An Adaptive TCP Algorithm to Support Handoffs in Heterogeneous Overlay Networks

In this paper, an adaptive TCP algorithm is proposed to support handoffs in heterogeneous overlay networks. The algorithm is implemented as a collection of units. The main body, namely the TCP implementation unit, considers the optimization of TCP parameters over different wireless networks. This unit is decomposed into three modules: transmission control, congestion control, and error detection. Based on this module decomposition, several TCP versions are re-constructed, and the different combinations of their congestion control and error detection modules are studied. Aided by other units in our adaptive TCP algorithm, such as the realtime report and throughput evaluation units, when a mobile user experiences acute changes in access parameters due to handoffs, the adaptive TCP algorithm will be triggered to reconfigure TCP parameters or TCP module combinations in the TCP implementation unit, thus optimizing the TCP performance over heterogeneous wireless networks