Adaptive cross-layer bandwidth allocation in a rain-faded satellite environment

Two control schemes, based on cross-layer adaptation and a hierarchical parametric optimization of the bandwidth allocation, are described and investigated in a satellite network environment, in the presence of both real-time and best-effort traffic flows. A number of earth stations (traffic stations) operate in different weather conditions, with different levels of fade, which affect the transmitted signals. The call admission control policy for real-time connections is administered locally at the traffic stations. A master station is charged to manage the time division multiple access bandwidth allocation policy, by defining bandwidth partitions to the traffic stations. Upon detecting significant fade changes, the signalling from the traffic stations triggers new bandwidth redistributions. The control schemes are compared, and the effect of fade countermeasures, applied at the physical layer, on the bandwidth occupation is explicitly accounted for. For each policy, figures of merit such as loss, blocking and dropping probabilities are computed for a specific real environment, based on the Italsat satellite national coverage payload characteristics.