Energy-Efficient Multi-Radio Microwave and IAB-Based Fixed Wireless Access for Rural Areas

TL;DR

This work tackles rural broadband connectivity where fiber deployment is impractical by proposing a unified multi-hop framework that combines long-haul microwave, IAB-based FWA, and mmWave/mid-band access to extend coverage and capacity. It addresses the critical issue of energy consumption in multi-hop networks by introducing a five-state microwave radio model and optimizing radio states together with RB allocation via dual decomposition and Disciplined Multi-Convex Programming with dynamic programming. The coupled optimization problems aim to minimize energy use while meeting data-rate requirements, and are solved with an energy-aware, scalable approach. Simulation results on a rural-like Montreal topology demonstrate meaningful energy savings and sustained performance compared to baselines, indicating practical relevance for rural broadband deployments.

Abstract

Deploying fiber optics as a last-mile solution in rural areas is not economically viable due to low population density. Nevertheless, providing high-speed internet access in these regions is essential to promote digital inclusion. 5G Fixed Wireless Access (5G FWA) has emerged as a promising alternative; however, its one-hop topology limits coverage. To overcome this limitation, a multi-hop architecture is required. This work proposes a unified multi-hop framework that integrates long-haul microwave, Integrated Access and Backhaul (IAB), and FWA to provide wide coverage and high capacity in rural areas. As the number of hops increases, total energy consumption also rises, a challenge often overlooked in existing literature. To address this, we propose an energy-efficient multi-radio microwave and IAB-based FWA framework for rural area connectivity. When the network is underutilized, the proposed approach dynamically operates at reduced capacity to minimize energy consumption. We optimize the off, start-up, serving, deep sleep, and wake-up sates of microwave radios to balance energy use and satisfying data rate requirements. Additionally, we optimize resource block allocation for IAB-based FWA nodes connected to microwave backhaul. The formulated optimization problems aim to minimize the energy consumption of long-haul microwave and multi-hop IAB-based network while satisfying data rate constraints. These problems are solved using dual decomposition and multi-convex programming, supported by dynamic programming. Simulation results demonstrates

Figures (17)

• Figure 1: Illustration of our system model.
• Figure 2: Microwave radio states and sub-states.
• Figure 3: Mid-band and mmWave states at IAB station.
• Figure 4: Selected cluster (in red) to represent rural area.
• Figure 5: Network topology for rural area and the distance between nodes.

Theorems & Definitions (1)

• Remark 1