5G has been fully commercialized, and human communication technology has once again embarked on a period of rapid development. With the development of rocket recovery, low-orbit satellites, and 6G satellite Internet technology, sci-fi communication methods are not far away from us.
In 2019, the Ministry of Industry and Information Technology established a 6G research group to promote 6G-related work. In April of the same year, the University of Oulu hosted 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 rate reaches 100%, millimeter-level sensing, and positioning, unit power consumption is greatly reduced, transmission bandwidth will reach TB level, and the density of connected hundreds of devices will reach per cubic meter.
On April 20, 2020, the China Development and Reform Commission clarified 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 deploy the satellite Internet industry.
1. 1G-6G satellite network communication technology, a huge change every ten years
1G communication technology
Mobile communication technology promotes the rapid development of the information technology industry, improves people’s living standards, and promotes social development and prosperity. Since the 1980s, mobile communication technology has undergone a new change every nearly ten years.
1G is the first generation of mobile communication technology and is a cellular wireless telephone system based on analog technology. Originating in the 1980s and completed in the 1990s, it mainly uses analog modulation technology and frequency division multiple access (FDMA) technologies. The main disadvantages of this technology are low spectrum utilization and signaling interference with voice services.
In the 1G era, frequency division multiple access (FDMA) is the most basic multiple access method. FDMA divides channels by carrier frequency, and each channel occupies a carrier frequency, and the requirements for transmission bandwidth should be met between adjacent carrier frequencies. Frequency division multiple access is the most commonly used multiple access method in analog mobile communications, and the interval between each carrier frequency is 30kHz or 25kHz. Under FDMA technology, different users occupy different frequency bands, thereby avoiding mutual interference and realizing differentiation.
2G communication technology
2G is the second-generation mobile communication technology, which mainly adopts digital time division multiple access (TDMA) and code division multiple access (CDMA) technologies. Under 2G technology, it is not possible to directly send information such as e-mail, software, etc.; it only has phone communication technical specifications such as time and date transmission. However, SMS (Short message service) can be implemented in some specifications of 2G.
The second-generation mobile communication digital wireless standards mainly include GSM in Europe and IS-95CDMA introduced by Qualcomm in the United States. China mainly uses GSM, and the United States and South Korea mainly use CDMA.
3G communication technology
3G is the third-generation mobile communication technology, and its most basic feature is intelligent signal processing technology. The intelligent signal processing unit will become a basic functional module that supports 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-speed images, and TV images.
The communication standards of the 3G system have three branches: WCDMA, CDMA2000 and TD-SCDMA. In China, China Mobile uses TD-SCDMA, China Telecom uses CDMA2000, and China Unicom uses WCDMA.
4G communication technology
4G is the fourth-generation mobile communication technology, which is mainly based on Orthogonal Frequency Division Multiplexing (OFDM). 4G technology is a technology product that integrates 3G and WLAN and can transmit high-quality video images and the image transmission quality is comparable to that of high-definition TV.
Orthogonal Frequency Division Multiplexing (OFDM) is a high-speed transmission technology in a wireless environment. OFDM technology is characterized by a highly scalable network structure, good anti-noise performance, and anti-multi-channel interference capabilities, and can provide wireless data technology with higher quality (high rate and low delay) services and better cost performance, can provide better solutions for 4G wireless networks.
5G communication technology
5G is the latest generation of cellular mobile communication technology. 5G is not an independent, brand-new wireless access technology, but a general term for the technological evolution of existing wireless access technologies and some newly added complimentary wireless access technology integrated solutions.
2. Satellite Internet, 5G mid-to-late new technology
Satellite Internet is a kind of Internet-based satellite communication, which can realize communication between multiple earth stations. Satellite Internet refers to a new type of network based on satellite communication technology that forms a large-scale network by launching a specific number of satellites to provide ground and air terminals with broadband Internet access and other communication services.
2.1. There are three stages in the development of satellite Internet
2.1.1. At the stage of the competition with terrestrial communication networks, provide services such as voice, low-speed data, and the Internet of Things. With the rapid development of terrestrial communication systems, satellite communication systems have gradually been at a disadvantage in terms of communication quality and tariff prices, and have lost in the competition.
2.1.2. In the supplementary phase of the terrestrial communication network, represented by New Iridium, Globalstar, and Orbital Communications Corporation, supplement and extend the terrestrial communication system.
2.1.3. In the phase of integration with terrestrial communication networks, companies represented by OneWeb and SpaceX are leading the construction of new satellite Internet constellations. The operating frequency bands of satellites are gradually increasing, and the construction of satellite Internet is gradually entering the period of broadband Internet.
