Where to Deploy an Airborne Relay in Unknown Environments: Feasible Locations for Throughput and LoS Enhancement

TL;DR

This paper analyzes optimal airborne relay placement in obstacle-rich environments to maximize line-of-sight probability and throughput, providing a mathematical framework for deployment decisions in complex terrains.

Contribution

It introduces a closed-form expression for LoS probability in 3D space and characterizes feasible relay locations satisfying specific communication constraints.

Findings

Derived a closed-form LoS probability expression.

Identified 3D manifolds of feasible relay locations.

Optimized relay placement for throughput enhancement.

Abstract

The deployment of heterogeneous teams of both air and ground mobile assets combines the advantages of mobility, sensing capability, and operational duration when performing complex tasks. Air assets in such teams act to relay information between ground assets but must maintain unblocked paths to enable high-capacity communication modes. Obstacles in the operational environment may block the line of sight (LoS) between air assets and ground assets depending on their locations and heights. In this paper, we analyze the probability of spanning a two-hop communication between a pair of ground assets deployed in an environment with obstacles at random locations and with random heights (i.e. a Poisson Forest) using an air asset at any location near the ground assets. We provide a closed-form expression of the LoS probability based on the 3-dimensional locations of the air asset. We then compute a 3-D manifold of the air asset locations that satisfy a given LoS probability constraint. We further consider throughput as a measure of communication quality, and use it as an optimization objective.