Efficient Optical Resource Allocation and QoS Differentiation in Optical Burst Switching Networks Utilizing Hybrid WDM/OCDM

In this paper, a QoS differentiation framework is proposed for an optical burst switching (OBS) multiservice network. Furthermore, hybrid wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) scheme is used to mitigate the blocking probability of OBS networks. In our study, the measurement criteria of QoS are the blocking probability, OBS network delay, transmission rate, and OCDM probability of error. In order to increase the bandwidth efficiency and control the multiplexing interference effect of OCDM, an advanced optical resource allocation strategy is introduced. The proposed strategy is also compared with a conventional strategy based on random allocation. The comparison shows the superiority of our technique. The blocking probability of the proposed WDM/OCDM-based OBS scheme is evaluated by utilizing both the generalized Engset model and 2-D Markov model. The effect of multiplexing interference is also investigated in computing the probabilities of error and outage. Additionally, an upper bound on the OBS network delay is derived by computing the expected values of burst assembly and burst transmission queuing delay. To proceed further, a four-class OBS network is numerically de- signed to explain the details of QoS differentiation framework and to highlight the advantages of the proposed scheme. Numerical results reveal that by using hybrid WDM/OCDM technique, the blocking probability of OBS networks is significantly reduced. Moreover, the probabilities of error and outage are reduced employing intelligent resource allocation.