The Optical Future of High-Speed Networks

Abstract

With the ever increasing optical transmission rate, now exceeding 1 Tb/s on a single fiber thanks to Wavelength Division Multiplexing (WDM) technologies, electronic routing/switching is quickly becoming a performance bottleneck in high-speed backbone networks. WDM optical networking, though rooting in the physical and link layers, is by no means yet another ordinary low layer technology as it may affect the designs of the upper electronic layer. Specifically, WDM optical networks can be configured to bypass intermediate electronic components by switching/routing data in the optical domain. This will not only reduce electronic processing and I/O loads, but also provide bit-rate and coding format transparency. However, this may also lead to unexpected “shortest” and “alternate” paths in the electronic layer. In addition, primitive optical logic, and especially the lack of optical memory (buffer) are major challenges in order to realize the vision of building a bandwidth-abundant infrastructure, which is ubiquitous and yet efficient, based on WDM optical networks. In this talk, I will describe these issues and along relevant optical switching paradigms, namely wavelength-routing (as a form of optical circuit switching), optical packet switching, and optical burst switching (OBS), and discuss how the next generation Optical Internet may support QoS and provide multicast services in the WDM optical layer.