Wireless communication technology is widely used in different research fields. This book mainly introduces the key technologies, new technologies and related applications of wireless communication system. APPLICATIONS+ Profi WiFi hotspot coverage+ Commercial radio coverage+ Hotel Wireless application+ Country coverage+ Internet for passengers (bus, train, plane, …)+ Security Surveillance+ Some special scene application+ Heavy-duty industrial environment useThe main contents include: key technologies of wireless communication, RFID wireless communication technology, ZigBee wireless communication technology, WLAN wireless communication technology, Bluetooth wireless communication technology, mobile communication technology, other wireless communication technology, future development trend of wireless communication, etc.Let's take a look at **WLAN wireless communication technology**:A WLAN is a Wireless local area network (LAN) built using wireless technology. WLAN in a broad sense refers to a network that uses radio waves, lasers, infrared and other wireless signals to replace part or all of the transmission media in the priority LAN.Using WLAN technology, users can easily access the wireless network and move freely within the coverage area of the wireless network, completely getting rid of the shackles of the wired network

When several devices are connected to the same AP, they can communicate with each other.Wireless is more insecure than wired, so there is no security and no wireless. Wireless is generally used to encrypt data and verify access devices.

**Bluetooth wireless communication technology**The so-called Bluetooth technology is actually a short-range wireless communication technology. The use of “Bluetooth” technology can effectively simplify the communication between mobile communication terminal devices such as handheld computers, laptops and mobile phones, and also successfully simplify the communication between these devices and the Internet. This will allow the transmission of data between these modern communications devices and the Internet to become faster and more efficient, opening the way for wireless communication. Generally speaking, Bluetooth technology enables modern mobile communication equipment and computer equipment to be easily carried without the help of cables to network, and can realize the wireless Internet, its practical application scope can also be extended to a variety of household appliances, consumer electronic products and automobiles and other information appliances, forming a huge wireless communication network.The background of “Bluetooth” is as follows: In May 1998, five famous manufacturers, such as Ericsson, Nokia, Toshiba, IBM and Intel, put forward Bluetooth technology when they jointly carried out standardization activities of short-range wireless communication technology. Its purpose is to provide a short-range and low-cost wireless transmission application technology. The five companies have also formed a Bluetooth Special Interest Group to help Bluetooth become the future wireless communication standard. Chip kingpin Intel makes semiconductor chips and transmission software, Ericsson makes radio frequency and mobile phone software, and IBM and Toshiba develop interface specifications for notebook computers. In the second half of 1999, the famous industry giants Microsoft, MOTOROLA, Sankong, Lucent and the Bluetooth special group of five companies jointly launched the establishment of Bluetooth technology promotion organization, thus setting off a global “Bluetooth” boom. The global industry is about to develop a large number of Bluetooth technology applications, so that Bluetooth technology presents a very broad market prospects, and indicates that the early 21st century will usher in a magnificent wave of global wireless communication.