BPL 200 Mbps
join:2006-11-05
Toms River, NJ
| reply to W1RFI
Re: DS2 200 Mbps BPL tech is working with ARRL Laboratory !!!
it should be up to 600Mbps BPL ... !!!
up to 600 Mbps !!!
Corinex Communications showcases the 600Mbps
Multi Dwelling Unit Gateway at HITEC 2006
World’s First MDU Networking device that offers up to three simultaneous
200Mbps Powerline and Coax backbones within a building
(»broadbandoverpowerlines.blogspot···ces.html)
re: "In addition to utilizing Ambient’s industry-leading, FCC-certified X2 BPL Access Node (with up to three 200Mbit BPL interfaces), Ambient-designed next-generation overhead and underground couplers and BPL modems in the deployment, Ambient will provide the engineering and technical support needed to design, support and assist in the deployment and management of the network. The deployment will also include X2 nodes with integrated 802.11a/b/g Wi-Fi support to provide wireless access. "
(»http://broadbandoverpowerlines.b···has.html)
Will this answer your BANDWIDTH slowdown fear ?
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Unleash the opportunities of a SYMMETRICAL 200Mbps “Smart Grid”, IPTV and in-home networking for business optimisation of your commercial opportunities of BPL/PLC with killer applications & services: in-home MDU networking, IPTV and triple-play... !!! |
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W1RFI
join:2003-05-12
Burlington, CT
| Nice Ambient commercial. 
said by BPL 200 Mbps  :it should be up to 600Mbps BPL ... !!! ... Will this answer your BANDWIDTH slowdown fear ? I'm not sure what fear you think I have, but so far, the systems I have seen don't come anywhere NEAR 200 Mb/s to the end user.
And my quip about your screen name is that 200mbs is 200 millibits/second. You may want to use the correct capitalization and use a capital M to indicate megabits/second.
Ed |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs: | Thanks again, Ed, for providing some facts based on real world use and testing.
73, Jim KQ6EA
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One man's Magic is another man's Engineering. |
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rf_engineer
join:2003-08-04
USA
| reply to BPL 200 Mbps
said by BPL 200 Mbps :it should be up to 600Mbps BPL ... !!! up to 600 Mbps !!! Will this answer your BANDWIDTH slowdown fear ? No. I haven't seen a BPL subscriber getting anything near 200 Mbs. (If there was a subscriber getting 200Mbs, you would certainly see press releases and articles here.) And if you knew anything about networks, 200 Mbs would be the backbone speed, not the end user speed. Has any vendor gotten 200 Mbs BPL to work on an overhead line and actually deliver a full 200 Mbs? |
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W1RFI
join:2003-05-12
Burlington, CT
| Shannon's information theorum says that with absolutely perfect modulation, to attain 200 Mb/s using a 20 MHz channel, the signal-to-noise ratio at the end of the circuit would have to be 30 dB. With an estimated 15 dB loss between an injector and the repeater located 1000 feet away, the system would have to start out at 45 dB signal-to-noise. Unfortunately, at typical noise levels, that would put the system well above the FCC emissions limits.
At a more reasonable 10 dB signal-to-noise ratio, 70 Mb/s is the upper theoretical limit.
This assumes perfect modulation and demodulation. In practice, getting within 10 dB of the Shannon limit is considered to be pretty good. That would give a typical 20 Mb/s to the end user, not counting any bits used for system overhead.
The only G2 system whose data rate I tested had other indications that something was actually wrong with the system, so its results are really not useful at this time. I do expect to get back there, though, and as these other commerical systems come on line, sooner rather than later, we will see independent speed tests done for G2 as they have beend done for G1.
Ed |
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rf_engineer
join:2003-08-04
USA
| said by W1RFI :Shannon's information theorum says that with absolutely perfect modulation, to attain 200 Mb/s using a 20 MHz channel, the signal-to-noise ratio at the end of the circuit would have to be 30 dB. With an estimated 15 dB loss between an injector and the repeater located 1000 feet away, the system would have to start out at 45 dB signal-to-noise. Unfortunately, at typical noise levels, that would put the system well above the FCC emissions limits. At first I was thinking your 20 Mhz channel was a bit too small, considering there's about 80 Mhz of spectrum BPL is using (1 to 80 Mhz). But the lower 21 Mhz is not contiguous space as there's the mandatory NTIA notches and the amateur band notches. Then there's frequency reuse that needs to be considered. Each BPL repeater segment needs a different frequency band as the repeater can't prevent RF from one segment bleeding onto another; you're depending strictly on line attenuation for isolation between segments. I'm guessing n=3 or n=4 frequency reuse? Last you need separate frequencies for transmit and receive, so you need double the frequency bands/"channels". So, it's conceivable that one would need six to eight "channels" to work with. So your 20 Mhz channel figure is reasonable as the required number of channels would fit into what's usable in the 80 Mhz of spectrum.
Your 15 dB of loss between the coupler and repeater seems low to me, especially if you consider VHF frequencies. Have you seen this in practice or in your modeling?
At a more reasonable 10 dB signal-to-noise ratio, 70 Mb/s is the upper theoretical limit.
This assumes perfect modulation and demodulation. In practice, getting within 10 dB of the Shannon limit is considered to be pretty good. That would give a typical 20 Mb/s to the end user, not counting any bits used for system overhead. And no ISP in their right mind would give an end user the same speed that they have on their backbone. It would be too easy for one user to saturate the network and wreck the service for others. 10 to 25% would be reasonable. |
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