The expanding universe of coherent pluggable optics

There is no one-size-fits-all in coherent optics. When the highest wavelength capacity and greatest distances are the top requirements, operators will choose embedded optics over pluggables. But for an increasing number of applications, coherent pluggable optics can meet capacity and distance needs. With innovation booming, operators now have a diverse set of coherent pluggable suppliers and functions from which to choose.

Heavy Reading launched the first Coherent Optics Market Leadership Program in 2021 to investigate emerging opportunities and challenges in coherent optics, spurred by the advent of 400ZR optics. The most recent 2023 project was based on a global network operator survey conducted in November that attracted 88 qualified responses.

This is the second installment of three blogs highlighting the key findings from the 2023 survey project. It focuses on network operators' feature and function priorities with coherent pluggables.

Top priorities

From past research, we know that module price and power consumption are the top decision factors for coherent pluggable optics. In this year's survey, Heavy Reading wanted to get a deeper understanding of operator priorities when these two known factors — price and power — are taken out of the equation. For the global survey group, manageability tops the list (selected by half of the survey respondents). The last blog focused on the importance of manageability, particularly for IP over DWDM architectures. High transmit power (important for ROADM-based networks) and deployment over third-party open optical line systems are also significant.

Parsing the survey data further, Heavy Reading found significant differences in priorities when comparing Tier 1 operators (defined as those with greater than $1bn in annual revenue) with Tier 2 and 3 operators. Tier 1 operators place both manageability and point-to-multipoint (P2MP) functionality much higher on their list of priorities than their Tier 2 and 3 counterparts. Larger networks, by definition, have more network elements and, therefore, are more complex. Both ease of manageability and P2MP functionality address network costs as well as operational complexity.

The results in this year's survey (especially the Tier 1 data) represent a major shift in operator views on pluggables management and P2MP-enabled coherent optics, as championed by the Open XR Forum. P2MP coherent optics, particularly, had only registered modest interest until now.

What are your top priorities when selecting a coherent pluggable apart from power consumption and price? (Tier 1 vs. others)

(Source: Heavy Reading, 2023)

Delving into features

Looking further at specific feature requirements for 400G coherent pluggables, automation coupled with security is important. Selected by two-thirds of operators surveyed, secure onboarding of new pluggables (or zero-touch provisioning) tops the list of feature requirements for current pluggables. Coherent pluggable innovation is advancing rapidly, and pluggables are addressing a wider and wider set of applications. This includes new host types like routers/switches and new network segments, such as edge and access. The ability to automate onboarding of large numbers of coherent modules saves labor costs and provisioning time.

Secure onboarding is not the only critical feature requirement. Dynamic capacity allocation and system-level features, including embedded communication channels, automation discovery, control plane, embedded OSA and streaming telemetry, were each selected by more than half of the respondents.

What features do you expect from current 400G coherent pluggables?

(Source: Heavy Reading, 2023)

Management flexibility

Manageability is perhaps the key theme for coherent pluggables in 2024. Operators want compatibility between pluggables and host devices, but they also clearly want to maintain management independence from that host device. At 87%, the vast majority of operators surveyed believe that host-independent management is at least "important," and 36% see independent management as "critical."

The likely reason is flexibility. Host-independent management of pluggables gives operators extra flexibility in running networks as the host base for these modules becomes more diverse. For example, while basic management functions may be supported by the host devices, management support for more advanced functions may come from outside the host device. Such an approach offers operators key benefits, including ensuring operational and management consistency across all host platforms, aligning IP and optical operations with the organizational structure and decoupling development timelines for pluggables and hosts to accelerate access to coherent innovation.

How much do you value managing coherent pluggables independently from any specific support in the host device OS?

(Source: Heavy Reading, 2023)

The combination of improving performance and expanding supplier diversity in coherent pluggable optics is good news for network operators — whether they are looking at coherent optics for traditional architectures or for IPoDWDM. Now, they must prioritize the features and functions they really need and select the supplier (or suppliers) that suits them best.

For more information on this topic and the Heavy Reading survey, check out this archived Light Reading webinar: Coherent Pluggable Optics: The Next Frontier.

This blog is sponsored by Infinera.