A binary graph reduction algorithm for multi-constrained QoS routing

A lot of network services and applications are being designed to support quality-of-service (QoS) routing. One of the key problems is to find a feasible path that satisfies multiple QoS requirements, i.e., Multi-Constrained Path (MCP) problem which is known to be NP-complete. Many heuristic and approximation algorithms have been proposed to solve this problem. However, most of them converted it into the classic shortest path problem by transforming multiple QoS weights into single weight. In this paper, we propose a binary graph reduction (BGR) algorithm to convert network graph into a simplified graph by removing redundant edges before constructing a routing path. BGR improves system performance from two aspects: i) BGR decreases the decision-making time, which then decreases the delay of end users; ii) BGR removes some abnormal anti-heuristic redundant edges from network graph, so that the actual routing algorithm could get a better result. We use a multimedia delivery system to illustrate these advantages in this paper. Simulation results also approve the efficiency of the proposed BGR algorithm.