Increasing Baud Rates Delivers Twice the Capacity and Longer Reaches
History has shown that increasing baud rate is an efficient way to enable more cost-effective optical networks by reducing the number of optics required to support a given transmission capacity. As highlighted in the graphic below, by doubling the baud rate between successive generations, Class 3 products such as Acacia’s CIM 8 1.2T module supports twice the capacity per carrier over greater reaches than Class 2 solutions. This approach provides a simple, scalable path that supports higher capacity per carrier over the reaches needed for existing network architectures.

Network operators leveraging Class 3 140Gbaud solutions for DCI, metropolitan, long-haul, and subsea applications can maximize their network coverage across a wider distance than ever before. This results in the capability to transmit native 400G client traffic over virtually any network application, delivering 3x400G over 1.2Tbps per carrier capacity for high-capacity DCI interfaces, 2x400G over 800Gbps per carrier capacity for most optical links using 4 bits/symbol (~16QAM) modulation and 2 bits/symbol (400G QPSK) over ultra-long-haul and subsea distances.

Acacia’s Dayou Qian, Product Line Manager, will discuss the migration to high baud rate 400G QPSK during a live panel presentation titled Class 3 Optical Transport Systems: from DCI to Subsea at OptiNet China on June 20.

Learn More about Acacia’s Performance Optimized Solutions
As the first coherent module on the market to break through the terabit threshold, Acacia’s 1.2T CIM 8 module has proven its outstanding performance with multiple record breaking field trials across a wide range of applications. Visit this link to learn more.

As the first coherent module on the market to break through the terabit threshold, Acacia’s 1.2T Coherent Interconnect Module 8 (CIM 8) has proven its outstanding performance with multiple record breaking field trials across a wide range of applications. The most recent was Verizon with a successful 1.2 Tbps transmission over its live commercial fiber network in metro Long Island, NY.  And on the heels of that was Windstream Wholesale with a 1 Tbps wavelength over a 1,100-kilometer link across multiple routes on Windstream’s Intelligent Converged Optical Network (ICON).

Verizon Trial Demonstrates its Ability to Deliver Increased Speed, Reliability, and Overall Capacity
Leveraging the CIM 8’s advancements in terabit optics, Verizon was able to carry 1.2 Tbps of data using a single wavelength over longer distances through more nodes. In the trial, a 1.0 Tbps single-wavelength was transmitted over the Cisco NCS 2000 line system over 205km traversing 14 fiber central offices. In metropolitan networks, the number of central offices traversed is a key performance metric due to the progressive filtering and signal-to-noise ratio degradation as the wavelength passes through each office. Additionally in the trial, 800 Gb/s transmission was achieved over 305km through 20 offices and a 1.2 Tb/s wavelength traversed three offices.

According to Adam Koeppe, SVP of Technology Planning at Verizon, “We have bet big on fiber. Not only does it provide an award-winning broadband experience for consumers and enterprises, but it also serves as the backbone of our wireless network. As we continue to see customers using more data in more varied ways, it is critical we continue to stay ahead of our customers’ demands by using the resources we have most efficiently.”

Cisco’s Bill Gartner, SVP/GM Cisco Optical Systems and Optics, said “This trial demonstrates our commitment to continuous innovation aimed at increasing wavelength capacity and reducing costs. The Verizon infrastructure built with the Cisco NCS 2000 open line system supports multiple generations of optics thus protecting investments as technology evolves.”

Windstream Wholesale Trial Highlights Superior Performance of the CIM 8
Windstream Wholesale’s successful CIM 8 trial was enabled by the Cisco NCS 1014 C-Band 2.4T WDM Transponder Line Card with the CIM 8 module.  This transmission success showcased the high performance of the CIM 8, which was demonstrated over a third-party line system (150Ghz Channel). Following are the key wavelength transmissions that were achieved across Windstream ICON routes:

• Successful roundtrip transport of 1Tbps over 1,100 km from Miami to Jacksonville, Florida
• Successful transport of 800G over 1,387 km of mixed fiber from Miami through Tallahassee, Florida, to Atlanta, Georgia
• Successful roundtrip transport of 600G over 2,774 km from Miami, Florida, to Atlanta, Georgia

According to John Nishimoto, Windstream Wholesale senior vice president of products, marketing, and strategy, “This tremendous achievement further proves our commitment to technology leadership and networking expertise. We developed ICON to provide multi-vendor flexibility and seamlessly integrate the newest optimized technology into our disaggregated network. Achievements like this reinforce our 800G wave strategy and offer improved design and network planning options among our 100G and 400G solutions.”

