MultiPhy eyeing 400 Gig after completing funding round
MultiPhy is developing a next-generation chip design to support 100 and 400 Gigabit direct-detection optical transmission. The start-up raised a new round of funding in 2013 but has neither disclosed the amount raised nor the backers except to say it includes venture capitalists and a 'strategic investor'.
The start-up is already selling its 100 Gig multiplexer and receiver chips to system vendors and module makers. The devices are being used for up to 80km point-to-point links and dense WDM metro/ regional networks spanning hundreds of kilometers. "In every engagement we have, the solutions are being sold in both data centre and telecom environments," says Avi Shabtai, CEO of MultiPhy.
The industry has settled on coherent technology for long-distance 100 Gig optical transmission but coherent is not necessarily a best fit for certain markets if such factors as power consumption, cost and compatibility with existing 10 Gig links are considered, says Shabtai.
The requirement to connect geographically-dispersed data centres has created a market for 100 Gig direct-detection technology. The types of data centre players include content service providers, financial institution such as banks, and large enterprises that may operate their own networks.
In every engagement we have, the solutions are being sold in both data centre and telecom environments
MultiPhy's two chips are the MP1101Q, a 4x25 Gig multiplexer device, and the MP1100Q four-channel receiver IC that includes a digital signal processor implementing the MLSE algorithm.
The chipset enables 10 Gig opto-electronics to be used to implement the 25 Gig transmitter and receiver channels. This results in a cost advantage compared to other 4x25 Gig designs. A design using the chipset can achieve 100 Gig transmissions over a 200GHz-wide channel or a more spectrally efficient 100GHz one. The latter achieves a transmission capacity of 4 Terabits over a fibre.
ADVA Optical Networking is one system vendor offering 100 Gig direct-detection technology while Finisar and Oplink Communications are making 100 Gigabit direct-detection optical modules. Oplink announced that it is using MultiPhy's chipset in 2013.
Overall, at least four system vendors are in advanced stages of developing 100 Gig direct-detection, and not all will necessarily announce their designs, says Shabtai. Whereas all the main optical transmission vendors have 100 Gig coherent technology, those backing 100 Gig direct detection may remain silent so as not to tip off their competitors, he says.
We assume we can do more using those [25 Gig] optical components with our technology
Meanwhile, the company is using the latest round of funding to develop its next-generation design. MultiPhy is focussed on high-speed direct-detection despite having coherent technology in-house. "Coherent is on our roadmap but direct detection is a very good opportunity over the next two years," says Shabtai. "You will see us come with solutions that also support 400 Gig."
A 400 Gigabit direct-detection design using its next generation chipset will likely come to market only in 2016 at the earliest by which time 25 Gig components will be more mature and cheaper. Using existing 25 Gig technology, a 400 Gig design requires 16, 25 Gig channels. However, the company will likely extend the performance of 25 Gig components to achieve even faster channel speeds, just like it does now with 10 Gig components to achieve 25 Gig speeds. The result will be a 400 Gig design with fewer than 16 channels. "We assume we can do more using those [25 Gig] optical components with our technology," says Shabtai.
MultiPhy targets low-power coherent metro chip for 2013
MultiPhy has given first details of its planned 100 Gigabit coherent chip for metro networks. The Israeli fabless start-up expects to have samples of the device in 2013.
"We can tolerate greater [signal] impairments which means the requirements on the components we can use are more relaxed"
Avi Shabtai, CEO of MultiPhy
"Coherent metro is always something we have pushed," says Avi Shabtai, CEO of MultiPhy. Now, the company says it is starting to see a requirement for coherent technology's deployment in the metro. "Everyone expects to see it [coherent metro] in the next 2-3 years," he says. "Not tomorrow; it will take time to develop a solution to hit the target-specific [metro] market."
MultiPhy is at an advanced stage in the design of its coherent metro chip, dubbed the MP2100C. "It is going to be a very low power device," says Shabtai. MultiPhy is not quoting target figures but in an interview with the company's CTO, Dan Sadot, a figure of 15W was mentioned. The goal is to fit the design within a 24W CFP. This is a third of the power consumed by long-haul coherent solutions.
The design is being tackled from scratch. One way the start-up plans to reduce the power consumption is to use a one-sample-per-symbol data rate combined with the maximum-likelihood sequence estimation (MLSE) algorithm.
MultiPhy has developed patents that involve sub-Nyquist sampling. This allows the analogue-to-digital converters and the digital signal processor to operate at half the sampling rate, saving power. To use sub-Nyquist sampling, a low-pass anti-aliasing filter is applied but this harms the received signal. Using the filter, sampling at half the rate can occur and using the MLSE algorithm, the effects of the low-pass filtering can be countered. And because of the low-pass filtering, reduced bandwidth opto-electronics can be used which reduces cost.
This low-power approach is possible because the reach requirements in metro, up to 1,000km, is shorter than long haul/ ultra long haul optical transmission links. The shorter-reach requirements also impact the forward error correction codes, needed which can lessen the processing load, and the components, as mentioned. "We can tolerate greater [signal] impairments which means the requirements on the components we can use are more relaxed," says Shabtai.
The company also revealed that the MP2100C coherent device will integrate the transmitter and receiver on-chip.
MultiPhy says it is working with several system vendor and optical module partners on the IC development. Shabtai expects the first industry products using the chip to appear in 2014 or 2015. The timing will also be dependent on the cost and power consumption reductions of the accompanying optical components.
A 100Gbps direct-detection optical module showing MultiPhy's multiplexer and receiver ICs. The module shown is a WDM design. Source: MultiPhy
100Gbps direct detection multiplexer chip
MultiPhy has also announced a multiplexer IC for 100 Gigabit direct detection. The start-up can now offer customers the MP1101Q, a 40nm CMOS multiplexer complement to its MP1100Q receiver IC that includes a digital signal processor to implements the MLSE algorithm. The MP1100Q was unveiled a year ago.
Testing the direct-detection chipset, MultiPhy says it can compensate +/-1000ps/nm of dispersion to achieve a point-to-point reach of 55km. No other available solution can meet such a reach, claims MultiPhy.
MultiPhy's direct-detection solution also enables 10 Gigabit-per-second (Gbps) opto-electronics components to be used for the transmit and receive paths. At ECOC, MultiPhy announced that it has used Sumitomo Electric's 10Gbps 1550nm externally-modulated lasers (EMLs) to demonstrate a 40km reach.
Using such 10Gbps devices simplifies the design since no 25Gbps components are required. It will also enable more optical module makers to enter the 100 Gigabit marketplace, claims MultiPhy. "It is twice the distance and about half of the cost of any other solution on the market - much below $10,000," says Shabtai.
MultiPhy's HQ in Ness Ziona, Israel
The multiplexer device can also be used for traditional 4x28Gbps WDM solutions to achieve a reach in existing networks of up to 800km.
MultiPhy says that it expects the overall 100 Gigabit direct detection market to number 4 optical module makers and 4-5 system vendors by the end of 2012. At present ADVA Optical Networking is offering a 100Gbps direct-detection CFP-based design. ECI Telecom has detailed a 5x7-inch MSA direct-detection 100 Gigabit module, while Finisar and Oclaro have both announced that they are coming to market with 100Gbps direct-detection modules.