SPAVM: A SFC Placement and VNF Migration Framework for VNF Instance Reuse in Vehicle-Infrastructure Collaboration

In the context of Vehicle-Infrastructure Collaboration (VIC), this study addresses the critical challenge of optimizing Service Function Chains (SFCs) deployment within resource-constrained and delay-sensitive vehicular edge networks. By leveraging Virtual Network Function (VNF) technology, which shifts network services from traditional hardware to a more agile, container-based edge computing architecture, we aim to enhance the Quality of Service (QoS) for vehicular users. SFCs, composed of multiple VNFs arranged in a specific sequence, are pivotal for delivering a range of functional services essential for QoS enhancement. Our objective is to optimize the placement of SFCs by reusing VNF instances to minimize both delay and operational costs. The reuse of VNF instances, however, introduces two significant challenges: the effective placement of SFCs within vehicular edge networks and the optimization of VNF instance containers positioning. To address these challenges, we propose a robust framework called SPAVM (Service Placement and VNF Migration), which consists of two primary components: one for SFC placement and the other for VNF migration. For SFC placement, we introduce the Service Placement based on VNF Instance Reuse algorithm (SPVIR), which maximizes the utilization of existing VNF container resources. For VNF migration, we propose the VNF Instance Migration algorithm (VIMA), which considers edge server connectivity to determine optimal migration targets for VNF instance containers. Extensive experiments validate the proposed algorithms' performance, demonstrating their effectiveness in reducing delay and costs, thereby enhancing the overall efficiency of vehicular edge networks.