Analysis of Blocking Probability in OBS Networks

The quality of an optical signal degrades due to physical layer impairments as it propagates from source to destination. Due to this signal quality at the receiver or destination may be degraded, leading to increased call blocking. A performance indication of an All-Optical Network is the call blocking probability. The goal is to achieve a low overall blocking probability at an affordable cost and at the same time to make sure that other performance measures are within reasonable limits. This blocking probability can be affected by many factors such as network topology, traffic load, Routing and Wavelength Assignment(RWA) algorithm employed and whether wavelength conversion is available or not. In this paper, the performance of the some wavelength assignment algorithms is calculated in terms of blocking probability. Further, a new wavelength assignment algorithm “wavelength reservation” is proposed in this paper. The performance of this proposed wavelength reservation algorithm is compared with some other algorithms. The blocking probability is calculated to observe the effect of number of channels, number of nodes and load (in Erlangs) on each link in