Submarine cable capacity doubled with flick of switch

With a flick of a switch, NTT has boosted the capacity on its Japan-US PC-1 cable link more than 2.5 times to 8.4 terabits per second.

The company's announcement heralds the beginning of a rollout that will ultimately take in NTT's intra-Asian submarine cables. NTT has been trialling 100 Gbps digital coherent optical systems from Infinera since 2011, but says only now has it resolved all the technical challenges in achieving stable channels.

“By optically optimising the PC-1’s network architecture, including with strategically placed optical repeaters and an enhanced optical fibre layout, NTT Com has now achieved the world’s first commercial deployment of 100 Gbps digital coherent technology on a transpacific route,” NTT said in an announcement.

Now that the transpacific system is live, NTT says it will begin implementing the systems on its Asia Submarine-cable Express system, which links Japan, the Philippines, Hong Kong, Malaysia and Singapore.

Construction of the ASE cable was completed by Fujitsu and NEC in February 2013.

In the meantime, Alcatel-Lucent is touting capacities far beyond those now being implemented by NTT, successfully demonstrating a 31 Tbps, 7,200 km link, with a repeater spacing of 100 km, in its Villarceaux laboratory near Paris.

Alca-Lu says the 31 Tbps demonstration offers triple the capacity of current advanced submarine cables. To achieve the high data rates, the company ran a DWDM scheme with 155 individual lasers and a channel spacing of 50 GHz, with individual transmissions operating at 200 Gbps.

The experiment was detailed in a post-deadline paper presented at the OECC (Opto-Electronic Communication Conference) earlier this month. ®