What miracle will the satellite network create in the 6G era
5G has arrived, 6G is not far away, satellite networks will shine, but the road ahead is bumpy
5G has arrived, 6G is not far away, satellite networks will shine, but the road ahead is bumpy
Text | Xie Tao
“Star-Ground Integrated Network” and “Seamless Air-Space-Ground Coverage” are the scenarios described in the “6G Overall Vision and Potential Key Technology White Paper”, which was published by the China IMT-2030 (6G) Promotion Group in 2021. Released on the 6th.
The white paper predicts that 6G (sixth generation mobile communication technology) will be commercially available in 2030, enabling the transition from the Internet of Everything to the Intelligent Connection of Everything. Unlike the previous five generations of mobile communications, which were mainly ground communications, satellite networks in the 6G era will assume an important role.
However, judging from today’s technical level, the satellite industry chain is far from realizing the scenarios in the white paper in areas such as development, production, networking, operation and maintenance, and applications. Looking to the future, we need to lay a solid foundation for the industrialization of emerging technologies as well as leapfrog long-term planning.
Satellite Internet: a key infrastructure for 6G
For people in the non-communication industry, the IMT-2030 (6G) Promotion Group is an unfamiliar name. IMT is the abbreviation of “International Mobile Communications”. IMT-2030 (6G) is the working group to promote China’s 6G process. Its predecessor is IMT. -2020 (5G) Promotion Group. The 5G promotion group includes China’s major telecom operators, equipment manufacturers, universities and research institutions. Under the promotion of the Ministry of Industry and Information Technology, this is a platform that aggregates China’s industry, academia, research, and use forces to promote China’s 5G research and international exchanges and cooperation. It actively participates in, influences and guides the 5G standardization work of the ITU (International Telecommunication Union). In June 2019, almost at the same time that the Ministry of Industry and Information Technology issued the 5G commercial license, the original 5G promotion group was upgraded to the 6G promotion group.
In June 2020, ITU formally solicited technical views on the future development of IMT from all member states including China, and plans to complete the “Future Technology Trend Report” in 2022. This report will set the tone for global 6G programs and standards.
The “6G Overall Vision and Potential Key Technology White Paper” is the latest achievement of China’s 6G research, and is a mobile communication plan submitted by China to the ITU for the next ten years.
In this plan, the significant difference between 6G and 5G systems is that it clearly proposes to achieve “seamless global coverage” and build a “inclusive and intelligent human society”-this goal must be achieved with the help of key supplements from non-ground facilities such as satellites. . The white paper shows that 6G services will form eight business applications such as holographic communication, digital twins, immersive cloud XR, sensory interconnection, and global coverage, and can be further classified into three categories of application scenarios: immersion, intelligence, and global coverage. Global coverage will provide an integrated air, space, and ground network with seamless global coverage, so that there will be no mobile Internet blind spots on the planet. Ten years later, mankind will truly realize the “ubiquitous” network for the first time on earth. The perspective of global coverage helps answer a common question from all walks of life: 5G networks are characterized by high speed, large bandwidth, and low latency. 5G has just begun. How can 6G be put on the agenda again? The white paper gives the answer: humans have entered the 5G era for two years, but there are still more than 80% of the land area and 95% of the ocean area without mobile network signals, and the communication objects are limited to the space within 10,000 meters above the surface. , It is impossible to realize the “sky, sea and sea” Internet surfing. At the same time, there are still 3 billion people without basic network access facilities in the world, and the digital divide in economic and social development is widening. The SpaceX (Space Exploration) company founded by Musk has been intensively implementing Starlink two years ago because its business model is also based on the needs of these mobile network blank spaces. Currently, Starlink has launched 28 batches of low-Earth orbit global networking satellites, with more than 1,600 satellites in orbit. Starlink will deploy a total of 42,000 satellites-occupying 40% of the total capacity of low-Earth orbit satellites. Starlink has begun to land terminal services in Europe and the United States. Some people may ask: Will this space-based satellite Internet subvert the existing ground-based cellular network facilities featuring optical fibers, base stations, and iron towers? The white paper also gives the answer: satellite networks will not replace terrestrial networks, but provide strategic supplements in areas where the economics of terrestrial facilities are poor or beyond the reach of infrastructure, and ultimately integrate with terrestrial networks. In April 2020, the National Development and Reform Commission made it clear that “satellite Internet” is an important part of the construction of new infrastructure. In May 2021, China Satellite Network Group was formally established, and the new infrastructure of satellite Internet is steadily advancing. We believe that the ideal result of this new infrastructure is to build a high-speed network that is ubiquitous and without perception in real life. 6G vision calls for satellite network “leopard change” Satellite Internet is a product of the continuous development of satellite communications. With satellite communications, it has experienced three development stages of different orbit heights, different communication systems, different business types, and different coverage areas. From the 1960s to the 1980s, through the analog communication satellites in geosynchronous orbits, they mainly provided communication services to the government and public sectors; from the 1980s to the end of the last century, digital communication and low-orbit satellite communication