Satellites are mainly divided into three categories: low, medium, and high orbits according to their orbital heights. Among them, low-orbit satellites have the advantages of small transmission delay, low link loss, and flexible launching, and are the mainstream implementation of satellite Internet services.
2.2. The LEO satellite system has the following two major advantages
2.2.1. It can realize the seamless connection service of the global Internet. Traditional high-orbit synchronous orbit satellites are expensive to construct, and have communication blind spots, time extensions, and limited bandwidth, which can no longer meet the global mass interconnection capacity requirements. In contrast, the low-orbit satellite system has lower transmission delay, higher reliability, higher loss, and 29.5dB lower orbit, and can realize seamless global Internet connection services.
2.2.2. The core application scenarios of low-orbit satellite communications include communications in remote areas, broadband for marine operations and scientific expeditions, aviation broadband, and disaster emergency communications. Among them, the remote area application market mainly includes satellite phones, Internet TV, and satellite broadband; the marine operations and scientific research application markets include satellite positioning and maritime satellite phones; the aviation application market is mainly airborne Wifi; the disaster recovery application market includes emergency calls and data Protection and recovery and remote disaster recovery system, etc.
In recent years, under the leadership of companies such as OneWeb and SpaceX, the satellite Internet industry has embarked on a period of rapid development. China first clarified the scope of new infrastructure on April 20, 2020, including three aspects: information infrastructure, integrated infrastructure, and innovation infrastructure.
Among them, information infrastructure mainly refers to the infrastructure based on the evolution of new-generation information technology, including 5G, the Internet of Things, Industrial Internet, and Satellite Internet. Satellite Internet was included in the communication network infrastructure category for the first time at the national level.
Many Chinese companies have begun to actively deploy the satellite Internet industry. It is estimated that by 2030, the overall market size of China’s satellite Internet will reach hundreds of billions.
It is estimated that China will launch about 3,100 commercial satellites by 2025. The manufacturing cost of a single satellite is 4.29 million U.S. dollars, while the manufacturing cost of a single satellite of StarLink and Amazon is only 500,000 and 1 million U.S. dollars. In contrast, my country’s satellite manufacturing costs still have room for further optimization. In the future, satellite manufacturing companies are expected to increase their gross profit margin and competitiveness, or they will continue to benefit.
Operational services are the link with the highest proportion in the value chain of the satellite industry, and communications satellite operations are an important component. With technological progress, market demand growth, and commercialization, satellites have played an important role in communications, meteorology, remote sensing, broadcasting, navigation, and other fields, and their application fields have continued to be enriched.
According to statistics from 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%; satellite services realized revenue of US$126.5 billion, accounting for 45.6% of the satellite industry’s revenue. 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 No. 3 system has been 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 a global satellite navigation system.
Based on the application of Beidou’s precise space-time technology, it will become an important force to promote the development of satellite navigation and location service industries.
3. Starlink Project
Starlink realizes global networking in three steps, launching approximately 12,000 satellites in total. The StarLink plan is divided into three steps.
In 2015, SpaceX proposed the StarLink plan to use a large number of low-orbit high-throughput satellites to form a constellation to provide users around the world with high-speed and fast network communications. According to SpaceX’s official website information, on the morning of March 4, 2021, Eastern Time, SpaceX put a new batch of 60 Starlink Internet satellites into orbit. This launch brings the total number of Starlink satellites launched to 1,205.
Starlink realizes global networking in three steps, launching approximately 12,000 satellites in total. The StarLink plan is divided into three steps.
1). Launch 1,600 low-orbit low-Earth satellites to achieve initial coverage, with 32 orbits and 50 satellites in each orbit;
2). A total of 2825 satellites were launched in four groups to achieve global networking, with different orbital numbers and orbital inclinations for each group;
3). Launch 7,518 satellites to form a low-orbit constellation. Among them, the first two steps of satellite operating frequencies are in the traditional Ka and Ku bands, and the third step is in the V bands with frequencies ranging from 40 GHz to 75 GHz.
As part of Musk’s umbrella, the Starlink project and Tesla self-driving cars can form a synergy. Through wireless communication technology, the vehicle’s onboard equipment can not only guarantee the distance between the vehicle and the vehicle when the vehicle is running but also help the vehicle owner navigate in real time and improve the efficiency of traffic operation.
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 of its vehicles through Starlink.
