Breakthroughs in Photonics 2014: Optical Physical-Layer Network Coding, Recent Developments, and Challenges

Network coding is a revolutionary technique that can enhance network throughput and protection. This paper introduces optical physical-layer network coding (OPNC) and the recent development of OPNC, with focused discussion on “common-channel” OPNC that can efficiently utilize network resources. It also describes the challenges ahead of OPNC, including incorporating more than two signals for OPNC; circumventing the higher signal processing complexity when higher order modulations are adopted; and exploiting OPNC in more sophisticated multichannel systems.