Multiple Access And Bandwidth Allocation Strategy In Broadband Satellite Communication System

As complement and extension of the terrestrial network,broadband satellitenetwork will be an important component in future integration network system. But themultiple access and bandwidth allocation strategy of broadband satellite network playsan important role to improve the utilization of satellite system channel，success rate ofuser access and transmission ability of business meanwhile protects the customers’business needs. At present, some of the traditional multiple access and bandwidthallocation technique can achieve higher channel utilization and lower end-to-end delayon the continuous stream of data service and voice service, but for the strong burstmultimedia business and diversified business needs, these techniques have not qualified.The dissertation makes a deep and systemic research on the traditional multipleaccess and bandwidth allocation technique on the latest research. The dissertationpresents a new multiple access technique CFDAMA-FP and also improves thebandwidth allocation algorithm, aiming to improve the channel utilization and quality ofservice, to adapt to the burst characteristics. The main contributions are:(1) Through the analysis and evaluation of Combined Free/Demand AssignmentMultiple Access (CFDAMA) protocol based on combined assignment, it can come tothe conclusion that CFDAMA allocation effectively reduces the average transmissiondelay byusing a free time slot allocation.But with the channel load increases, free timeslot allocation is reduced and the reservation number caused the decline of the networkperformance.To solve this problem, according to the design requirements and buildingthe system model, a multiple access protocol based on fast reaction mechanism ispresented. The protocol improves random access algorithm and reduces the accesscollision probability; then, using periodic sending user bandwidth requirement in theallocation of resources to update the information in a way that, instead of repeatedly forresource reservation, inherited the idea of Burst Target/Demand Assignment, caneffectively reduce the average access delay; Finally, this paper establishes access end toend delay calculation model, proved that the protocol can reduce the access delay andaverage transmission delay and improved the channel utilization;(2) In broadband satellite networks based on bandwidth allocation, the access delaycaused by the waste of resources. The traditional distribution mode using predictedbusiness strategy to the rational use of this period of time, but due to burst data, forecast value and the actual business is very difficult to achieve the consistent. this paperproposed a new bandwidth allocation algorithm based on prediction and on-boardcontrol. Thisprotocol adopt a source model called largest Lyapunov exponent chaotictime series prediction, put forward a method called user priority ranking, thus optimizethe user time-slot application process and satellite resource scheduling algorithm,reduce the delay of data packets, improve the transmission efficiency of channel and thefairness of user access.Finally, modeling and comparing simulation are built, the results show that underPareto ON-OFF source model, CFDAMA-FP protocol can achieve better averageend-to-end delay/throughput performance and better user access fairness performancethan CFDAMA-PA and CFDAMA-PB in a larger number of users and high burst sourceconditions.