The digitalization of industries and consumer experiences is expanding from the ground to the sky, both at low and high altitudes, driven by airline transformation, a rising drone economy, and the gradual maturation of the Advanced Air Mobility market. This creates growing demand for a high-quality 5G Air to Ground (ATG) network, which seamlessly integrates aerial and terrestrial stakeholders. 5G ATG represents a major technological innovation in mobile communications, utilizing 5G technology to establish a three-dimensional communications network that supports a wide range of use cases, including Inflight Connectivity for airlines, reliable datalinks for drones and eVTOLs, and sensing, based on the concept of an Integrated Sensing and Communication Network (ISAC).

Huawei and SkyFive IFC China have successfully completed the verification of 5G ATG technology based on the 4.9GHz frequency band and a standard 3GPP air interface. This milestone involved establishing communications between the 5G ATG base station and the airborne ATG terminal. Key advancements include the alignment of frame formats of the ATG network and public terrestrial networks, the mitigation of interference between 5G ATG and low-altitude sensing, and the mitigation of interference between 5G ATG and public terrestrial networks. With this, coexistence of 5G ATG with low-altitude aerial networks and public terrestrial networks is ensured, spectrum utilization is maximized, and seamless connectivity is enabled, which enables new use cases for digitalization in aviation.

5G ATG will establish stable communications between base stations on the ground, covering flight routes, and the airborne ATG terminal onboard the aircraft. This solution allows passengers to enjoy a seamless, high-speed mobile network experience at high altitudes while offering airlines new business opportunities, such as high-quality Internet services and in-flight online shopping. Additionally, 5G ATG will enhance the operational communications between aircraft and its corresponding ground systems, making processes smarter and thus improving efficiency and safety.

The application of 5G ATG holds significant potential, but deployment also presents numerous challenges:

• The first challenge is the complexity of the ground network. 5G ATG must not interfere or suffer interference from terrestrial networks. Huawei and SkyFive IFC China have successfully mitigated such interference by adopting a unified frame structure for both 5G ATG and public terrestrial network.
• The second challenge is ensuring consistent coverage of the aerial network. The high speed of the aircraft leads to frequent handovers, which can negatively impact the user experience. To address this, the coverage radius of a base station should be large. Huawei leverages key technologies such as Extremely Large Antenna Arrays (ELAA), multiple antennas, wide-angle coverage, and high Effective Isotropic Radiated Power (EIRP). These are combined with intelligent beamforming capabilities to create a seamless, high-quality coverage network in the sky.
• The last challenge is the Doppler shift caused by the high speed of aircraft, which impacts the quality of the connection. To address this, Huawei and SkyFive IFC China have implemented Doppler shift compensation for very high speeds. By utilizing the airborne ATG terminal to estimate and pre-compensate for frequency shifts, the impact on network access can be minimized, therewith ensuring reliable performance even at aircraft speeds of up to 1,200 kilometers per hour.

Looking ahead, Huawei is eager to collaborate with industry partners to develop a "1+1+N" 5G-ATG integrated network architecture. This framework encompasses a high-experience, high-reliability, three-dimensional 5G ATG network and an intelligent, efficient data processing platform, designed to support multiple digital economies. As 5G ATG gradually enters commercial use, it will not only address the increasing connectivity demands of the low-altitude and aviation sectors but also drive the industry towards greater intelligence and safety at large.

Huawei and SkyFive IFC China continue to showcase their exceptional capabilities in technological innovation and network value optimization. Building on their successful collaboration, both companies are committed to further strengthening their partnership and, together with industry allies, delivering superior wireless network services to users worldwide.

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About SkyFive IFC China:

SkyFive Inflight Connectivity (Beijing) Co. Ltd. is a sister company of SkyFive AG, operating independently as the leading provider of true broadband Internet services for China’s aviation industry. Leveraging Air-to-Ground (ATG) technology successfully deployed in the European Aviation Network (EAN), we are committed to developing and implementing our cutting-edge 5G ATG solution to enable seamless connectivity across China's skies. With extensive global operational experience, SkyFive IFC China aims to establish itself as the foremost leader in China's inflight connectivity market.

About SkyFive AG:

SkyFive provides Inflight Connectivity services based on its unique Air-to-Ground technology. The company’s mission is to deliver true broadband services to airline passengers, enable the real-time transfer of vast amounts of aircraft data, and support ultra-reliable low latency communications required for the mass proliferation of Advanced Air Mobility. SkyFive connects aircraft of any kind and size through giant cells in the sky, thereby leveraging the performance and cost benefits of the 4G and 5G mobile ecosystem. SkyFive was established as a spin-off from Nokia in 2019, is headquartered in Munich, Germany, and operates several sites for R&D and service delivery in major aviation markets.