Performance evaluation of a Dynamic Wavelength Allocation protocol in WDM-TDM PONs servicing Pareto ON-OFF traffic

Hybrid Wavelength-Time Division Multiplexing (WDM-TDM) Passive Optical Networks (PONs) become strong candidates for Next Generation PONs and, therefore, merit deep performance evaluation. In this paper, we concentrate on the performance of a Dynamic Wavelength Allocation (DWA) protocol, under multi-dimensional traffic which is modeled by a Pareto ON-OFF model; it resembles the bursty nature of traffic by considering ON and OFF transmission periods, whose duration is Pareto distributed. The investigated protocol may cause service delay to existing connections, if they will be found in state OFF, while no connection is found in state ON at the same time. In this case, the occupied wavelength is released, and a new wavelength (however, not always available, hence the delay) will be allocated to OFF connections, upon request from a connection to return to state ON. The delay caused by the so-called Delay Wavelength Release (D-WR) protocol, as well as other performance measures, are evaluated via simulation, and compared with the delay and corresponding measures of the same protocol, when the ON-OFF traffic under service has exponentially distributed ON and OFF periods.