Huawei's Mate60's "mobile phone directly connected to satellite" function realizes voice communication between consumer terminals and satellites, and Elon Musk's Starlink (Starlink) low-orbit constellation operates on a large scale and achieves profitability, and on the basis of being far ahead in the field of broadband satellite Internet, the "mobile phone directly connected to satellite" business plan has been launched. At present, commercial aerospace and low-altitude economy, as representatives of new quality productivity, have become the strategic direction of the next stage of development of the digital economy.
Mobile operators are the basic operators of the mobile Internet, and satellite operators are responsible for the construction and operation of low-orbit satellite constellations. In the upcoming 6G era, it has become an industry consensus to realize "mobile phone direct connection to satellite", so what changes will occur in the relationship and positioning between mobile operators and satellite operators in this context?
The development status of "mobile phone direct connection to satellite" at home and abroad
Satellite communication is a relatively advantageous field in Europe and the United States, Starlink has successfully launched more than 6,000 low-orbit satellites, achieved large-scale operation of more than 2 million users, and achieved a positive single-quarter operating cash flow in 2023, which makes commercial aerospace and satellite Internet the focus of competition among countries, and opens the "horse race" movement of "frequency preservation and orbit occupation" of low-orbit constellations in various countries.
Three satellite companies, including AST, Lynk (American Satellite Telecommunications Corporation), and Starlink, will all start to try "mobile phones directly connected to satellites" in 2023. On April 25, 2023, AST opened the world's first "satellite-to-cell" voice call, on June 2, 2023, Lynk announced the connection to space-based voice calls, and Starlink and six terrestrial mobile operators launched a new Direct to Cell service, planning 2016 satellites, and plans to complete the commercial deployment of "handset direct-to-satellite" in 2025.
Huawei's Mate60 mobile phone launched in 2023 integrates consumer terminals with Tiantong satellite terminals, integrating the "mobile phone directly connected to satellite" function into ordinary smart consumer terminals. Different from the "mobile phone directly connected to satellite" in Europe and the United States for ordinary 4G mobile phones, the 4G/5G mobile phone and satellite terminal highly integrated mode currently adopted by the mainland belong to the dual-mode terminal model, and the two are very different in the way they are realized. The "mobile phone direct connection satellite" mentioned in this article refers more to the "cellular mobile phone direct connection to satellite" mode in Europe and the United States, rather than the dual-mode terminal model, and the three major domestic mobile operators are actively carrying out research on "cellular mobile phone direct connection satellite" based on 3GPP NTN (non-terrestrial network).
With the gradual clarity of the vision of 6G space-air-ground integration, 3GPP has made rapid progress in the standardization of the "mobile phone directly connected to satellite" protocol, and NTN was introduced for the first time in R17 in 2022, and the evolution route and standard of "mobile phone direct connection to satellite" have gradually become clear. In the construction of low-orbit satellite constellations, the mainland focuses on the research and planning of "mobile phone direct connection satellites" based on NTN technology. At the WRC-23 (World Radiocommunication Conference) held last year, ITU (International Telecommunication Union) clearly put forward the frequency plan of "mobile phone direct connection to satellite", and launched the relevant technical research of "mobile phone direct connection to satellite" in the frequency range of 600MHz to 2.7GHz. Figure 1 illustrates the evolution of the 3GPP NTN standard.
Figure 1 Evolution of the 3GPP NTN standard
Non-terrestrial vs. terrestrial networks
The NTN network provides air interface services through satellites at an orbital altitude of 500 km, and its coverage and capacity are very different from those of terrestrial networks.
Overlay comparison
The NTN network is based on a low-orbit constellation, which can easily achieve global outdoor coverage, and for indoor areas, the NTN network cannot cover.
TN (terrestrial) network is based on the construction of land base stations, which is very difficult to build, and can only achieve 99% population coverage in China, the global mobile network, and less than 40% of the land coverage area;
Capacity comparison
Assuming that in the future, satellite antennas can reach nearly 1,000 square meters, and the single satellite beam can reach 300, and each satellite can cover at least 2,000 square kilometers with a single beam, even if the 100 megahertz frequency is used to directly connect to the satellite, considering the spectrum utilization efficiency, the ultimate capacity per square kilometer will not exceed 150K bit/s (data comes from the limit simulation), and the capacity of the terrestrial mobile network can be as high as 10 T bit/s per square kilometer, and the two are not at the same level at all.
From the above analysis, it can be seen that there is no mutual substitution relationship between NTN network and TN network, TN network has been unable to solve the problem of wide coverage from 1G to 5G, and NTN network can effectively solve this problem; NTN cannot meet the unified capacity requirements, and TN network still needs TN network for high-capacity coverage, NTN and TN network are completely complementary relationships, NTN network is only suitable for wide coverage scenarios, but TN network is the best choice in areas with capacity requirements.
