Keynote lecture: next generation broadband access networks: metro-access integration and optical-wireless convergence
Authors: Leonid G. Kazovsky
Venue: Proceedings of the 6th WSEAS International Conference on Applied Electromagnetics, Wireless and Optical (2008)

Because of emerging multimedia applications, such as video-on-demand, video conferencing, interactive gaming, IPTV and e-learning, bandwidth demands from end users are constantly increasing. The copper wire technologies (e.g. cable and DSL) bridging users and the Internet have been stretched to their bandwidth limits, and become the so-called first/last mile bottleneck. To address current bottleneck of the Internet infrastructure, passive optical networks (PONs) and wireless mesh networks have been proposed as the most efficient approaches for broadband access services. Fiber is an ideal replacement for the copper wires in the access networks. TDM PONs are currently being deployed by service providers all over the world. Meanwhile, next-generation PONs are being investigated to provide better services for triple play (voice, data and video). To support more users and more bandwidth, next generation optical access will move toward higher bit rate and more wavelengths. The challenging issue is how to migrate from current TDM PONs to future WDM PONs in a scalable and cost-efficient manner. Meanwhile, the integration of metro and access networks will provide a transparent and efficient infrastructure for broadband service in metropolitan areas. Even though fibers can provide broadband services, PONs are constrained with a fixed infrastructure and limited coverage. For future mobile broadband applications, ubiquitous access networks are highly desirable. Due to recent advances in wireless technologies, wireless access such as wireless mesh networks (WMNs) becomes a promising solution to fulfill emerging mobile services. In the future, convergence of optical and wireless technologies is inevitable for quadruple play (voice, data, video and mobility). However, as the traffic behavior and channel quality of these two technologies are far from each other, seamlessly integrating PONs and WMNs presents a very challenging task. This talk discusses next generation broadband access networks, and in particular, the integration of metro and access networks and the convergence of optical and wireless technologies. The network architecture, routing algorithm and enabling technologies for next generation broadband access networks are presented in detail. This first part of this talk will review current TDM PON standards and next generation broadband optical access technologies. Evolutionary approaches to migrate from TDM to WDM PONs in a scalable and efficient manner are demonstrated with two SUCCESS (Stanford University Access Network) projects. The second part of this talk discusses the integration of optical metro rings with passive optical networks. A flexible metro-access architecture is proposed for resource sharing and dynamic bandwidth allocation in the integrated network. The third part of this talk presents a converged optical and wireless network for broadband, ubiquitous access services. The network consists of a passive optical backhaul and a wireless mesh, combining the advantages of both optical and wireless technologies - the high capacity of optical fibers and the flexibility of wireless mesh. Taking into consideration the hybrid network architecture, an integrated routing algorithm is developed to achieve load balancing and improved network performance. Finally, this talk concludes with a discussion of research issues in future optical and wireless access networks.