satellites came onto the stage and gradually began to provide services to businesses and families. , Individuals provide services; from the beginning of this century to the present, multi-orbit high-throughput satellites (HTS) have brought true satellite Internet, providing users with more diverse network access options. One of the most famous forerunners is Motorola’s aborted Iridium project. At present, under the background of accelerating and deepening 5G commercial use, the development plan of satellite Internet is to transfer 5G base stations from ground towers to low-orbit small satellites, and dynamically splice ground coverage through multi-satellite networking. The signal is transmitted to the terminal without ground network signal. According to our research, the country is in the early stages of satellite Internet development, and “rigorous needs” in industries such as emergency disaster reduction, resources and environment, transportation and logistics, and energy pipeline networks are constantly emerging. The Internet of Vehicles, Internet of Things, and Industrial Internet are crossed by 5G technology. In converged applications, satellite networks will be very useful. With the advancement of technology research and development in 5G on the satellite, integration of communication-navigation-remote sensing, and air-space network connection, smart agriculture, smart city, smart manufacturing, smart cultural tourism, autonomous driving, financial services, home and individual users Other application scenarios will also be supported by satellite networks. And moving from 5G to 6G will be a process in which satellite network services are more convenient and easy to use, scenes are constantly enriched, and the domestic market scale is growing exponentially. We estimate that if 100 billion yuan is invested in satellite development and deployment during the infrastructure period (initial in 2021), the downstream terminal and industry solution market is expected to reach 200 billion yuan after three or four years. After 2026, industry applications and The scale of the space-time big data service market will reach 700 billion yuan. At the beginning of the construction of a new generation of satellite networks, how to maximize the capability structure, utilization efficiency and cost advantages of low-orbit satellite communications through innovation is the key to whether the 5G network can go to the sky and the 6G vision can be realized as scheduled. Starting from the new infrastructure needs of China’s “satellite Internet”, we believe that the technological innovation direction of satellite networks is to finally form a space infrastructure with complete “communication, navigation, remote, calculation, and storage” space-time big data service capabilities. The construction of satellite networks should draw development momentum from the latest ICT technologies, which have not yet been included in the vision of traditional spacecraft development departments: one is the “intelligence” that can integrate artificial intelligence, machine learning, quantum computing, blockchain and other technologies; The second is the “opening” of interfaces, software and hardware, the market to the industrial ecology, which minimizes supply chain costs and enhances user experience; the third is to build end-to-end, endogenous dynamic “security” at the beginning of satellite networking. Satellite evolution speed lags behind network demand In low-Earth orbits at altitudes of 200 km to 2,000 km, with the rapid increase in global small satellite networking activities, in the 5G commercial period, satellite networks have highlighted three development trends, including both new forces and constraints. First, the application density of new technologies in satellite networks has increased. For example, satellite research and development are achieving low-cost and miniaturization, and launching costs are also decreasing. Technologies such as Hall propulsion, composite materials, inter-satellite optical communications, and fully electronically scanned phased array antennas have gradually entered the industrialization stage, providing for satellite network upgrades. A new technological basis has been created. Second, the digital economy has brought about an incremental market for satellite services. The interconnection of everything, wide area coverage, and ultra-large bandwidth are the characteristics of 5G network services. Satellite network users are also looking forward to an application experience similar to terrestrial 5G business scenarios, and are willing to pay for the service providers who are the first to meet their special scenario requirements. In the 6G era, satellite networks are the most effective solution in the face of the global digital divide due to factors such as geographic conditions, population distribution, and economic development levels. In addition to commercial forces, social and political driving forces will also be increasingly strengthened. The third is that the satellite network presents “abundant scarcity”, which is a technical challenge accompanied by a positive situation. On the one hand, with the technological iteration of multiple satellites and even dozens of satellites, the difficulty of expanding the scale of satellite networks is reduced, and the number of satellites in orbit has also changed from scarcity to ample; but on the other hand, a single satellite is limited by energy and weight. Such restrictions, insufficient resources available for networking adjustments, resulting in huge fluctuations in user experience. Behind this “abundant scarcity” is today’s satellite supply-side technology that needs to be improved urgently. For example, satellite in-orbit storage and computing, satellite-to-satellite and satellite-to-ground data transmission capabilities are obviously lagging behind; the control planes of different satellites lack standardized interfaces and are poorly compatible, making it difficult to realize intelligent networking; communication standards and protocols have yet to be unified; satellite control is mainly Relying on mission planning on the ground, the efficiency is low and there are hidden safety hazards; the satellite network security architecture is easily compromised, and the data transmitted through the air interface is easily intercepted. On the user side, compared with terrestrial 5G, the convenience of satellite network applications is far from 6G expectations. For