The Rise of UAV Fleet Technologies for Emergency Wireless Communications in Harsh Environments

TL;DR

The paper addresses the challenge of delivering reliable emergency wireless communications in harsh disaster environments. It proposes MuHun, a multi-tier heterogeneous UAV network that combines high-endurance aerial platforms, low-altitude UAVs, RIS-enabled reflectors, and coil-based underground connectivity to achieve full coverage, high capacity, low latency, and energy efficiency. Key contributions include (i) a refreshed KPI framework for EcoNets, (ii) a MuHun-based architecture with deployment, routing, and cross-layer optimization, and (iii) four advanced solutions: hybrid-channel adapted resource allocation, RIS-UAV communications, competitive HetNets, and meta-MI A2G/A2UG links. These approaches collectively enhance resilience and responsiveness in disaster rescue, enabling robust coverage for ground and underground users while managing scarce resources. The work lays a foundation for intelligent, future-proofEcoNets that integrate beyond-5G/6G techniques to support rapid decision-making and recovery operations in real-world emergencies.

Abstract

For unforeseen emergencies, such as natural disasters and pandemic events, it is highly demanded to cope with the explosive growth of mobile data traffic in extremely critical environments. An Unmanned aerial vehicle (UAV) fleet is an effective way to facilitate the Emergency wireless COmmunication NETwork (EcoNet). In this article, a MUlti-tier Heterogeneous UAV Network (MuHun), which is with different UAV fleets in different altitudes, is proposed to flexibly serve various emergencies. We refresh the key performance indicators of full coverage, network capacity, low latency, and energy efficiency in harsh environments. Then, we present the special challenges regarding shadowing-dominated complex channel model, energy supply limited short-endurance, various communication mechanisms coexistence, and communication island for underground users in UAV-based EcoNet, followed by the MuHun-based EcoNet architecture and its advantages. Furthermore, some potential solutions such as the new hybrid-channel adapted resource allocation, reconfigurable intelligent surface assisted UAV communications, competitive heterogenous-networks, and magnetic induction based air-to-ground/underground communications are discussed to effectively achieve full coverage, high capacity, high energy efficiency, and diverse qualities of services for EcoNets in harsh environments.

Figures (6)

• Figure 1: The MuHun-based emergency wireless communications network architecture.
• Figure 2: PDF of shadowing-dominated channel.
• Figure 3: The capacities with the EcoNet channel adapted resource allocation schemes (including joint power-bandwidth optimization and power allocation) and traditional channel adapted resource allocation schemes (including joint power-bandwidth optimization and power allocation).
• Figure 4: The energy efficiencies with different numbers of traditional UAVs and RIS-UAVs.
• Figure 5: Spectrum utilization for competitive HetNet and throughput performance evaluation for the proposed coexistence scheme. (The numerical results shows the individual throughput and sum throughput performance with channel utilization of LTE-U, where FDTT denotes Full-duplex based two-threshold methods, FD-DC denotes Full-duplex based duty-cycled methods. HD-DC denotes Half-duplex based duty-cycled methods, $P_{FA}$ denotes false alarm probability, $P_{MD}$ denotes miss detection probability, and $q$ denotes the probability that detected energy falls between two thresholds.)