Our world is rapidly changing and the demand for fibre optic networks is evolving at an unprecedented pace. This implies that sooner or later, there will be a need to re-evaluate how bandwidth and multiplex channels are allocated. Consequently, the significance of Reconfigurable Optical Add-Drop Multiplexer (ROADM) technologies has grown substantially over the last decade. These advanced technologies offer a remarkable solution to overcome compatibility issues and enhance cost efficiency, taking flexibility to an entirely new level.
It’s time we explore the capabilities of next-generation, open ROADMs and witness how they revolutionise the way we address these challenges.
Understanding ROADM: The Basics of Reconfigurable Optical Add-Drop Multiplexers
A reconfigurable optical add-drop multiplexer (ROADM) is a device designed to enable the transmission of multiple channels of light (DWDM) through a fibre pair. It allows for the addition, removal, passing and redirection of data-carrying wavelengths, in turn providing the flexibility to customise fibre networks. One of its key applications involves adding or dropping specific wavelengths at an intermediate point (B) between a starting point (A) and an endpoint (C).
The distinctive characteristic of ROADMs lies in their ability to be easily reconfigured remotely, enabling the allocation of bandwidth and the routing of WDM network traffic at the wavelength level. This is achieved through the utilisation of Wavelength Selective Switch (WSS) technology, an active component of ROADMs responsible for wavelength switching. Additionally, ROADMs possess an important feature that allows them to monitor the power of optical channels and automatically balance power levels across wavelengths. These capabilities make ROADMs highly valuable for optimising network traffic, accommodating new bandwidth requirements, and enhancing cost efficiency.
What Does a ROADM Degree Entail?
When discussing ROADMs, the concept of degrees often arises, which pertains to the switching capabilities or the direction of switching. It is directly linked to the transmission fibre pairs. For example, a two-degree ROADM can switch in two directions, while a four-degree ROADM can switch in four directions, and so forth. Adding each direction necessitates an additional WSS element, resulting in a linear increase in cost as the number of degrees grows.
Enhanced Flexibility: ROADM versus OADM
ROADMs and OADMs are two types of multiplexers used in fibre optic networks. The main purpose of these multiplexers is to transmit multiple WDM channels over a fibre pair. Both OADMs and ROADMs have the ability to add, drop, pass, and redirect these WDM channels, allowing for the customisation of fibre optic networks.
However, there is a key difference between the two. The “R” in ROADMs stands for “remote reconfigurability.” This means that ROADMs can be easily reconfigured without the need for physical modifications on-site by a technician, unlike OADMs. This remote reconfigurability feature provides flexibility in bandwidth assignment, allowing for adjustments after installation and easy reconfiguration as needs change over time.
In addition to remote reconfigurability, ROADMs are also designed to automatically balance power levels and equalise signal loss across wavelengths without disrupting the traffic already passing through the system. This ensures efficient and reliable operation of the fibre optic network.
The Advantages of Next-Generation ROADM Technology
The next generation of Reconfigurable Optical Add-Drop Multiplexers (ROADMs) offers several advantages compared to earlier generations, thanks to technological advancements. One notable improvement is the FlexGrid feature, which allows the independent configuration of the spectral width for each wavelength. As a result, the next-gen ROADMs can accommodate a greater number of wavelengths over the same network.
Furthermore, the progress in other network components and protocols plays a crucial role in the overall development of tomorrow’s optical networks, including the next-gen ROADMs. These advanced ROADMs are compatible with cutting-edge network protocols such as 400 ZR and can be seamlessly integrated with the latest transceivers, switches, and open-line systems. This integration of components is set to significantly enhance network capacity, cost-effectiveness, flexibility and overall performance.
Enhancing ROADM Compatibility: The Objective of the Open ROADM Initiative
Proprietary ROADM architectures present a challenge due to their tendency to restrict users to a particular vendor. To address this issue, the Open ROADM Multi-Source Agreement (MSA) was established, aiming to foster greater openness in next-generation ROADM technology. This collaborative effort involves industry leaders joining forces to develop and implement interoperability specifications for ROADM systems.
The initiative offers several advantages for service providers. Firstly, embracing open standardised interfaces and interoperability empowers them to select the most suitable components for their specific needs. This objective aligns with the Open ROADM project’s overarching goal of promoting innovation, competition, and widespread adoption of next-generation ROADM technology.
Nonetheless, integrating ROADM and other network components from different vendors, without a shared management system, introduces additional challenges. It introduces unnecessary complexities and inefficiencies when it becomes difficult to perform fault detection and configuration management for the entire network using a unified interface. To overcome this hurdle, the initiative is also working towards establishing common, open management systems. These systems hold immense potential for enabling efficient management of disaggregated networks, thereby enhancing ROADM flexibility and optimisation.
Smartoptics: Empowering Open Networking Through Innovation
As a longstanding partner, we are fully committed to harnessing the power of Smartoptics products. Our primary goal is to aid organisations and government agencies throughout Australia and New Zealand in optimising their networks. We demonstrate our dedication not only by supporting open networking but also by guaranteeing the highest levels of interoperability and flexibility in the latest solutions for fibre optic networking.
The Smartoptics DCP-R family is an exceptional choice, with its open architecture and ability to accommodate multiple traffic formats. It enables you to effortlessly deploy a wide range of ROADM-based network topologies. This is achieved by breaking down the once monolithic optical platforms into separate entities such as open line systems, switches with embedded transceivers, and transponders, providing an unmatched level of versatility.