example, satellite remote sensing data charges are high, satellite communication charges per unit bandwidth resource and per unit bit transmission are high, and the charging model is rigid and unfriendly; the timeliness of the satellite data supply chain is poor, and it cannot stably and continuously meet the needs of refined applications; the interface of satellite applications With poor interface ease of use, users and developers face technical barriers far higher than those of general Internet applications. In the policy field, many uncertainties still restrict the development of the satellite network industry. How to reasonably plan and allocate the radio frequency and orbital location resources required by the satellite network in commercial scenarios is a question that market entities expect clearly. Since space belongs to the human “commons” space, with the increase in satellite deployment, the ownership of its data assets in the “commons” has yet to be clarified by the international legal system. At the same time, geopolitics directly affect the overseas deployment of satellite network ground measurement and control infrastructure. Multinational businesses need to balance market competition and access risks, and overseas market expansion and user service delivery are difficult. Task List of China’s Satellite Industry Moving from 5G to 6G will inevitably face a series of technical discussions, policy games, and commercial competition. Many uncertainties still need to be resolved through demonstration and practice after the release of the white paper. However, the white paper can be used as a long-term action for the Chinese satellite industry to grasp the current situation. pointer. We foresee that in order to serve commercial 6G networks in 2030, a new generation of satellite networks must meet the following four application expectations: One is the flexible networking of a large number of satellites. Building a flexible intelligent network architecture based on the number of satellites can reconstruct and expand the topology and functions of the satellite network at any time as needed. The second is multi-load, multi-task, and soft handoff. In order to improve the efficiency of space resource utilization, each satellite and each satellite network is equipped with multiple types of loads. The software defines satellite functions and on-orbit updates, which can perform soft handover in response to different tasks and establish a network topology suitable for new tasks. , Call the payload and complete the task. The third is the integration of world resources. Satellites can coordinate the utilization of space and earth network resources including perception, transmission, calculation, storage, communication protocols, frequencies, tasks, etc., follow uniform commercial standards and maximize the utilization of energy, bandwidth, frequency, orbit, and data. The fourth is the integration of perception, transmission, storage, and computing. In the data link between the networked satellites, the integrated design of information collection, transmission, calculation, and application is realized, and the change of demand scenarios is swiftly responded to, and data security is ensured. With these expectations, which satellite technologies will help support the 6G vision? Standing in the 5G era, in which areas should the commercial satellite industry invest in innovation and R&D in order to build the four pillars of the air-space-ground integrated network? We believe that the satellite network in the 6G era can be divided into seven functional domains in the space segment and one functional domain in the ground segment. The functional domains of the space segment include perception, transmission, storage, computing, platform, function, and network security (see Table 1); the functional domains of the ground segment are mainly used for ground support, including ground stations, launch sites, and satellite-to-ground integration Core network, etc. Some of the technologies in these eight functional domains have entered commercial use and tend to be stable and mature, while most of them are still in the verification and testing stage, requiring strategic investment to achieve key breakthroughs. At this stage, the more important thing is the transformation of the satellite industry chain. The immediate question is whether the commercialization of satellite development and production will bring about a reduction in the cost of satellite networks and applications? At the same time, how to use the saved costs to break through the bottleneck of existing satellite design and research and development, and to drive a moderately advanced technology research and development for 2030? China’s private commercial aerospace has only started for a few years, but the “catfish effect” has begun to appear. The cost of the entire satellite and the launch cost of satellites are decreasing, and the delivery cycle of satellite products is gradually shortening. The design method and process innovation of “onboard integration” is conducive to the on-demand customization of satellite functional loads. Mass production of small satellites required for future constellation networking in a flexible manner will gradually become the mainstream practice for domestic delivery of commercial satellite orders. Those enterprises with capacity reserves and technical preparations will gain a leading edge in the new satellite network infrastructure that started in the 5G era and ended in the 6G era, and will drive the prosperity of the entire satellite industry chain. In order to solve the “question list” set out by China’s 6G vision for satellites, the main players in the industry chain must collaborate to form an innovative network, in software-defined satellites, on-satellite 5G, standardization, inter-satellite link technology, innovative satellite configurations, and ground Terminal applications and integration of communication, navigation and remote control have surpassed the international advanced level, forming a new generation of satellite product pedigree with China’s independent and controllable core technology. 5G has arrived, and 6G is not far away. We hope to work with China’s commercial aerospace partners to use epoch-making satellite hard technology innovation to shape a smarter and more beautiful human future. * Originally published in Caijing Magazine on June 21, 2021.The author is the founder and CEO of Jiutian MSI; Editor: Mark