Cognitive optical networks: key drivers, enabling techniques, and adaptive bandwidth services

To support efficient delivery of packet and circuit services simultaneously in future optical networks, software will play more and more important roles, not only in control and management plane, but also in transport plane. This article discusses a new concept of cognitive optical networks utilizing intelligent software (e.g., digital signal processing in the optical transport plane and GMPLS in the optical control plane) as well as flexible optics (e.g., colorless, directionless, contentionless, gridless ROADM, and optical OFDM). The software-defined CON architecture with advanced capabilities such as quality of transmission awareness and client service awareness is capable of provisioning adaptive bandwidth services at wavelength and sub-wavelength levels, making future optical networks more cognitive and reconfigurable.

Introduction

Driven by new applications such as cloud-based flexible bandwidth services, IP video, and wireless backhaul, optical transport networks are now undergoing big evolutions. The first technical trend is to increase optical network capacity dramatically by developing 100/400/1000 Gb/s per wavelength technologies based on coherent detection and advanced modulation/coding formats [1]. One of the most attractive features of 100G or beyond 100G technologies is the transparency that provides the transport network with the future-proof capability to accommodate line rate increases associated with higher bandwidth requirements and new traffic types related to new services.