Enabling High Capacity Flexible Optical Networks

Current bandwidth demands are encouraging the exploration of optical frequency comb generators and flexible modulation formats to enable very high-capacity transmission beyond the C-band, which can be augmented with existing real-time digital electronic signal processing for pre-emphasis and post-impairment compensation at very high clock speeds. But for exploitation and deployment in commercial networks these devices will require support for remote management embedded with service providers' operation and business-support systems. However, installed network management systems must deal with a range of dissimilar network devices. This diversity spans across electronic packet switches, optical circuit switches, and monitoring instrumentation for telemetry, ranging from legacy to state-of-the-art models. Software defined networking (SDN) flexible management approach unlocks exciting possibilities to jointly exploit the full capabilities of digital electronic packet switching and the many degrees of freedom presented by analogue optical EM carriers. In this paper, we will expose some of these possibilities, where these technologies can, through SDN, be reimagined to enable flexible high-capacity systems. We will be revisiting the potential for multi-carrier transmitters, and utilising analogue methods to monitor transmitter performance. We will also show how existing protocols can be used to support both legacy and state-of-the-art SDN-enabled devices, incorporating to management operating systems such as ONOS, showing that a smooth transition to fully automated networks with closed-loop control is now a real prospect.