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Top Three Key Insights on the Evolution of Coherent Pluggables

portrait of Fady Masoud

May 16, 2024
By Fady Masoud
Senior Director, Solutions Marketing

Heavy Reading recently released a comprehensive report on coherent pluggables, “Coherent Pluggable Optics: A 2023 Heavy Reading Survey.” It provides the industry’s most in-depth look at the current state and future trajectory of coherent optical transmission. The report is based on a survey of 88 qualified network operators worldwide where respondents were involved in network planning and/or purchasing network equipment. Some of the key findings were highlighted in Sterling Perrin’s blog.  While I encourage you to read the entire report, I will highlight the top three findings that stood out for me as I read it.

1. Support for point-to-point (P2P) and point-to-multipoint (P2MP):

When respondents were asked about the top three priorities when selecting a coherent pluggable apart from power consumption and price, Tier 1 service providers ranked manageability, support for P2P and P2MP, and high transmit power (+0 dBm) as top of mind (Figure 1). Supporting P2MP expands the application scope for coherent pluggables to include the delivery of high-speed business services over single fiber on existing PON infrastructure while simplifying the network and dramatically reducing CapEx/OpEx. Supporting both P2P and P2MP, Infinera’s ICE-X 100G and 400G XR can operate over a fiber pair or a single fiber. P2MP support in ICE-X 400G also enables a software-configured 4 x 100G coherent breakout mode to provide service redundancy and optimize the utilization of router ports.

“What are your top priorities when selecting a coherent pluggable apart from power consumption and price? (Tier 1 vs. other; select up to three)”
Figure 1: “What are your top priorities when selecting a coherent pluggable apart from power consumption and price? (Tier 1 vs. other; select up to three)”

2. Managing coherent pluggables independently from any specific support in the host device operating system:

Another insightful data point from this report is about the preferred management scheme for coherent pluggables as their host base becomes more diverse. 87% of respondents consider that managing coherent pluggables independently from the host operating system is important – and more than a third think it’s critical (Figure 2). We can identify three major challenges with today’s coherent pluggables management scheme:

  • Organizational challenges (IP team, optical team), especially when a coherent pluggable is deployed in a host device other than a DWDM platform.
  • Operational challenges, as the current management scheme is limited to basic functions such as frequency, modulation, and launch power, and hence lacks alarm correlation, auto-discovery, and power control loops between the host and the pluggable.
  • Multi-host deployment challenges – if some work is done to ensure that coherent pluggables are now fully functional in a certain router, there is no guarantee that this will apply to other models, or operations support systems, or host devices from other vendors.

To overcome these complex management challenges, the Open XR Optics Forum published specifications for a dual-management approach where coherent pluggables can be managed as any grey optics pluggable through the host device for basic configurations like setting frequency, power, and modulation. In addition, they can also be managed independently of any host support for more sophisticated optical functions to maximize performance and deployability and to expand optical configurations to include point-to-multipoint networks. The benefits of using a dual-management approach can be summarized as follows:

  • Decouple the pluggable from the host development cycle and provide management uniformity regardless of the type of host device.
  • Accelerate development timeline and enable fast access to advanced optical features, without disrupting the network by having to upgrade the router, or host, operating system. This is key, especially for IPoDWDM applications in disaggregated networks.
  • Ensure operational and management consistency with the optical domain to enable alarm correlation, auto-discovery, and power control loops across the entire optical link.

Hence, the data point from the Heavy Reading report that 87% of respondents consider host-independent management to be important or critical is a key indicator that providers are eager to overcome their management challenges.

“How much do you value managing coherent pluggables independently from any specific support in the host device OS?”
Figure 2: “How much do you value managing coherent pluggables independently from any specific support in the host device OS?”

3. The market for 800G coherent pluggables is within sight:

The Heavy Reading report also revealed the expected timeline for adoption of 800G coherent pluggables. We are just starting to see the first wave of host devices (e.g., routers) capable of supporting 800G coherent pluggables. While some early 800G coherent implementations based upon 5-nm DSP technology have been announced, we believe the bulk of the market will adopt pluggables based upon 3-nm DSPs. The 3-nm generation, like Infinera’s ICE-X 800G, will deliver higher performance, lower power, and multi-vendor interoperability, with advanced features like standardized probabilistic constellation shaping (PCS). This is reflected by the Heavy Reading report, with only 12% of service providers beginning deployment in 2024 and 75% anticipating deployment to begin in 2025, 2026, or 2027 (Figure 3), with 2025 representing the most frequent response. The timeline aligns well with Infinera’s market introduction of the ICE-X 800G ZR/ZR+ coherent pluggables in the first half of 2025.

“When will you deploy 800G coherent pluggable optics in your network?”
Figure 3: “When will you deploy 800G coherent pluggable optics in your network?”

As we delve into the specifics of this report, it becomes clear that service providers, especially Tier 1s, value programmability in coherent pluggables – to operate in point-to-point and point-to-multipoint, and thus expand application scope to include high-speed business services over existing PON. Service providers also value management flexibility – enabling them to manage and operate pluggables in a manner that works best for them – either through the host device or via host independence. And finally, the expected wide deployment of 800G coherent pluggables is within sight, highlighting the fast-paced evolution of coherent pluggables and their game-changing impact on optical networks.

For more details on Infinera’s ICE-X coherent pluggables, please visit us at https://www.infinera.com/innovation/icex-coherent-optical-pluggables/