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In a high-altitude test that could reshape the future of global satellite communications, China has successfully transmitted data at 1 gigabit per second (Gbps) from a geostationary orbit using a 2-watt laser. The signal, sent from 36,000 kilometers above Earth, outpaces the performance of Starlink by a factor of five—using significantly less power and without the need for a massive satellite constellation.
The breakthrough, led by researchers from Peking University and the Chinese Academy of Sciences, leverages a novel optical system capable of maintaining data integrity despite the vast distance and signal distortion caused by atmospheric turbulence. With this demonstration, China presents a compelling alternative to low-Earth orbit (LEO) models currently dominating the satellite internet industry.
The technology was successfully tested at the Lijiang Observatory in southwestern China, offering a tangible shift toward laser-based satellite networks—a domain that promises faster speeds, lower latency, and broader bandwidth than traditional radio-frequency (RF) systems.
Beyond LEO: A New Model for Orbital Data Transmission
China’s system breaks from the crowded LEO approach taken by companies like SpaceX, which relies on thousands of satellites orbiting just 550 kilometers above the Earth. Instead, Chinese scientists demonstrated a high-speed optical link from a geostationary satellite, positioned over 36,700 kilometers away.
According to reporting from the South China Morning Post, the experiment achieved 1 Gbps data throughput using a 2-watt laser, maintaining signal quality over a transmission range rarely attempted for such high bandwidth.
The system relies on a dual-technology solution known as AO-MDR synergy, which combines adaptive optics (AO) to correct signal distortion in real-time with mode diversity reception (MDR) to recover scattered laser signals. The corrected signal is then split into eight transmission channels via a multi-plane light converter (MPLC), where a real-time algorithm identifies the most coherent paths, enhancing reliability and reducing transmission errors.
The detailed technical analysis is available via Interesting Engineering, which confirmed that this system raised the usable signal rate from 72% to 91.1%, marking a significant gain in performance stability at long range.
Laser vs. Radio
While Starlink continues to expand its LEO network, offering internet access with median download speeds around 67 Mbps, the Chinese test proposes a model that could scale more efficiently. Traditional satellite internet systems using RF signals are increasingly constrained by spectrum congestion and regulatory bottlenecks. Optical laser systems, by contrast, offer greater bandwidth, minimal interference, and narrower beam profiles, enabling targeted, high-capacity links.
More importantly, the laser-based method reduces dependence on power-heavy amplification systems. The Chinese satellite needed just 2 watts—roughly the output of a household LED bulb—to transmit high-speed data from over 36,000 kilometers, compared to the hundreds of watts typically required for RF-based systems over similar distances.
According to the Acta Optica Sinica, which published the study, the system used 357 micro-mirrors within the adaptive optics array to reshape the incoming signal distorted by Earth’s atmosphere. The resulting signal was sufficiently strong and stable to be processed and decoded in real time, despite natural environmental interference.
A Foundation for Defense and Deep Space Communications
The implications of this demonstration stretch far beyond civilian broadband. Reliable, low-error laser communication systems from geostationary orbit have direct applications in space-based command and control, military communications, and deep space telemetry.
Laser communication also offers reduced detection risk, making it an appealing choice for encrypted government transmissions. While the project was framed as a scientific demonstration, China’s broader investment in satellite-based infrastructure suggests long-term strategic ambitions.
Laser communications also support more responsive control over planetary missions, with potential benefits for upcoming Moon and Mars operations. Because of their low latency and error rates, such systems are ideal for high-value, real-time data streams where every bit counts—especially where RF interference or distance has traditionally hampered fidelity.
The core challenge now lies in scaling the system. China will need to deploy multiple high-orbit satellites equipped with precision optical payloads and maintain a reliable global network of receiving ground stations. But the cost-to-performance ratio of laser-based GEO systems could ultimately undercut LEO constellations that require thousands of satellites to maintain full coverage.
