Blocking Analysis in Hybrid TDM-WDM Passive Optical Networks

Optical access networks are the ultimate solution to the problem of the last mile bottleneck between high-capacity metro networks and customer premises, capable of delivering future integrated broadband services. Nowadays, passive optical networks are the most promising and cost-effective class of fiber access systems. This rapid evolvement of fiber in access networks motivates the study of their performance. In this paper we develop teletraffic loss models for calculating connection failure probabilities (due to unavailability of a wavelength) and call blocking probabilities (due to the restricted bandwidth capacity of a wavelength) in hybrid TDM-WDM passive optical networks with dynamic wavelength allocation. The springboard of our analysis is well-established recursive teletraffic models. The proposed models are derived from one-dimensional Markov chains which describe the wavelengths occupancy in the optical access network. The optical access network accommodates multiple service-classes with infinite or finite number of traffic sources. The accuracy of the proposed models is validated by simulation and was found to be absolutely satisfactory.