Fairness of congestion avoidance schemes in heterogeneous networks

Traditional congestion avoidance and control schemes used in wireline networks do not perform well in mixed wireless-wireline networks due to the high probability of random loss on the wireless links. In this paper, we study additive increase/multiplicative decrease schemes, specifically designed for such heterogeneous networks, which use some knowledge of the random loss probability to modify the rate at which a source sends packets into the network. We show that, unlike wireline networks, the choice of values for the increase/decrease parameters is crucial to provide fair treatment to all the users of the network. Specifically, we characterize the range of values for these parameters that leads to high utilization and fairness, i.e., an operating regime where the used capacity is close to the available capacity and the transmission rates for all the sources are equal.