Feeds

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

Big Blue boffins, AT&T brainboxes beg to differ

Designing a Defense for Mobile Applications

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. ®

Securing Web Applications Made Simple and Scalable

More from The Register

next story
Google Nest, ARM, Samsung pull out Thread to strangle ZigBee
But there's a flaw in Google's IP-based IoT system
Orange spent weekend spamming customers with TXTs
Zero, not infinity, is the Magic Number customers want
Want to beat Verizon's slow Netflix? Get a VPN
Exec finds stream speed climbs when smuggled out
US freemium mobile network eyes up Europe
FreedomPop touts 'free' calls, texts and data
'Two-speed internet' storm turns FCC.gov into zero-speed website
Deadline for comments on net neutrality shake-up extended to Friday
GoTenna: How does this 'magic' work?
An ideal product if you believe the Earth is flat
NBN Co execs: No FTTN product until 2015
Faster? Not yet. Cheaper? No data
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.