Airstring connects your drone to the internet using the mobile phone network.

Once your drone is online, you can simply connect to it via your internet connected smartphone or PC, using common apps, like Tower and Mission Planner, allowing you to upload missions, check flight parameters and send commands like Return-To-Home, wherever your drone is.

If it has mobile network coverage, it is connected.

Airstring is easy to set up, and comes with a DF13 connector that plugs directly into your Pixhawk telemetry port. Once your drone is switched on, Airstring immediately starts sending telemetry to the server.

Features

How Airstring works

Airstring is designed to make drone connectivity easy. The air module sends telemetry information to a server, which then forwards this information to the ground stations

AirString is composed of the following components, explained below.

Airstring Air

The Air module reads telemetry data from the pixhawk autopilot and relays them to the Airstring Server. It works with any SIM card.

The following picture depicts how to set up Airstring – Air.

Airstring App

The Airstring companion app connects to the server via the Internet and to the Air module via bluetooth. It has 2 main features:

• Allowing you to log in to the server and authenticate yourself as the user of the drone.
• Making changes to the configuration of the Air module

Although the Air module will attempt to configure itself with the information your SIM carrier provides, having a dedicated Android App makes it easier to make any possible changes to the configuration. Using an App is much more comfortable than running scripts or editing configuration files.

AirString Server

Network communications aren’t easy. Even less so when you are communicating through the phone Network and need a stable data stream. That is why we are offering our own servers to receive your telemetry and forward it to your smartphone or PC based ground control station. The service will be available for a 6$ monthly subscription fee.

However, we are aware that some users might prefer not to rely on 3rd parties when operating their drone. That is why we will release the server code Open Source, allowing you to run your own server at no cost, should you choose to do so.

The AirString Server offers the following functionalities:

• Instant, no hassle flight logs
• Remote assistance
• Fleet monitoring
• Location reporting

All these extra functionalities are further explained in the following sections.

Ground Control Station

You can use a common Ground Control Station such as Mission Planner, Tower, etc.

The Ground Control Stations integrate seamlessly with the Airstring app, allowing you to monitor and control your drone, just like a regular radio.

Security

You don’t always want to share your flight data, neither do we. Communication from Airstring to the Ground Control Station will be end-to-end encrypted, meaning no one (not even us!) has access to your flight data. If you decide to share your location we will read that before encrypting the traffic.

Extra Functionalities

AirString also provides several additional functionalities, explained below.

• Instant, no hassle flight logs  

Have all your flight history stored in the server and access it whenever you need. We are in talks to partner with online flight analysis services, to let you analyze these flights right from your browser.

• Remote assistance  

Imagine being on the field and having a problem with your drone that you can’t solve on your own. Just get your drone online and let the manufacturers’ support team see your telemetry, and make changes right from their office.

• Fleet monitoring  

You have a fleet of drones, that fly in different locations, or maybe you rent your drones to other operators. Are they operating them safely? With Airstring, you can monitor all your drones from anywhere, without bothering your employees or customers

• Location reporting  

Keep your location private, or make it available online, it’s up to you. In the long run, knowing where every UAV is flying will improve safety and awareness from other airspace users, manned or unmanned.

• Transparent UART mode

We will even implement a transparent UART feature, letting you connect any UART device (Drones, robots, arduinos, alarms, etc.) and access the data stream via UDP. If you do this, just know that the UDP transmission might change the order of your packets so you will have to re-order them later!

Technical specifications

• Maximum Bitrate: 114 kbps
• Latency: 2-4 seconds (not suited for joystick input)
• Based on Mediatek NT2505 (Designed specifically for IoT devices)
• Quad-band: 850/900/1800/1900 MHz (Worldwide coverage)
• Dimensions: 28mm X 23mm
• Connector: DF13 UART input
• Nano SIM
• Clock speed 260 MHz
• Other interfaces (not currently used): I2C, SPI, GPIOs, Bluetooth

Compatibility

Airstring is designed and tested for the Pixhawk autopilot. We even provide the necessary DF13 connector. If you’re using this flight controller, compatibility is guaranteed.

However, other autopilots and drones can also be compatible with the Airstring air module.

• Mechanical connection

To use the module you need to access the UART telemetry port on your drone and build a cable that fits the Airstring connector.

• Software connection

The input used for telemetry in the Airstring Air module is an UART port. If your drone uses a different port, like the CAN Bus in DJI Drones, it will not be compatible.

Airstring is designed for the Mavlink protocol. If the telemetry protocol of your drone is Mavlink, there are good chances that Airstring will work without extra configuration. This might be the case with the APM Flight Controllers or the 3DR Solo, but Airstring is NOT tested on these devices. We only own Pixhawk based drones so we currently cannot test on other platforms.

If your drone uses another telemetry protocol, you can try the experimental “Transparent UART mode”, which transmits the UART port without verifying the data.

If you have questions about compatibility for a particular UAV or Flight Controller please contact us for advice. We plan to extend compatibility to other flight controllers in the future.

Meet the Team

We are two telecommunications engineers with a passion for robotics and UAVs in particular. We have successfully taken part in ambitious projects like the integration of sensors for self driving cars, or the development of mission control software for a gasoline powered helicopter UAV.

For the last 2 years we have been building and operating drones regularly and were never satisfied with the communication systems available.

We started creating GSM telemetry for our own use, but we can make a much better contribution by offering high quality telemetry systems for drone operators worldwide. Airstring is the first step in this long term plan and we would love to have you on board.

Schedule

• June 2016: Finishing Air Module
• July 2016: Finishing server
• Aug 2016: Defining final hardware
• Sep-Oct 2016: Tests and Troubleshooting buffer
• November 2016: Shipping

Budget

The budget for the project will be allocated as follows: