The Wi-Fi logo
The Wi-Fi Alliance was founded in 1999 as the Wireless Ethernet Compatibility Alliance (WECA). In October 2002, it was officially renamed the Wi-Fi Alliance. Commonly known as: Wireless Router
Wi-Fi was originally an acronym for wireless fidelity, and the full name of Wi-Fi in English is wireless fidelity, which in the context of wireless LANs refers to "wireless compatibility authentication. ", essentially a commercial certification, but also a wireless networking technology, previously connected to the computer through the network cable, and now it is through the radio waves to connect to the network; common is a wireless router, then in the effective range of the radio wave coverage of this wireless router can be used WIFI connectivity for networking, if the wireless router connected to an ADSL line or other Internet lines. If the wireless router is connected to an ADSL line or other Internet lines, it is also known as "hotspot". Now the common wireless router on the market is 54M speed and 108M speed, and another 300M speed Wi-Fi router is gradually becoming more common. Wi-Fi next generation standard development to start the highest transmission rate of up to 6.7G. Of course, this speed is not the speed of the Internet, the speed of the Internet mainly depends on the WIFI hotspot of the Internet line.
Edit Pronunciation
The phonetic translation of "wifi" is "waifai" or "waifi". According to the latest edition of Le petit Robert, the most authoritative French dictionary, the phonetic symbol for wifi is [wifi], which is close to the Chinese word "weifi". However, it is now often pronounced as waifai.
Editing the origin
Bluetooth + wifi wireless devices
The first version of IEEE 802.11 was published in 1997, which defined the medium access control layer (MAC layer) and the physical layer. The physical layer defines two wireless FM modes and one infrared transmission mode operating in the ISM band at 2.4 GHz, with a total data rate designed to be 2 Mbit/s. Communication between the two devices can be free and direct (ad hoc), or coordinated at a Base Station (BS) or Access Point (AP). ) are coordinated. Two complementary versions were added in 1999: 802.11a defined a physical layer with data rates up to 54 Mbit/s in the 5 GHz ISM band, and 802.11b defined a physical layer with data rates up to 11 Mbit/s in the 2.4 GHz ISM band. The 2.4GHz ISM band is used by most countries in the world, so 802.11b is the most widely used. Apple named its own development of the 802.11 standard AirPort. 1999 saw the formation of the Wi-Fi Alliance by industry to address the production and device compatibility of 802.11-compliant products. Wi-Fi is the organization that developed the 802.11 wireless network, and does not stand for wireless networking.
Introduction
Wi-Fi is commonly known as wireless broadband (China Telecom will CDMA 1X/3G also known as wireless broadband) BlackBerry 8320 Wi-Fi cell phone
The so-called Wi-Fi, in fact, is the alias of the IEEE 802.11b, which was created by a group called the "Wireless Ethernet Compatibility Consortium" (Wireless Ethernet Compatibility Alliance). It is a short-range wireless transmission technology that supports radio signals for Internet access within a range of several hundred feet. As the technology has evolved, and with the advent of standards such as IEEE 802.11a and IEEE 802.11g, the IEEE 802.11 standard is now collectively referred to as Wi-Fi. From an application level, in order to utilize Wi-Fi, the user must first have a Wi-Fi compatible client device. Wi-Fi is an Internet technology that helps users access e-mail, the Web, and streaming media. It provides users with wireless broadband Internet access. It is also a fast and convenient way to access the Internet at home, in the office, or on the go. Places where Wi-Fi networks can be accessed are called hotspots.Wi-Fi or 802.11G operates in the 2.4Ghz band and supports speeds of up to 54Mbps.There are two other protocols in the 802.11 space, including (a) and (b). They are also in public use, but 802.11G is most commonly used in the world. A Wi-Fi hotspot is created by installing an access point on an Internet connection. This access point carries the wireless signal over a short distance - typically covering 300 feet. When a Wi-Fi-enabled device, such as a Pocket PC, encounters a hotspot, the device can wirelessly connect to that network. Most hotspots are located in places that are accessible to the general public, such as airports, coffee shops, hotels, bookstores, and campuses. Many homes and offices also have Wi-Fi networks. While some hotspots are free, most stable public **** Wi-Fi networks are provided by private Internet Service Providers (ISPs) and therefore charge users a fee when they connect to the Internet. Wi-Fi enabled laptops
The full name is Wireless Fidelity. 802.11b is sometimes incorrectly labeled Wi-Fi, which is actually a trademark of the Wireless LAN Alliance (WLANA), which only guarantees that goods using the trademark will work with each other, and has virtually nothing to do with the standard itself. However, people have since grown accustomed to using WIFI to refer to the 802.11b protocol. Its biggest advantage is its high transmission speed, which can reach 11Mbps, and its long effective distance, as well as its compatibility with various existing 802.11 DSSS devices. The laptop technology, Centrino, is based on this standard. IEEE ([American] Institute of Electronics and Electrical Engineers) 802.11b wireless network specification is an extension of the IEEE 802.11 network specification, the highest bandwidth of 11 Mbps, in the case of weak signals or interference, the bandwidth can be adjusted to 5.5 Mbps, 2 Mbps and 1 Mbps, the bandwidth is automatically adjusted to effectively guarantee the stability and reliability of the network. Its main characteristics are: fast speed, high reliability, in the open area, the communication distance can reach 305 meters, in the closed area, the communication distance is 76 meters to 122 meters, easy to integrate