On bufferbloat and delay analysis of multipath TCP in wireless networks

With the rapid deployment of cellular net-works, modern mobile devices are now equipped with at least two interfaces (WiFi and 3G/4G). As multi-path TCP (MPTCP) has been standardized by the IETF, mobile users running MPTCP can access the Internet via multiple interfaces simultaneously to provide robust data transport and better throughput. However, as cellular networks exhibit large RTTs compared to WiFi, for small data transfers, the delayed startup of additional flows in the current MPTCP design can limit the use of MPTCP. For large data transfers, when exploiting both the WiFi and cellular networks, the inflated and varying RTTs of the cellular flow together with the small and stable RTTs of the WiFi flow can lead to performance degradation. In this paper, we seek to investigate the causes of MPTCP performance issues in wireless environments and will provide analyses and a solution for better performance.