The Impact of Smartphone-Satellite Integration on Uninhabited Areas

In an era where connectivity is crucial, what happens when you lose your mobile signal in remote locations—deep forests, vast deserts, or isolated wilderness? At such moments, a smartphone with satellite calling functionality could be a lifesaver.

Thanks to China’s innovation in satellite communication, ordinary smartphones can now connect to the world without requiring a SIM card change. This milestone, achieved through the Tiantong-1 satellite mobile communication system, is a result of the collaborative efforts of China Telecom, Huawei, and other industry leaders over two years of research and development.

Checking mobile signal strength to stay connected.

Overcoming Design Challenges

One of the biggest hurdles faced by the R&D team was integrating satellite connectivity into a standard smartphone without an external antenna. Traditional satellite phones rely on bulky external antennas and satellite chip modules to connect to satellites positioned 36,000 kilometers above the Earth. However, these features were not compatible with the sleek designs of modern smartphones.

Initially, the team considered an attachable antenna that could be connected when needed. However, a Huawei engineer insisted that consumers would not accept such a cumbersome design. The team ultimately decided to embed the antenna within the phone, a move that required redesigning the motherboard layout and increasing the number of antennas to enhance signal transmission and reception. By leveraging innovative technologies such as discontinuous transmission and efficient power management, the satellite module, originally occupying half the mainboard, was reduced to the size of a fingernail.

Ensuring Stable Smartphone-Satellite Connectivity

While integrating an internal antenna was a major achievement, ensuring stable satellite connectivity posed another challenge. Given the high altitude of geostationary satellites, simply increasing antenna gain was insufficient. The team explored two options: increasing signal power or reducing the data transmission rate. The latter proved to be the more viable solution.

Through rigorous testing and software optimization, they determined that reducing the data transmission rate to 800 bits per second struck the right balance between network capacity and call quality. However, this was just the beginning. To ensure the system’s reliability, the team conducted field tests across some of the most remote areas in China, including Lop Nur, Qiangtang, and Mohe, covering over 3,000 kilometers. Engineers spent months in harsh conditions to fine-tune the system, ensuring seamless connectivity in even the most challenging environments.

Bridging the Gap Between Satellite and Ground Networks

One of the final obstacles was integrating satellite and terrestrial networks to allow users to make satellite calls using their existing phone numbers. Traditionally, satellite and ground networks operate independently, making it impossible to use the same number for both. During testing, calls made with the Tiantong-specific number 1740 were frequently mistaken for spam and ignored.

To resolve this, the team developed a solution enabling the Tiantong system to recognize standard mobile numbers. This required rewriting and updating protocols—over 1.65 million words of technical documentation—to ensure seamless integration. The result was a unified system where smartphones could automatically switch between ground and satellite networks without user intervention.

A New Era of Connectivity

In August 2023, Huawei’s Mate 60 Pro became the first commercially available smartphone featuring direct satellite calling. This breakthrough not only enhances personal communication in remote areas but also has significant implications for emergency response, disaster relief, and national security.

Reflecting on the journey, the R&D team acknowledged the immense challenges they had overcome, pioneering technology that has the potential to transform global communication. Looking ahead, China

Telecom and its partners aim to further enhance innovation, leveraging digital technology to develop new applications that improve everyday life.

As the world moves towards a more connected future, satellite-enabled smartphones mark a significant step forward, ensuring that no one is ever truly out of reach—no matter where they are.