The Starlink project is used in telemedicine to help indigenous tribe members to provide medical and health services. Telemedicine refers to relying on computer technology and remote sensing, telemetry, and remote control technology, and taking advantage of the medical technology and medical equipment of large hospitals or specialized medical centers, to remotely treat the wounded and sick in remote areas, islands, or ships with poor medical conditions.
Distance diagnosis, treatment, and consultation can not only reduce the time and cost of transporting patients but also enable doctors to break through geographical limits and share patient medical records and diagnosis photos.
In December 2020, 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 various content such as medical and health services.
Starlink plans to help VR and HD live broadcasts. VR is a computer simulation system that can create and experience a virtual world. It uses a computer to generate a simulation environment to immerse users in it, with features such as immersion, interactivity, and autonomy. In September 2018, SpaceX announced that Japanese billionaire entrepreneur Yusaku Maesawa was the first paying passenger for SpaceX’s mission to orbit the moon. The plan is expected to be implemented in 2023. The journey will be broadcast live in high-definition VR. SpaceX will use the relay satellites of the Starlink project to handle the communication blind spots on the far side of the moon.
The Starlink project can push cloud computing to space. Flexible satellite communications, coupled with Azure’s high-performance computing, machine learning, and data analysis capabilities, help to further meet customer needs.
4. Aerospace integration in the 6G era
As the big data society continues to evolve and become more widespread, spectrum resources are constantly decreasing, but data capacity requirements are constantly 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 the IMT-2030 Promotion Group, to promote 6G-related work. In April of the same year, the University of Oulu hosted the world’s first 6G summit with the theme of paving the way for the arrival of 6G.
The overall 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 reaches 100%, the millimeter-level perception positioning, and the power consumption is greatly reduced. , The transmission bandwidth will reach 1000G level, and the density of connected devices will reach hundreds per cubic meter.
The application scenarios of 6G are based on 5G but are broader
6G high-speed Internet access in the air (exceeding the wide coverage of 5G, achieving 100% in-depth coverage, allowing Internet access in both air and earth)
Holographic communication (to restore and empower the true three-dimensional display ability of the virtual world with more realistic vision, touch and smell, and other multi-dimensional sensory data);
Advanced intelligent industry (realize millimeter-level positioning, deeply participate in industrial manufacturing, and realize more advanced solutions for the industrial Internet);
Human body intelligent twin (real-time monitoring of the human body’s vital organs and various systems through countless human sensors, realizing the twinning of human body data in the virtual world);
Intelligent mobile manned platform (advanced intelligent vehicle networking, networking of various manned tools such as automobiles, various aircraft, cruisers, etc.);
The current trend of 6G technology lies in the aspects of super-dimensional antenna technology, space-earth integration technology, and terahertz band.
The world-earth integration technology enables the world’s intelligent spectrum sharing, minimalist, and extremely intelligent connection by establishing a flexible and reconfigurable network architecture, efficient space-based computing, a unified space-space-earth resource management, and control mechanism, and efficient and flexible mobility management and routing mechanisms. Incoming, multi-beam coordinated transmission and unified waveform, multiple access, coding, and other designs. In the future, users only need to carry one terminal to realize global seamless roaming and non-sensing handover.
The rapid development of air-space-ground integrated network technology and the formation of a complete network system are conducive to occupying the commanding heights of aerospace technology and seizing opportunities for resources and technology. At present, the development of an integrated air-space-ground information network has become a 6G consensus, and it is believed that technological integration needs to be practiced in the 5G era and fully realized in the 6G era.
The air-space-ground integrated network can play an important role in a variety of business scenarios. For communication business scenarios with massive connections such as environmental monitoring, forest fire prevention, drone inspection, ocean-going container information collection, etc., the air-space-ground integrated network can effectively expand the coverage and meet the needs of larger connections and lower power consumption.
In addition, the Internet of Vehicles business requires high-reliability, low-latency communications over a large range, and the wide-area coverage of the air-space-ground network can meet the information transmission requirements and real-time communications of vehicles and drive test systems within a range of 100 kilometers.
From 1G to 5G, after about 40 years of development, mobile communication technology has finally moved from serving people to serving the industry, empowering the digital transformation of the economy and society. At the same time, satellite communications have once again become the focus of attention, especially the Starlink plan proposed by Musk.
As a space power, China has a strong technical reserve for satellite communications. The next-generation 6G communication technology will be a mobile communication network ubiquitous in air, space, earth, and sea, and satellite communication will play an important role in it. When 5G has just been commercialized and is in the ascendant, it is time to start 6G research.