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BT Runs an 800Gbps Channel On Old Fiber
judgecorp writes "BT has demonstrated an 800Gbps 'superchannel' on a 410km fiber in its core network, which was not able to carry 10Gbps channels using older technology. The superchannel is an advanced dense wave division multiplexing (DWDM) technique, created by combining multiple coherent optical signals into one channel, which had previously been shown in laboratory tests. BT ran the test on a fiber with optical characteristics (high polarization mode dispersion) that made it unsuitable for 10GBps using current techniques. That's a good result for BT, because it means its existing core fiber network can be upgraded to handle more data. It's also a good customer story for Ciena, which makes the optical switches used in the test."
But when will they upgrade my 4Mbps down / 256Kbps up DSL connection that I pay through the nose per month for? Cuz really, I keep reading about those marvelous link speeds but in the past 10 years, I haven't seen much of that reach the average Joe Blow internet user like me...
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Might want to change the title...
For what it's worth, it's not providing any more bandwidth than the old technique, which had 80 channels at 10Gbps each. What it's doing is, instead of saying I have 80 channels, each of them needs to be clean in order to pass 10Gbps, it's saying I have these big channels which are noisy, but we have ways to mitigate that. Once all our mitigation is done you can expect 800Gbps (that may or may not be with error correction/other overhead factored in. Depends on the marketing department I suppose, but usually with fiber they give max achievable throughput)
The advantage in running unchannelized is on each 10Gbps channel they were holding extra bandwidth in reserve for error correction/overhead. With this you get the whole thing and your error correction is done on the aggregate, with less probable overhead and such.
That's BT for you, instead of investing in the network, they flog the life out of the old crap they have to avoid investing in the network, and give more money to shareholders.
Take Nobody's Word For It.
They are the only ones that can lay fiber and invest into last mile, and they stubbornly refuse to do that.
I hate them so much for it. UK is falling further and further behind the rest of the world, it's just ridiculous.
--Coder
No news here people. The fact that existing fiber optic cable can be reused with new terminating equipment to increase transmission speed is not anything new.
MCI was doing this throughout the 1990s.
The inherent properties of the fiber optic cable have always meant that their potential "max speed" was much higher than the current terminating equipment of the time.
This is as interesting as someone saying "Hey, I bought a new sports car and drove it faster on this old road today than I did on my motor scooter yesterday!"
For what it's worth, it's not providing any more bandwidth than the old technique, which had 80 channels at 10Gbps each.
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which was not able to carry 10Gbps channels using older technology