Availability-Aware and Delay-Sensitive RAN Slicing Mapping Based on Deep Reinforcement Learning in Elastic Optical Networks

To ensure reliable network services, the link protection method is widely employed for light-path provision. However, it inevitably increases propagation delay due to different transmission distances between active and backup light-paths, leading to a longer transport delay. Consequently, a crucial challenge is how to coordinate link protection and transport delay to maximize service availability while satisfying the delay requirements of each service. In this paper, we investigate the availability-aware and delay-sensitive (AADS) radio access network (RAN) slicing mapping problem with link protection in metro-access/aggregation elastic optical networks (EONs). We initially provide the mathematical model of availability and propagation delay for both unprotected and protected RAN slicing requests. Subsequently, we propose a mixed-integer linear programming (MILP) model and a deep reinforcement learning (DRL)-based algorithm to maximize the availability of RAN requests while satisfying the specified delay requirements of each slice. Finally, we analyze the availability under various 5G services (i.e., enhanced Mobile Broadband, ultra-Reliable Low-Latency Communication, and massive Machine Type Communication) from a delay perspective in both small-scale and large-scale networks. Simulation results demonstrate that our proposed DRL-based method can achieve up to a 14.1% increase in availability compared to the benchmarks.