1.2T Delivering Maximum Capacity, Reach & Fiber Efficiency

Acacia, now part of Cisco, is once again introducing a ground-breaking coherent solution with the industry’s first 1.2 terabits per second (1.2T) faceplate pluggable coherent module, highlighting a new 8th generation Coherent Interconnect Module family, powered by Acacia’s Jannu 5nm CMOS digital signal processor (DSP) ASIC. This solution delivers industry-leading performance with single carrier 1.2T operation and combines the Jannu DSP with 3D Siliconization packaging technology which includes the silicon photonics integrated circuit (SiPh PIC), high-speed modulator driver and transimpedance amplifier (TIA) in a single optoelectronic package.

The Jannu DSP is designed to offer network operators the ability to maximize transmission data rate across a wide range of multi-haul network applications including DCI, metro, long-haul and subsea. “By leveraging the latest 5nm CMOS process node and our advanced signal processing algorithms, we’re delivering exceptional performance with less than half the power per bit of competing solutions, enabling a pluggable deployment model,” says Christian Rasmussen, Sr. Director, DSP and Optics Engineering and Founder at Acacia.

The Industry’s Next Class of Coherent Interconnect

The architecture of the new Coherent Interconnect Module 8 (CIM 8) solution builds upon the success of the Acacia AC1200 product family and aligns closely with the latest client data rates and coherent industry standardization efforts. The CIM 8 is designed to enable network operators to double their transmission capacity over even greater reaches. For links requiring maximum capacity, the new module can provide 1.2T capacity over a single wavelength.

“Historically, Acacia has been a groundbreaker in advancing coherent technology, and the company continues to demonstrate a long-term vision for how multi-haul coherent optics should evolve over time,” said Dr. Scott Wilkinson, Lead Analyst for Optical Components at Cignal AI. “Acacia’s new Coherent Interconnect Module is a great example of market leadership. This solution is a logical next step following the widely adopted Pico DSP-based products and will provide pluggability that is attractive to both traditional and cloud operators.”

The below figure illustrates how coherent technology has evolved in response to growing bandwidth demands. Different baud-rate classes are grouped based on technological capabilities, industry standardization (such as OIF, IEEE, Open ROADM, OpenZR+ MSA, CableLabs, ITU) and common industry investments. As the below figure depicts, the next class of coherent optical products, Class 3, enables a doubling of baud rates from the current Class 2 technology. Class 2 products include both multi-haul embedded modules and 400G faceplate pluggables where the latter was driven by standardization efforts that drove heavy investments into products centered around 16QAM, 60+Gbaud per 75GHz channel transmission.

Throughout this evolution, it has been critical that each successive class provide network architecture compatibility to the previous class, primarily reach and channel width. Acacia’s Class 3 product will support 150GHz channels with double the capacity per carrier and longer reach than that of the previous class, providing a simple, scalable path that is compatible with the previous network architecture generation.

The CIM 8 family is a Class 3 solution that can address transmission of multiple 400GbE client interfaces over virtually any network application, delivering 1.2T per carrier capacity for high-capacity DCI interfaces and 800G per carrier capacity over most optical links using 4 bits/symbol (~16QAM) modulation.

Leading in Performance and Fiber Utilization

The Jannu DSP features Acacia’s second-generation 3D Shaping technology, which leverages enhanced probabilistic constellation shaping (PCS) algorithms and Adaptive Baud Rate, a feature introduced in Acacia’s Pico DSP and widely embraced by network operators. The Jannu DSP provides customers with continuous baud rate adjustment up to 140Gbaud to optimize utilization of available spectrum in a single-span or in cascaded ROADM paths. These 3D Shaping features give service providers unprecedented transmission flexibility to match their network’s architecture, optimize fiber utilization, simplify deployment, and save on both CAPEX and OPEX.

