Efficient Index-Based Multi-User Scheduling for Mobile mmWave Networks: Balancing Channel Quality and User Experience

Millimeter Wave (mmWave) communication technologies have the potential to establish high data rates for next-generation wireless networks, as well as enable novel applications that were previously untenable due to high throughput requirements.  Yet reliable and efficient mmWave communication remains challenged by intermittent link quality due to user mobility and frequent line-of-sight (LoS) blockage, thereby making the links unavailable or more costly to use.  These factors are further exacerbated in multi-user settings where beam alignment overhead, limited RF chains, and heterogeneous user requirements must be balanced.  In this work, we present a hybrid multi-user scheduling solution that jointly accounts for mobility-and blockage-induced unavailability to enhance user experience in mmWave video streaming applications.  Our approach integrates two key components: (i) a blockage-aware scheduling strategy modeled via a Restless Multi-Armed Bandit (RMAB) formulation and prioritized using Whittle Indexing, and (ii) a mobility-aware geometric model that estimates beam alignment overhead cost as a function of receiver motion.  We develop a comprehensive and efficient index-based scheduler that fuses these models and leverages contextual information, such as receiver distance, mobility history, and queue state, to schedule multiple users in order to maximize throughput. Simulation results demonstrate that our approach reduces system queue backlog and improves fairness compared to round-robin and traditional index-based baselines.