Packet Loss and Delay Combined Optimization for Satellite Channel Bandwidth Allocation Controls

The paper studies the bandwidth allocation process over satellite communication systems as a multi-objective programming (MOP) problem and evaluates an allocation method called "combined Utopia minimum distance" (combined UMD). The entities of the system are earth stations and, for each of them, a set of performance metrics (represented by specific analytical functions), which compete to access the satellite channel. Combined UMD is aimed at approaching the performance obtained for each performance metric when there is no conflict among them to access the channel. In short, it assigns the bandwidth so to approach a non-competitive situation where each metric "sees" the overall channel bandwidth availability as close as possible. In more detail, in this work two kinds of performance metric have been considered: the packet loss probability, which is a typical QoS metric for the TCP based traffic and the average delay, which is typical for UDP based traffic. The allocation method is tested through the ns2 simulator by using TCP and UDP traffic generators and by varying the fading level of the satellite channel over time. Combined UMD has been compared with other approaches taken from the literature in the field.