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Chapter 1Introduction pThis dissertation also focuses on a rigorous analysis of the two adopted contentionresolutions algorithms of the DVB/DAVIC protocol (exponential backoff algorithm andsplitting tree algorithm). Here, we study in detail performance characteristics,optimisation and implementation issues for each algorithm. Furthermore, threeenhanced contention slot allocators are introduced (Simple-CSA, Forced-CSA andVariable-CSA), which dynamically adjust the bandwidth used for contention access,significantly increasing the system performance when different bounds and traffic loadsare considered.The major contributions of this research are the introduction of novel improvements andnew techniques (presented below), which will enable the DVB/DAVIC MAC protocolto provide the delay requirements optimally for the delivery of delay sensitive servicesand high-speed Internet traffic.In this dissertation, we introduce three novel reservation request techniques, namelyReserved-Request, Unsolicited Grant Slot and Enhanced-Pure Reservation Request thatreduce or avoid the increased risk of collisions during large periods of congestion. Inaddition, we compare the performance of these three mechanisms with the enhancedreservation request strategies introduced in Schunke [101] (Continuous ReservationRequest, Piggyback Request and Continuous Piggyback Request).A second approach for the delivery of delay sensitive services involves Quality ofService (QoS) with a guaranteed delivery. In this research, a prioritised mechanism thatprovides reduced access delays for isochronous streams (during contention access) isdescribed. Additionally, the effect of considering header suppression for the delivery ofVoIP traffic is approached.We also present a performance comparison between the DVB/DAVIC and the DOCSISprotocol, where the major characteristics and the fundamental performance properties ofeach protocol are evaluated. For each analysis we provide saturation points, maximumnumber of streams supported and reasons for inefficiencies.1-17