First Canadian High Speed Internet over Power Grid
oO0(MjB)0Oo writes "Sault Ste. Marie, a northern Ontario town, is going to be the first installation of BPL (Broadband Power Line technology) in Canada. As reported in the Toronto Star, wireless access points will be set up along medium-voltage power lines, providing roaming capability throughout the city to all users."
There's sure to be at least one moron that'll fry himself.
Machine9dotNet
Also, will this cause any other sort of interference? My TV reception (over antenna) is already crap because of Ontario Hydro -- I live within 0.5km of the high-voltage pylons and my TV reception is terrible on VHF because of it.. (during the huge power outage last summer, I was able to very clearly receive stations all through New York state)
Actually the article does say the data is put on the medium-voltage distribution grid, which is the transmission medium between their fibre backbone (presumably at the substations) and the WAPs mounted on hydro poles in neighbourhoods. They're just not running it on the 240v drop to the customer as in some implementations.
The fiber network is not everywhere.... do you think they have fiber on every pole? (fiber is usually buried, btw)
Backbone == NOC. They are using medium voltage power lines as a large network between their backbone and the access points... the article headline, despite being on slashdot, is acccurate.
For those not following the broadband-over-power-lines debate, the basic problem is lack of shielding. Cable modems use coax cable, where the outside of the coax acts as a shield, and so very little RF gets out. The wires carry broadband internet, but don't interfere with anything. In the case of DSL/telephone, you have twisted pair (or at the very least, two wires running very close to each other). They effectively shield each other (meaning that each generates a field in the opposite direction, and the fields cancel out if you're not too close to the wire). More RF gets out than coax, but it's still negligable compared to desirable transmissions. In the case of power lines, they are, depending on power line configuration and frequency, either a significant fraction of a wavelength apart, or several wavelengths apart. In some directions, you get destructive interference, but in others, you get constructive interfence. In the directions of constructive interference, you have a lot of signal being broadcast. As a result, they act as a directional antenna, which interferes with anything on the same wavelengths as power-over-power-lines.
:)
Signal strength goes a square of distance. That means that if I have an antenna running 10 meters from my house, and I'm trying to tune into a station 10 kilometers aways, that station needs to be putting out a million times more power than the segment of powerline running next to me. Ouch.
This probably won't interfere with typical consumer applications (television, FM radio), because if it did, there would be significant political reprecussions, and it would be banned (in other words, it's probably engineered to operate outside of those frequencies). On the other hand, according to the ARRL, it very likely will interfere with amateur radio and therefore emergency communications services.
My view is that it may be a good idea in some third world countries, with no telephone service, where there are no alternatives for Internet. However, in modernized countries, we're better off spending the few extra dollars to put in DSL on top of all phone lines or sticking with modems for a while longer, than in the short term, sacrificing emergency communications infrastructure, and in the long term, entrenching a system of broadband that takes away a significant chunk of the spectrum, and prevents all sorts of innovative uses of that spectrum we haven't thought of yet. Spectrum is a scarce resource, and it's gonna get scarcer. The population growing, but amount of spectrum stays constant, sans a few one-time improvements from better utilization (there are fundamental limits on signal strength vs. noise vs. bandwidth vs. bitrate -- with antenna arrays/directional transmissions, there are limits on directionality vs. frequency vs. transmitter size -- we cannot improve utilization forever). In contrast, all the benefits of power-over-power-lines are short-term -- we only gain the one-time cost of not having to modernize our infrastructure (maintanance costs of the two possible infrastructures aren't significantly different).
I don't know how this initiative works, but my impression is that it sends broadband over powerlines, and then the last gap is sent via wireless. If this is the case, it has all of the standard problems associated above. If not, I need more information than is in the article to evalute it
Here in Ireland, the Electricity Supply Board (ESB) - our State electricity company, is setting up something similar. They have a fibre ring following the trunk electricity routes - it's just fibre piggy-backed on their existing infrastructure.
I'm just amazed they haven't done this ages ago - it puts them at a huge advantage to those who have to dig up stuff and lay fibre from scratch.
Not sure what ESBs plan is to connect this main telecomms artery to anything useful...
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