Abstract: Abstract: For the problem of low availability and high cost of path switching for single-path transmission in complex environments， this paper proposes a QoE-driven and SDN-assisted MPTCP path switching scheme for high-availability transmission services. Firstly， a path planning model with path disjoint is constructed based on the mesoscopic centrality of data plane nodes in SDN architecture. Secondly， a two-stage strategy is used to perform bandwidth compensation and path switching separately， the transfer of subflows on the transmission blocked path is accelerated to achieve path switching with lower throughput. Finally， Levy flight is introduced into the model update of AOA to prevent the algorithm from converging prematurely and enhance the ability to jump out of the local optimum， thus ensuring that the algorithm is optimal when optimizing the subflow path weights. Experimental results show that the method proposed in this paper has the advantages of smaller fluctuation range of throughput， lower delay and less jitter when performing sub-stream path switching. In addition， the improved AOA algorithm can obtain higher convergence efficiency when calculating the optimal weight vector.

Key words: Key words: software defined network, QoE, multipath transmission, bandwidth compensation, arithmetic optimization algorithm