The Growing Number of CIM 8 Trials
Verizon and Windstream Wholesale are just the latest providers to join the Terabit Era using Acacia’s CIM 8 module. Previously, Nysernet, China Mobile and Windstream Wholesale (in their first CIM 8 trial) announced record breaking field trials over ultra long haul, long haul and regional distances.  As all these trials demonstrate, the CIM 8 enables network operators to achieve the highest capacity and reach today while maximizing transmission data rate across a wide range of multi-haul network applications.

The CIM 8 Provides Full Network Coverage While Achieving 65% Power-per-Bit Savings Over Current Competing Solutions
Acacia’s CIM 8 enables full multi-haul network coverage as the high baud rate capabilities transport nx400GbE client traffic across a service provider’s entire network. As this previous blog discussed, the CIM 8 doubles the baud rate from the prior generation to achieve 140Gbaud capability while also leveraging the power of silicon technology to obtain cost and power advantages. These advancements have enabled the CIM 8 to provide 65% power-per-bit savings compared to current competing solutions that utilize alternative optical material systems.

Join the Terabit Era
If you’re ready to join the Terabit Era with CIM 8, contact us to schedule a field trial.

To date, multiple system vendors have converged around Class 3-based solutions (Figure 1), recently announcing their next generation offerings. This industry convergence creates the benefit of economies of scale and broad industry investments into the technology used in this baud rate class, the same class being used for 800G MSA pluggable solutions.

Figure 1.  Acacia and other coherent vendors have announced Class 3 Terabit Era solutions.

Advancements Resulting in 65% Power-per-Bit Savings Over Current Competing Solutions
Doubling the baud rate from Class 2 to Class 3 in silicon was a significant engineering achievement, combining design advancements in high-speed Radio Frequency (RF) and Analog to Digital Converter (ADC) and Digital to Analog Converter (DAC) components plus well-designed co-packaging integration of silicon and silicon photonic (SiPh) components. These achievements led to Acacia’s successful 140Gbaud in-house capability that is being leveraged in the commercially available CIM 8 solution.

With high-volume shipments of multiple coherent Class 2 module products utilizing Acacia’s 3D Siliconization, this proven co-packaging integration solution provided the foundation for extending this capability to Class 3 140Gbaud implementation utilized in the CIM 8 (Figure 2). 3D Siliconization maximizes signal integrity by co-packaging all high-speed components including the coherent Digital Signal Processor (DSP) application-specific integrated circuit (ASIC), transmitter and receiver silicon photonics, and 3D stacked RF components into a single device that is manufactured in a standard electronics packaging house. Silicon technology has demonstrated cost and power advantages over alternative technologies, making it the material system of choice for these higher baud rates. These advancements enabling a doubling of the baud rate have led to a 65% power-per-bit savings of CIM 8 over current competing solutions that utilize alternative optical material systems. In addition, the size and power savings of this latest generation enabled the ability to house this 1.2T 140Gbaud solution in a pluggable form-factor.

Figure 2.  An example of 3D Siliconization used in the CIM 8 module, resulting in a volume electronics manufacturable high-speed single device larger than a quarter.

2^nd Generation 3D Shaping Advances Coherent Performance
The CIM 8 is powered by Jannu, Acacia’s 8^th generation coherent DSP ASIC. The design greatly expands on the success of the Pico DSP ASIC predecessor used in the widely deployed performance-optimized Class 2 AC1200 module (Figure 1). The AC1200 was the first module to introduce 3D Shaping, which provided finely tunable Adaptive Baud Rate up to 70Gbaud as well as finely tunable modulation up to 6 bits/symbol. The AC1200 had achieved record breaking spectral efficiency at the time of its introduction, as evidenced by a subsea trial over the MAREA submarine cable connecting Virginia Beach, Virginia to the city of Bilbao in Spain. Finely tunable baud rate helps maximize spectral efficiency in any given passband channel, converting excess margin into additional capacity/reach, and avoids wasted bandwidth due to network fragmentation.

