| Summary: | 博士 === 國立中央大學 === 資訊工程研究所 === 93 === In an Heterogeneous Networks of Workstations (HNOW), many different speed types of workstations can have distinct send and receive overhead. Previous research has shown that finding an optimal routing scheme in an HNOW is not easy [16,2], because properly arranging all workstations in the scheduling tree is difficult. Therefore, this investigation focuses mainly on enhancing the performance of an HNOW by properly arranging fastest nodes into the internal nodes of upper levels in the scheduling tree and using two sub-networks to broadcasting an HNOW. This dissertation is organized into two parts. In the first part, three efficient contention-free algorithms for broadcasting on heterogeneous networks of workstations (HNOW) are presented. In the second part, we present broadcast algorithms using two sub-networks.
Fastest node first is fundamental in designing an efficient algorithm. Three schemes called EBS,VBBS, and VBBSWF are presented in the first part. All of these three schemes can be executed in O(nlog(n)) time, where n is the number of workstations. They are all contention-free when broadcasting in an HNOW. Based on the simulation result, the proposed schemes outperform the broadcast with minimal steps [17] and the scheduling tree [31] generated by dynamic programming in an HNOW.
Furthermore, we also present efficient algorithms for broadcasting on heterogeneous networks of workstations by two partitioned sub-networks. Previous research presented that routing by two sub-networks in a NOW can significantly increase system’s performance [20]. We propose two schemes TWO-EBS and TWO-VBBS for broadcasting in an HNOW.
These two schemes divide an HNOW into two sub-networks that are routed concurrently, and simultaneously combine EBS and VBBS to broadcast in an HNOW. Based on simulation results, TWO-VBBS outperforms EBS,VBBS, VBBSWF[19], the postorder recursive doubling[17] , and the optimal scheduling tree [31] generated by dynamic programming in an HNOW.
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