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Beyond Line-of-Sight UAV &
Remote Pilot Communications

Leveraging SyTech RADIUS and the Iridium Satellite Network for Beyond-Line-of-Sight Radio Communications.

Unmanned aerial vehicles (UAVs) have become an integral part of many industries, including agriculture, construction, and photography. However, for commercial UAVs to comply with Federal Aviation Administration (FAA) regulations, they must offer a means of communication with ground stations and registered aircraft while airborne. Beyond-Line-of-Sight (BLOS) radio communications provide a solution to this challenge. In this article, we will discuss how SyTech RADIUS and the Iridium Satellite Network have enabled UAV operators to comply with FAA regulations while operating from any location with an IP connection.

The SyTech RADIUS nPoint RoIP over Satellite Communications

The SyTech RADIUS nPoint Solution over Satellite Communications

The SyTech RADIUS solution enables remote pilots to communicate via radio-over-IP to the airborne radio installed on the UAV. The resulting network allows the remote pilot to communicate with ground control will complying the proper FAA frequency management. The encompassing network creates a Radio-over-IP (ROIP) environment unbound by distance, platform, or location.

The RADIUS Solutions incorporates four key subsystems: (1) the Radius Distribution Service, (2) the Radius Client Program for Windows, (3) the satellite link, and (4) the Radius nPoint RoIP gateway connected to the aircraft’s radio.

SyTech RADIUS nPoint - UAV Diagram.jpg

The Radius Distribution Service

The Radius Distribution Service (DS) functions as the operating system for the encompassing RoIP network. Built from the Linux kernel to functions as a RoIP management service, system owners can choose from a variety of the Radius DS form factors including a (1) Radius DS server node or gateway, (2) a dedicated Linux server, (3) or an instance of the Radius DS software accessible from the cloud. The Radius DS manages all nets, users, and status messages operating throughout the Radius network.

The Radius Client

The Radius Client functions as the graphical user interface for the Radius system. The Radius Client offers easy-to-use features designed for radio-over-IP communications as well as advanced features for multi-operator dispatch and command and control.

The Radius Client features remote radio control for select radio models. The Radius Virtual Control Head (VCH) enables virtual radio control features such as channel selection, zone selection, and other available functions of the radio.

RADIUS with APX and XTL monitor.png

The Radius Client provides a seamless communication experience for remote pilots, enabling them to operate UAVs from any location with an IP connection.

Iridium Satellite Network

The Iridium Satellite Network provides global coverage, enabling UAV operators to communicate with their aircraft from anywhere in the world. The network utilizes a constellation of 66 low-earth orbiting (LEO) satellites, providing reliable and low-latency communications.

The SyTech RADIUS solution leverages the Iridium Satellite Network to provide BLOS communications between the ground station pilot and the airborne VHF radio. The network provides a reliable and secure communication channel, ensuring compliance with FAA regulations.

Existing deployments of the BLOS Radius solution allows for 22 kps / 88 kps for up and downlink. SyTech developed the Radius solution to operate with clear audio down with a utilization of 9.6 kps per audio stream.

Radius nPoint

The Radius nPoint functions analog-to-digital radio interface gateway installed on the aircraft. The Radius nPoint physically connects to the airborne radio’s auxiliary port, allowing for two-way transmit and receive capabilities. The nPoint runs on 5 volts DC, with a power draw of 300mA. Its small size and low power requirements make it ideal for use in UAVs.

RADIUS nPoint.png

The nPoint receives radio audio and digitizes the reception. The nPoint utilizes an onboard Linux processor to compress the audio to 9.6 kps. Audio is packaged as UDP, reducing bandwidth requirements over the satellite link. The audio is then transported through the aircraft modem, the satellite network, and down to the RADIUS DS and Radius Client. SyTech property methodology insures clear, smooth audio at the operator locations in both transmit and receive from the remote pilot to the aircraft and from the ground station to the remote pilot.

The Radius nPoint offers the ability to communicate via RS-232 to the onboard radios, enabling remote radio control capabilities from the Radius Client. The resulting configuration allows the remote pilot to change frequencies as directed by ground control.

The SyTech RADIUS solution provides UAV operators with a means of complying with FAA regulations while operating from any location with an IP connection. The BLOS radio communications provided by the SyTech Radius solution enables clear, reliable communication between the ground station pilot and the airborne VHF radio. The solution leverages the Iridium Satellite Network, providing global coverage while enabling operators to communicate with their aircraft from anywhere in the world. 

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