Open optical networking, the optical network design methodology that disaggregates transponders from the underlying optical line systems, appears to be gaining momentum in the marketplace. To better understand the demand for and the potential impact of open optical networking on the evolution of service providers’ transport networks, ACG Research conducted primary research during Q2 2021 on the value of open optical networking, the approach service providers are likely to take in their open optical networking investments and deployments, and their preferences about how they will work on this network transition over the coming years. We surveyed 52 network engineering and planning practitioners, globally, and engaged in detailed interviews with an additional four service provider managers and executives.
This blog examines the reasons for and evidence of the demand for open optical networking based on insights gained from these surveys and interviews. The survey study also analyzes how the popularity of open optical networking varies with the service provider type. In addition, it addresses the benefits of and barriers to optical networking, sources of network growth, and the automation and management of open optical networks, but those topics are not taken up in this blog.
Service providers seem to be prepared to shift a significant portion of their upcoming optical network deployments to open optical networking. To judge the reality of this impending ramp-up of open optical networking deployment, the surveys and interviews focused on two questions: whether service providers have clear reasons to embark on this network transformation and whether they are ready to make the change to the new optical design paradigm.
Reasons for Transforming the Network to an Open Model
The results of the survey revealed that service providers believe the greatest benefit they would gain from open optical networking is its support of faster innovation cycles, which allows quicker adoption of technological advances as they occur as compared to using closed systems. This concept of rapid innovation in optical networking is not merely hypothetical. The industry is currently experiencing the emergence of two applications that are greatly facilitated by open optical networking, 400G coherent optical pluggable modules and 800G coherent transponder technology.
The use of 400ZR modules has generated intense interest among service providers. Accordingly, the online survey picked up this interest among the respondents with 59% reporting that they
have either deployed or will have deployed 400ZR by the end of this year. The 400ZR+ coherent optical pluggable module is proving to be nearly as popular as the 400ZR, with 48% of the respondents anticipating deployment of 400ZR+ by the end of this year.
The demand for optical network systems that offer 800 Gb/s coherent optical channels is reflected in the 83% of online respondents indicating that this technology is important enough to source it from a nonincumbent vendor. Service providers also anticipate needing this 800G capability soon, with 79% of the respondents indicating that their companies will deploy 800G coherent technology by the end of 2022.
Readiness to Transition to Open Optical Networking
The initial form of open optical networking, support of alien wavelengths, has already been deployed by a significant portion of the service providers. Most of the online respondents indicated that between 40% and 100% their networks currently provide this version of open optical networking. Further, 73% of the respondents expect to deploy open optical networking solutions by the end of 2022.
A factor that facilitates deployment of open optical networking is rapid network growth. Such growth can enable the introduction of open optical networking without requiring the replacement of existing infrastructure. Online survey respondents and the interview respondents indicated that their traffic growth is increasing optical network demand by 40% to 70% annually.
Based on these survey and interview responses, it is safe to conclude that the reasons to deploy open optical networking are valid (or are at least embraced by the service providers). Further, these results indicate the readiness of service providers to begin (or, in many cases, continue) deployment of open optical networking systems.
Click to read more and download the survey: https://www.infinera.com/blog/three-trends-accelerating-the-future-of-optical-transport-networks/tag/open-optical-networking/
 In the context of this study, an optical line system consists of the fiber pair segments and optical equipment (combiner/splitters, optical amplifiers and optical add/drop multiplexers) that support the transmission of wavelengths between transponders. Each transponder’s optical transmitter presents a single wavelength optical signal to an optical multiplexer that places multiple such optical signals on the transmit fiber. Each optical signal is transmitted from its origination site to its termination site via fiber connections to amplifier(s) that boost the signal and optical add/drop multiplexer(s) that redirect the optical signal (at its particular wavelength) to the fiber segment that connects to the destination. There the signal is extracted from the fiber segment with an optical demultiplexer and connected to a transponder’s receiver.
 An alien wavelength is an optical signal between transponders sourced from a different vendor than that of the optical line system.