Service Function Chain Migration in LEO Satellite Networks

With the advancements of software defined network(SDN) and network function virtualization(NFV), service function chain(SFC) placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO) satellite networks.While due to the scarcity of bandwidth resources and dynamic topology of LEO satellites, the static SFC placement schemes may cause performance degradation, resource waste and even service failure. In this paper, we consider migration and establish an online migration model, especially considering the dynamic topology. Given the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as possible. Due to its NP-hardness, we propose a heuristic minimized dynamic SFC migration(MDSM) algorithm that only triggers the migration procedure when new SFCs are rejected. Simulation results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity.