At present, a new round of scientific and technological revolution and industrial transformation is accelerating, and major cutting-edge technologies and disruptive technologies continue to emerge. Especially in the field of satellite communications, the international competitiveness of domestic high-end products represented by satellite direct mobile phones has been significantly enhanced.
Recently, the Ministry of Industry and Information Technology and other seven departments jointly issued the "Implementation Opinions on Promoting the Innovation and Development of Future Industries", which proposes to look forward to the layout of key technologies such as 6G, satellite Internet, and mobile phone direct connection to satellite.
Some experts said that in this "battle for position" in the satellite communication industry, whoever can lead the track of direct connection to satellites with mobile phones will be able to occupy the commanding heights of standard formulation and rule shaping of non-terrestrial communication in the future 6G era.
New standard equipment for smartphones
Nowadays, satellite communication is gradually becoming the new standard for high-end smartphones. In August 2023, Huawei launched the world's first smartphone for satellite voice calls, the Mate60Pro. At the end of the same year, OP-PO and Honor also announced the release of ** mobile phones that support satellite calls on the same day, catching up with Huawei.
Prior to this, in September 2022, Huawei had launched the Beidou satellite messaging function on its Mate50 mobile phone, allowing users to send text and location information through Beidou satellites. This marks the first time that a mass-consumer mobile phone has directly integrated satellite communication without relying on any external devices. Around the same time, Apple also added a satellite messaging emergency call feature to its iPhone 14, which is limited to sending messages to designated communicators and cannot receive replies. The race for satellite communications in consumer-grade mobile phones has begun.
He Xiao, an engineer at China Telecom's Satellite Application Technology Research Institute, said in an interview with a reporter from China City Daily: "After Huawei realizes satellite SMS communication, it also realizes satellite voice calls through Tiantong satellite technology, and then develops to satellite data transmission and gradually increases the transmission rate." ”
He further introduced that at present, SMS and voice are mainly realized through high-orbit satellites, while data transmission is more dependent on low-orbit satellites, and the ultimate goal is to fully integrate satellite communication functions into mobile phones.
In the past few decades, satellite communications have been in the era of portable dedicated terminals, during which satellite systems such as Iridium, Globalstar, and Via-Sat have emerged one after another. However, for a long time, the special terminal for satellite communication has not changed significantly due to its large size and single function. Even Starlink, the U.S. space exploration company SpaceX, relies on dedicated equipment to access the Internet, making it impossible to talk while moving. Industry experts generally believe that the small user base of satellite communication terminals, coupled with the difficulty of forming scale and reducing costs, limits the large investment in the industrial chain to improve equipment.
The key to promoting the commercial application of satellite communications at a larger level is to activate the consumer market. At present, the direct connection of mobile phones to satellites is mainly realized through three technical paths: the first is the "old satellite new machine" mode that integrates the existing satellite communication technology into the mobile phone, the second is the "new star old machine" mode in which the new special satellite is developed to be compatible with the existing mobile phone, and the third is the "new star new machine" mode that designs the next-generation system in accordance with international standards. Among them, the "old satellite new machine" model, which relies on mature satellite systems such as existing high-orbit satellites, is considered to be a way that can be quickly put into the market. It is reported that Huawei, Honor, OPPO and other brands have launched or will soon launch satellite call mobile phones have adopted this technical route, based on the Tiantong satellite operated by China Telecom to develop new machines.
Lan Tianyi, founder of Beijing Qianyu Aerospace Consulting, said: "The mobile phone manufacturers use satellites in orbit, and they can't change it much, so they can only change it more closely on the ground terminal, so this round of satellite communication fever is pushed out by mobile phone manufacturers." ”
Blue Sky Wing pointed out that the core breakthrough point of the technology implementation is to integrate the satellite-specific terminal communication system composed of antennas, radio frequency, baseband and other components into thin and light mobile devices with reduced size and low power.
Finally, to complete the direct connection of mobile phones to satellites, operators need to adjust and optimize on the network side. He Xiao said: "The principle of realizing mobile phone satellite call is that the mobile phone is directly connected to the satellite, and the satellite will send the information back to the ground station indiscriminately, and after the ground station receives and completes the analysis, it will be transmitted to the core network, and finally dialed to the 4G and 5G base stations through the core network to achieve the connection with the target." ”
He Xiao also mentioned that China Telecom has achieved the unification of satellite network and terrestrial network protocols, and has obtained 42 patents in this field.
At present, the newly established China Satellite Network in 2021 and a number of commercial aerospace companies, including Galaxy Aerospace, are actively deploying low-orbit satellite Internet and trying to build a test network for satellite-ground integration.
How to "pierce the sky".
According to China Telecom's "5GNNTN Technology *** Data" released in November 2023, more than 80% of the world's land areas and more than 95% of marine areas still lack terrestrial network coverage. Satellite communications can better compensate for the fact that terrestrial communication systems are difficult to cover due to terrain limitations.
Tiantong Satellite began to be civilianized in 2016, and China Telecom became the only licensed satellite communication operator in China. He Xiao said that China Telecom has developed 35 special terminals in the past few years, involving multiple application fields such as vehicle-mounted, ship-borne and airborne. In order to break through the bottleneck of growth, China Telecom has also moved from the dedicated field to the mass consumer market, and has begun to verify the feasibility of directly connecting mobile phones to satellites.
