Energy-Aware Resource Optimization for Improved URLLC in Multi-Hop Integrated Aerial Terrestrial Networks

The development of futuristic wireless infrastructure necessitates low power consumption, high reliability, and massive connectivity. One of the most promising solutions to address these requirements is the integration of aerial base station (ABS) based communication systems that employ both in the air (aerial) and on the ground (terrestrial) components. This integration enhances line of sight connections, enabling the fulfillment of escalating quality-of-service (QoS) demands. This article examines the problem of resource allocation in ABS assisted multi-hop wireless networks. We investigate a joint optimization problem that involves subcarrier (SC) assignment, power allocation, and blocklength allocation, subject to delay, reliability, and QoS constraints to improve the sum-rate under the finite blocklength (FBL) regime. We propose an approach for SC allocation and selection of cooperative ABSs based on matching theory. Subsequently, we employ an alternating optimization method to propose a novel bisection-based low-complexity adaptation (BLCA) algorithm to optimize the resource allocation policy. This algorithm includes a two-step projected gradient descent-based strategy to optimize the power allocation on each SC using dynamic and geometric programming. Furthermore, we examine flexible blocklength and power allocation use cases under the next generation of multiple access techniques. Monte-Carlo simulations validate that the proposed algorithmic solution significantly achieves a near-optimal solution while requiring 1600 times less computational cost compared to benchmarks in its counterparts.

I. Introduction

The emergence of advanced wireless infrastructure has transformed how information is generated, disseminated, received, and perceived [1]. The capacity is expected to increase by up to 1000 times to support the growing number of wireless users and Internet of things (IoTs) devices [2]. Therefore, a few novel communication paradigms are needed to address three key connectivity types that align with the new technical requirements: enhanced mobile broadband (eMBB) to provide high throughput for demanding clients, massive machine-type communication (mMTC) to support low-cost, low-power IoT devices, and ultra-reliable low-latency communication (URLLC) to support mission-critical IoT devices, such as tactile Internet and autonomous vehicles, which require stringent quality of service (QoS) requirements to achieve a delay of less than one millisecond and reliability greater than 99.9999% [3].