Che
Intel Inside
join:2002-05-31
Sacramento, CA
| Broadband over powerlines? Stupid idea.
Broadband over power lines is NOT necessary, rediculous and dangerous. I am a licensed ham, and have been since before broadband existed. Broadband is fine as is. What should be CRIMINAL, is to interfere with long distance radio communications which have served the world so well in times of war and disaster. |
|
EdibleTarget
Real Gamers Dont Use Consoles
join:2004-12-02
Lowell, MA | it would be worthwhile if they were able to bring the prices down to compete.
It is far from criminal not to have it though. I think much more research needs to be done. |
|
moonpuppy
join:2000-08-21
Glen Burnie, MD
 ·Verizon Online DSL
| said by EdibleTarget  :it would be worthwhile if they were able to bring the prices down to compete. It is far from criminal not to have it though. I think much more research needs to be done. First off, prices for DSL may have come down BUT cable just raises the speeds (which DSL can't do due to distance.) BPL is far worse in that respect and can't compete on distance.
As for it being criminal not to have it, the spectrum pollution put out by BPL is criminal enough. My guess is that the power companies will put out the cheapest solution and try to say there is no interference. Hope California can pay for the lawsuits.  |
|
aaronfitz
Premium
join:2004-03-06
Cedar Rapids, IA
| reply to Che
said by Che :Broadband over power lines is NOT necessary, rediculous and dangerous. I am a licensed ham, and have been since before broadband existed. Broadband is fine as is. What should be CRIMINAL, is to interfere with long distance radio communications which have served the world so well in times of war and disaster. Stupid idea? Hardly. It's a rather genius idea, really. Right now the technology is being tested. Sure, it has interference issues. But if they fix them, wouldn't you agree that it's going to be useful?
--
"Time is in abundance for procrastinators," So you should become one like me! I claim no responsibility if anyone is unable to understand my twisted, sarcastic sense of humor... |
|
ctceo
Premium
join:2001-04-26
South Bend, IN
clubs:
| Its already past the "test" phase. The only reason new areas have to start as "test" beds is because they cannot guarantee that the service once powered up won't create interference due to oversensitive radio equipment, or bad wiring/equipment.
--
ASUS SK8N nForce3 - 8GB PC2700 - AXP 64 3400+ - nVidia 6800 Ultra w/512mb - CL Audigy 2 PP - WD SATA150 36GB + Hitachi GST 250GB - Plextor PX708A + Sony CRX300A - Dual 600 Watt PSU's. |
|
Daishi7
Premium
join:2002-02-24
clubs: 
edit:
December 13th, @10:35PM
| reply to aaronfitz
No, because power is stepped down enough at the pole tranformers (ed :P) that they can't run data over the main line. They have to run all the data on fiber almost all the way. I don't know how many homes passed per transistor, but for the most part they are running fiber to the pole, then offloading on power. This practice is nearly pointless, because once they are that close they might as well skip the power part and use 802.11 wireless. |
|
JPCass
join:2001-01-23
Denver, CO
| said by Daishi7 :I don't know how many homes passed per transistor, but for the most part they are running fiber to the pole, then offloading on power. This practice is nearly pointless, because once they are that close they might as well skip the power part and use 802.11 wireless. Interesting point. Could that be their longterm strategy, to get all the infrastructure in place for delivery on their own wires, and then once they have their foot in the door, argue to be allowed to use the infrastructure already in place to deliver by wireless? |
|
rf_engineer
join:2003-08-04
USA
| reply to ctceo
said by ctceo :Its already past the "test" phase. The only reason new areas have to start as "test" beds is because they cannot guarantee that the service once powered up won't create interference due to oversensitive radio equipment, or bad wiring/equipment. It's also because power utilities move at glacial speeds and there's still regulatory uncertainty.