with the existing wired Ethernet network, the cost of networking is lower. Wi-Fi (WirelessFidelity, wireless compatibility certification) is formally known as "IEEE802.11b", and Bluetooth, the same belongs to the office and home in the use of short-range wireless technology. While the technology is less secure than Bluetooth in terms of data security, it is slightly better in terms of airwave coverage, and Wi-Fi has a range of up to 300 feet or so (about 90 meters), which can be used in offices, not to mention in smaller buildings. For this reason, Wi-Fi has been the technology favored by businesses to implement their own wireless LANs. There is another reason why Wi-Fi seems to be superior to the costly 3G enterprise networks. The hotspots for Wi-Fi were all born in 2002, and in the United States, Wi-Fi, like the early days of the Internet, is showing signs of being a starburst. In 2003 it is destined to have a bright future around the world. Wi-Fi will bring high-speed wireless Internet access as commonplace as cell phone calls today. Vendors are now aggressively applying the technology to devices ranging from PDAs to desktop computers to create new selling points. As the number of Wi-Fi devices increases, their prices will drop, and the annual global production of Wi-Fi devices will reach 33 million units in 2006. WiFi kiosk
WIFI highlights the advantages One of them is the wide coverage of radio waves. The coverage of radio waves based on Bluetooth technology is very small, with a radius of about only about 50 feet or so, or about 15 meters, whereas the radius of Wi-Fi can be up to about 300 feet or so, or about 100 meters, and the office, needless to say, can be used in the whole building. A new switch was recently introduced by Vivato. It is said to be able to extend the current communication distance of 300 feet (nearly 100 meters) for Wi-Fi wireless networks to 4 miles (about 6.5 kilometers). Secondly, although the quality of wireless communication transmitted by Wi-Fi technology is not very good, the data security performance is a little worse than Bluetooth, and the transmission quality needs to be improved, but the transmission speed is very fast and can reach 54mbps, which is in line with the needs of personal and social informatization. Third, the threshold for manufacturers to enter the field is relatively low. Manufacturers only need to set up "hotspots" in airports, stations, coffee shops, libraries and other densely populated places, and connect the Internet to these places through high-speed lines. In this way, because the "hot spots" emit radio waves that can reach a radius of tens of meters to 100 meters from the access point, the user can access the Internet at high speed as long as the laptop or PDA that supports wireless LAN is brought to the area. In other words, manufacturers do not have to spend money to network wiring access, thus saving a lot of cost. USB wireless LAN card
WIFI speeds vary depending on the standard used by the wireless LAN card. Among them, IEEE802.11b is up to 11Mbps (some vendors can reach 22Mbps with matching equipment), IEEE802.11a is 54Mbps, and IEEE802.11g is also 54Mbps (the Netgear SUPER G technology can increase the speed up to 108Mbps, but is not part of the 802.11n standard). WIFI is a wireless network composed of AP (Access Point) and wireless network card, AP is generally known as network bridge or access point, it is used as a bridge between traditional wired local area network and wireless local area network, so any PC equipped with a wireless network card can share the resources of the wired local area network or even wide area network through the AP, and its working principle is equivalent to a built-in wireless transmitter HUB or a router. The principle of operation is equivalent to a built-in wireless transmitter HUB or router, and the wireless card is responsible for receiving the signal transmitted by the AP CLIENT end of the device. And wireless b/g indicates the model of the card, according to its speed and technology can be divided into 802.11a, 802.11b, 802.11g, 802.11n. Speaking of wireless networks, we all have a plausible feeling that wireless is a simple interconnection of two computers? No wiring and the use of relative freedom, to establish a new feeling of people on the wireless LAN. Demand determines the development of the market, and it is rare to see any IT technology or product that can have such a rapid growth momentum as it is, without any constraints to access the Internet anytime, anywhere is no longer a dream, in which WiFi plays a crucial role. Wi-Fi stands for "wireless fidelity", referring to the full compatibility of the IEEE 802.11 standard. 802.11 standard IEEE802.11b subset, which uses the open 2.4GHz direct sequence spread spectrum, the maximum data transmission rate of 11Mbps, but also according to the signal strength of the transmission rate can be adjusted to 5.5Mbps, 2Mbps and 1Mbps bandwidth. The transmission range is up to 300 meters outdoors and 100 meters indoors when there are obstacles, and it is the most used transmission protocol nowadays. It has many advantages over wired networks: No wiring required Wireless LAN card for desktop machines
The most important advantage of WiFi is that it does not require wiring, and can be used without the limitations of wiring conditions, so it is very suitable for the needs of mobile office users, and it has a broad market outlook. It has already expanded from its traditional specialties of healthcare, inventory control, and managed services to more industries, and has even begun to make inroads into the home as well as educational institutions. Health and Safety IEEE802.11 stipulates that the transmit power must not exceed 100 milliwatts, and the actual transmit power is about 60~70 milliwatts, what kind of concept is this? The transmit power of a cell phone is about 200 mW to 1 watt, handheld walkie-talkie up to 5 watts, and the wireless network is not used in a way like a cell phone in direct contact with the human body, it is absolutely safe.
