Feeds

What's most important? Bandwidth over kilo-miles, or milli-watts?

Big Blue boffins, AT&T brainboxes beg to differ

Internet Security Threat Report 2014

AT&T boffins reckon they can fling 400Gb/sec down 12,000km of fibre using a new modulation technique. Meanwhile, IBM's bods say they managed 25Gb/sec over just a few millimetres - but using just 24 milliwatts.

Both teams will present their research at next week's OFC-NFOEC conference in Anaheim, California, where the future of optical communications will be discussed by 12,000 or so delegates. The mega-corps' technologies lie at two extremes of optical chatter: AT&T is focussed on getting data around the world while IBM just wants to reach the other side of the computer.

Getting data around with a circuit board may seem trivial, what with the copper tracks all over the place, but engineers are increasingly looking at radio and optical links between components that can't be connected easily across a packed motherboard. The team from IBM, funded by everyone's favourite boffinry bankrollers DARPA, is looking to fit the technology into "exascale" computers it expects to be developed by 2020.

To that end, the Big Blue team has created a laser that consumes only 24 milliwatts while transmitting data at 25Gb/sec, smashing previous records (we're told) thanks to a collection of technologies too obscure to have decent acronyms: silicon-on-insulator complementary metal-oxide-semiconductor (SOI CMOS) combined with advanced vertical cavity surface emitting lasers (VCSELs), according to Science Daily.

Telecoms giant AT&T, meanwhile, is more interested in getting data around the world, and has developed a new encoding technique that can apparently throw 400Gb/sec down 12,000km of fibre by running eight separate signals, 100GHz apart, multiplexed by wavelength to pack more data into the transmission.

Disappointingly, the transmitter and receiver weren’t actually 12,000km apart, but instead the signal was sent over the same 100km lengths until it degraded, suggesting that it could have survived the 12K trip if it had needed to.

Radio communications today only uses about 100GHz of spectrum in total, right at the bottom of the dial, but we've spend decades squeezing more data into each megahertz of bandwidth. Visible light, way up in the terahertz range, can't go through walls nor bounce off the ionosphere, but there are plenty more frequencies available below that and we've a lot to learn about how to make the most of them. ®

Top 5 reasons to deploy VMware with Tegile

More from The Register

next story
Same old iPad? NO. The new 'soft SIMs' are BIG NEWS
AppleSIM 'ware to allow quick switch of carriers
Arab States make play for greater government control of the internet
Nerds told to get lost in last-minute power grab bid at UN meeting
Brits: Google, can you scrape 60k pages from web, pleeease
Hey, c'mon Choc Factory, it's our 'right to be forgotten'
Of COURSE Stephen Elop's to blame for Nokia woes, says author
'Google did have some unique propositions for Nokia'
It's even GRIMMER up North after MEGA SKY BROADBAND OUTAGE
By 'eck! Eccles cake production thrown into jeopardy
Mobile coverage on trains really is pants
You thought it was just *insert your provider here*, but now we have numbers
Don't mess with Texas ('cos it's getting Google Fiber and you're not)
A bit late, but company says 1Gbps Austin network almost ready to compete with AT&T
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Win a year’s supply of chocolate
There is no techie angle to this competition so we're not going to pretend there is, but everyone loves chocolate so who cares.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.