As a single carrier design, the Jannu DSP also includes Acacia’s advanced line-rate processing algorithms to efficiently overcome fiber transmission impairments over greenfield or brownfield fiber infrastructures. These power-efficient algorithms are designed to compensate for linear and non-linear impairments, as well as provide state-of-polarization (SOP) tracking with industry leading response times. In addition, the Jannu DSP leverages Acacia’s new innovative soft-decision error correction (SD-FEC) to further enhance performance.

Scaling Optical Network Architectures

Acacia has been working towards a clear vision of how to cost-effectively scale network capacity for many years. The Jannu DSP builds on the performance and architectural benefits that have made the Pico DSP such a successful Class 2 coherent solution, but with double the baud rate and enhanced performance that supports transmission up to 1.2T in 150GHz channels. With adaptive baud rate capabilities, the CIM 8 also offers maximum capacity over any reach and channel plan.

“Today is an exciting new milestone in Acacia’s history as we once again introduce an exciting new product that delivers the type of disruption needed to cost-effectively scale network capacity in the future,” said Mehrdad Givehchi, Sr. Director of Engineering for Hardware and Software and Founder at Acacia. “With every generation of product, we have been able to deliver higher transmission data rates, lower power consumption and higher performance and I am proud to see this new product carry on that legacy.”

Crossing the Pluggable Terabit Threshold with High-Density Integration

Acacia’s 3D Siliconization is a major contributing factor in how the CIM 8 can cross the terabit capacity threshold and support faceplate pluggable optics that simplify network deployment and maintenance. 3D Siliconization applies integration and 3D stacking packaging techniques to enable a single device to include all the high-speed optoelectronic functions necessary for coherent transceivers. This device decreases footprint by including the DSP, SiPh PIC, drivers, TIAs, and is manufactured using standard CMOS packaging processes that leverage the same reliability, cost, and volume scaling advantages. With 3D Siliconization, the high-speed RF interfaces are tightly coupled together, resulting in improved signal integrity for high baud rate signals.

The high-density packaging as well as an advanced high-speed modulator design provides superior frequency response that enables the 140Gbaud performance as explained in this white paper.

Acacia Technology Leadership and Vision

Transforming industry trends into a development strategy takes the kind of vision Acacia has repeatedly shown in driving the adoption of pluggable digital coherent optical (DCO) modules based on silicon photonics. However, Acacia’s silicon photonics expertise expands beyond just pluggable coherent solutions. As shown in the above figure, Acacia has previously introduced multi-haul products in previous classes. In fact, the AC400 Class 1 product was the first commercially deployed all silicon photonics-based coherent module for submarine applications and the silicon photonics-based AC1200 was the industry’s first Class 2 multi-haul solution. The newly introduced CIM 8 continues this history of technology leadership by providing industry leading performance based on the same silicon photonics used in high volume pluggable modules. In addition, Acacia is leveraging the investments being made in next-generation standardized solutions. Aligning these developments helps Acacia to accelerate time to market for both standardized and multi-haul products and benefit from the combined scale.

Acacia was a pioneer of silicon photonics for coherent applications in 2012 when it was the first coherent module vendor to envision silicon as the platform for the integration of multiple discreet photonic functions, increasing the density and reducing cost of optical interconnect products.

“Acacia’s vision and technology leadership has enabled us to transform coherent transmission. Our pioneering role in silicon photonics has led to the introduction of industry leading coherent pluggable and multi-haul solutions,” said Benny Mikkelsen, CTO and Founder of Acacia. “With every new product introduction, we have delivered the right solution at the right time to help our customers meet their growing bandwidth demands, and this new product introduction is a culmination of this proven technology leadership.”

To learn more, visit Coherent Interconnect Module 8 page or contact us.

The Pacific Telecommunications Council (PTC) annual conference is the “Pacific Rim’s premier telecommunications event,” and Acacia will have a front row seat for it this year. PTC ‘19 kicks off Sunday, January 20 and runs through Wednesday, January 23, 2019, where subsea communications will be a hot topic, as organizations are faced with the challenge to enable increased utilization of deployed fiber for improved network capacity.

