Over the past ten to fifteen years, WDM networks have evolved from simple point-to-point systems to advanced, interconnected, mesh architectures. This has been driven by Reconfigurable Optical Add/Drop Multiplexers (ROADMs) and the underlying Wavelength Selective Switch (WSS) technology. ROADM technologies have become popular among service providers because of the ability to create flexible metropolitan, regional and long-haul networks that are easy to modify, even remotely, as network requirements change. Other benefits of a ROADM-based architecture are support for automatic power balancing and the ability to make configuration changes without affecting traffic already passing through the system.
A decade later: time for a technology refresh
Today, a little over a decade since ROADMs started to pave the way for more flexible optical networks, earlier installations present a number of challenges. The most obvious of which is that significant advances have been made in ROADM technologies.
While earlier ROADM solutions were based on fixed wavelength windows, up-to-date solutions support flex-grid. This allows for increased flexibility as the spectral width of each wavelength can be configured independently. Over time, the granularity of how the solution allocates spectrum bandwidth within ROADMs has also improved, allowing for an increased number of wavelengths to be carried over the same network. Both factors have come to play an increasingly important role in the continuous struggle to secure more bandwidth in service provider networks.
We also cannot neglect that yesterday’s solutions support yesterday’s and at the very best today’s capacity requirements – but not necessarily tomorrow’s. Supporting the upcoming low-cost, high-performance 400G ZR standard, which will further improve network capacity, is another driving force for a technology refresh.
Another more practical challenge faced by operators needing to update or expand their networks is that many of the providers that were active on the market at the beginning of the millennium are no longer even in business.
Cost-efficiency and flexibility in focus for next-generation ROADM solutions
Once you’ve realized that many operator ROADM-based networks are up for a technology upgrade, the question of the hour becomes, what else should we be looking for in a next-generation ROADM solution?
The earlier metro network ROADM implementations tended to be strictly tied to solutions from a single vendor. For service providers, this meant that, if you decided to buy ROADMs from one equipment manufacturer, you were typically more or less locked into buying the complementary equipment such as transponders and management systems from the same vendor. Today, the Open ROADM initiative and the Multi-Source Agreement (MSA) are important driving forces for a more flexible and modern direction. Today’s up-to-date solutions have taken a huge step away from traditional lock-in solutions towards disaggregated networking. This open approach to networking increases flexibility and performance as it allows service providers to handpick best-of-breed components for every part of their network.
As ROADMs have gained in popularity, many service providers are now also considering deploying them further out in the metro or even the access network in a way similar to the solutions already considered highly effective in regional and long-haul networks. As the number of units quickly multiply when moving further out in the network, cost typically becomes an issue. When every dollar counts, the technologies chosen for these edge ROADMs must not only support the latest technology advancements but also present a cost-efficient alternative to traditional ROADM solutions.
The combination of cost-efficient technology solutions and the increased flexibility that comes with increased openness and standardization lays the foundation for optimizing the total cost of ownership for the metro and regional access networks of tomorrow.
Smartoptics brings openness to the ROADM table
Smartoptics is not only fully committed to supporting the Open ROADM initiative – we also aim to be an active force in the market for increased standardization and open line networking. The Smartoptics way is making sure that you, the service provider, are in charge and given full flexibility to choose and combine network elements as best suits your networking needs. Our recently launched family of open line system components named DCP-F and DCP-R has been designed to meet the flexibility demands in relation to configuring flexible, cost-efficient, and open metro and regional networks based on ROADM technologies.