uAvionix has received approval from the FAA to develop and test an “ADS-B like” solution for Unmanned Aircraft Systems Remote Identification and Detect and Avoid capability.
The solution, with the working title “UDS-B,” leverages similar protocols and structures as ADS-B, but operates on a different, non-interfering frequency, according to uAvionix officials. It also contains message content that is adjusted to be appropriate for unmanned systems, officials add.
Core principals of the UDS-B framework include:
- UDS-B leverages an FAA authorized protected spectrum. This means both the FAA and the FCC have to approve devices that transmit in this range, and approval can be specific to each operation. The use of this spectrum would also allow more secure and higher power transmission for longer ranges than devices operating in the Industrial, Scientific, and Medical (ISM) frequencies, such as Bluetooth or Wi-Fi.
- The starting point for the message protocol is the Universal Access Transceiver (UAT) protocol of ADS-B. This protocol is well understood and works well in deconflicting messages in a high traffic environment, uAvionix officials note. It is expected that ultimately fields could be altered under an industry initiative to expand the available unique addresses, as well as include important fields like launch location or operator info, and address encryption.
- Existing ADS-B radios can be “retuned” to adjust to the new frequency. Existing antennas should work well, company officials said. This opens the possibility to put “UDS-B In” receivers in manned aircraft, near airports, or develop worldwide crowdsourced receiver networks like those that can be found on FlightRadar24.com.
- If need be, “translators” — much like today’s Traffic Information Service-Broadcast (TIS-B) and ADS-Rebroadcast (ADS-R) systems —could be deployed to selectively translate a UDS-B target to an ADS-B target without years of development.
The key to success for the L-Band application is to utilize what is known as “DME Whitespace,” uAvionix officials said.
Overall, at any given time at a given location and altitude, dozens of DME channels in the 960-1215MHz range are unused owing to their known geographic distribution within the National Airspace System, relatively short transmission range, and very low transmission rates. A section of airspace where DME frequencies are currently not in use is known as “DME Whitespace.” DME Whitespace represents available spectrum that can be used by low-altitude UAS for command and control or surveillance applications by leveraging modern digital radios that are location-aware and can change their operating frequencies prior to or during flight, company officials explain.
Initial testing will be conducted in Bigfork, Montana, at the uAvionix headquarters.