Heuristic Contention-Free Broadcast in Heterogeneous Networks of Workstations with Multiple Send and Receive Speeds

Abstract

This paper presents three efficient contention-free algorithms for broadcasting on heterogeneous networks of workstations (HNOW). In an HNOW, many multiple speed types of workstations that their send and receive overhead are distinct. Previous research has shown that finding an optimal routing scheme in an HNOW is not easy [R. Libesking-Hadas and J. Hartline, 2000, M. Banikazemi, et al., 1998], because properly arranging the scheduling tree in routing is difficult. Therefore, this investigation focuses mainly on enhancing the performance of an HNOW by properly arranging fastest nodes to the internal nodes of upper levels in the scheduling tree. The fastest node first is fundamental in designing an efficient algorithm. This paper presents three schemes named EBS, VBBS and VBBSWF. All of these three schemes can be implemented in O(nlog(n)) time, where n is the number of workstations. They are all contention-free when broadcasting in an HNOW. The post-order recursive doubling is used as a platform to design our algorithms. Based on the simulation result, the performance outperforms the broadcast with minimal steps [R. Libeskind-Hadas, et al., 1998] and the scheduling tree [A. Singhal, et al., 2001] generated by dynamic programming in an HNOW.