5g has been fully commercialized, and human communication technology has once again embarked on a period of rapid development. In the future, with the development of rocket recovery, LEO satellites and 6G technology, science fiction communication seems to be not far from us.
In 2019, the Ministry of industry and information technology set up a 6G research group to promote 6G related work. In April of the same year, olu University held the world’s first 6G summit. 6G is expected to achieve further technical indicators: the air interface delay is less than 0.1ms, the network depth coverage reaches 100%, millimeter level sensing and positioning, the unit power consumption is greatly reduced, the transmission bandwidth will reach TB level, and the density of connected devices will reach hundreds per cubic meter.
On april20,2020, the national development and Reform Commission defined the scope of “new infrastructure” for the first time, and included satellite Internet into the scope of communication network infrastructure. At present, many domestic enterprises have begun to actively layout the satellite Internet industry.
1、 Communication technology – a great change every ten years
Mobile communication technology promotes the rapid development of information technology industry, improves people’s living standards, and promotes the development and prosperity of society. Since the 1980s, mobile communication technology has undergone a new change every decade.
1g, the first generation mobile communication technology, is a cellular wireless telephone system based on analog technology. Originated in the 1980s and completed in the 1990s, it mainly adopts analog modulation technology and frequency division multiple access (FDMA) technology. The main disadvantages of this technology are low spectrum efficiency and signaling interference with voice services.
In the 1g era, frequency division multiple access (FDMA) is one of the most basic multiple access methods. FDMA divides channels by carrier frequency, each channel occupies a carrier frequency, and the adjacent carrier frequencies shall meet the requirements of transmission bandwidth. In analog mobile communication, if division multiple access is the most commonly used multiple access method, and the interval between each carrier frequency is 30kHz or 25kHz. Under FDMA technology, different users occupy different frequency bands, thus avoiding mutual interference and realizing differentiation.
2G, the second generation mobile communication technology, mainly adopts digital time division multiple access (TDMA) and code division multiple access (CDMA) technologies. Under 2G technology, information such as e-mail and software cannot be directly transmitted; Only the technical specifications of mobile phone communication such as call, time and date transmission are available. However, SMS (shortmessage service) can be implemented in some 2G specifications.
The second generation mobile communication digital wireless standards mainly include GSM in Europe and is-95cdma launched by Qualcomm in the United States. China mainly adopts GSM, while the United States and South Korea mainly adopt CDMA.
3G is the third generation mobile communication technology. Its most basic feature is intelligent signal processing technology. The intelligent signal processing unit will become a basic function module, supporting voice and multimedia data communication. It can provide various broadband information services that the previous two generations of products cannot provide, such as high-speed data, slow image and TV image.
The communication standards of 3G system have three branches: WCDMA, CDMA2000 and TD-SCDMA. In China, China Mobile adopts TD-SCDMA, Chinatelecom adopts CDMA2000, and China Unicom adopts WCDMA.
4G, the fourth generation mobile communication technology, mainly takes orthogonal frequency division multiplexing (OFDM) as the technical core. 4G technology is a technical product that integrates 3G and WLAN and can transmit high-quality video images, and the image transmission quality is equal to that of high-definition TV.
Orthogonal frequency division multiplexing (OFDM) is a high-speed transmission technology in wireless environment. OFDM technology is characterized by highly scalable network structure, good anti noise performance and anti multi-channel interference ability. It can provide higher quality (high speed, small delay) services and better performance price ratio for wireless data technology, and can provide a better solution for 4G wireless network.
5g is the latest generation of cellular mobile communication technology. 5g is not an independent and brand-new wireless access technology, but a general term for the technical evolution of existing wireless access technologies and some new complementary wireless access technology integrated solutions.
2、 Satellite Internet, 5g new technology in the middle and late stage
Satellite Internet is an Internet based on satellite communication, which can realize the communication between multiple earth stations. Satellite Internet refers to a new network based on satellite communication technology, which forms a large-scale network by launching a specific number of satellites and provides broadband Internet access and other communication services to ground and air terminals.
There are three stages in the development of Satellite Internet:
1. At the stage of competition with the ground communication network, provide voice, low-speed data, Internet of things and other services. With the rapid development of the ground communication system, the satellite communication system is gradually at a disadvantage in terms of communication quality and tariff price, and is defeated in the competition.
2. In the phase of supplementing the ground communication network, the new iridium, global satellite and orbital communication companies are represented to supplement and extend the ground communication system.
3. In the stage of integration with ground communication network, companies represented by oneweb, SpaceX, etc. are leading the construction of new satellite Internet constellation, the satellite working frequency band is gradually improved, and the construction of Satellite Internet is gradually stepping into the era of broadband Internet.