Mobile phone WiFi is the trend WLAN is the abbreviation of Wireless Local Area Network (WLAN), which is a kind of 802.11n/b/g/a standard based on the use of WiFi wireless communication technology will be connected to the PC and other devices, constitute can communicate with each other, to achieve the resources **** enjoy the network. In the past two years, there are more and more smartphones with WLAN connectivity on the market that support technologies such as UMA (Unlicensed Mo-bile Access). They can not only make calls with the help of GSM/CDMA mobile communication networks, but also enjoy PC Internet access or VoIP calls in the area covered by WiFi wireless LAN***. Below, we will take WiFi cell phones with Windows Mobile operating system as an example to introduce how cell phones can access the Internet via WLAN. The list of cell phones with WiFi function: Nokia N97mini , Nokia N80, Nokia 5800XM, Nokia C5 03, Nokia 5730XM, Nokia E66 (mainland licensed goods do not support) Nokia 5800w, Nokia 5530, Nokia C6-00, Nokia C6-01, Nokia C7, Nokia N8, Nokia N79, Nokia N78, Nokia E52, Nokia E71, Nokia E72i, Nokia X6, Sony Ericsson W960, Sony Ericsson J20, Samsung i8320 (Vodafone360 H1), Samsung SGH-T709, Samsung i5508, Motorola XT3, Motorola A910, Motorola A3100, Dopod 838, Apple Iphone 4, etc. Wireless router to access the Internet in order to be able to use the cell phone lying in bed to access the Internet, open the GPRS. helpless GPRS Internet access is not only difficult to satisfy people's speed, the rate is not cheap. You can't buy a laptop just for the sake of laziness, right? Of course not. In fact, just a wireless router, we can let the phone and PC *** enjoy broadband Internet access. At present, accessing the Internet through a wireless router or wireless AP has become the choice of many Internet users. Through the wireless router, LAN or WLAN, PC can easily use ADSL, Cable, FTTX and other broadband access to the Internet. WiFi cell phone through the wireless router *** enjoy Internet access is also very convenient, most WiFi phones do not need to do any setup, in the wireless router's signal coverage, the WiFi cell phone and the wireless router under the default settings WiFi cell phones can automatically obtain an IP address for wireless connection, and use the cell phone comes with IE, MSN and other software to access the Internet wirelessly. Of course, if the WiFi cell phone can not enjoy the Internet through the wireless router when both the WiFi cell phone and the wireless router are turned on normally, we need to check the settings of the device. Wireless Router Settings First, make sure the PC can access the Internet normally through the wireless router, if not, check whether the wireless router is normally turned on and set correctly. Second, in the IE address bar of any PC with normal access to the wireless network, enter the IP address of the wireless router and log into the management page of the wireless router to check. Focus on checking the following: make sure the DHCP server is enabled and there is enough address pool; allow SSID broadcasting; cancel any non-essential security authentication and keys; and turn off the firewall function of the wireless router. If necessary, you can also restart the wireless router or restore it to the factory settings in the setup interface, and then reset the broadband network. First, open "Start → Settings → Connections", and in the "Advanced → Select Network" option, make sure that the "In the program to automatically connect to the network" option is set to "In the program to automatically connect to the network", and then "In the program to automatically connect to the network" option is set to "In the program to automatically connect to the network". In the "Advanced" option, make sure that "Use: when the program automatically connects to the Internet" is set to "Internet settings". Next, in the "Connections → Network cards (network adapters, network interface cards)" option, go to "Configure network adapters" and make sure that "My network card connects to:" is selected as the "Default unit setting". "Default unit settings" or "Preset work settings". Finally, in the "Connections→Network card" option, select the network card of your phone (usually WLAN or WiFi Wireless Adapter), and then select "Use server-assigned IP address" or "Obtain an IP address automatically" in the configuration screen. "Obtain an IP address automatically" in the configuration screen. In addition, if the wireless router does not broadcast SSID for security reasons, you need to find the SSID field in the "Wireless Network" configuration of your WiFi phone and fill in the corresponding SSID name. If you are prompted to enter the key during the connection process, you can choose "Auto key" or enter it manually. Today is an era of rapid technological progress, in the public **** places in major cities in China, a variety of hotspots to provide WiFi services have long been integrated into the life of everyone. Now even a roadside wonton stall, not installed a WiFi is embarrassed to say hello to people. However, in the face of all kinds of WiFi hotspots like the mushrooming of a variety of complicated, you dabbler often turn on the device, it becomes a lost rabbit in the forest. What looks like a dead tree branch is actually a WiFi signal strength detector. It is similar in shape to the TV remote control device of some days ago, designed to improve the old wireless network detector technology. The method of use is very simple, as long as both hands holding the end of the fork, and then look around for WiFi signals can be, the strength of the signal will be in the stick with the indicator to show, which is similar to the signal strength of the wireless management software on the computer display.