What have people done online since 1993?

Since 1993, people can not only see words, but also see pictures and hear sounds online? Sound makes the online world beautiful and colorful, which is mainly attributed to "www".

World Wide Web WWW is the abbreviation of World Wide Web, also known as Web, 3W, etc. WWW is a combination of information discovery technology and hypertext technology based on client/server mode. WWW servers organize information into illustrated hypertext through Hypertext Markup Language (HTML), and use links to jump from one site to another. This completely gets rid of the limitation that the previous query tools can only find information step by step according to a specific path.

The World Wide Web enables people all over the world to communicate with each other on an unprecedented scale. People who are far apart, even people of different ages, can develop intimate relationships or sublimate each other's ideological realm through the internet. The advantage of digital storage is that it can query information resources on the network more efficiently than consulting libraries or real books. Getting information is faster than searching in person, by mail, telephone, telegram or other means of communication.

The World Wide Web is the most profound and extensive media in human history. It can connect its users with other people scattered around the world, and their number far exceeds the number that can be achieved through specific connections or the sum of all other existing media.

Nowadays, the Internet is a household name, the mobile Internet is in full swing, and the satellite Internet is also emerging in Ran Ran. These networks, like transportation, electricity, gas and tap water, are indispensable infrastructures of human society. If the previous infrastructure transmits material and energy, the Internet, mobile Internet and satellite Internet transmit information, so it is called information infrastructure. Different from matter and energy, information has natural permeability, knowledge and intelligence, and the marginal cost of its production and dissemination is far less than that of matter and energy. Therefore, it promotes the development of human society far more than matter and energy.

In the new infrastructure launched by China to cope with the impact of COVID-19 epidemic on the global economy, information infrastructure such as 5G, Internet of Things, industrial Internet and satellite Internet, as well as related infrastructure such as intelligent transportation and smart energy have become the main construction contents. The inclusion of satellite Internet in the category of new infrastructure has excited people in the satellite communication industry in China, and the whole industry suddenly seems to have a feeling of turning over as a master. Undoubtedly, it is a good thing for the development of satellite communication in China to incorporate satellite Internet into the new infrastructure. At this moment, in order to know where the content of new infrastructure comes from, it is necessary to review the development history of Internet, mobile Internet and satellite Internet. Because, review the past and learn the new.

Internet dominates the world.

When it comes to the Internet, we have to look for meaning from literature. Internet originated in America, and its English name is Internet. It was first transliterated to the Internet in China. Literally, the Internet is a combination of Inter and net, representing an interconnected network. The Internet began with 1969, which is a research project of military communication network interconnection, and the main object of connection is computers. At that time, the private networks of PSTN (public telephone network), X.25 (public data network), DDN (public digital data network) and IBM DEC were all business networks serving specific fields, which were heterogeneous and could not communicate with each other. The ARPA network interconnection research project plans to develop a set of protocols with TCP/IP (Transmission Control Protocol/Internet Protocol) as the core, aiming at connecting various heterogeneous networks and realizing the interconnection between computers. So the early Internet was also called computer network.

TCP/IP is simplified from the OSI (Open Systems Interconnection) seven-layer protocol of ISO (International Organization for Standardization), which is divided into five levels: physical layer, link layer, network layer, transport layer and application layer. Physical layer is to realize the transmission of signals on various media, and channel coding and modulation and demodulation are the main technologies. Link layer realizes point-to-point transmission between network nodes, and synchronization and error correction are the main technologies. The network layer realizes the transmission of data packets from source to destination, and routing and switching are the main technologies; The transport layer realizes end-to-end conversation and confirmation; The application layer provides interfaces and interfaces for various applications. IP and TCP correspond to the network layer and the transport layer respectively, and IP is the backbone of the Internet protocol family.

Nodes in the Internet are well-known routers, which connect various heterogeneous networks with IP protocol. End-user data is encapsulated into IP packets in a unified format, including globally unique IP addresses. IP packets are encapsulated in various network protocols, and routers perform packet routing and relay delivery. This process is vividly called IPover everything, which refers to various heterogeneous networks.

In the early days, routers had to deal with various network protocols, such as X.25, Frame Relay, ISDN (Integrated Services Digital Network) and ATM (Asynchronous Transfer Mode). Because there are not many users and the amount of data processed is not large, the general router can be handy. From 65438 to 0993, the Clinton administration of the United States put forward the National Information Infrastructure (NII) or the information superhighway plan, and people's awareness of the importance of information networks has never been higher. Because of its strong openness and inclusiveness, the Internet has rapidly surpassed the well-designed ISDN and ATM networks in the telecommunications industry. The popularity of WWW based on HTML (Hypertext Markup Language), the packetization of voice and video, and the packetized transmission of IP have enriched the application of the Internet, and also made the amount of data on the Internet increase exponentially, which has had a huge impact on the original data transmission and exchange mode of the Internet.