Relationship and positioning of LEO satellite operators with mobile operators
On the one hand, low-orbit satellite operators are actively carrying out the construction of low-orbit constellations, and the first impact is the traditional satellite operators, with the construction of low-orbit satellite constellations, the traditional satellite operators' to B, to H, to G markets are preempted. Data shows that Elon Musk has more than 2 million users, most of whom come from other traditional satellite markets, after all, Starlink has better coverage, better performance and more cost-effective services, forming a crushing of traditional satellite operators. On the other hand, in the 5G era, mobile operators have gradually developed their services from simple to C and to H to to B and to G, and have assumed the responsibility of infrastructure network construction in the construction of a network power and digital China. In the process of 6G development and evolution, the integration of air-space-ground wireless ubiquity has become one of the core visions of 6G, and mobile operators are also actively carrying out research on NTN standardization, technology, network, and application. Figure 2 shows the business relationship between satellite operators and mobile operators.
Figure 2 Business relationship between satellite operators and terrestrial operators
Starlink and T-mobile are actively cooperating in the "mobile phone direct satellite connection" business, Starlink undertakes the task of building the aerial constellation, and uses T-mobile's 2×5MHz frequency resources to provide "mobile phone direct satellite connection" service for T-mobile users. In the cooperation between the two parties, Starlink assumes the function of "Sky Tower", and the users are mainly T-mobile users, and the trial promotion stage adopts a free method, and in the future, it may adopt a function charging model, with T-mobile charging users and then sharing revenue with Starlink.
On the one hand, low-orbit satellite operators actively apply for Sub-6 frequency for the development of "mobile phone direct connection satellite", on the other hand, with the 2G and 3G network clearing and withdrawal, mobile operators are also re-cultivating some frequency resources, focusing on solving the coverage problem.
From the perspective of the agenda of the ITU WRC-23 conference, ITU has given more consideration to the feasibility of using existing IMT frequencies for "mobile phone direct connection to satellites", and the frequency range from 600MHz to 2.7GHz has basically been "carved up", and the path for low-orbit operators to apply for new frequencies for "mobile phone direct connection to satellites" has been basically blocked.
Satellite Internet is one of the strategic emerging industries, low-orbit satellite operators on the one hand actively apply for Ku or Ka frequency and orbital position, using Ku or Ka frequency to build a global broadband satellite Internet, on the other hand, with mobile operators, using mobile operator frequency to build a "mobile phone directly connected to satellite" network that complements the advantages of mobile network.
LEO satellite operators and mobile operators are more complementary than competitive and alternative for four reasons.
First, mobile operators have access to user resources. At present, domestic mobile operators have 1.74 billion mobile phone users, 640 million broadband users, and 2.33 billion Internet of Things users. Users have established long-term service relationships with mobile operators, and in the future, more of them will belong to stock competition, and there is not much room for increment.
Second, mobile operators have built a four-level service system of "group-province-city-county". Mobile operators have established a well-established four-level response mechanism for network operation and maintenance assurance and user service systems, while emerging satellite operators need a considerable amount of time and considerable investment to build such capabilities, so there are more opportunities for win-win cooperation between the two.
Third, mobile operators have mastered the core frequency resources of "mobile phones directly connected to satellites". With the simplification of the network, mobile operators will have a large number of frequency resources, especially the valuable L and S frequency bands, which have just been cleared out and have inherent advantages for "mobile phones directly connected to satellites".
Fourth, low-orbit satellite operators master core resources such as Ku or Ka frequencies and orbits. In the field of satellite Internet, especially in the satellite network part, low-orbit satellite operators have inherent advantages: on the one hand, they have core resources such as Ku or Ka frequencies and tracks, and have inherent advantages in rocket launches, satellite manufacturing, satellite tracking and control, and satellite operations; on the other hand, low-orbit satellite operators not only undertake commercial applications, but also take into account special support tasks such as national defense.
To sum up, in the field of "mobile phone direct connection to satellite" in the future, mobile operators and low-orbit satellite operators are complementary, rather than competitive and substitutional, low-orbit satellite operators play more of the role of "air tower", and mobile operators still master core resources such as users and channels. The two complement each other in the future 6G era, and low-orbit satellite operators will further let satellites enter thousands of households and industries through the massive user channel resources of mobile operators, so as to achieve the commercial success of giant satellite constellations;
With the gradual maturity of the "mobile phone directly connected to satellite" technology, the problem of wide network coverage that plagues mobile operators finally has the ultimate solution, and the blessing of a large number of to C mobile phone users has also effectively solved the problem of commercial monetization of giant constellations. With the strong support of equipment manufacturers such as Huawei and ZTE, as well as mobile operators, the development of "mobile phone direct connection to satellite" will be further accelerated, and the mainland will continue to maintain a leading position in the 5G era in the formulation of 3GPP NTN standards and technology development. It is believed that in the near future, the "mobile network and low-orbit satellite constellation" will be further integrated to provide a basic guarantee for the digital development and progress of human society.