Research On Deployment Strategy Of Service Function Chain In Space-Air-Ground Integrated Network Architecture

The space-air-ground integrated network(SAGIN)holds immense potential in extending ground network and satisfying the diverse service demands of various emerging applications.Software defined network(SDN)and network function virtualization(NFV)construct orderly service function chain(SFC)of virtualized network function(VNF)nodes required for services and map them to the physical network layer,enabling flexible deployment of space-air-ground integrated network.However,existing SFC deployment strategy research mainly focuses on optimizing either resource consumption or latency,neglecting user communication model features and failing to coordinate and optimize heterogeneous communication and computing resources,resulting in load imbalances.To address these issues,this thesis first proposes an SFC deployment strategy based on joint adaptive optimization of expenditure cost and latency for different communication user types,achieving joint optimization of resource consumption and latency.Subsequently,the thesis introduces an SFC deployment strategy based on resource optimization in a coordinated space-air-ground network,realizing the coordination,balance,and optimization of communication and computing resources.The main contributions and innovations of this thesis are as follows:1.To address the problem that the SAGIN topology changes frequently and the information exchange is frequent,making it difficult to control it directly and effectively,this thesis integrates the concept of network function virtualization into SAGIN and proposes an SDN-based SAGIN architecture.By deploying SDN controllers at the ground core nodes and satellite nodes,the network can be flexibly scheduled and controlled,providing architectural and strategic support for subsequent service function chain deployment.2.In response to the high deployment cost and long delay issues in the user-oriented SFC deployment of the ground network architecture,this thesis proposes an adaptive SFC deployment strategy based on the joint optimization of resource consumption and delay for different user types.By considering the similarity between user geographic locations and node cache content,low-load node sharing is achieved,and the number of additional nodes is reduced by adaptively updating node cache content.Finally,by taking into account the power consumption of the link set,the optimal virtual link mapping scheme is determined.Simulation results show that compared with existing solutions,the proposed strategy reduces SFC deployment costs by about 22.3%,reduces deployment delays by about 13.7%,and improves the overall deployment success rate by about 13.4%.3.To address the issue of imbalanced and insufficient utilization of heterogeneous communication and computing resources in space-air-ground integrated network architectures,we propose a resource-optimized service function chain deployment strategy.This strategy balances the use of communication and computing resources and optimizes the resource costs required for SFC deployment within limited heterogeneous resources.We also present a resource-aware heuristic SFC deployment strategy to reduce computational time complexity.Simulation results show that compared with traditional deployment strategies,the proposed method can balance system resource utilization while reducing the probability of business blocking by about 7.9% and resource consumption by about 12.5%.