A Control Method of Guaranteeing Throughput for TCP Communication Considering Handover over WLAN

In wireless LAN environments, the frequency of handover has been increased by the rapid spread of mobile devices such as smartphones and tablets. In such environments, streaming applications such as video feeds, are quite common and have high bandwidth (throughput) requirements. Here, QoS is an important metric for assurance of network quality. QoS-TCP has been proposed as one of the techniques for guaranteeing the throughput, it controls only the terminal. In this study, we treat TCP-AV as one of the typical QoS-TCPs. However, TCP-AV was originally developed for wired networks. It has difficulty in guaranteeing adequate throughput in a wireless LAN environment because it does not consider handover. Given the frequency of handover in wireless LAN environments, (1) we modify the parameters of TCP-AV, and (2) we propose advertise window size control by an access point (AP). Simulation results show that the method proposed herein, which uses both (1) and (2), can attain the necessary throughput, unlike the original TCP-AV approach.