Abstract

The advent of 5G networks has facilitated various Industry 4.0 applications requiring stringent Quality-of-Service (QoS) demands, notably Ultra-Reliable Low-Latency Communication (URLLC). Multi-Access Edge Computing (MEC) has emerged as a key technology to support these URLLC applications by bringing computational resources closer to the user, thus reducing latency. Meanwhile, Network Function Virtualization (NFV) plays a broader role in supporting 5G networks by offering flexibility and scalability in service provisioning across a range of applications. Despite their benefits, MEC networks must adapt to dynamically fluctuating user demands and varying workloads, which can create challenges in maintaining QoS. This paper addresses the Virtual Network Function (VNF) placement problem in MEC networks, focusing on minimizing costs while ensuring QoS through VNF reuse. We propose a novel solution based on the Deep Transformer Q-network (DTQN) algorithm, leveraging reinforcement learning to optimize VNF placement and redeployment. Extensive simulations demonstrate that our DTQN algorithm outperforms baseline approaches, achieving up to a 9% improvement over the D3T-based method and up to 56% over the DQN-based method in terms of average rewards under certain scenarios. This leads to significant enhancements in cost efficiency, resource utilization, and QoS maintenance.