Skip to main content
Published on

Ciena and EXFO experts answer 5 questions on next-gen coherent optics

Patricia Bower from Ciena kindly shared her thoughts with us on how next-generation optical pluggables are driving the network evolution. Patricia recently collaborated with EXFO’s test expert Jean-Marie Vilain to produce a webinar that explores the implementation and testing aspects of high-speed coherent optical modules (you’ll find the link to this in-depth webinar at the end of this blogpost).

Without further ado, here are the questions we shot at the Ciena/EXFO collab.

Q1. Coherent optics is all the buzz. Why this sudden interest?

Patricia: Coherent technology is one of the fundamental enablers of network evolution.  Over the last decade, this technology has paved the way for scaling of fiber capacity in service provider and data center networks to meet ever-growing bandwidth needs. Coherent technology has also provided operators with gains in network efficiency by reducing the cost per bit and maximizing spectral efficiency. It will continue to be one of the key elements underpinning network transformation going forward.

Q2. What are some of the applications of pluggable coherent optical transceivers?

Patricia: Coherent technology is already widely deployed throughout most operators’ submarine, backbone, data center interconnect (DCI) and metro networks. Pluggable coherent transceivers will be used in a range of network applications including Metro-DCI and Metro-Regional. Critically, they will also support expanding the use of coherent technology in access networks for higher capacity edge connect requirements. In general, their use will depend on network topology, traffic capacity and reach requirements.

Q3. What about the form factors? How do you expect them to evolve?

Patricia: The CFP2-DCO, QSFP-DD and OSFP form factors will all support transport rates from 100 to 400 Gbit/s.  For 400ZR DCI applications, the primary target form factors are QSFP-DD and OSFP for smallest area and highest density faceplate implementations. CFP2-DCO, owing to its larger size and higher power envelope, will enable more functionalities and features and is, therefore, more likely to be used in Metro-Regional applications.    

Q4. Why is it vital to test coherent optics?

Jean-Marie: Given the complex nature of these new devices aiming to ensuring error-free transmission and fulfill stringent SLA requirements, the right testing methods and tools will play an essential role. There is no way around it if you want to avoid repeat truck rolls, costly downtime and churn. This is critical also as these devices support multiple configurations and various client rates. Proper testing is paramount to ensure the functionality of the device.

Q5. What are some of the challenges in testing coherent transceivers?

Jean-Marie: CFP2-DCO will be deployed alongside a number of other client interfaces in the network so you need to be able to test a mixed bag of interfaces on the go. With ZR pluggables expected at the same time as CFP2- DCO, you’d want to consider equipment that have the necessary future-proofing capability to follow suit in this rapidly evolving environment. This is the reason behind the Open Transceiver System (OTS) that we have designed to enable the same test solution to work with multiple current and future pluggable interfaces without the need for expensive hardware changes.

What did the attendees say about this webinar?
“Good high-level summary of the 100G/400G landscape.”
Michael Lane, VP Research and New Technologies
Accton Technology

Want to learn more? Follow this link to view the on-demand webinar at your convenience.