Channel Modeling and Performance Analysis of Airplane-Satellite Terahertz Band Communications

TL;DR

This paper explores the feasibility of using the terahertz band for airplane-satellite communications, proposing a detailed channel model and analyzing capacity to enable high data rates during flights.

Contribution

It introduces a comprehensive channel model for aerial THz communications considering Earth geometry and frequency selectivity, and evaluates link characteristics and capacity for aviation applications.

Findings

Airborne THz links can reach up to 120 Gbit/s capacity.

The model accounts for Earth curvature and frequency-selective effects.

Airplane-to-satellite THz links become preferable at certain altitudes.

Abstract

Wireless connectivity in airplanes is becoming more important, demanded, and common. One of the largest bottlenecks with the in-flight Internet is that the airplane is far away from both the satellites and the ground base stations during most of the flight time. Maintaining a reliable and high-rate wireless connection with the airplane over such a long-range link thus becomes a challenge. Microwave frequencies allow for long link distances but lack the data rate to serve up to several hundreds of potential onboard customers. Higher bands in the millimeter-wave spectrum (30 GHz-300 GHz) have, therefore, been utilized to overcome the bandwidth limitations. Still, the per-user throughput with state-of-the-art millimeter-wave systems is an order of magnitude lower than the one available with terrestrial wireless networks. In this paper, we take a step further and study the channel characteristics for the terahertz band (THz, 0.3 THz-10 THz) in order to map the feasibility of this band for aviation. We first propose a detailed channel model for aerial THz communications taking into account both the non-flat Earth geometry and the main features of the frequency-selective THz channel. We then apply this model to estimate the characteristics of aerial THz links in different conditions. We finally determine the altitudes where the use of airplane-to-satellite THz connection becomes preferable over the airplane-to-ground THz link. Our results reveal that the capacity of the airborne THz link may reach up to 120 Gbit/s, thus enabling cellular-equivalent data rates to the passengers and staff during the entire flight.