994 International Conference on Parallel Processing a Comparative Study of Star Graphs and Rotator Graphs*
994 International Conference on Parallel Processing a Comparative Study of Star Graphs and Rotator Graphs*
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994国际并行处理会议星图和旋转图的比较研究*
DOI:
10.1109/icpp.2004
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发表时间:
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期刊:
影响因子:
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通讯作者:
M. Sampels
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文献类型:
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作者:
M. Sampels
Star graph is an extensively studied Cayley graph, considered to be an attractive alternative to the popular binary cube. The rotator graphs are a set of directed Cayley graphs introduced recently. In this paper we compare the structural and algorithmic aspects of star graphs with that of rotator graphs. In the process we present some new results for star graphs and rotator graphs. We present a formula for the number of nodes at any distance from the identity permutation in star graphs. The minimum bisection width of star and rotator graphs is obtained. Partitioning and fault tolerant parameters for both star and ro tator graphs are analyzed. The node disjoint parallel paths and hence the upper bound on the fault diameter of rotator graphs are presented. We compare the minimal path routing in star and rotator graphs using simulation results. INTRODUCTION The performance of any multiprocessor system depends main ly on the communication efficiency of the underlying intercon nection topology. Numerous interconnection networks for both general purpose and special purpose applications have been in troduced in the literature. Continuing search for communication efficient symmetric interconnection structures for multiproces sors has led to Cayley graphs as possible interconnection net works [11]. Some examples of Cayley graphs include star graph [1, 2], rotator graph [4], and cycle prefix digraphs [8], binary n-cube and the cube connected cycles. Due to their simplicity' and the fact that the real world communication links (e.g. optical links) are often realized by directed communication links, the directed counterparts of some of the undirected networks have also appeared in the literature, e.g., uni-directional hypercube [3], and uni-directional star graphs [6]. The n-rotator graph and the cycle prefix digraphs are directed by definition. Since these directed Cayley graphs have some interesting properties like easy routing, low diameter and average diameter compared to the star graph, a comparative analysis of these graphs is worthy of study. In this paper, we present some new results for star and rotator graphs. We present a formula for calculating the number of nodes at any distance from the identity permutation, using the cyclic structure of the star graph. The minimum bisection width, an important measure in VLSI models, is obtained for both star and rotator graphs. We show that the rotator graphs of size n! have n-1 node disjoint parallel paths of length at most n + 1 for n > 2. Other fault …