At 400G, it's signal reliability that's the rub.
Chromatic dispersion increases 10-fold and polarization mode dispersion is up to three times worse: Key components used today were provisioned for 10G.
What's been lacking is a simple migration from 10G to higher speeds without sacrificing performance or dramatically increasing costs. Just in time for OFC 2014, ClariPhy Communications Inc. believes it has the answer (or at least, an answer) with its new LightSpeed-II SoCs (systems-on-chip) that provide a multi-rate, multi-modulation platform supporting 40G to 200G per wavelength.
According to Paul Voois, chief strategy office at ClariPhy, "The challenge was the amount of integration involved. These are the most complex SoCs in the communications industry, all in a single chip. They're cost- and space-efficient and enable high performance."
LightSpeed-II is, according to Clariphy, the only standard product SoC to enable 400G next-gen line cards as well as integrate a transmit DSP (digital signal processor) with high-speed digital-to-analog converter (DAC). The company also claims LightSpeed-II is the first standard product SoC to support 200G 16QAM modulation on a single wavelength, enabling 400G dual-carrier super channels. This doubles the data rate capability of 100G coherent optical components and cuts cost per bit in half.
ClariPhy’s expertise in DSP algorithm, coherent detection, and the company's reputation for integration are behind the development of the single-chip SoCs. LightSpeed-II provides one platform for 40G and 100G apps, so that the OEMs that use this product to build their systems can use the same chip architecture, same FEC (forward error correction), firmware and pin out for 40G, 100G and 400G solutions.
The architecture features lower sensitivity to impairments and doubles the reach of network segments. As an all-CMOS (complementary metal–oxide–semiconductor) solution, it has power dissipation characteristics that deliver significant power savings for upcoming high-performance network equipment.
Coherent detection, rather than direction detection, enhances OSNR (optical signal-to-noise ratio) sensitivity and reach capabilities for metro, long-haul and submarine apps, simplifies deployment, and lowers system costs. An embedded microprocessor runs the software stack and optical monitoring capabilities, a feature that, Clariphy believes, makes the solution particularly useful for software-defined networking (SDN). For DWDM, 100G coherent detection is particularly important for service providers to economically scale their optical networks.
It's refreshing when a new product is announced that is already sampling, and ClariPhy expects the product to become commercially available later this year.
No doubt we'll hear more about 400G developments at OFC in mid-March, when other chip firms will also be seeking to attract the attention of those systems vendors that don't have their own inhouse chip developments teams. (See Broadcom Helps Out With a Key 100G Part.)
— Carolyn Mathas, contributing editor, special to Light Reading