The satellite communication industry has launched a "positioning battle."

Currently, a new round of technological revolution and industrial transformation is accelerating, with major cutting-edge technologies and disruptive technologies continuously emerging. Especially in the field of satellite communication, the international competitiveness of domestic high-end products represented by satellite direct connection mobile phones has significantly increased.

Recently, the Ministry of Industry and Information Technology and seven other departments jointly issued the "Implementation Opinions on Promoting Innovation and Development of Future Industries," which proposed to proactively layout key technology research such as 6G, satellite internet, and mobile phone direct connection to satellites.

Experts have stated that in this "race for position" in the satellite communication industry, whoever can take the lead in the mobile phone direct connection to satellites will occupy a high ground in the standard setting and rule shaping of non-ground communication in the future 6G era.

　　New standard configuration for smartphones

Today, satellite communication is gradually becoming a new standard configuration for high-end smartphones. In August 2023, Huawei launched the world's first satellite voice call smartphone, the Mate60Pro, before its official release. By the end of the same year, OPPO and Honor also announced the release of new phones supporting satellite calls on the same day, catching up with Huawei.

Prior to this, in September 2022, Huawei had already introduced the Beidou satellite messaging function on its Mate50 phone, allowing users to send text and location information via Beidou satellites. This marked the first time that consumer-grade mobile phones directly integrated satellite communication functions without relying on any external devices. Almost simultaneously, Apple also added a satellite emergency contact function to its iPhone 14, limited to sending messages to designated contacts without the ability to receive replies. The competition among consumer-grade mobile phones for satellite communication thus began.

He Xia, an engineer at China Telecom Satellite Application Technology Research Institute, stated in an interview with China City News: "After achieving satellite SMS communication, Huawei has realized satellite voice calls through Tiantong satellite technology, and will next develop satellite data transmission, gradually increasing transmission rates."

He further introduced that currently, SMS and voice are mainly realized through high-orbit satellites, while data transmission relies more on low-orbit satellites, with the ultimate goal of fully integrating satellite communication functions into mobile phones.

In the past few decades, satellite communication has been in the era of portable dedicated terminals, during which satellite systems such as Iridium, Globalstar, and ViaSat have emerged one after another. However, for a long time, dedicated satellite communication terminals have not seen significant improvements due to their large size and single functionality. Even SpaceX's Starlink requires dedicated equipment to access the internet, making it impossible to communicate while on the move. Industry experts generally believe that the user base for dedicated satellite communication terminals is small, and the difficulty in forming scale and reducing costs has limited significant investment in the industry chain to improve equipment.

To promote the commercial application of satellite communication on a larger scale, the key is to activate the consumer-grade market. Currently, mobile phone direct connection to satellites is mainly achieved through three technical paths: the first is to integrate existing satellite communication technology into mobile phones in the "old satellite new device" model; the second is to develop new dedicated satellites to be compatible with existing mobile phones in the "new satellite old device" model; the third is to design the next generation system according to international standards in the "new satellite new device" model. Among them, the "old satellite new device" model, which relies on existing high-orbit satellites and other mature satellite systems, is considered a way to quickly enter the market. It is reported that brands such as Huawei, Honor, and OPPO have launched or are about to launch satellite call phones using this technical route, based on the Tiantong satellite developed by China Telecom.

Lan Tianyi, founder of Beijing Qianyu Aerospace Consulting Co., Ltd., stated: "Mobile phone manufacturers are using in-orbit satellites, which cannot be significantly changed, so they can only focus more on modifying the ground terminal side. Therefore, this round of satellite communication boom is driven by mobile phone manufacturers."

Lan Tianyi pointed out that the core breakthrough for technology implementation lies in miniaturizing and reducing the power of the satellite dedicated terminal communication system, which consists of components such as antennas, RF, and baseband, and integrating it into lightweight mobile devices.

To ultimately achieve mobile phone direct connection to satellites, operators also need to make adjustments and optimizations on the network side. He Xia stated: "The principle of achieving mobile phone satellite calls is that the mobile phone directly connects to the satellite, which then indiscriminately transmits the information back to the ground station. The ground station receives and parses it, then sends it to the core network, and finally dials to the 4G or 5G base station to connect to the target phone."

He Xia also mentioned that China Telecom has unified the protocols of satellite networks and ground networks, and has obtained 42 patents in this field.

Currently, the newly established China Star Network in 2021, along with several commercial space companies including Galaxy Aerospace, are actively laying out low-orbit satellite internet and attempting to build a trial network that integrates satellite and ground.

　　How to "break through the sky"

According to the "5G NTN Technology White Paper" released by China Telecom in November 2023, over 80% of land areas and over 95% of ocean areas globally still lack ground network coverage. Satellite communication can better compensate for the limitations of ground communication systems due to terrain.

Tiantong satellites began civilian use in 2016, with China Telecom becoming the only licensed satellite communication operator in the country. He Xia stated that China Telecom has developed 35 dedicated terminals over the years, covering multiple application fields such as vehicle-mounted, ship-mounted, and airborne. To break through the growth bottleneck, China Telecom is also moving from dedicated fields to the consumer market, working to verify the feasibility of mobile phone direct connection to satellites.

In December 2021, China Telecom took the lead in organizing terminal, chip, and other manufacturers to streamline related processes. He Xia stated that at that time, the industry faced two choices: one was to integrate the existing Tiantong satellite dedicated solution into mobile phones, and the other was to adopt the non-terrestrial network (NTN) solution led by the international standardization organization 3GPP.

