Spectrum-block consumption for shared-path protection with joint failure probability in flexible bandwidth optical networks

We address the problem of providing shared-path protection for a set of connection requests in a flexible bandwidth optical network under the constraint that the joint failure probability of the primary path and backup path of each request is below a given maximum joint failure probability threshold. The overall objective of the problem is to minimize spectrum consumption while meeting the maximum joint failure probability requirements. We propose the minimum free spectrum-block consumption algorithm (MFSB) for providing shared-path protection with joint failure probability requirements in flexible bandwidth optical networks, and we introduce two additional algorithms, named the conventional shared spectrum-block (CSSB) consumption algorithm and the maximum shared spectrum-block (MSSB) consumption algorithm, for comparison. Simulation results show that MFSB not only achieves better performance in terms of blocking probability, spectrum consumption, spectrum redundancy, and hop counts compared to the CSSB and MSSB algorithms, but also guarantees a joint failure probability that is lower than the MSSB algorithm. Furthermore, the spectrum efficiency of these three algorithms increases with the growth of the maximum shared degree, especially for the MFSB algorithm. Therefore, the MFSB algorithm provides a better tradeoff between the minimum spectrum-block consumption and the average joint failure probability.