Least cost heuristic for the delay-constrained capacitated minimum spanning tree problem

This study deals with the Delay-Constrained Capacitated Minimum Spanning Tree (DC-CMST) problem arising in topology discovery of local network. While the traditional Capacitated Minimum Spanning Tree (CMST) problem deals with only traffic capacity constraint of a port of a source node, and Delay-Constrained Minimum Spanning Tree (DCMST) considers only the maximum end-to-end delay constraint, the DC-CMST problem deals with mean network delay and traffic capacity constraints simultaneously. The DC-CMST problem consists of finding a set of minimum cost spanning trees to link end-nodes to a source node which satisfy the traffic requirements at end-nodes and the required mean delay of a network. We formulate the DC-CMST problem and present the Least-Cost DC-CMST Heuristic, which consists of node exchange algorithm, node shift algorithm, and mean delay link capacity algorithm to solve the DC-CMST problem. Results from performance analysis show that the proposed heuristic can produce, in a very short computation time, better results than the previous CMST algorithms modified to solve the DC-CMST problem. The proposed Least-Cost DC-CMST Heuristic can be applied to the topological design of large local networks and to the construction of least cost broadcast and multicast trees for efficient routing algorithms.