Given the fact subsea is of particular importance to Acacia and its customers, we’re excited it will be a big part of the “From Pipes to Platforms” theme at the conference – and that it comes on the heels of three subsea trials Acacia collaborated on and a blog article on the topic:

• Acacia announced the first 400G Transmission Across 6,600km Trans-Atlantic Marea Cable Using the Acacia AC1200 Coherent Module
• Cisco demonstrated the NCS 1004 driving a single wavelength of 300G over a 10,000km sub-sea link
• ADVA delivered 300G over trans-Atlantic distance in FSP 3000 TeraFlex trial
• Hongbin Zhang shared Two Key Elements Needed for Future Transponders in Submarine Systems in his recent blog post which discusses power limitations of submarine systems and reducing cost per bit for both transponder and wet-plant

“Transmission of 400G over 6,600 km is a significant milestone and demonstrates what can be achieved with higher performance transmission optics combined with a well-designed line system. This field demonstration of an advanced solution that is just becoming commercially available highlights the value of Marea’s open architecture to evolve with the latest technology. By allowing early adoption of new technologies such as Acacia’s AC1200, we are able to increase the utilization of our deployed fiber, maximize our investment and improve network capacity.”

—Mark Filer, Principle Optical Engineer, Azure Networking, Microsoft Corp.

The 400G subsea field demonstration, conducted by Acacia in collaboration with Microsoft and Facebook, helped to demonstrate that improvements in capacity and spectral efficiency can enable increased utilization of deployed fiber and improved network capacity. Modulation formats greater than 4 bits/symbol were utilized to achieve a spectral efficiency of 6.41 b/s/Hz on the 6,600 km cable. This was achieved using Acacia’s suite of 3D Shaping features that enable fine-tune adjustment of the modulation characteristics to provide network operators with the flexibility to customize the transmission to their network requirements. This is especially important in a submarine network where multiple providers share the same fiber link, and are trying to optimize its capacity utilization of their assigned spectrum.

In his recent blog post on the growth of submarine cables and how the Cisco NCS 1004 fits, Cisco’s Product Manager Optical Systems & Optics Group, Sushin Suresan, talks about how spectral efficiency is the key metric to maximizing capacity on expensive submarine cable assets.

The Cisco NCS 1004 is the latest product in the DCI form-factor NCS 1000 series. It delivers multi-haul coherent DWDM transponders that provide state of the art performance for sub-sea applications using granular baud-rate + bits per symbol tuning, time-hybrid modulation, transmit signal shaping and non-linear equalization. Each 2RU form-factor NCS 1004, powered by Acacia’s Pico Digital Signal Processor chip, provides 8 coherent DWDM ports that operate from 100G to 600G.

ADVA announced that its FSP 3000 CloudConnect TeraFlex succeeded in transporting 300Gbit/s of data per wavelength over a 6,800km fiber link. ADVA and Acacia conducted the trial, which was the first in the industry to cover the trans-Atlantic distance with a fiber link typical of a cost-optimized submarine cable using 300Gbit/s channels and a commercially available transponder with real-time digital signal processing (DSP). The demo, which also achieved the highest spectral efficiency for such a link carrying 300Gbit/s per wavelength with 70GHz channel spacing, highlights the capabilities of the ADVA FSP 3000 TeraFlex solution, which incorporates the suite of advanced performance features in Acacia’s Pico coherent DSP, to support flexible, ultra-high-capacity, long-haul and subsea data transport.

Triggered by the increasing demand for data driven by cloud-based services, we’re seeing a significant expansion in long-haul and subsea cable networks. We believe these trials give a major boost not only to long-haul and submarine network operators but also to cloud-content and digital media providers looking for ways to cost-efficiently deliver more to their customers around the globe.

Attending PTC? Alan Gibbemeyer, senior director of global business development at Acacia, will be on hand at the conference along with other members of the team to discuss these developments. To schedule a meeting at PTC ’19 contact us.

