Faster Algorithms for Construction of Recovery Trees Enhancing QoP and QoS

Medard et al. proposed an elegant recovery scheme (known as the MFBG scheme) using red/blue recovery trees for multicast path protection against single link or node failures. Xue et al. extended the MFBG scheme and introduced the concept of quality of protection (QoP) as a metric for multifailure recovery capabilities of single failure recovery schemes. They also presented polynomial time algorithms to construct recovery trees with good QoP and quality of service (QoS). In this paper, we present faster algorithms for constructing recovery trees with good QoP and QoS performance. For QoP enhancement, our O(n + m) time algorithm has comparable performance with the previously best O(n²(n + m)) time algorithm, where n and m denote the number of nodes and the number of links in the network, respectively. For cost reduction, our O(n + m) time algorithms have comparable performance with the previously best O(n²(n + m)) time algorithms. For bottleneck bandwidth maximization, our O(m log n) time algorithms improve the previously best O(nm) time algorithms. Simulation results show that our algorithms significantly outperform previously known algorithms in terms of running time, with comparable QoP or QoS performance.