Satellites are mainly divided into three categories: low orbit, medium orbit and high orbit. Among them, LEO satellites have the advantages of small transmission delay, low link loss and flexible launch, and are the mainstream implementation method of Satellite Internet services.
Specifically, LEO satellite system has the following two advantages:
1. It can realize the global Internet seamless link service. The construction cost of traditional high orbit synchronous orbit satellites is high, there is a communication blind zone, the time is extended and the bandwidth is limited, which has been unable to meet the capacity demand of the global massive interconnection. In contrast, the LEO satellite system has lower transmission delay, higher reliability, higher loss and 29.5db lower orbit, and can realize the global Internet seamless link service.
2. The core application scenarios of LEO satellite communication include remote area communication, marine operation and scientific research broadband, aviation broadband and disaster emergency communication. Among them, the application market in remote areas mainly includes satellite phone, Internet TV and satellite broadband; The marine operation and scientific research application market includes satellite positioning and maritime satellite telephone; The aviation application market is mainly airborne WiFi; The disaster recovery application market includes emergency call, data protection and recovery, remote disaster recovery system, etc.
In recent years, led by oneweb, SpaceX and other companies, the satellite Internet industry has embarked on a period of rapid development. Since 2014, China has issued a series of measures for this industry to actively promote the development of satellite application industry and commercial satellites. In particular, the national development and Reform Commission first defined the scope of “new infrastructure” on april20,2020, including information infrastructure, integration infrastructure and innovation infrastructure.
Among them, information infrastructure mainly refers to the infrastructure evolved based on the new generation of information technology, including 5g, Internet of things, industrial Internet and satellite Internet. For the first time at the national level, Satellite Internet has been included in the scope of communication network infrastructure.
Many domestic enterprises have begun to actively deploy the satellite Internet industry. During the 13th Five Year Plan period, two major central enterprises, mainly China Aerospace Science and technology and China Aerospace Science and industry, put forward the low orbit satellite Internet plan of “Hongyan constellation” and “Hongyun project” respectively, and launched test satellites. Among them, “Hongyan” constellation is the first global LEO satellite mobile communication and space Internet system in China, which can realize the combination of broadband and narrowband worldwide and provide users with real-time two-way communication. The “Hongyun project” constellation is committed to meeting the high-speed access needs of the global mobile Internet. It is composed of 156 LEO satellites, and the maximum support rate of each satellite is 4gbps. At present, many domestic enterprises have begun to actively layout the satellite Internet industry. With the gradual launch of the plan, China’s satellite Internet industry is expected to usher in rapid development.
The satellite Internet industry chain is divided into four parts: satellite manufacturing, satellite launching, ground equipment, satellite operation and service. Among them, satellite manufacturing is divided into satellite platform and satellite load; Satellite launching includes rocket manufacturing and launching services; Ground equipment includes fixed ground station, mobile station and user terminal; Satellite operation and services include satellite mobile communication services, broadband broadcasting services and satellite fixed services. According to the calculation of CCID think tank, it is estimated that the overall market scale of China’s satellite Internet will reach 100 billion by 2030.
2020 is the first year of Satellite Internet. According to the data of future think tanks, it is expected that the scale of investment in the manufacturing of LEO Satellite Internet satellites in China will reach a peak around 2023.
According to the 2018 China commercial aerospace industry investment report, it is estimated that China will launch about 3100 commercial satellites by 2025, with a single satellite manufacturing cost of US $4.29 million, while the manufacturing costs of Starlink and Amazon are only US $500000 and US $1million. By comparison, China’s satellite manufacturing costs still have room for further optimization. In the future, satellite manufacturing enterprises are expected to improve their gross profit margin and competitiveness, or continue to benefit.
The cost can be reduced from the following four parts:
Rocket recovery technology. Rocket recovery technology refers to the technology of recovery and reuse after the launch of the rocket, which can realize the recovery and utilization of resources, improve the reuse rate of the rocket and reduce the cost. According to the official website of SpaceX, the quotation of its Falcon 9 rocket at the first launch was US $61.98 million, and the quotation at the 13th launch was only US $2.88 million, which was 4.65% of the first quotation, significantly reducing the launch cost.
“One arrow has many stars”. The satellite launch link mainly includes rocket manufacturing and launch services. Rocket manufacturing includes propulsion system, rocket body manufacturing, telemetry system, engine manufacturing, guidance and control system, safety self destruction system and other components; Launch services include rocket control system, escape system, launch and telemetry system and launch site construction. In recent years, China’s rocket launch technology has achieved significant breakthroughs. Technologies such as “one rocket with multiple satellites” and rocket recycling have directly promoted the reduction of launch costs.