Figure 3.  A popular feature is the fine-tunability of baud rate introduced by Acacia with the Class 2 AC1200; CIM 8 incorporates the same Adaptive Baud feature (as part of 2^nd Generation 3D Shaping) for Class 3 baud rate tunability.

The 5nm Jannu DSP ASIC in CIM 8 intelligently optimizes optical transmission using 2^nd Generation 3D Shaping with an increased Adaptive Baud Rate tunable range up to 140Gbaud, as well as finely tunable modulation up to 6 bits/symbol using enhanced Probabilistic Constellation Shaping (PCS). With 2^nd Generation 3D Shaping, the CIM 8 module can achieve a 20% improvement in spectral efficiency.

Terabit Era Solutions Provide Full Network Coverage
Class 3 technology not only ushers in the terabit era, but also enables full multi-haul network coverage as the high baud rate capabilities transport nx400GbE client traffic across a service provider’s entire network. Full network coverage is not only enabled by adjustment of the modulation, but also implies the capability to optimize for various network conditions which include overcoming transmission impairments.

Figure 4. CIM 8 1.2T, 1T, 800G, and 400G transmission constellations operating at Class 3 baud rates providing wide network coverage addressing multiple applications.

CIM 8 offers significant power-per-bit reductions as well as cost efficiencies for various optical network transport applications.

DCI/Metro Reaches
For transporting 3x400GbE or 12x100GbE client traffic with metro reaches in a single carrier, the CIM 8 is tuned to ~6 bits/symbol (equivalent to 64QAM, example constellation on left). Data center interconnect (DCI) applications would take advantage of this high-capacity 1.2T transport capability to tie data center locations together. This amounts to 38.4T per C-band fiber capacity.

Long-Haul Reaches

For transporting 2x400GbE with long-haul reaches, the CIM 8 is tuned to ~4 bits/symbol (equivalent to 16QAM, example constellation on the right). Wide 800G network coverage is achieved with the Class 3 140Gbaud capabilities enabling service providers to provide end-to-end 2x400GbE, 8x100GbE, or native 800GbE transport across their networks, covering essentially all terrestrial applications.

Ultra-Long-Haul/Subsea Reaches

And for ultra-long-haul/subsea reaches, the CIM 8 is tuned to ~2 bits/symbol (equivalent to QPSK, example constellation on the left). As with the previous scenarios, spectral efficiency with a wavelength channel is optimized by fine-tuning of the baud rate. These high spectrally efficient modes can carry mixed 100GbE and 400GbE traffic over the longest subsea routes in the world with lowest cost per bit. It’s worth noting that almost a decade ago, Acacia demonstrated SiPh capabilities for subsea coherent deployments. CIM 8 incorporates second generation non-linear equalization (NLEQ) capabilities to mitigate the non-linear effects of optical transmission especially for these ultra-long-haul/subsea links providing additional OSNR.

In all the above scenarios, the CIM 8 utilizes advanced power-efficient algorithms to compensate for chromatic and polarization dependent dispersion. In addition, the module accounts for coverage of aerial fiber network segments that require fast state-of-polarization (SOP) tracking and recovery due to lightning strikes. The SOP tracking speed of CIM 8 is double the speed of its predecessor. This fast SOP tracking feature can also be utilized for sensing applications.

Network Operators Achieve Record Breaking Field Trials with CIM 8
CIM 8 capabilities have already been put to the test as illustrated by multiple record breaking field trials across a wide range of applications. These include >5600km 400G transmission over a mobile carrier’s backbone network, 2200km 800G transmission over a research and education network, and >540km 1T transmission over a wholesale carrier’s network.

Acacia continues to demonstrate its technology leadership by leveraging mature knowledge in proven silicon-based coherent technology, producing the first shipping coherent solution to lead the industry into the Terabit Era with the 1.2T pluggable CIM 8 module. With the breakthrough capability of 140Gbaud transmission along with the advanced Jannu DSP ASIC using 2^nd Gen 3D Shaping and leveraging 3D Siliconization, network operators can support full network coverage for multi-haul applications, especially to support growing demands for nx400GbE and upcoming 800GbE traffic.

