Radio Channel Characterization of Mid-Band 5G Service Delivery for Ultra-Low Altitude Aerial Base Stations

Abstract

This paper presents a study which evaluated the potential for using ultra-low altitude, unmanned aerial vehicles to deliver fifth-generation (5G) cellular connectivity, particularly into areas requiring short-term enhancement in coverage. Such short-term enhancement requirements may include large gatherings of people or during disaster scenarios where there may be service outages or a need for increased bandwidth. An evaluation of this approach was conducted with empirically generated results regarding signal quality and cellular coverage-illustrating the potential of using unmanned ultra-low altitude aerial vehicles to deliver 5G cellular mobile services. Specifically, channel gain, mean time delay of the received signals (τ mean), and the root-mean-square spread of the delay (τ rms) were investigated for two distinct user modes at three different drone heights for three selected environments-an open area (field), a tree-lined environment, and an enclosed area. Maximum likelihood estimates for the various drone heights, user modes, and operational environments were found to be Rician distributed for the received signal strength measurements, whereas τ mean and τ rms for the open and tree-lined environments were Weibull distributed with the enclosed area tests being lognormally distributed. The paper also investigates how the channel gain may be affected when operating in each of the various global bands allocated for mid-5G communications, namely, Europe, China, Japan, South Korea, and North America. These regional mid-5G band allocations were found to yield minimal variance for all the environments considered.

A Comprehensive Survey on UAV Communication Channel Modeling

“…where d is distance in meter, α represents the path loss exponent and β is the intercept point with the line d = 1 m, and X σ is a random variable that accounts for shadowing variation modeled with normal distribution and standard deviation σ . Using ultra-low altitude (5 m -15 m) UAVs to deliver 5G cellular mobile services, Catherwood et al [69] investigated the channel gain, mean time delay and the RMS spread of the delay at three different drone heights for an open area, a tree-lined environment, and an enclosed area at 3.4 GHz -3.8 GHz. They find that it is Rician distributed for the received signal strength, whereas mean time delay and RMS-DS for the open and tree-lined environments are Weibull distributed with the enclosed area tests being lognormally distributed.…”

Switched Low-Noise Amplifier Using Gyrator-Based Matching Network for TD-LTE/LTE-U/Mid-Band 5G and WLAN Applications

“…Band 42 and Band 43 range from 3.4 to 3.6 GHz and 3.6 to 3.8 GHz, respectively [16]. Moreover, 3.4-3.8 GHz is also the range for mid-band 5G communications for the EU licensed band [17]. The shared 5-GHz LTE-U band ranges from 5.150 to 5.925 GHz [2].…”

A survey of radio propagation channel modelling for low altitude flying base stations

“…However, the RPC modelling needs to be further investigated for the partially and fully obstructed channel because channel models in LOS distinctly differ from that of non-LOS (NLOS) [62]. An A2G channel modelling in the open area by investigating both large and small scale parameters within 3.4 -3.8 GHz frequencies was done in [63]. Another measurement campaign limited to open area and 40 m altitude in 1.2 GHz band for A2G channel modelling was done in [64].…”