한국미래기술교육연구원(kecft)은 25일 여의도 전경련회관에서 ‘UAM 민간 시장 확대를 위한 인프라/서비스 운영 및 기술’ 세미나에서 UAM 통신 및 자율주행 회랑 설계 방안에 대해 발표했다. UAM 본격 활성화가 되기 위해서는 국제 표준 UAAN 통신부터 상용화가 필요하다는 전문가의 의견이 제시됐다.
UAM Communications Requires Dedicated Solution to Complement LTE
ETRI, Drone Communication Network Standard UAAN Established
As national development is actively underway to secure the UAM (Urban Air Mobility) market, which has emerged as the next-generation mobility, experts have suggested that commercialization of international standard UAAN communication is necessary for full-scale activation of UAM.
On the 25th, the Korea Institute for Future Technology Education (KECFT) presented a plan for designing UAM communication and autonomous driving corridors at the seminar titled ‘Infrastructure/Service Operation and Technology for Expanding the UAM Private Market’ held at the Federation of Korean Industries building in Yeouido.
“While current drones are sufficiently advanced, there is no suitable drone communication solution worldwide,” said Hwang Hyeon-gu, a researcher at the Electronics and Telecommunications Research Institute (ETRI). “We need to actively invest in the communications field, such as commercializing the Unmanned Aircraft Area Network (UAAN), which is the only commercializable technology for drone-only communications.”
According to Researcher Hwang, the current status of UAM-related technology development is such that drones are being used for a variety of purposes, including filming and agriculture, but there is no suitable communication solution other than LTE communication.
While manned aircraft have ADS-B, a wireless communication method for recognizing each other and avoiding collisions, drones flying at low altitudes of 300 to 600 meters do not have a means of mutual recognition and collision avoidance communication, making them difficult to use with helicopters. Accidents such as drone collisions are frequent. LTE communication disruptions become more severe as altitude increases, requiring improvement, and Wi-Fi also has severe interference and short communication ranges in urban areas.
Ultimately, the construction of a dedicated communication system other than LTE is the top priority for UAM control. LTE has several limitations. It has problems such as the risk of network downtime, the need to pay for use, and repeater noise at high altitudes, so it needs to be supplemented.
In addition, UAM should ultimately aim for autonomous operation without a pilot on board and should be able to be remotely controlled, but autonomous flight does not require high-spec specifications such as LTE. There is also the problem that LTE base stations already provide services to smartphone users on the ground.
■ Domestic research team establishes drone communication network standard 
ETRI established the drone communication network standard UAAN last March. The technology is academically named EVAN. This enables information exchange as a common communication standard for all drone manufacturers.
It covers three areas: video communication, control communication, and shared communication, and shared communication, which mainly supports communication between drones, is attracting attention. According to the SCI paper, UAAN has been officially recognized as the only commercially viable technology.
The main features of UAAN are that it operates autonomously without ground base station infrastructure, and can be used free of charge once frequency allocation is completed. The frequency is the same as ADS-B, and it covers a communication distance of about 5 km. In addition to broadcasting, it supports one-to-one communication for path negotiation to avoid collisions.
The small tone channel that acts as a base station satisfies communication stability because the communication distance is more than twice as long and the data channel does not collide. Researcher Hwang added, “The fast unmanned contribution is also a tone channel, so the communication efficiency is good, and it is stable even when a large number of unmanned vehicles are deployed, and the complexity is also low.”
Using UAAN communication, not only drones but also related devices can be interconnected. Detection and avoidance services can use shared communication to recognize which drones are nearby and detect and negotiate risks. For detection, drones can first broadcast their basic locations, and then broadcast path points to achieve collision avoidance between drones.
In addition, service functions utilizing UAAN communication include: △Using it as a means of detecting illegal drones by transmitting data to the ground, △Attaching to real-time moving obstacles that do not appear on the 3D map during autonomous operation to avoid obstacles, △Real-time location tracking and monitoring/tracking based on drone and other drone information, △Dynamic geofencing settings, etc.
Researcher Hwang said, “We will work with the Ministry of Land, Infrastructure and Transport to create a model over the next two years and then conduct drone tests,” adding, “As the global drone market is being dominated, companies that commercialize communications will hold the key.”