A survey of task deployment and recovery in space-air-ground integrated networks based on SDN and NFV

The space-air-ground integrated network, as a key technology in 6G, faces challenges such as node heterogeneity and service diversity when integrating the space-based, air-based, and ground-based networks. These challenges subsequently lead to issues such as the resource allocation, competition, and failure risks. Based on this, the task deployment and recovery of the space-air-ground integrated network focusing on software defined network (SDN) and network functions virtualization (NFV) were addressed. Firstly, the space-air-ground integrated network system architecture was elaborated, introducing the composition of each layer of the network, the principles of SDN and NFV, as well as their related applications. Subsequently, in response to the above-mentioned challenges, based on the service function chain technology, corresponding strategies including the task-oriented service function chain optimized deployment, dynamic scheduling achieved through intelligent algorithms, and failure recovery accomplished via a matching game algorithm were proposed. Finally, a use case was constructed, setting node deployment and service function chain modeling. The effectiveness of the proposed strategies in improving the completion efficiency of service function chains and dealing with resource failures was verified, providing a theoretical basis for the resource allocation for the space-air-ground integrated network.