In order to cope with the above shocks, the Internet has three important solutions. One is to use PPP (Point-to-Point Protocol) running on high-capacity SDH (synchronous digital hierarchy) optical fiber network to replace various low-speed service networks in backbone layer, convergence layer layer and access layer; The other is to introduce MPLS (multi-protocol label switching) and other technologies into the router to improve the data processing speed. According to different application scenarios and business processing capabilities, routers are divided into backbone, convergence and access routing. In addition, there are home routers. The third is to give priority to processing various application data and provide carrier-level services for voice and other applications. In addition, in the process of Internet commercialization, network access technologies are also emerging one after another. XDSL (Digital Subscriber Line) based on telephone twisted copper wire and DOCSIS (Cable Data Service Interface Specification) based on cable TV cable both played an important supporting role, but they were eventually replaced by WiFi (Wireless Fidelity) wireless network and various PON (Passive Optical Network) optical fiber networks.

At this point, the internet has completed a gorgeous turn. Instead of relying on others, it is independent, and the integration of telephone network and cable TV network has been realized in the triple play. Today, people are accustomed to IP phone, IPTV and OTTTV, which are typical products of triple play. They are similar to telephone networks and television networks in application form, but the network structure is the Internet. This result is vividly called EverythingoverIP, where Everything refers to various contents and applications. Today, so-called Internet companies, such as Facebook, Google and Twitter abroad, and Baidu, Ali and Tencent in China, are actually engaged in Internet applications, such as e-commerce and social networking, while the physical Internet is mainly in the hands of telecom operators.

3. The mobile Internet is attacking the city.

It should be said that although wireless and microwave transmission also played a certain role, the Internet was originally developed mainly on wired networks. The goal of the Internet is to connect computers all over the world. The goal of mobile network is to communicate anytime and anywhere. From 1970s to now, mobile communication is basically updated every ten years. If the original 1G is an analog voice mobile communication system, it has nothing to do with the Internet, then every step of the development of mobile communication has been strongly influenced by the Internet since 2G digital communication, and eventually it has become an important part and application form of the Internet, which is likely to catch up with it.

The gradual integration of mobile communication into the Internet and its development to the mobile Internet was completed in the 2G and 3G periods, and its starting point was GPRS (General Packet Radio Service) in the 2G period. GPRS is a wireless packet switching technology based on voice circuit switching in GSM network, which provides end-to-end and wide-area wireless IP connection and data transmission. GPRS is a 2.5G technology for the transition from GSM network to 3G, which realizes the connection between mobile communication and Internet. Its theoretical bandwidth can reach 17 1.2Kbps, and the actual bandwidth is about 40~ 100Kbps. On top of GPRS, WAP (Wireless Application Protocol) converts HTML data on the Internet into a simple WML (Wireless Markup Language) format to adapt to the application scenarios with limited network speed and mobile phone intelligence at that time.

After entering the 3G era, in order to meet the demand of bandwidth growth brought by smart phones such as Apple and various value-added applications, technologies such as HSDPA (high-speed downlink packet access) and HSUPA (high-speed uplink packet access) with higher speed than GPRS and their enhanced HSPA+ began to appear one after another. The uplink rate of HSPA+ is 5.76Mbps and the downlink rate is 2 1Mbps or 28Mbps.

Unlike 2G and 3G, which transmit voice and data through circuit domain and packet domain respectively, 4G completely cancels the circuit domain and uses a unified packet domain to carry all services. It handles real-time services such as voice through IMS(IP Multimedia Subsystem), and VoLTE (Long Term Evolution Voice Bearer) is the standard for voice transmission through IP. It can be seen that 4G has transformed mobile communication into a real mobile Internet. Entering the stage of 5G mobile Internet, its application fields have expanded from ordinary Internet applications to Internet of Things, Internet of Vehicles and Industrial Internet. Not only that, 5G has also realized the system integration of Internet of Things, cloud computing, big data and blockchain technology, which has brought the whole society into the era of artificial intelligence. The internet in the era of artificial intelligence is more like a human brain. It has hearing, vision and touch, can analyze, calculate, store and judge, and may eventually have self-awareness.

Satellite Internet has expanded its territory.

