Ranovus developing DWDM links for the data centre

Ranovus has raised US $11 million in funding to develop Terabit capacity links for the data centre. The Ottawa-based start-up plans to use dense wavelength-division multiplexing (DWDM) technology to create huge data pipes that reduce significantly the power consumption, and cost, per bit.

Source: Gazettabyte

"Fibre [in the data centre] is not abundant and will become rarer," says Saeid Aramideh, co-founder and chief marketing and sales officer at Ranovus. "If you had a way to scale into Terabits in the 1550nm regime, doing WDM inside the data centre cost effectively, that would be the preferred way."

Such technology will be able to link equipment across all sizes of data centre, and even between data centres hundreds of kilometers apart. The start-up is also investigating how the technology could be integrated within equipment such as servers for chip-to-chip communication.

Ranovus has quantum dot laser technology that operates at 1550nm. It will use its lasers as part of a silicon photonics circuit combined with digital signal processing (DSP) technology. "To do a disruptive platform, you have to take advantage of various technology elements," says Aramideh.

The tiny quantum dot lasers will enable multi-channel transmission. "You can have simultaneous emission of 80 or 96 channels [in a fibre]," says Aramideh. Indeed the company's technology has the potential to support up to 200 channels across the C-band, he says. Such an interface will allow single mode fibre only to be used to serve all reaches in the data centre. At present, multi-mode fibre is used for high-speed links up to 100m and single mode interfaces for longer reaches.

Ranovus has not detailed its product plans. But it has said that its interface will offer Terabit capacities and can support 80 or 96 channels across the C-band. The technology could even support up to 200 channels. Assuming 25G or 50G data rates per channel, the interface will likely support anything from 400 Gig to 10 Terabits at reaches from a few cms up to several hundred kilometers. Source: Gazettabyte

The company says that it is not a silicon photonics start-up but rather a user of the technology to make its interface. Ranovus will use a foundry to make its optical chips.

Ranovus includes former staff of the coherent transmission and DSP specialist, CoreOptics, acquired by Cisco Systems in 2010. "Electronics, as we learnt from our previous endeavour, can impact in a big way the cost-performance of links," says Aramideh. "It doesn't have to be expensive equaliser technology we developed in the past, but there are ways of using similar technology in CMOS ICs to solve some of the network problems."

This suggests that DSP will be used to help cram the multiple channels in the fibre as well as achieve several hundred kilometers of reach. But the DSP will use simpler algorithms than those for long-distance coherent transmission.

Aramideh says its Terabit interface is inevitably a proprietary design. "[Industry] standards are important and you need to have dual sourcing, but people value having disruptive technologies," he says. "The challenge the industry has is that there hasn't been a lot of innovation going into technologies specifically for the data centre."

The start-up's technology is being validated with several lead customers. "It is early proof of technology and the platform in terms of configurations that the customers will be using," he says.

The $11m funding raised will be used to commercialise the technology and make the first products for lead customers. "We are very advanced in our plans with respect to delivery of our product," says Aramideh. Ranovus expects to provide first details of its product at OFC 2014.