He Xia told China City News: "Nothing is ready-made. Satellites and core networks need significant changes, and the chip industry has yet to have a recognized, commercially viable solution."

Ultimately, with Huawei's support, based on the direct connection method of the existing Tiantong network, both parties successfully verified the feasibility of commercialization after repeated network joint debugging and terminal ground signal testing.

To develop smartphones with satellite communication capabilities, the first problem to solve is to establish a connection between the mobile phone antenna and the Tiantong satellite located 36,000 kilometers away. To address this challenge, Huawei adopted engineering innovations: distributing the mobile phone antenna around the mainboard and optimizing the signal reception and transmission capabilities by increasing the number of antennas and adjusting their spatial layout, demonstrating its independent research and development capabilities in the field of satellite communication.

He Xia revealed that China Telecom originally planned to retain the external antenna, but Huawei insisted on making breakthroughs. After joint efforts from both companies, the current mobile phone design was achieved. In addition, China Telecom also optimized the network side, reducing the requirements for the mobile phone side antenna, such as lowering voice transmission rates and increasing network capacity.

Miniaturization of chips is another major challenge. He Xiao pointed out that the satellite terminal chip module originally needed to occupy half the area of an ordinary mobile phone, but through collaboration among various parties in the industry chain, this size has been significantly compressed, and it has now reached about 100 square millimeters, roughly equivalent to the area of a fingernail.

Although satellite communication modules will increase the production costs of mobile phones, He Xiao pointed out that the high shipment volume of smartphones can more effectively share the costs.

After a series of tests and adjustments, the terminal side for direct satellite connection by mobile phones is basically ready in the first half of 2023. Blue Sky Wing pointed out that Huawei's attempts have played a demonstrative role, showcasing the feasibility of this goal and inspiring other manufacturers to actively explore different technological paths.

It is worth mentioning that Honor also launched a development and verification project for a mobile phone direct satellite connection solution called 'Hongyan' two years ago.

　　Expected to become a trillion-yuan market

Currently, the 'old star new machine' solution commonly adopted by Chinese mobile phone manufacturers has inherent limitations such as limited capacity and high costs. As satellite phones become more prevalent, can the bandwidth of Tiantong satellites effectively support this?

Yang Guang, a senior chief analyst at Omdia's telecom strategy, pointed out that the current 'old star new machine' model relies on dedicated chips and links to communicate with satellites. Proprietary systems operate independently from ground 4G, 5G, and other cellular networks, requiring users to manually switch to make satellite calls. In contrast, the second-generation satellites planned for deployment by the American company AST and SpaceX adopt a 'new star old machine' model, which utilizes existing frequency bands of operators to achieve satellite signal transmission and reception, allowing for the rapid launch of satellite communication services and maximizing the utilization of the existing mobile phone market. However, this model places higher demands on satellite R&D capabilities and faces many challenges in implementation.

In fact, it is very difficult to increase capacity through modifications for satellites that have already been launched into orbit; capacity can only be improved by enhancing the efficiency of existing capacity utilization through ground-side chips and network modifications. For example, during the implementation of the Tiantong solution, in order to maximize the preservation of the fidelity of Chinese voice and tone frequency bands, the voice bandwidth for calls was compressed by nearly 97%.

Currently, the recommended satellite call duration for the Huawei Mate60Pro is five minutes. This limitation is partly due to the fact that the Tiantong satellite itself is a professional-use satellite with limited transmission resources, with only about 30% of its capacity allocated for civilian communication; at the same time, when making satellite calls, the relevant satellite communication module in the phone generates high power, leading to heat dissipation issues.

Yang Guang believes that theoretically, the NTN technology route led by 3GPP may be a better path choice. The NTN standard is unified, and once the technology and business model are established, it can quickly reduce costs by relying on the global annual shipment of over one billion mobile phones. Under the NTN technology path, satellite networks will organically integrate with ground networks, allowing users to make calls without manually switching networks.

A reporter from China City learned from the R&D department of Honor that terminal manufacturers are likely to promote R&D internally in a multi-point synchronous manner for verification, rather than solely 'betting' on a specific technology path. Currently, whether considering the maturity of operator services or the practical application maturity of mobile phone technology, the solution relying on Tiantong satellites is the most feasible.

Regardless of the technology path adopted, the entry of satellite communication into the consumer market has become an unstoppable trend. Lin Guangrong, an architect of the Galaxy Aerospace constellation communication system, believes that there are over 5.2 billion mobile phone users globally, and even if only a small portion of users are willing to pay extra for satellite communication services, it represents a huge market potential. He pointed out that compared to satellite calls, the prospect of providing satellite internet services to remote areas is clearer. This is because in many remote areas, satellite internet is more economically feasible compared to the ground deployment costs of laying fiber optics or building base stations.

Lin Guangrong stated that the satellite communication industry is expected to become a trillion-yuan market in the future. It can not only enrich special application scenarios such as ocean communication, oil exploration, and emergency rescue but also fill the communication network gaps covering over 80% of the land and ocean globally. This will stimulate innovation across the entire industry chain, including operators, component manufacturers, and equipment vendors, thereby promoting the progress of the entire industry.

■ Reporter Sun Xuefei from China City