Although the terrestrial Internet is very developed, it only covers 20% of the earth's land area and 5.8% of the earth's surface. To truly realize the vision of 5G's Internet of Everything and access at any time, it is also necessary to use the satellite Internet that can truly cover the whole world.

It should be said that the internetization of satellite communication network began as early as 2000, and the combination of VSAT network with DVB-S (Digital Video Broadcasting-Satellite) and DVB-RCS (Digital Video Broadcasting-Satellite backhaul) is a key link. DVB-S was originally a set of technical standards formulated by ETSI for satellite digital video broadcasting, including source coding, channel coding and modulation. Later, with the development of satellite channel coding and modulation technology, ETSI successively put forward DVB-S2 and DVB-S2X standards, with a period of exactly ten years. DVB-RCS is a backhaul channel standard proposed by ETSI to meet the development needs of satellite broadband communication. DVB-S series and DVB-RCS standards are supported by the mainstream VSAT network equipment manufacturers in the world, which makes the global VSAT networks have the same open standards, thus laying a solid foundation for the IP of satellite communication networks and the development of satellite Internet.

In the forward channel of satellite Internet based on DVB-S series and DVB-RCS standard, IP packets are segmented by MPE (Multiprotocol Encapsulation) and then loaded into MPEG-2-TS (Transport Stream) packets. IP packets of the reverse channel can be packetized through ATM or MPE and then loaded into MPEG2-TS. Initially, the forward channel rate of this satellite Internet can reach 45Mbps, and the reverse channel rate can reach 2Mbps. With the introduction of high-capacity HTS (Qualcomm Quality Satellite) and more efficient channel coding and modulation technology, the forward and reverse channel rates have increased by more than ten times, which fully meets the bandwidth requirements of consumers' broadband access, mobile platform access, base station relay, content delivery and other applications.

At present, satellite Internet mainly appears in the form of HTS, which includes GEO (high orbit), MEO (middle orbit) and LEO (low orbit). Among them, GEOHTS system has a long transmission delay and weak coverage in high latitudes, but the system structure is simple and can cover a wide area, which is suitable for applications such as airborne communication, maritime communication, consumer broadband access, video broadcasting and content delivery. LEOHTS is more complex, but the delay is shorter, and it can achieve seamless global coverage, which is suitable for low-latency applications such as base station relay and Internet of Things. MEOHTS is somewhere in between. As for GEO satellites, the capacity of Viasat-2 and Jupiter-2 in North America will reach 300Gbps and 220Gbps respectively, and the capacity of Viasat-3 and Jupiter-3 under construction will reach 1 Gbps and 500Gbps respectively, while the capacity of traditional communication satellites is only about 1 Gbps. In MEO constellation, SES currently has 20 O3b in orbit, which are mainly used for relay and backhaul. In October17, 165438+ 10, O3b plans to add 30 satellites. Among LEO constellations, SpaceXLEO constellation takes the lead and finally plans to launch 42,000 satellites. At present, space exploration technology company has completed seven launches through the technology of one arrow and 60 stars. When the number of satellites reaches 800, it can have the initial service capability. It is worth mentioning that DVB-S series and DVB-RCS standards are mainly applicable to GEO satellites. For MEO and LEO satellites, due to the change of channel characteristics, more suitable air interface standards and protocols are usually needed, but VSAT networks are similar.

Satellite Internet is a natural extension of the Internet, especially the mobile Internet. In order to promote the integration of satellite Internet and 5G, ITU, 3GPP, SaT5G (Satellite 5G Alliance), CBA(C-Band Alliance) and other international standardization organizations are all carrying out related research work. At the 20 19 European Network and Communication Conference (EuCNC20 19), SaT5G gave a series of satellite 5G demonstrations:

1) MEC (Mobile Edge Computing) using satellite and terrestrial networks: bit rate adaptation, link selection and enhanced video streaming;

2) Video caching and live content distribution based on satellite multicast technology;

3) Airborne communication based on MEO satellite;

4) 5G local content cache using hybrid backhaul network and MEC;

5) Satellite network 5G video demonstration;

6) Hybrid 5G base station relay for rural market and large-scale assembly activities. Among them, airborne communication and rural broadband are the most attractive.

2065438+In May 2009, Telesat, the University of Surrey in England and Newtec in Belgium jointly conducted the 5G backhaul test of LEO satellite, and the round-trip delay was18-40ms. The main applications include 8K streaming media transmission, web browsing and video communication. These test results show that satellite Internet and 5G have achieved full integration. Satellite Internet will provide broad development space for Internet and mobile Internet, and play a unique role in universal service, so that all human members can enjoy the basic rights of surfing the Internet and information services.