Alcatel-Lucent Boosts Broadband Over Copper To 300Mbps 160
alphadogg writes "Alcatel-Lucent has come up with a way to move data at 300Mbps over copper lines. So far the results have only been reproduced in a lab environment — real products and services won't be available for at least a year. From the article: 'Researchers at the company's Bell Labs demonstrated the 300Mbps technology over a distance of 400 meters using VDSL2 (Very high bitrate Digital Subscriber Line), according to Stefaan Vanhastel, director of product marketing at Alcatel-Lucent Wireline Networks. The test showed that it can also do 100Mbps over a distance of 1,000 meters, he said. Currently, copper is the most common broadband medium. About 65 percent of subscribers have a broadband connection that's based on DSL, compared to 20 percent for cable and 12 percent for fiber, according to market research company Point Topic. Today, the average advertised DSL speeds for residential users vary between 9.2 Mbps and 1.9Mbps in various parts of the world, Point Topic said.'"
Gigabit (Score:4, Informative)
The problem with all copper lines is capacitance,
which acts as a low pass filter. The longer the line the more high frequencies are lost, which in effect takes the "edges" off of the pulses, making differetiation difficult. No ammount of technolgy is going to change the laws of physics. (:
All kinds of tricks are use such as QAM and different forms of compression to cram more down a copper pair.
All POTS work on 2 wires. Even if one has several pairs coming into the premises it is unlikely that there will be enough spares all the way to the exchange.(Would you put in double the ammount of copper needed on the off chance that it might be needed later.
The extra incoming wire are mainly for spares in case of faults.
Here in .au I have ADSL2 which at my current location provides 15mb/s.
Re:Good Bye Comcast (Score:3, Informative)
Re:So... 85% copper (Score:3, Informative)
RG-6 is copper plated steel. cheaper.
Re:1 KM really does not exist. (Score:3, Informative)
The issue isn't just distance.
It's things like bridge taps that cause destructive interference and mangle the DSL signal, grounding issues, cumulative interference, etc, that are the real problems with getting very high speed DSL out into the boonies. Even improper termination or a rusty nail rubbing against the line can cause enough interference to kill a DSL signal!
Doubt this will help longer lines (Score:3, Informative)
Sounds nice for those with short lines...
I live about ~3km from my exchange (in Australia), which unfortunately reduces my 24 Mbps (max) ADSL2+ service to 6.2 Mbit (without interleaving) or 7.7 Mbit (with interleaving). Any technology that can squeeze a bit more out of my old rusty copper wire sounds nice to me, at least until the national broadband network (fibre) gets rolled out in 3-4 more years.
Having said that I have a funny suspicion this won't help anyone stuck on a longer line (i.e. any line that wouldn't really support VDSL now). The move from ADSL1 to ADSL2 and ADSL2+ improved the 'max' speed of the service for those close to the exchange, but any xDSL technology seems to hit a certain distance where that benefit is lost.
This graph [on.net] shows this nicely - ADSL2+ (in green) is way faster than ADSL1 (blue) for shorter/less attenuated lines. But beyond around 4km, it offers virtually no improvement at all. And I suspect the laws of physics are at play here such that this new VDSL variant wouldn't be any different.
Re:VDSL2 (Score:2, Informative)
VDSL2 is not symmetric, nor does it give anywhere near 50mbit at 1km. At 1km (~3000ft) and in the real world, you will get around 30-35mbit down, 3-4mbit up, and this is with VDSL2 8B (~20.5db launch power), not the lower power VDSL 1.5 crap AT&T deployed.
VDSL2 has many band plans, some of which (ie: VDSL2 12A & 30A) can support symmetric bandwidth if the loop is short enough. Higher frequencies attenuate faster than lower frequencies, since the 2nd upstream band starts at 3.75mhz, very few VDSL2's loop can support symmetric speeds, even if the loop is short.
Re:VDSL2 (Score:4, Informative)
I suspect that even in the UK (which has a much higher population density than the US) the majority of people live more than 1km from an exchange ...and this assumes that the copper is relatively new and has clean connections ....
It's not distance from the CO building that matters, but from the DSLAM [wikipedia.org], which are easy to deploy in any densely populated area, and relatively cost effective.
The ~1.5 Km range is from one of these [wikimedia.org]
Re:nice. what's the backchannel like? (Score:1, Informative)
How is this modded insightful? If anybody knew anything at all about VDSL and VDSL2, they would realize the technology is symmetric in nature, meaning that the connection speed per end-point is equal for up and down. So it'd be 300Mbps/300Mbps, you insensitive clod.