Transmission reaches for metro applications have to be above 50 km for metro/access and below 1000 km for metro/regional applications. This requires compact, scalable, cost-efficient, and easy-to-use digital coherent transport solutions such as the Acacia CFP2 module.

Figure 1: CFP2 coherent module

Acacia’s engineering team led by Hongbin Zhang recently demonstrated real-time transmission of 16 Tb/s (80x200Gb/s) over 1020km TeraWave ULL fiber with 170km span length using the 200Gb/s CFP2 module. The length, while much longer than typical metro/regional spans, was chosen to stress the OSNR budget while showing achievable amplifier spacing with ultra-low loss fiber. The results showed a record low power consumption less than 0.1W/Gbps. This is the lowest reported power consumption per bit for coherent optical transceivers.

Figure 2: Circulating loop setup for transmission experiments.

For the purpose of this experiment the CFP2 module was implemented in multi-source agreement (MSA) 107.5 mm x 41.5 mm form factor. Test specifics include:

• To test the 200Gb/s transmission performance as a function of OSNR for PM-8QAM on a 50GHz grid (4 bits/s/Hz SE) and PM-16QAM on a 37.5GHz grid (5.33 bits/s/Hz SE), we placed the 4 CFP2 channels next to each other in the middle of the C-band. One of the middle CFP2 channels was selected by a 50GHz optical demux in front of the coherent receiver and the real-time BER was measured as a function of received OSNR by varying the EDFA output power and subsequently converted into Q2-factor.
• To test the transmission performance as a function of the wavelength, we determined the Q2-factor from the measured real-time BER of the two middle channels among 4 consecutive CFP2 50GHz-spaced channels as they are moved across the C-band.

Relying on pluggable CFP2 transceiver modules, we were able to demonstrate successful 200Gb/s real-time transmission of 80 PM-8QAM and PM-16QAM channels at 4 bits/s/Hz spectral efficiency over 1020 km distance using very long 170km spans of TeraWave ULL fiber showing 2.8dB and 1.2dB Q²-margin, respectively. We were also able to prove an increase in system capacity as well as a decrease in power consumption per bit for coherent optical transceivers.

The research paper, published by Optics EXPRESS, is available to read or download here.

The 3D-shaping capability in the AC1200 enables fine-tune adjusting of the line-side modulation characteristics helping network operators to optimize capacity and reach for their particular network or link.  3D-shaping pushes the AC1200 performance closer to the theoretical Shannon limit in a very power-efficient manner, providing network operators with the performance and density required for a wide range of network configurations and requirements.

The key features enabling 3D-shaping include:

• Shaping of the constellation points’ probability to increase capacity using Acacia’s patented Fractional QAM modulation
  

• Shaping of the constellation points’ location to increase reach
  
• Shaping of the spectral width to match the available channel passband by adapting the baud rate (400G on 75GHz grid example shown below).
  

In addition to 3D shaping, the AC1200 features:

• Client Interfaces to support a wide range of applications with  100GbE, 400GbE and FlexE interfaces to the host card
• Internal Crossbar Switch to enable increased traffic flexibility, including mapping of 3x400GbE client traffic on to two line-side wavelengths carrying 600Gbps each
  
• Enhanced Turbo Product Code SD-FEC for ultra-high net coding gain (NCG) to extend reach, while maintaining low power dissipation.
  

The robust feature set of the AC1200 provides many advantages to increase the efficiency of DCI/Cloud, Metro, and Long Haul applications.  For more information about the AC1200, please visit the links below or contact us.

Additional Resources:

Press Release – September 20,2017: Acacia Communications Unveils 1.2 Tbps AC1200 Coherent Module for DCI, Metro, and Long-Haul Applications

Blog Post – October 23, 2017: Introducing the AC1200 Coherent Module for DCI, Metro, and Long-Haul Applications

Press Release – March 12, 2018: Acacia Communications Demonstrates AC1200 Coherent Module for DCI, Metro and Long-Haul Applications