References:
Blog: Terabit Today: Maximize Network Coverage
Blog: How Industry Trends are Driving Coherent Technology Classifications
Blog Series: The Road Ahead for Next-Generation Multi-Haul Designs Part 1, Part 2, Part 3

At the same time, network operators are adopting higher speed interfaces.  Since last year’s conference, we’ve continued to see the aggressive ramp of 400 Gigabits per second (G) pluggables as they’ve made their way into new markets and applications. While coherent pluggables have been migrating towards shorter reaches for quite some time, customers are now increasingly interested in using them for long-haul applications traditionally serviced by embedded coherent modules.  While the high-performance embedded market continues to be strong today, we expect the trend towards pluggables to continue in the future as service providers take advantage of their low power, small size and performance wherever they can.  Standards bodies are looking to define both 800G and higher performing 400G interop modes for next generation MSA pluggable optics.

Coherent pluggable ports are expected to exceed embedded ports in 2023.

 Acacia had the honor of participating in 13 sessions and 2 interoperability demonstrations at this year’s OFC.  Below is a recap of three of the sessions presented in the Market Watch Theater that reinforce the trends toward higher speed interfaces and expected transition from embedded modules to pluggables including industry standardization advancements.

OIF Panel: Defining 800ZR and 800LR; An OIF Update

Tom Williams, Acacia’s Sr. Director, Technical Marketing, gave an Optical Interoperability Forum (OIF) update on 800ZR and 800LR standardization progress. Tom highlighted the rapid success that has been achieved with 400G pluggables and what’s happening next in the standards bodies.

400G Developments Continue
The 400G developments continue in three areas.  The first is ongoing deployments of high transmit power 400G ZR+ QSFP-DD pluggables that support OpenZR+ and Open ROADM modes.  These modules expand the use cases for 400G QSFP-DD pluggables to metro and regional ROADM networks and enable increased transponder density in transport equipment. The second is 400G ER1 which targets 40km point-to-point applications.  The third area is standardization and development of 400G long-haul.

400G developments continue with high TX power 400G ZR+, 400G ER1, and 400G long haul pluggable modules.

800G Standardization in Progress
The current focus of standardization is on 800LR/ZR and Open ROADM products. Network operators are looking for higher baud rate pluggables to take advantage of improvements in cost and power. Increasing baud rates has become an efficient way to enable more cost-effective optical networks by reducing the number of optics needed to support a given transmission capacity.

Focusing next on 800ZR standardization, Tom highlighted how these considerations are like 400ZR, but different. While 800ZR has the potential for more varied use cases depending on the network operator, some are waiting for 1.6T solutions. The key assumptions are that 800ZR will include 16QAM modulation at 118Gbaud, which is double the 400ZR baud rate.  On the receiver side, Open Forward Error Correction, or oFEC, has been selected for improved Optical Signal to Noise Ratio (OSNR) sensitivity and the minimum input power is higher at 118Gbaud. On the transmitter side, there is recognition that the 400G market now includes both amplified and unamplified configurations and co-existence with 400ZR on the same line system requires 3dB higher transmit power for 800ZR.  Tom also highlighted three different transmitter power ranges that have been proposed with each option having use cases that bring value to the market.  These include:

• -11 to -14dBm: Lowest Cost
• -7 to -11dBm: Co-exist with 400ZR
• 0 to -7dBm: Co-exist with traditional DWDM

800G and Beyond Pluggable Coherent – Building on the Success of 400G

Torben Nielsen, Acacia’s Product Line Manager, Pluggable Modules and Distinguished Engineer, also kicked off his presentation by highlighting the 400ZR/ZR+ success story. As the fastest ramping coherent technology to date, these modules benefitted greatly from the work done early on with industry standards.

400G pluggables have been the fastest ramping coherent technology to date.

 Standardization and Vendor Interoperability
Standardization of optical networking technology helps network operators by providing simplicity, interoperability and volume-driven cost. Torben explained that, in the 400G pluggable market, standardization started with 400ZR and quickly evolved as carriers demanded higher performance. This led to the creation of both the Open ROADM and OpenZR+ MSAs.  As a result, today we are seeing 400G pluggables being used across a wide range of applications, using the same component technology throughout each form factor.

