either don't know, or are misled to, about. They think "Internet over powerlines", and figure it's a great way to have access anywhere you have power, especially out in the sticks. The problem is, is that it doesn't travel all that far, and to *really* get it everywhere the power goes, you'd need to build _another_ infrastructure on top of the existing power system.
It's just a loser of a system for high-speed data transmission, and yet the FCC keeps pumping away at it. Another good example of the FCC going down the tubes when they put *politicians* in charge instead of Engineers.
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One man's Magic is another man's Engineering. | |
W1RFI
join:2003-05-12
Burlington, CT
| said by drjim :They think "Internet over powerlines", and figure it's a great way to have access anywhere you have power, especially out in the sticks. The problem is, is that it doesn't travel all that far, and to *really* get it everywhere the power goes, you'd need to build _another_ infrastructure on top of the existing power system. IBEC is actually going after the rural market, primarily through RUS federal loans to municipalities to help them deploy broadband.
You are correct about the infrastructure, but any broadband system will require infrastructure. With BPL, I have often seen the figure of 2000 feet distance between repeaters, indicating that the maximum distance along overhead power lines is up to 2000 feet. In practice, in the field, I have seen as little as 300 feet as as much as about 1400 feet between repeaters.
If they are willing to put up a digital BPL repeater every 1000 feet along overhead power lines, it can be delivered for a few miles along a particular power line. Much beyond that, the latency (time delay) issues really start to mung things up.
Ed | |
rf_engineer
join:2003-08-04
USA
| said by W1RFI :You are correct about the infrastructure, but any broadband system will require infrastructure. Hi Ed,
That's true, but when you look at cable, the cable system itself is the backhaul network, and the repeaters (line amplifiers) are already in place and have been for years. While DSL has an 18,000 foot limit, telcos often have SLIC huts in neighborhoods with T1s going to them already to handle POTS service. I'm 65,000 feet from the CO in a rural area and nearly two years ago DSL came into my area. Presumably they're sticking DSLAMs in these huts to reach people like me. The point being, with cable and DSL, the infrastructure is already there. BPL is starting from scratch and really can't piggyback an existing network, and certainly not one that is already paid for like a cable network. The exception to this would be if the power company had fiber ran along the route of BPL feedpoints. In my neck of the woods this is done, but the fiber routes are few and far between and the ones on MV lines are targeting very urban areas. The ones in rural areas are on HV lines (up on 100' pylons) and are going between urban areas for transport. Granted these could be used to light up substations, but in my case, the substation servicing my location is about 10 miles away.
Ironically, the industry has been running on the claim that the infrastructure, power lines, is already there, despite it being the worse possible broadband medium around. The general public translates this to mean that BPL can be easily turned up with the flip of a switch. | |
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