Multipath TCP in SDN-enabled LEO satellite networks

Abstract

Satellite systems such as Low Earth Orbiting (LEO) networks play an important role in the next generation 5G networks. To facilitate the integration of satellite and terrestrial networks, software-defined networking (SDN) is embraced which brings flexibility, user-customized services and reduces the cost of network configurations. However, it has been long known that communications via LEO satellite network suffer from long delay and frequent ground-satellite handovers, both are problematic for TCP connections. The emergence of Multipath TCP (MPTCP) provides a new solution to these challenges. In this paper, we study the performance of MPTCP over SDN-enabled LEO satellite networks. MPTCP maintains multiple simultaneous subflows in space to increase throughput. In anticipation of handover, MPTCP creates subflows that run in backup mode and shifts traffic smoothly. To support MPTCP, we design an SDN controller that identifies MPTCP subflows attached to the same MPTCP session and splits them to disjoint paths. The SDN architecture centralizes the routing logic, so the system is more scalable and on-board processing is minimized. Simulations are run to evaluate the proposed MPTCP-SDN framework. It is shown that compared to previous solutions, our strategy significantly improves throughput performance and prevents the interruption of transmission during handover.