The 400ZR/ZR+ success story was enabled in part by standardization and interoperability resulting in 400G pluggables being used across a wide range of applications.  

Torben also discussed how 400ZR/ZR+ leveraged advancements in co-packaging and how these developments are now being extended to future product development using the same common platform that leverages silicon photonics. For example, the same packaging technology that Acacia used in its highly successful 400G pluggable products is now being utilized in its CIM 8 module, which is enabling a pluggable performance optimized solution operating up to 140Gbaud. Acacia will continue leveraging this same approach for future generations such as 800G and 1.6T modules.

800G Coherent Pluggables
Torben next shared how the industry is already looking ahead to 800G pluggables, with first deployments expected in 2024. Currently, 800ZR/LR is being defined in OIF, as Tom shared in his OIF update, with 118Gbaud 16QAM modulation. 800ZR+ will need standardized media interface specification which will likely be 131Gbaud PCS modulation.  Acacia’s silicon photonics can support all transmission rates proposed for both 800ZR and 800ZR+. The high transmit power version can be supported similar to the 400G Bright ZR+ high transmit (TX) power pluggable module.

800G will likely come in ZR, ZR+, and LR versions.

1.6T Coherent Pluggables
In terms of 1.6 coherent pluggables, Torben suggested they are likely needed in the 2025 timeframe or later. He believes 240Gbaud single carrier pluggable is feasible and can have the best potential cost structure with fewer optical components than multi-carrier approaches. There are several engineering challenges to overcome when developing these products including signal integrity, power and thermal design, but the industry has a great track record when it comes to overcoming these challenges.

1.6T coherent pluggables are expected to emerge in the 2025+ timeframe and much work is yet to be done for that to happen.

Market Watch Panel IV: Performance-Centric Long Haul

Anuj Malik, Acacia’s Director, Product Management & Strategy, gave an overview of performance-centric coherent modules. The primary goal of these modules has been to help reduce CapEx and OpEx for network operators. Transceiver cost per bit and number of regenerations are the key CapEx drivers.  Power, footprint and manageability are the key OpEx drivers.

Key to these solutions has been the development of features such as probabilistic constellation shaping (PCS), adaptive baud rate, and advanced compensation algorithms. These technology innovations give service providers unprecedented transmission flexibility to match their network’s architecture, optimize fiber utilization, and simplify deployment.

Performance-centric solutions leverage key technology innovations that provide “knobs” for dialing in performance. 

Anuj also discussed the implications of approaching the Shannon limit, where spectral efficiency gains are only incremental. The focus has been on reducing cost, power and footprint. This will require doubling the baud rate with every generation, designing efficient network architectures and leveraging the benefits of silicon photonics and advanced packaging techniques that can be leveraged across multiple generations of products.

The path to creating cost and power efficient coherent transceivers includes significant increases in capacity and density while reducing power, continued integration, and packaging techniques.

As mentioned earlier, these “terabit era” products were highlighted at this year’s OFC, led by Acacia’s CIM 8 module, with field trials having been announced by China Mobile, NYSERNet and Windstream Wholesale. By leveraging common development approaches with the 400G pluggable modules and Acacia’s proprietary DSP algorithms, the operational benefits of pluggability were brought to the performance-centric multi-haul market segment.  Acacia believes the industry may continue migrating performance-centric towards pluggable modules to take advantage of high performance and power efficiency. This may include the development of high performance 400G long haul pluggables and 800ZR+ with up to 131Gbaud.

Welcome to the Terabit Era!
Customer interest has been strong for high-performance multi-haul modules, such as Acacia’s single optical carrier 1.2T Coherent Interconnect Module 8 that is now shipping and currently in Tier 1 carrier network field trials. We expect 120+ Gbaud coherent technology to be a hot topic at the show. Get up to speed on this new technology’s cost and performance benefits beforehand by attending this Webinar on Thursday, February 23 titled, Terabit Coherent Optics – Maximizing Network Performance with 1.2 Terabit Coherent Optics.

Coherent Interoperability Participation
Continuing its commitment to building an industry-wide ecosystem, Acacia will be participating in the following interoperability events at OFC.

