Dynamic priority-based alternate routing for multiple classes of traffic in intelligent optical networks

Abstract

Priority-based alternate routing (PAR) and dynamic priority-based alternate routing (DPAR) are introduced for multiple classes of traffic in intelligent optical networks. A discrete event simulation platform was implemented to compare the performance of different priority schemes. As usual, the call interarrival and holding time for each class of traffic were assumed to be exponentially distributed in the simulation. The results show that PAR can significantly decrease the blocking probability of optical networks, especially for traffic with low priority. Because the weights of links of the network in DPAR increase with the increment of wavelength occupation, links with more idle wavelengths are more easily chosen as part of the shortest path. This mechanism benefits to the load balance of the network and as a result, DPAR has better performance than PAR. In order to utilize the advantage of the wavelength reservation-based priority scheme (RES), which provides low blocking for traffic with high priority, the combination of DPAR and RES was also investigated. The simulation results show that DPAR with the proper RES provides the lowest blocking probability for every class of service compared to the corresponding class of other priority schemes.