talking about WiFi everyone knows that wireless Internet access is available, but is it clear to WiFi itself? In fact, WiFi is a wireless connection, not a wireless network or other wireless devices and so on. It is the starting point of this article to differentiate WiFi wireless networking technology from other concepts. Through this article, I hope you can recognize it.
WiFi Wireless networking technology
Wi-Fi is a technology that allows terminals, such as PDAs and mobile phones, to connect wirelessly to one another in a wireless way. Wi-Fi is a brand of wireless internet communications technology, held by Wi-Fi Alliance. The goal is to improve interoperability between wireless network products based on IEEE 802.11 standards. At present, the average person will confuse Wi-Fi and IEEE 802.11. Even the Wi-Fi equivalent to the wireless internet. The name of the
WiFi wireless networking technology
Wi-Fi Alliance was founded in 1999 and was named Wireless Ethernet Compatibility Alliance (WECA). In October 2002, it was officially renamed Wi-Fi Alliance.
Popular saying: WiFi is a wireless networking technology, formerly connected to the computer through a network cable, and now is through radio waves to connect the network; Common is a wireless router, then the wireless router in the effective range of radio coverage can be used WiFi connection mode for networking, If the wireless router is connected to an ADSL line or other Internet line, it is also called "Hot spot".
Now the most common wireless routers on the market is 54M speed, the previous level is 108M speed, of course, this speed is not the speed of your Internet, the speed of the Internet is mainly dependent on the WiFi hotspot of the internet line.
The origins of WiFi wireless networking technology
The first version of IEEE 802.11 was published in 1997, which defines the media Access Access control layer (MAC layer) and physical layer. The physical layer defines two wireless FM modes working at the 2.4GHz ISM band and an infrared transmission, with the total data rate designed for 2mbit/s. Communication between the two devices can be done in a free, direct (ad hoc) manner, or in coordination with the base station (base station,bs) or access point (Access Point,ap).
In 1999, two additional versions were added: 802.11A defines a single, 5GHz ISM bandThe data transfer rate can reach the physical layer of 54mbit/s, 802.11B defines a physical layer on the 2.4GHz ISM band but with a data transfer rate up to 11mbit/s. The
2.4GHz ISM Band is common to most countries in the world, so 802.11b is the most widely used. Apple called AirPort the 802.11 standard it developed. In 1999, the industry established a Wi-Fi Alliance to address the production and equipment compatibility issues of 802.11 compliant products. Wi-Fi is for the organization of 802.11 wireless networks, not for wireless networks.
A new generation of wireless networks that will create a fresh feel for wireless LANs without wiring and using relative freedom. Demand determines the development of the market, rarely see which it technology or products like it has such a rapid growth momentum, unfettered by any constraints access to the Internet is no longer a dream, in which WiFi plays a vital role. Wi-Fi represents "wireless fidelity", refers to a fully compatible 802.11 standard ieee802.11b subset, it uses open 2.4GHz direct sequence spread spectrum, the maximum data transfer rate of 11Mbps, can also be based on the signal strength of the transmission rate of 5.5Mbps, 2Mbps and 1Mbps bandwidth. No straight transmission range for the outdoor maximum of 300 meters, indoor barriers in the case of the maximum 100 meters, is now used most of the transport protocol.
WiFi wireless networking has many advantages over wired networks: The main advantage of
without wiring
WiFi is that it does not require wiring and can be free from cabling conditions, so it is ideal for mobile office users. has a broad market prospects. It has been expanding to more industries from the traditional health care, inventory control and management services, and has even begun to enter the family and educational institutions.
Health and safety
IEEE802.11 The emission power must not exceed 100 MW, the actual launch power of about 60~70 watts, what kind of concept? The cell phone emits about 200 MW to 1 watts, and the handheld walkie-talkie is up to 5 watts, And the way the wireless network is used is not as direct contact with the human body, it is absolutely safe.