The new mode of “integration of heaven and earth + commercial operation”. During the 13th Five Year Plan period, China’s Launch Vehicle Technology Research Institute developed rockets to provide international commercial launch services for Laos, Belarus and other countries. In 2015, the China Academy of rocket Sciences initiated the new mode of “Heaven Earth integration + commercial operation” in the Lao No. 1 radio and communication satellite project, expanding new ideas in the international commercial launch market and enhancing the international competitiveness of the long march series launch vehicles.
Operation service accounts for the highest proportion in the satellite industry value chain, and communication satellite operation is an important component. With the progress of technology, the growth of market demand and the improvement of commercialization, satellites play an important role in communication, meteorology, remote sensing, broadcasting, navigation and other fields, and their application fields are constantly enriched.
According to the statistics of the American satellite industry association, the total revenue of the global satellite industry in 2018 was US $277.4 billion, a year-on-year increase of 3.3%; The revenue from satellite services reached US $126.5 billion, accounting for 45.6% of the revenue of the satellite industry. Among them, communication satellite operation is an important component of the satellite service industry, including satellite broadcasting, satellite fixed, and satellite mobile services
The beidou-3 system was fully completed, pushing the industry to a new level. In July, 2020, the beidou-3 global satellite navigation system was officially opened, and China became the third country in the world to independently own the global satellite navigation system. With the full completion of the system, China’s satellite navigation and location service industry will enter a long-term and stable growth stage. According to the data of the 2020 white paper on the development of China’s satellite navigation and location service industry previously released by China satellite navigation and positioning Association, the overall output value of China’s satellite navigation and location service industry will reach 345billion yuan in 2019, and it is expected to form a new market for space-time information services with a scale of trillions in the future.
At present, the country is actively promoting the development strategy of “new infrastructure”. The application of Beidou precision space-time technology is an indispensable starting point for the construction of new infrastructure to move towards digitalization, intelligence and upgrading. It will become an important force to promote the development of satellite navigation and location service industry.
3、 Star chain plan
Starlink program is a program launched by SpaceX in 2015 to provide global users with high-speed and fast satellite network communication. At present, 1205 “Starlink” satellites have been launched.
In 2015, SpaceX put forward the Starlink plan, which uses a large number of low orbit high-throughput satellites to form a constellation to provide global users with high-speed and fast network communication. According to the information on the official website of SpaceX, on the morning of March 4, 2021 US Eastern time, SpaceX put a new batch of 60 Starlink Internet satellites into orbit. This launch brought the total number of Starlink satellites launched to 1205.
Starlink has realized global networking in three steps, with a total of about 1.2 launches. Ten thousand satellites. The Starlink program is divided into three steps:
1. 1600 low orbit and near earth satellites were launched to achieve preliminary coverage, with 32 orbits and 50 satellites in each orbit;
2. A total of 2825 satellites were launched in four groups to realize global networking, with different orbital numbers and orbital inclination in each group;
3. 7518 satellites were launched to form a LEO constellation. In the first two steps, the satellite operates in the traditional Ka and Ku bands, and in the third step, the satellite operates in the V band with the frequency of 40GHz to 75ghz. As a part of musk, star chain program and Tesla autonomous vehicle can form a synergy. Through the wireless communication technology, the on-board equipment of the vehicle can not only guarantee the distance between vehicles, but also help the owner to navigate in real time and improve the traffic operation efficiency. Tesla uses the Starlink service. On the one hand, it can add satellite receivers to Tesla vehicles so that each Tesla model can be directly connected to the Starlink network. On the other hand, Tesla can push wireless software updates to all its vehicles through Starlink. The star chain program is applied to telemedicine to help aboriginal tribal members provide health care services. Telemedicine refers to the long-distance diagnosis, treatment and consultation of patients in remote areas, islands or ships with poor medical conditions by relying on computer technology, remote sensing, telemetry and remote control technology and giving full play to the advantages of medical technology and medical equipment of large hospitals or specialized medical centers. It can not only reduce the time and cost of transporting patients, but also enable doctors to break through the limitations of geographical scope and share patient medical records and diagnostic photos. In december2020, SpaceX cooperated with Canada’s fset information technology company to bring Starlink Internet services to indigenous tribes. At present, its 3000 members have been able to enjoy medical and health care services and other contents. Star chain plan helps VR and HD live broadcast. VR is a computer simulation system that can create and experience a virtual world. It uses computers to generate a simulation environment to immerse users. It has the characteristics of immersion, interactivity and autonomy. In september2018, SpaceX announced that Japanese billionaire entrepreneur youzuo Maezawa had become the first paying passenger of SpaceX’s lunar orbiting mission. The plan is expected to be implemented in 2023. The journey will be broadcast live in HD VR. SpaceX will use the relay satellite of the star link plan to deal with the communication dead corners at the far end of the moon. The star chain program can push cloud computing into space. Cloud computing is a computing method that provides shared software and hardware resources and information to computers and other devices on demand based on the Internet. Among them, the network providing resources is called “cloud”. In October, 2020, Microsoft announced the launch of azure space cloud computing platform, which, in cooperation with Starlink, will provide high-speed, low delay satellite broadband for azure modular data center. Flexible satellite communications, coupled with the high-performance computing, machine learning and data analysis capabilities provided by azure, help to further meet customer needs.
