As service providers continue evolving their infrastructures to scale and support higher speed client traffic, they also need to optimize their return on investment while minimizing risk. Network operators transitioning their optical transport capabilities from supporting nx100 Gigabit Ethernet (GbE) client traffic to nx400GbE are now able to take advantage of new wide network coverage terabit era solutions to implement this transition. These coherent optical transport solutions are based on proven silicon-based technologies. As a result, we soon expect to see an increasing number of service providers offering 400GbE interconnect services over these types of transport infrastructures which leverage lower power and higher-density coherent solutions. These terabit era solutions expand reach capabilities to maximize network coverage for metro/DCI, long-haul and subsea applications, enabling service providers to meet their needs today and in the future.
Class 3 Baud Rate Solutions Provide Wide Network Coverage to Support nx400GbE
As widely known in the industry, the two primary “knobs” for optimizing coherent transmission capacity and reach are the baud rate and the bits/symbol modulation order. While rapid advances to increase capacity have pushed the upper modulation order to the current 6 bits/symbol (equivalent to 64QAM), further increases in modulation order provide incremental improvements in spectral efficiency with significant reductions in network coverage. Because of this, the industry focus to reduce cost and power consumption per bit has shifted toward achieving higher baud rate modulation per wavelength. Technology advancements that resulted in achieving 120+Gbaud coherent modulation speeds, as Figure 1 illustrates, have enabled a new generation of Class 3 capabilities which have propelled the industry from gigabit to terabit transmission capacity.
Terabit era performance-optimized solutions such as Acacia’s shipping Coherent Interconnect Module 8 (CIM 8), powered by the Jannu DSP, as well as announced solutions from several other optical transport vendors are now leveraging this Class 3 baud rate standardization. While this operating baud rate class enables a capacity of 1.2T for metro/DCI reaches, a key benefit is the ability to provide full network coverage at 800G to support transport of 2x400GbE clients, as shown in Figure 2. In addition, subsea applications can also be supported with greater flexibility to achieve optimal spectral efficiency. The flexibility, full coverage, and availability of these terabit era solutions make them attractive for supporting evolving transport needs as native 400GbE traffic requirements are becoming more commonplace.
The CIM 8 achieves Class 3 140Gbaud rate capability using proven silicon technology to successfully break through the terabit-per-wavelength threshold. Silicon technology has demonstrated cost and power advantages over alternative technologies, making it the material system of choice for these higher baud rates. This module enables a coherent transmission solution capable of providing full network coverage to support nx400GbE traffic.
Terabit Era Solutions Support 400GbE Today, Ready for 800GbE in the Future
Supporting 400GbE client traffic over a network operator’s transport infrastructure is expected to be the dominant trend for many years to come. Terabit era solutions are ideal for these providers because they can implement a straightforward 2x scaling of channel spacing to evolve from Class 2 to Class 3 technology, as illustrated in Figure 1.
With full network coverage at 800G using ~4 bits/symbol transmission, the CIM 8 module can not only support today’s 2x400GbE client traffic, but it is also ready to enable 800GbE interconnections when that end-user demand materializes in the future.
With More than 65% Power-per-bit Savings, Why Delay on Achieving Power Reduction Goals?
CIM 8 takes advantage of Acacia’s most advanced silicon photonics technology that enables 140Gbaud capabilities resulting in doubling the capacity of each wavelength without doubling the component count, size, and power of the coherent device. In addition, advancements such as Acacia’s 3D Siliconization, which leverages highly integrated opto-electronic packaging, as well as the adoption of power-efficient signal processing algorithms, all contribute to a 65% power-per-bit savings of CIM 8 over current competing solutions being deployed.
With the industry striving to reduce overall power consumption, adoption of available solutions such as the Acacia CIM 8 can help towards achieving these goals sooner. Delaying the deployment of power saving technology on a network-wide scale can result in continued carbon emissions at current levels, delaying the achievement of power consumption reduction goals.
By incorporating coherent technology innovations to achieve low power Class 3 140Gbaud transmission while leveraging volume processes, CIM 8 is a result of the investments Acacia has made over generations of silicon-based products, providing a significant advantage for providers looking to drive long-term power-per-bit reductions without sacrificing performance and reach.
Maximizing Coverage for the Long-Term with Terabit Era Solutions
Network operators have multiple options to consider when migrating their infrastructures to support the growth of nx400GbE client traffic and preparing for 800GbE. While router-based optics solutions are gaining momentum, those wanting to maintain a transport optical layer are looking towards terabit era performance-optimized coherent solutions such as Acacia’s CIM 8 to support this growth. The CIM 8 module is shipping today and not only provides flexibility in supporting nx400GbE client traffic with wide network coverage, but also follows the direction of industry baud rate standards that allow for scalable network/channel-spacings as well as the utilization of mature silicon technology. This enables service providers to future proof their networks for traffic demands, while optimizing their return on investment and minimizing risk.
