15KM ultra-long-distance WiFi module wireless communication type The impact of wireless communication networks on us, wireless communication (English: Wirelesscomunication) refers to the use of battery waves rather than transmission through cables. The wireless communication industry covers a wide range, including aviation navigation, radio and television, transportation, public security, meteorology, fire and flood prevention, mobile communication, telecommunications, electricity, mining, defense equipment, etc. Compared with wired communication, one of the main advantages of wireless communication is that it does not need to be limited by the site like wired cable transmission, and has wide coverage, good mobility, and rapid establishment. At the beginning of wireless communication, due to technical limitations, signals were easily interfered or intercepted, and the confidentiality was poor, which limited the coverage area of wireless communication. With the development of wireless communication technology, wireless communication began to be applied to all aspects of life. At the same time, modern wireless communication Technology is developing in the direction of digitization and anti-interference.
According to the use and service objects of wireless communication, the wireless communication of 15KM ultra-long distance WiFi module can be divided into private network wireless communication and public network wireless communication. Private network wireless communications serve specific departments or groups, mainly for public safety, public utilities, and some industrial and commercial customers. Public network wireless communication mainly serves the public's personal communication. According to the different frequencies and wavelengths, wireless communication can be roughly divided into long-wave communication, long-wave communication, medium-wave communication, short-wave communication, ultra-short-wave communication, microwave communication, etc. At present, the technology developed by Tengyuan Intelligent is the field of wireless microwave communication.
Very long wave communication, frequency band name: very low frequency (VLF), radio waves with a wavelength of 10~100km (frequency 3~30km). Its characteristics are: small propagation loss, strong diffraction ability, and long communication distance; it can pass through the ionosphere to bypass space stars; strong seawater penetration; For long-range command communications from shore to deep submarines. Long-wave communication (Long-wavecomunication), frequency band name: low frequency (LF), electromagnetic wave radio communication with a wavelength range of 1km-10km (30-300kHz), also known as low-frequency communication. It can be subdivided into long wave (wavelength 101000 meters), very long wave (100km10km), ultra long wave (1000km1000km) and extremely long wave (1~10000km). His development history can be traced back to the transoceanic communication experiment of Italian physicist G. Marconi in the last century. The communication distance of his application ranges from thousands to tens of thousands of kilometers. With the development of missiles and nuclear weapons, more and more military installations were moved underground. 15KM ultra-long-distance WiFi module long-wave underground communication will be an important means to ensure emergency communication between underground command posts.
Medium wave communication, frequency band name: medium frequency (MF), electromagnetic wave radio communication with wavelength of 1000~100m and frequency of 300~3000kHz. The medium wave band is one of the bands used in the early development of radio communications. On December 12, 1901, G. Marconi's first transatlantic radio transmission experiment used an 800 kHz intermediate frequency signal. Short wave communication, frequency band name: high frequency (MF), radio communication technology with a wavelength of 10m-100m and a frequency range of 3 MHz to 30 MHz. The radio waves transmitted by short-wave communication can only reach the receiving equipment through the reflection of the ionosphere. Long communication distance is the main means of long-distance communication. The short-wave communication system consists of a transmitter, a transmitter antenna, a receiver, a receiver antenna and various terminal equipment. The front end of the transmitter and the receiver have been completely solid-state and miniaturized. Sending antennas mostly use broadband in-phase horizontal, rhombus or logarithmic periodic antennas, and receiving antennas can also use fishbone-shaped and adjustable loop antenna arrays. The main function of the terminal equipment is to increase the echo loss, prevent the vibration when the four-wire system of the transceiver branch is connected with the commonly used two-wire system, and provide the companding function.
Because the height and density of the ionosphere are easily affected by factors such as day and night, seasons, and climate, short-wave communication has poor stability and high noise. With the development of technology, short-wave communication equipment has the advantages of convenient use, flexible network, low price and strong resistance to damage. Ultrashort wave communication, frequency band name: very high frequency (VHF), wavelength 1m-10m, frequency band 30-300mhz, also known as meter wave communication, mainly rely on ground wave communication and space wave line-of-sight communication. Due to the wide frequency band, it is widely used in television, FM broadcasting, radar detection, mobile communication, military communication and other fields. Microwave communication, frequency band naming: UHF and above, wavelength 1m-0.1m, frequency band 300mHz-3000gHz. Different from the transmission methods of modern communication networks such as coaxial cable communication, optical fiber communication, satellite communication, etc., microwave communication directly uses microwaves as a medium for communication, and does not require a solid medium. Microwave transmission can be used when there are no obstacles within a straight-line distance between two points. Microwave communication has the characteristics of large capacity, good quality and long distance. It is an important means of communication in the national communication network and is also widely used in various special communication networks.
