HONET: An Integrated Services Wavelength Division Optical Network

of the Dissertation HONET: An Integrated Services Wavelength Division Optical Network by Milan Mihailo Kova cevi c Doctor of Philosophy in Computer Science University of California, Los Angeles, 1995 Professor Mario Gerla, Chair We investigate a class of high-speed ber-optic local and metropolitan area network architectures that can support a wide range of applications, namely: datagram (e.g., le transfer); real-time, connection oriented communications (e.g., voice and video), and; multicast/broadcast (e.g., video broadcasting and conferencing). Successful results have been reported by using WDM (wavelength division multiplexing) in two types of optical network architectures: single-hop (i.e., direct path between each source/destination pair), and multihop (store-andforward processing at intermediate nodes along the path). It has been observed that, while neither of these schemes can adequately satisfy all requirements, yet single-hop and multihop networks have positive and negative properties that tend to complement and compensate each other. We exploit this situation by proposing a hybrid architecture HONET (Hybrid Optical Network) which combines the concepts of both schemes retaining their advantages and avoiding their limitations. HONET uses a multihop network for packet service and a single-hop xvi network for circuit-switched service. We rst study possible virtual topologies for HONET's multihop network that can be established with channel sharing using a time division multiple access technique (TDMA) and determine the optimal degree of channel sharing which maximizes throughput. We then discuss some of the possible HONET implementations and compare them with other related optical network architectures. Next, we propose a novel time and wavelength division multiaccess scheme (T/WDMA) that supports circuit-switched tra c over HONET's single-hop network. The scheme employs subframe tuning and pipelining in order to allow an implementation with o -the-shelf, relatively slow tunable receivers. Thus, tuning time can be much longer than the TDM slot reserved for the connection. We then consider implementation of HONET over the Linear Lightwave Network (LLN) infrastructure. We identify a synchronization problem in LLN which complicates the implementation of slotted TDMA and T/WDMA networks. We propose a solution which permits us to implement HONET over LLN. The solution is based on using a new optical signal routing scheme called rooted routing instead of the originally proposed, shortest path routing. The impact of rooted routing on power loss and propagation delay is analyzed and an approach for minimizing power loss in LLNs with rooted routing is presented. In order to increase scalability and capacity of HONET, we also propose multilevel and multi ber extensions of the basic HONET. The multilevel architecture is hierarchically organized. It exploits tra c locality and wavelength reuse. The multi ber HONET utilizes a multi ber infrastructure, such as multi ber tree or multi ber LLN. xvii CHAPTER