RIS-Assisted Proactive Handover for Reliable mmWave Wireless Networks

2026-06-25

AI Summary

This work addresses the vulnerability of millimeter-wave networks to line-of-sight blockage and the inefficiency of proactive handover in the absence of neighboring base stations. It proposes a novel proactive handover mechanism that integrates reconfigurable intelligent surfaces (RIS) with vision-aided communication, explicitly incorporating RIS configuration time into handover decision-making. By offline optimizing end-to-end RIS-assisted links and dynamically allocating the number of RIS elements via particle swarm optimization under handover timing constraints, the approach jointly balances link quality and computational complexity. Experimental results demonstrate that the proposed method achieves a 15–30 dB signal-to-noise ratio gain in blocked regions, reduces energy consumption by 10% with only a 12% reduction in RIS elements, and ensures low-latency, energy-efficient handovers.

Abstract

Millimeter-wave (mmWave) networks are highly susceptible to line-of-sight (LoS) blockages. Vision-aided wireless communications (VAWC) enable proactive handovers (PHO) to mitigate such blockages; however, PHO becomes challenging when no nearby base station (BS) is available. In such cases, reconfigurable intelligent surfaces (RIS) can be used to restore connectivity. To ensure timely PHO, the RIS configuration time must be taken into account, as the large number of RIS elements can limit responsiveness in time-sensitive scenarios. This work proposes a novel RIS-assisted PHO approach that optimizes the number of allocated RIS elements to balance signal processing complexity and link quality under handover timing constraints, making the RIS-assisted link more energy-efficient. An optimization problem based on particle swarm optimization (PSO) is formulated to determine the optimal end-to-end RIS link setup that runs offline to bypass latency constraints. Results show that reducing the number of RIS elements by 12\% leads to a 10\% decrease in dissipated energy without compromising the signal-to-noise ratio (SNR). Moreover, the RIS-assisted link achieves a 15--30 dB improvement in blocked regions while maintaining accurate PHO timing.

Problem

• mmWave networks
• proactive handover
• line-of-sight blockage
• reconfigurable intelligent surfaces
• handover timing

Innovation

• Reconfigurable Intelligent Surface (RIS)
• Proactive Handover (PHO)
• mmWave Networks
• Particle Swarm Optimization (PSO)
• Energy Efficiency