In December 2021, China Telecom took the lead in working with terminals, chips and other manufacturers to sort out relevant processes. He Xiao said that at that time, the industry was faced with 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 Organization for Standardization 3GPP.
He Xiao told a reporter from China City Daily: "Nothing is ready-made. Satellite and core networks need to be overhauled, and the chip industry has not yet had a recognized and commercially available solution. ”
In the end, with the support of Huawei, based on the direct connection mode of Tiantong's live network, the two parties successfully verified the feasibility of commercialization through repeated network joint debugging and terminal ground signal tests.
To develop a smartphone with satellite communication function, the first problem to be solved is to realize that the mobile phone antenna is located in 360,000 kilometers away from the connection of the Tiantong satellite. To address this challenge, Huawei has demonstrated its independent R&D capabilities in the field of satellite communications by distributing mobile phone antennas around the motherboard, increasing the number of antennas, and adjusting the layout of antennas in space to optimize signal reception and transmission.
He Xiao revealed that China Telecom originally planned to keep the external antenna, but Huawei insisted that there must be a breakthrough. After the joint research of the two companies, the design of today's mobile phone was finally realized. In addition, China Telecom has also optimized the network side, reducing the requirements for the antenna on the mobile phone side, such as reducing the voice transmission rate and improving the network capacity.
Chip miniaturization is another challenge. He Xiao pointed out that the original satellite terminal chip module needs to occupy half of the area of an ordinary mobile phone, but through the cooperation of all parties in the industrial chain, this size has been significantly compressed, and has now reached a size of only about 100 square millimeters, roughly equivalent to the area of a fingernail.
While satellite communication modules will increase the cost of mobile phone production, He Xiao pointed out that the high volume of smartphone shipments can more effectively spread the cost.
After a series of tests and tuning, the terminal side of the mobile phone directly connected to the satellite has been basically completed in the first half of 2023. BlueSky pointed out that Huawei's attempt has played an exemplary role, demonstrated the achievability of this goal, and inspired other manufacturers to actively explore different technology paths.
It is worth mentioning that Honor also launched the development and verification project of a mobile phone direct connection satellite solution called "Hongyan" two years ago.
It is expected to become a trillion-yuan market
At present, the "old star new phone" scheme commonly adopted by Chinese mobile phone manufacturers has inherent constraints such as limited capacity and high cost. With the increase in satellite mobile phones, can the bandwidth of Tiantong satellite be effectively carried?
Yang Guang, senior chief analyst of telecom strategy at Omdia, a market research firm, pointed out that the current "old satellite, new machine" model relies on dedicated chips and links to communicate with satellites. The proprietary system operates independently from cellular networks such as terrestrial 4G and 5G, and users need to manually switch to make calls to satellites**. In contrast, the second-generation satellites planned to be deployed by AST and SpaceX adopt the "new star old machine" model, that is, borrowing the operator's existing frequency band to realize satellite transmission and reception signals, which can quickly launch satellite communication services and maximize the use of the stock mobile phone market. However, this model puts forward higher requirements for satellite R&D capabilities, and the implementation also faces many challenges.
In fact, it is difficult for satellites that have been launched into orbit to increase their capacity through transformation, and they can only improve the utilization efficiency of existing capacity through ground-side chip and network transformation. For example, in the implementation of the Tiantong solution, in order to maximize the fidelity of Chinese voice and intonation frequency bands, the call voice bandwidth was compressed by nearly 97%.
Currently, the Huawei Mate60Pro recommends a five-minute satellite call duration. This limitation is partly due to the fact that Tiantong Satellite itself is a professional satellite, with limited transmission resources, and only about 30% of the capacity is allocated to civilian communications; At the same time, when making a satellite call, the relevant satellite communication module in the mobile phone will generate higher power, which will cause heat dissipation problems.
Yang Guang believes that from a theoretical point of view, the NTN technology route led by 3GPP may be a better path choice. Once the NTN standard is unified, once the technology and business model are running, it can rely on the global annual shipment of more than one billion mobile phones to quickly reduce costs. Under the NTN technology path, the satellite network will be organically integrated with the terrestrial network, and users do not need to manually switch networks when dialing **.
A reporter from China City Daily learned from the Honor R&D department that when terminal manufacturers promote R&D internally, there is a high probability that they will promote and verify at multiple points, and will not "bet" on a certain technical path alone. At present, whether it is the maturity of the operator's business or the actual application maturity of the landing mobile phone technology, the solution relying on Tiantong satellite is the most feasible.
Regardless of the technology path, it has become an unstoppable trend for satellite communications to enter the consumer market. Lin Guangrong, the communication system architect of the Galaxy Aerospace Constellation, believes that there are more than 5.2 billion mobile phone users in the world, and even if only a small number of users are willing to pay additional fees for satellite communication services, they represent a huge market potential. He pointed out that the prospects for providing satellite internet services to remote areas are clearer than satellite calls. Because in many remote areas, satellite Internet is more economical and feasible than the cost of ground deployment of pulling optical fibers and building base stations.
Lin Guangrong said 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 gap of more than 80% of the world's uncovered communication networks on land and sea. This will stimulate the innovation momentum of the entire industry chain such as operators, parts manufacturers, and equipment manufacturers, thereby promoting the progress of the entire industry.
China City Daily reporter Sun Xuefei.