Showing papers by "Seung-Woo Seo published in 1996"
TL;DR: A novel network architecture is introduced, aimed at offering both ultra-high speed (up to 100 Gb/s) and maximum parallelism for future terabit data communications, based on several key state-of-the-art optical technologies that have been demonstrated.
Abstract: Most research efforts to date on optical networks have concentrated on wavelength-division multiplexing (WDM) techniques where the information from different channels is routed via separate optical wavelengths. The data corresponding to a particular channel is selected at the destination node by a frequency filter. Optical time-division multiplexing (OTDM) has been considered as an alternative to WDM for future networks operating in excess of 10 Gb/s. Systems based on TDM techniques rely upon a synchronized clock frequency and timing to separate the multiplexed channels. Advances in device technologies have opened new opportunities for implementing OTDM in very high-speed long-haul transmission as well as networking. The multiterahertz bandwidth made available with the advent of optical fibers has spurred investigation and development of transparent all-optical networks that may overcome the bandwidth bottlenecks caused by electro-optic conversion. This paper presents an overview of current OTDM networks and their supporting technologies. A novel network architecture is introduced, aimed at offering both ultra-high speed (up to 100 Gb/s) and maximum parallelism for future terabit data communications. Our network architecture is based on several key state-of-the-art optical technologies that we have demonstrated.
82 citations
TL;DR: An in-depth study of the generalization of the well-known shuffle network for ultrafast multihop lightwave communication and derives an exact model and an approximate model of the expected number of hops for various network topologies.
Abstract: Multihop networks with wavelength-division multiplexing (WDM) are one possible way to conduct high data-rate communication. We provide an in-depth study of the generalization of the well-known shuffle network for ultrafast multihop lightwave communication. In the classical definition of a shuffle network, i.e., N=kp/sup k/ where N is the number of nodes and k is the number of stages with nodes of degree p, the realizable values of N are very sparse and many of the intermediate values of N are not realizable. We use a new definition of the shuffle network, N=nk, where n is the number of nodes per stage, which was originally proposed by Krishna and B. Hajek (1990) as the shuffle-ring network. Based on this definition, we divide the shuffle networks into two classes: extra-stage and reduced-stage. We derive an exact model and an approximate model of the expected number of hops for various network topologies. The results can be used to determine an optimal network topology when given a value of N.
5 citations
TL;DR: An efficient optical packet-generation and -compression scheme is proposed that requires no fast electronics and uses exceptionally simple devices such as a tapped series of D flip-flops and frequency dividers.
Abstract: An efficient optical packet-generation and -compression scheme is proposed. Packet compression is achieved when the packet is sent through a series of semiconductor optical amplifiers, which have either a transmitting or an absorbing state. The proposed scheme requires no fast electronics and uses exceptionally simple devices such as a tapped series of D flip-flops and frequency dividers. A detailed performance analysis on the system size limitations is also provided by the consideration of pulse-spreading effects and semiconductor optical-amplifier noise.
4 citations
12 Aug 1996
TL;DR: Additional conditions which enable conflict-free routing in the original algorithm are pointed out and it is shown that the routing problem in the concatenation of two omega networks known as 2log/sub 2/N-stage shuffle network, is in the class of NP-completeness.
Abstract: We recently proposed a new algorithm which routes a class of 2log/sub 2/N- or (2log/sub 2/N-1)-stage rearrangeable networks. Although we discussed some of the general rules for proper routing, detailed strategies for resolving possible conflicts were not mentioned. In this paper, we point out additional conditions which enable conflict-free routing in the original algorithm. Cyclic property at the center stages is analyzed in more detail. We also show that the routing problem in the concatenation of two omega networks known as 2log/sub 2/N-stage shuffle network, is in the class of NP-completeness.
12 Jun 1996
TL;DR: Topological properties of a class of concatenated (2log/sub 2/N-1)-stage interconnection networks are investigated and their interstage correlations are introduced to provide an important background for developing a graphical representation model and a bidirectional tag scheme.
Abstract: This paper investigates topological properties of a class of concatenated (2log/sub 2/N-1)-stage interconnection networks and introduces their interstage correlations. A concatenated (2log/sub 2/N-1)-stage interconnection network is constructed by merging two (log/sub 2/N)-stage cube-type networks with overlapped center stages. In constructing concatenated (2log/sub 2/N-1)-stage interconnection networks, we consider all self-routable (log/sub 2/N)-stage cube-type networks which can establish a path to an output port with a self-routing tag. Each routing tag for a cube-type network can be generated by reordering destination address bits using a bit permutation mapping function. Based on two bit-reordering mapping functions for a given (2log/sub 2/N-1)-stage interconnection network, we formulate its interstage correlations into an algebraic function. Then, the topological equivalences among concatenated (2log/sub 2/N-1)-stage interconnection networks are introduced. The proposed classification scheme implies that any two concatenated networks in the same class are topologically equivalent and have isomorphic interstage correlation functions. This means that all the concatenated networks in the same class can use the same routing and application algorithms. In addition, several related important characteristics of each class are discussed. We expect that the results of this paper provide us with an important background for developing a graphical representation model and a bidirectional tag scheme.