Performance Evaluation of DiffServ Driven HFC System

Shared access networks such as hybrid fiber/coaxial and passive optical networks have emerged as promising ways to reduce the cost of the transition to a broadband access infrastructure and provide a graceful upgrade path towards the photonization of the local loop. The MAC protocol as the only arbiter of the upstream bandwidth directly affects the Quality of Service (QoS) provided to each upstream traffic flow and must meet several constraints. Such constraints include the adequate speed of operation, flexibility to support efficiently the largest number of services and applications offering an adequate number of QoS classes, and independence of higher layers, protocols and future extensions to traffic management specifications. The implementation of a MAC mechanism targeting these goals and aligned to the emerging Differentiated Services Internet strategy is evaluated using computer simulation results in this paper. The benefits of the adopted prioritization scheme to provide and guarantee different QoS levels are