"Oversensitive radio equipment" is a matter of opinion. Equipment that communicates around the globe with low power levels needs to be able to detect weak signals close to the noise floor. It's funny how people on this forum bust on Amateur Radio communications being outdated, meanwhile hams use advanced communications equipment more sensitive than most lab equipment. This illustrates a problem with BPL. The carriers and manufacturers don't understand the nature of HF radio communications and have built a system totally incompatible with the spectrum in which it emits energy. Now that they have sunk costs in a flawed system and can't turn back, engineers step aside, and PR people and lawyers are needed to push it. |
|
w2co
join:2003-07-16
Longmont, CO
| reply to ctceo
You don't even need an "oversensitive" receiver to have a interference problem from BPL. Even a 50 year old shortwave receiver will be rendered useless by it. BPL is still in the "test" phase. Why do you think the FCC only issues part 5 experimental licenses to the test sites so far? It's because if a part 5 licensee running a part 15 device interferes with any licensed services, they will have to be shut down. |
|
w2co
join:2003-07-16
Longmont, CO
moderated:
December 13th, @10:37PM
| reply to Daishi7
First off the poles have no transistors, they have transformers. Secondly Power is not stepped down, the voltage is. |
|
w2co
join:2003-07-16
Longmont, CO
| reply to aaronfitz
You said "But if they fix them" this is not possible to do considering an open wire with an hf signal applied will radiate period. This is in physics 101 and you can't change physics, so it will never be "fixed" until they use a shielded line and that sure as hell ain't gonna happen. |
|
Daishi7
Premium
join:2002-02-24
clubs:
| reply to w2co
I know the difference between a transistor and a transformer, it was mistake. You seem to have read up on this so I have a question. What spectrum does BPL transmit in, and what is the total available bandwidth for the forward and return paths (eg. what modulation is used)? Also, how many homes are usually on a transformer? |
|
ctceo
Premium
join:2001-04-26
South Bend, IN
clubs:
edit:
December 14th, @07:47AM
| reply to Daishi7
802.11 wireless barely has enough power to push through a couple layers of Sheetrock. You are expecting it to go through Siding, Insulation, Studs, Old Paint (lead filled probably), and a layer of Sheetrock (or 2) you might as well put your router outside within a few feet from the pole.
Through testing we've found that most 802.11 routers b or g, can barely push 150 feet under standard conditions (no walls of any kind between WAP, and AP. Testing included 2Wire, Belkin, Linksys, D-Link, Netgear, ParkerVision, SMC, and about 10 others.
The BPL in Manassas, VA is no longer in an FCC "Trial" phase it is now in it's first year of Market Testing to see if enough subscribers hop onboard. |
|
w2co
join:2003-07-16
Longmont, CO
| reply to Daishi7
BPL uses the spectrum between 1 and 80Mhz, the entire HF and low VHF spectrum where natural ionospheric skip occurs. Nowhere else in the known spectrum does this happen, and as a matter of fact, with ionospheric skip zone properties the BPL interference signals can unintentionally also skip to far away places. It is not hard to work a station in Europe from Colorado running only 1watt of power at 14Mhz. Anyway this is another unstudied aspect of BPL, when interference skips over the pole to USSR and elsewhere, they will again have to shut down because of the ITU and international Laws. The FCC has no control over these international laws concerning interference from other countries. When interference from the USA BPL sites grows strong enough to become a problem overseas, there will then be great concern. To answer your other question, I believe that each step down transformer can handle anywhere from 6 to 10 houses typically. Now with BPL, a bypass device must be placed across the transformer to allow hf signals to pass around the transformer which normally would be greatly attenuated through the transformer. This from the medium voltage side to the house 220V side. If this bypass device should fail "shorted" even for a milisecond, all of your appliances would have upwards of 30KV applied. I don't know about you but I would'nt want 30KV+ on the wiring in my house even for a short time. I cannot believe they have tested these bypass devices enough yet to be safe. There is no data that shows any results of testing of these devices that I know of, and nobody hardly even talks about it. Just another gottcha that is hiding under the politics. |