• OIF Interoperability Demo, Booth #5101 – This is OIF’s largest-ever multi-vendor interoperability demonstration of the critical solutions accelerating implementation of next-generation capabilities. It will feature four fundamental technology areas – 400ZR optics; co-packaging architectures; common electronical I/O (CEI) channels; and common management interface specification (CMIS) implementations. Acacia will participate in the 400ZR optics demonstration.
• OFCnet, Booth #5917 – OFC’s high-speed optical network, OFCnet, will enable select demonstrations of networking products, solutions and architectures. This live network will showcase emerging technologies including quantum networking, network element interoperability, SDN and programmability, and networking for big data/big science applications. Acacia will demonstrate OpenZR+ interoperability via a link from the Coherent QSFP-DD module to Acacia’s Bright 400G ZR+ module over an ADVA open line system.

Speaking Sessions
Below is a summary of the sessions that Acacia experts will be participating in during OFC.

Sunday, March 5th

• Workshop: Smart Pluggable Coherent Optics: Is it the end of Layered IP over DWDM?
  Panelist: Fenghai Liu, Sr. Director, Product Management
  Date/Time: March 5, 1:00 – 3:30 am
  Where: Room 6C
• Workshop: Where are the Boundaries Between IM-DD and Coherent?
  Panelist: Hongbin Zhang, Principal Engineer
  Date/Time: March 5, 1:00 – 3:30 am
  Where: Room 8

Monday, March 6^th

• Track S1: Datacom Subsystems and Systems
  Presentation: Power Efficient Coherent Detection for Short-Reach
  Invited Speaker: Hongbin Zhang, Principal Engineer
  Date/Time:   March 6, 8:00 am
• Optica Executive Forum: Panel 1: Where and What is the Coherent Edge?
  Panelist: Tom Williams, Sr. Director, Technical Marketing
  Date/Time: March 6, 9:00 – 10:15 am
  Where: Hilton
• M3I: Monolithic or 3D Electro-Optical Integration
  Presider: Long Chen, Distinguished Engineer
  Date/Time:  March 6, 2:00 – 4:00 pm
  Where: Room 8
• Technical Conference/Panel: 6Tb/s+ Intra-DC Network
  Panelist: Mark Heimbuch, Principal Engineer
  Date/Time: March 6, 4:30 – 6:30 pm
  Where: Room 6C

Tuesday, March 7th

• Market Watch Panel I: State of the Industry
  Organizer: Tom Williams, Sr. Director, Technical Marketing
  Date/Time: March 7, 10:30 – 12:00 pm
  Where: Theater 1
• Market Watch Panel III: 800G / 128GBaud Pluggable Coherent – Key Technologies and Applications
  Speaker: Torben Nielsen, Sr. Director, Product Management
  Date/Time:  March 7, 2:00 – 3:30 pm
  Where: Theater 1
• Panel: LiDAR Systems and Technologies with Integrated Photonics
  Speaker: Long Chen, Distinguished Engineer
  Date/Time:  March 7, 2:00 – 4:00 pm
  Where:  Room 7AB

Wednesday, March 8th

• Exhibit Hall/Panel: OpenZR+ MSA – New Developments and Next Steps
  Moderator: Tom Williams, Sr. Director, Technical Marketing
  Date/Time: March 8, 11:45 – 12:45 pm
  Where: Theater 2
• Panel: Defining 800ZR and 800LR; An OIF Update
  Panelist: Tom Williams, Sr. Director, Technical Marketing
  Date/Time: March 8, 1:00 – 2:00 pm
  Where: Theater 2
• Market Watch Panel IV: Performance-Centric Long Haul
  Speaker: Anuj Malik, Director, Product Management & Strategy
  Date/Time: March 8, 2:45 – 4:15 pm
  Where: Theater 1
• Poster Session: 32-λ×400 Gb/s Single-Carrier 120-GBaud QPSK Coherent Transmission Over 3075-km G.652.D Fiber Link Using OE-MCM Prototype Under Field-Deployed Configuration (W2B.16)
  Acacia authors: Philippe Jennevé, Shaoliang Zhang, Miquel A. Mestre, Dayou Qian
  Date/Time:  March 8 & March 9, 10:30 – 12:30 pm

Meet with Acacia at OFC
If you are attending the show, we would welcome the opportunity to meet with you. Click here to set up a meeting.  We hope to see you in San Diego!