Novel Architectures and Algorithms for Wireless-Optical Broadband Access Networks.

摘要

Internet users and their emerging applications require high-data-rate access networks with mobility and untethered convenience. This is creating an increasing demand for wireless and optical access networks---to bring the high capacity of fiber and untethered access of wireless closer to the user. Hence, in this dissertation we explore novel architectures and algorithms for Wireless-Optical Broadband Access Network (WOBAN), an access network with the cost-effectiveness of a wireless access network and high performance of an optical backhaul network.;The main topics of the dissertation are the following. (1) We propose a capacity- and delay-aware routing algorithm, called CaDAR, for WOBAN. This algorithm addresses two major challenges in WOBAN: (i) it efficiently utilizes the finite radio capacity at each wireless node by intelligently allocating the capacity on each outgoing wireless link of a WOBAN, and (ii) it performs shortest-delay routing across both wireless front-end and optical backhaul. (2) To improve the performance of a WOBAN, it is essential to enhance the capacity for wireless access using a low-cost solution to match the high capacity offered by the optical backhaul. We design a mixed-capacity wireless access (MCWA) architecture for WOBAN that enhances the capacity of a few wireless nodes using multiple radios to improve the overall performance of WOBAN. We also develop an intelligent channel and radio assignment (ICRA) for WOBAN that utilizes the MCWA architecture to distribute the network load over different radios and orthogonal wireless channels to reduce interference and contention in the wireless front-end. (3) Access networks are increasingly shaped by the services they provide to the users. We design a service-oriented network architecture that integrates a cloud with WOBAN, called Cloud-Integrated WOBAN (CIW). It provides cloud components in the wireless front-end of a WOBAN to handle some cloud requests locally. By bringing the cloud services closer to users, CIW offloads traffic from the wireless backhaul and improves the performance of a WOBAN. We also present a novel energy-saving routing mechanism, called Green Routing for CIW (GRC), that allows CIW to self-manage the activation of network components to minimize the overall energy consumption of CIW. (4) We also apply our knowledge obtained from the studies on the improvement of wireless backhaul in WOBAN for the enhancement of 3G and 4G backhaul. We discuss the performance bottleneck of 3G and 4G backhaul imposed by legacy copper lines and design a wireless overlay network (WON) using high-capacity point-to-point wireless links that increases the capacity of 3G and 4G backhaul, reduces the performance bottleneck, utilizes the bandwidth of deployed fibers more efficiently, and provisions backup paths during failures.