|
w2co
join:2003-07-16
Longmont, CO
| reply to Daishi7
Oh and your third question about bandwidth, it seems that with the test sites running so far, they are running around 1.5Mbps up and down that with very low numbers of users. Now when more users are added to the system the speeds will only go down because there is no more spectrum for it to use. The idea of using up the entire 1-80Mhz spectrum with spread spectrum like noise is really a blatant attack on a natural resource. This spectrum has been in use for many many years by licensed services as well as short wave listeners, military, aviation, maritime, government, and many others. Spectrum in this region is normally given out in Khz, not tens of Mhz at a time. We all have been using this spectrum in harmony with each others needs and concerns etc., and have been insuring we have the cleanest non interfering signals possible. Now with BPL, it creates pure havoc across the entire spectrum and ruins all practical communications even at short distances. |
|
rf_engineer
join:2003-08-04
USA
| reply to ctceo
said by ctceo :802.11 wireless barely has enough power to push through a couple layers of Sheetrock. You are expecting it to go through Siding, Insulation, Studs, Old Paint (lead filled probably), and a layer of Sheetrock (or 2) you might as well put your router outside within a few feet from the pole. Through testing we've found that most 802.11 routers b or g, can barely push 150 feet under standard conditions (no walls of any kind between WAP, and AP. Testing included 2Wire, Belkin, Linksys, D-Link, Netgear, ParkerVision, SMC, and about 10 others. The BPL in Manassas, VA is no longer in an FCC "Trial" phase it is now in it's first year of Market Testing to see if enough subscribers hop onboard. Amperion is somehow using 802.11 from the pole to the subscriber successfully. Corridor is using 802.11 natively on the powerline and depending on the natural radiation from the line to provide service to mobile and home customers (albeit very much in a testing phase).
It's funny how you're bullish on BPL, a technology with a handful subscribers and still fraught with problems, and down on 802.11  |
|
David95037
join:2003-04-16
Morgan Hill, CA
·Be There
| reply to ctceo
said by ctceo :Through testing we've found that most 802.11 routers b or g, can barely push 150 feet under standard conditions (no walls of any kind between WAP, and AP. Testing included 2Wire, Belkin, Linksys, D-Link, Netgear, ParkerVision, SMC, and about 10 others. Trying to use consumer equipment designed for in home use is stupid and shows how truly clueless the BPL engineers really are.
With the right WiFi equipment you can cover whole neighborhoods;
»www.vivato.net/press/press06232004.html |
|
ctceo
Premium
join:2001-04-26
South Bend, IN
clubs: | reply to rf_engineer
BPL is not "Standard" 802.11 gear. It is Extended 802.11 equipment capable of broadcasting at more than twice the maximum wattage of ANY typically used consumer 802.11 gear. |
|
rf_engineer
join:2003-08-04
USA
| said by ctceo :BPL is not "Standard" 802.11 gear. It is Extended 802.11 equipment capable of broadcasting at more than twice the maximum wattage of ANY typically used consumer 802.11 gear. Any 802.11 equipment can operate at the Part 15 limits which is 30 dbmW or about 1 watt (there is no concept of extended 802.11 that I'm aware of). Typical consumer gear operates around 24 dBmW or .25 watts. So the ratio is about 4 times, or 6 dB. However, coverage isn't strictly determined by transmitter power, but rather effective radiated power. This is where the antenna pattern comes into play. A cheap omnidirectional antenna may have 1 dB of gain whereas a tighter pattern antenna will have 6 or 8 dB of gain. Antenna gain is a two way street, so any gain in a better antenna at the pole can compensate for a lousy CPE antenna.
In any case, Amperion is using standard off-the-shelf 802.11 gear for CPE I believe, and they appear to be the most successful, at least from a numbers standpoint. 802.11 is very doable. |
|
Daishi7
Premium
join:2002-02-24
clubs: | reply to w2co
That is 1.5Mbps per user. What is the total available bandwidth from 1-80Mhz using what ever modulation method they are using. That number would have to be much much higher. |
|
