Quality of Service Issues in WDM-EPON Systems

Although many technologies involving fiber in the access network have evolved, yet passive optical networks (PON) remain the best option. Among various PON technologies the most popular is EPON. The drawback of EPONs is that it is not scalable, both, with respect to bandwidth and number of customers. WDM PONs can overcome the bandwidth and the scalability problems of EPON system. Among the many WDM-PON architectures proposed WDM-IPACT PON is an attractive option due to the simplicity of the algorithm and the fact that it is simply an upgrade of the IPACT existing in EPONs. In our work, we have simulated WDM IPACT PON (with wavelength scheduling) and WDM IPACT PON (without wavelength scheduling) for two wavelengths and compared their performances with the EPON network. It has been shown that WDM IPACT PON systems overcome the scalability problem of EPON systems performing satisfactorily even at very high upstream traffic. These networks were tested for the QoS issues and their performance compared with EPONs. It has been shown that WDM IPACT PON systems are better suited for satisfying QoS bounds as compared to EPON system.