4、 6G era air space integration
With the continuous evolution and popularization of the big data society, the spectrum resources are continuously decreasing. However, the requirements for data capacity are continuously improving, and more advanced communication technologies are gradually being put on the agenda.
In 2019, the Ministry of industry and information technology established a 6G research group, called imt-2030 promotion group, to promote 6G related work. In April of the same year, olu University held the world’s first 6G summit with the theme of “paving the way for the arrival of 6G”. At the summit, all parties collectively looked forward to the future. Some media claimed that the United States would skip 5g and compete with China on 6G.
The comprehensive performance of 6G is also expected to be 10-100 times that of 5g, and various technical indicators will be further improved: the air interface delay is less than 0.1ms, the network depth to coverage reaches 100%, millimeter level sensing and positioning, power consumption is greatly reduced, the transmission bandwidth will reach kilogram level, and the density of connected devices will reach hundreds per cubic meter.
The application scenarios of 6G are based on 5g but broader: high-speed Internet access in the air (beyond the wide coverage of 5g to achieve 100% deep coverage, and Internet access in both space and heaven), holographic communication (restore and enable the true three-dimensional display of the virtual world with more realistic multi-dimensional sensory data such as vision, touch and smell) Advanced intelligent industry (realizing millimeter level positioning, deeply participating in industrial manufacturing, and realizing more advanced solutions for industrial Internet), human intelligence twin (realizing real-time monitoring of important human organs and systems through numerous human sensors, and realizing the twin of human data in the virtual world) In terms of intelligent mobile manned platform (the advanced networking of intelligent vehicles, networking of vehicles, various aircraft, cruisers and other manned tools), the current trend of 6G technology lies in the ultra dimensional antenna technology, the integration of heaven and earth technology and terahertz band.
By establishing an elastic and reconfigurable network architecture, efficient space-based computing, a unified resource management and control mechanism for space, space, and space, and an efficient and flexible mobility management and routing mechanism, the space-based fusion technology carries out the design of intelligent spectrum sharing, minimax smart access, multi beam cooperative transmission, unified waveform, multiple access, coding, etc. of the space-based integration technology. In the future, users only need to carry one terminal to realize seamless global roaming and insensitive switching.
It is of great significance for China to build an integrated network of space, space and earth. By providing continuous support of all-time and space information, the air space earth integrated network can cover the surrounding areas of the “the Belt and Road” and the “four seas, two oceans” to meet the needs of information services in important land economic zones and overseas hot spots. The rapid development of space space integrated network technology and the formation of a perfect network system are conducive to occupying the commanding heights of space technology and seizing the first opportunity of resources and technology. At present, the development of space, space and earth integrated information network has become the 6G consensus, and it is believed that the technology integration needs to start practice in the 5g era and be fully realized in the 6G era.
The air space integrated network can play an important role in a variety of business scenarios. For the communication business scenarios with massive connections, such as environmental monitoring, forest fire prevention, UAV patrol inspection, ocean container information collection, etc., the air ground integrated network can effectively expand the coverage and meet the needs of larger connections and lower power consumption. In view of the physical abnormalities of the personnel during the exploration activities, the nearby medical and nursing personnel can be notified through the wide coverage of the air space integration network, and a large number of human digital twin data can be synchronized to the remote consultation senior medical personnel. In addition, the business of the Internet of vehicles requires high reliability and low delay communication in a large range. The wide area coverage of the space earth network can meet the information transmission requirements and real-time communication of vehicles and road test systems within a range of 100 kilometers.
The convergence business involves many fields, ranging from 1g to 5g. After about 40 years of development, mobile communication technology has finally moved from serving people to serving the industry, enabling the digital transformation of economic society. At the same time, satellite communication has once again become the focus of attention, especially the “star chain plan” proposed by musk. As an aerospace power, China has a strong technical reserve for satellite communication. The next generation 6G communication technology will be an ubiquitous mobile communication network in space, space, earth and sea, in which satellite communication plays an important role. When 5g has just been put into commercial use and is in the ascendant, it is time to start 6G research.
Editor in charge: lq6