Minimizing Average Path Cost in Colored Trees for Disjoint Multipath Routing

Multi-path routing (MPR) is an effective strategy to achieve robustness, load balancing, congestion reduction, and increased throughput by transmitting data over multiple paths. Disjoint multi-path routing (DMPR) requires the multiple paths to be link- or node-disjoint. Implementation of both MPR and DMPR poses significant challenges in obtaining loop-free multiple (disjoint) paths and effectively forwarding the data over the multiple paths, the latter being significant in data-gram networks. In this paper, we develop a disjoint multipath routing strategy using colored trees with an objective to minimize the total cost of the routing paths in a network. Two trees, namely red and blue, rooted at a given drain is formed. We demonstrate through extensive simulations that the developed technique is extremely effective in optimizing the average cost of the paths. In addition, we also observe that the developed approach minimizes the average minimum (minimum of the two paths) cost, which is lower than that obtained by earlier algorithms. The colored tree approach simply doubles the size of the routing table when two link- or node-disjoint paths to a specific node is needed.