Bell Labs Break Record With 31Tbps Via a Single 7200km Optical Fibre

Mark.JUK writes "Alcatel-Lucent's research and development division, Bell Labs, has successfully broken yet another record after it used 155 lasers (each operating at different frequencies and carrying 200Gbps of data over a 50GHz frequency grid) and an enhanced version of Wavelength Division Multiplexing (WDM) to send information at a staggering speed of 31 Terabits per second over a single 7200km long optical fibre cable. Previous experiments have been faster but only over shorter distances or by using a different type of fibre optic cable entirely."

For your "Staggering stat of the day"

[Anonymous Coward]

The switching is so dense and so fast, that the 7200km of cable has *in flight* 146 gigabytes of information at any given time. You can back up your typical "150GB" (143GB actual) OS hard drive and user data, and be done sending it before it starts reaching the other end (if you could buffer it to send that fast, naturally). Is that some crazy shit or what?

Re:For your "Staggering stat of the day"

[DutchUncle]

Back in 1979, when fiber was brand-new (and we were experimenting with speeds you wouldn't even bother with for TOSlink today), we hooked up a 5km spool of fiber to both sides of the same optical "modem". Using a Z80, we got an interrupt on the receive side apparently simultaneous (in the same clock cycle) to putting a byte in the transmit port - which sort of makes your DMA controller unhappy. Everyone figured there was a short or a cross-connection, because nobody could believe the speed. And that was a snail's pace in comparison to *each* laser of this system.

Re:Not going to happen.

[j1m+5n0w]

Wrong, this still requires amplifiers every 100km, just like today.

They don't explicitly say that there were no repeaters for this particular test, but that is strongly implied. (Sloppy reporting.) However, they do compare it to a test done recently over 10,000km with no repeaters:

Then in January 2012 a Japanese team working out of NEC successfully transmitted 4Tbps over a single “ultra-long haul” (10,000km) fibre optic cable (no repeaters) by making use of WDM just like Alcatel-Lucent (here). Lest we not forget all the other developments, such as the successful UK test of a new type of hollow fibre optic cable that earlier this year delivered speeds of 73.7 Tbps (here).

Alcatel-Lucent might have just set a new record and one that it is arguably most notable for its distance but such records are clearly made to be broken. GCHQ will probably get a headache if they want to “tap” (spy) on the next generation of transoceanic cables.

I had no idea that those kinds of distances were possible without repeaters. This is, indeed, big news.