Resource allocation and connection admission control in satellitenetworks

摘要

This work focuses on resource allocation and connection admissionncontrol (CAC) issues in broadband satellite networks. Broadband servicesncan now be provided by satellite systems operating in the Ka band, duento the large bandwidth available at such frequencies. In this context,nwe propose a resource allocation algorithm which integrates threenclasses of services at the MAC layer: constant bit rate (CBR), burstyndata, and best effort services. The double movable boundary strategyn(DMBS) is proposed to establish a resource-sharing policy among thesenservice classes over the satellite uplink channel. The DMBS is andynamically controlled boundary policy which adapts the allocationndecision to the variable network loading conditions. Connection-orientednand connectionless services can be supported by the system. The CAC andnslot allocation decisions are taken at the beginning of each controlnperiod after monitoring the filling level of traffic request queues. Anthreshold level for the bursty data request queue is defined to regulatenthe CAC process. The impact of the queue threshold value on thenperformance of the DMBS allocation policy is particularly evaluated innthis study. A dynamic variation of this value is also proposed tonenhance the system response to interactive applications. We present anbrief analytical formulation for the DMBS model, together withnsimulation study details and performance evaluation results. Thenobtained results indicate a good efficiency, in terms of overall channelnthroughput and CBR blocking probability, for both fixed and dynamic datanqueue threshold approaches. The dynamic approach, however, outperformsnthe fixed one in terms of overall encountered bursty data delay