What impact does the 15KM ultra-long-distance WiFi module wireless communication network have on us?
Since the Italian radio engineer Galilmo Marconi successfully realized wireless communication of hundreds of meters in 1895, wireless communication has entered the human field of vision. With its rapid development, it has been widely used in the fields of military, life and technological exploration. even into the universe. The emergence of 15KM ultra-long-distance WiFi module wireless communication makes human information interaction more and more timely, so as to meet people's communication needs of any form at any time and any place. The development requirement of human wireless communication is to maximize the use of frequency domain, time domain, code domain, air domain and other resources, provide large-capacity communication capabilities, support high-quality multimedia services, and realize multi-service, multi-band, multi-mode, multimedia To integrate the wireless environment, of course, the physical resource allocation mechanism of the wireless communication system and the design of communication signal processing have put forward higher requirements.
Taking the traditional wireless communication platform as an example, the large scale and high cost no longer meet the development requirements of the current era. At the same time, due to the limitations of working scenarios and working modes, the hardware platform is complex, and it is difficult to ensure real-time and high speed. With the popularization of small devices such as the Internet of Things and smart terminals, miniaturization, smart vocabulary, high flexibility, low power consumption, low cost, and high integration have become new topics in the contemporary background.
The development of cellular network communication technology has gone through five stages
In the first stage, in the 1G era, from 1950 to 1980, 1G used analog electronic technology to transmit a small amount of data, and frequency multiple access (FDMA) technology was used to reuse frequencies.
The second stage, 2G network, 1980-1990, since 2G, cellular communication began to enter digital communication technology from analog communication.
In the third stage, in the 3G era, in 1996, the International Telecommunication Union (ITU) proposed IMT-2000 (International Mobile Communication System), that is, the third-generation mobile communication system with a working frequency band of 2000mhz.
The fourth stage, 4G communication, the fourth generation communication system, includes LTE (LongTermevolution) and Time Duplex (TDD).
The fifth stage, in the current 5g era, that is, the fifth generation of communication technology, is a new generation of broadband mobile communication technology with the characteristics of high speed, low latency and large connections. It is the network infrastructure that realizes the interconnection of human, machine and things. In order to meet the needs of diverse application scenarios of 5g, the key performance indicators of 5g are more diversified. ITU defines eight key performance indicators of 5g, of which high speed, low latency and large connection have become the most prominent features of 5g. The user experience rate is 1gbps, the delay is 1ms, and the user connection capability is 1 million connections/km2.
In 1990, the IEE802 standardization committee established the IEE802.11WLAN standard working group, and subsequently produced the 802.11 standard (currently a general standard for wireless local area networks) with an initial rate of 2mbit/s. With the development of technology, the standards of wireless local area network include IEE802.11 standard series, HomeRF, HyperLAN2 and Bluetooth.
Among them, the 15KM ultra-long-distance WiFi module IEE802.11 series is the most widely used, especially the IEE802.11b standard, which is still developing and improving. HyperLAN2 was proposed by the European Telecommunications Standardization Institute (ETSI) Broadband Radio Access Network (BRAN) group, with a rate of up to 54mbp, and has been widely supported by the industry in Europe. HomeRF (American Home Radio Frequency Committee in 1997) mainly establishes interoperable voice and data communication networks for home users. The transmission distance and access users of Bluetooth are limited, so it is suitable for short-distance transmission.
Generally speaking, the wireless communication of 15KM ultra-long-distance WiFi module is developing towards seamless, broadband, high-speed, high-frequency spectrum and intelligence. With more and more wireless communication systems, software radios, baseband digital processing functions and basic peripherals of mobile phones Functions are concentrated in a system-on-a-chip (SOC), which has become a new development trend.
