China’s Tiantong vs. Starlink: Smartphones Can Now Call Directly via Satellite
Chinese engineers have developed the world’s first satellite that allows smartphones to make direct calls, bypassing ground-based cell towers. This innovative solution is designed for use in emergencies, such as natural disasters or other crises, when mobile networks may be disrupted.
Origins of the Tiantong Project
The concept for such a satellite emerged after the 2008 Sichuan earthquake, a tragedy that claimed over 80,000 lives. One of the main challenges during the disaster was communication breakdowns, which severely hampered rescue operations. In response, the Chinese government launched the Tiantong project—a satellite communication system aimed at providing universal access to communication services, regardless of social status.
Progress and Achievements
It has been 16 years since the Tiantong project began, and significant advancements have been made in satellite communication technology. The first Tiantong-1 satellite was launched in 2016, followed by two more in 2020 and 2021. Together, they form a network in geosynchronous orbit at an altitude of 36,000 km, covering the entire Asia-Pacific region.
Smartphones with Satellite Calling
Last year, Huawei Technologies introduced the world’s first smartphone capable of making satellite calls compatible with Tiantong satellites. Other Chinese smartphone manufacturers, including Xiaomi, Honor, and Oppo, have also released similar models. These products have been well received by Chinese consumers, and industry estimates suggest that Huawei alone has sold tens of millions of units, surpassing the reach of Starlink, which has over 2 million customers worldwide.
Technical Challenges and Breakthroughs
One of the main technical challenges for direct satellite communication with mobile phones was passive intermodulation (PIM), which hindered technological development. Chinese scientists conducted groundbreaking research to reduce PIM effects, leading to the creation of new suppression methods and advanced detection technologies.
China’s Leadership in Satellite Communications
The Tiantong project highlights China’s leadership in satellite communication technology and its commitment to solving key challenges in the aerospace industry. Additionally, China’s extensive patent portfolio in this field ensures local high-tech companies have free access to advanced technologies, protecting them from potential patent restrictions or sanctions from the West.
Starlink’s Approach and Future Competition
Earlier this year, SpaceX launched the first of several Starlink satellites capable of connecting to smartphones, with plans to begin commercial service next year. Starlink satellites operate in low Earth orbit, just a few hundred kilometers above the surface, and have smaller antenna areas, which reduces PIM interference. However, because a satellite can only cover a specific area for a short period, a large number of satellites is needed to achieve broad and continuous coverage.
Currently, most of the more than 5,000 Starlink satellites launched by SpaceX do not support direct mobile phone connections. However, the new Starlink satellites have a significant advantage: they can connect to older phones via 4G.
The Future of Satellite Communication
The ongoing rivalry between China’s Tiantong project and SpaceX’s Starlink satellite system is set to shape the future of satellite communication technology, with far-reaching implications for global connectivity.