Wi-Fi is an IEEE 802.11 wireless LAN technology. Devices that can use this technology include personal computers, game consoles, phones and tablets, digital cameras, some televisions, audio players, and modern printers.
Wi-Fi compatible devices can connect to the Internet via WLAN and a wireless access point. The latter has a range of about 20 meters indoors and much more outdoors. The coverage of access points can be small (a separate room with walls blocking radio waves) or very large (several square kilometers), which is achieved through the use of several overlapping points.
What it is?
The name of this wireless network - Wi-Fi - began to be used in August 1999. It was invented by the consulting firm Interbrand with the aim of creating a name that would be easy to remember.
The Wi-Fi Alliance for a short time after the creation of the brand used a meaningless advertising slogan that sounded like the “Wireless Accuracy Standard”. It was soon changed to WirelessFidelity.
How it works?
The basic information about Wi-Fi wireless networks is as follows.
The IEEE 802.11 standard is a set of media access control (MAC) and physical layer (PHY) specifications for implementing computer communications over a wireless local area network (WLAN) in the 2.4, 3.6, 5, and 60 GHz bands. They are created and maintained by the IEEE LAN / MAN Standardization Committee (IEEE 802). The basic version of the standard was released in 1997 and had subsequent amendments. They provide the foundation for wireless networking products using the Wi-Fi brand. Despite the fact that each amendment is officially canceled when it is included in the latest version of the standard, the corporate world tends to sell the changes, as they briefly indicate the capabilities of their products. As a result, each change tends to become its own standard.
Wireless Wi-Fi networks most often use 2.4-GHz (12 cm) UHF and 5.8-GHz (5 cm) radio frequency ranges of CBM. Anyone within the range of the modem may try to access the connection. For this reason, Wi-Fi is more vulnerable to attack than wired networks.
Wi-Fi Protected Access is a family of technologies designed to protect information moving over such networks, including personal and corporate. Security features are constantly evolving to provide better protection and new methods.
How to set up a wireless Wi-Fi network?
To connect to Wi-Fi LAN, the computer must be equipped with a wireless network interface controller. The combination of computer and controller interface is called a station. For all stations that use one radio frequency channel, transmissions on it are received within the range. Signal transition is not guaranteed and, therefore, is the best effort delivery mechanism. For data transmission, a carrier wave is used. Such waves are organized into packets routed over an Ethernet channel.
Access to the Internet
The technology of modern wireless Wi-Fi networks can be used to provide Internet access to devices in the signal range. Coverage of one or more interconnected access points can extend from a small space to a considerable number of square kilometers. For coverage in a larger area, a group of access points with overlapping coverage may be required.
Wi-Fi provides services in private homes, enterprises, as well as in public places with hot spots, which are installed either for free or on a paid basis, often using a specific web page to provide access. Organizations and enterprises, such as airports, hotels and restaurants, often provide free connections to attract customers.
Routers include a digital subscriber or cable modem and Wi-Fi access point. They are often installed in residential buildings and other buildings and provide Internet access and interconnection to all devices connected to them via a wireless network or cable.
Portable routers
Wi-Fi wireless networks can also be configured on portable devices. Battery powered routers may include a cellular Internet radio modem and Wi-Fi hotspot. When subscribing to a cellular storage medium, they allow neighboring stations to access the Internet through 2G, 3G or 4G networks using a linking technique. Many smartphones have built-in features of this type, including those based on Android, BlackBerry, Bada, iOS (iPhone), WindowsPhone and Symbian, although operators often disable this feature or charge a separate fee to enable it, especially for customers with unlimited traffic . Some laptops with a cellular modem card can also act as mobile Internet access points.
Ad-hoc Connection
Wi-Fi wireless networks also allow you to communicate directly from one computer to another without an intermediary point. This is called special signal transmission. This Ad-hoc wireless network mode has proven popular in multi-player handheld game consoles such as the Nintendo DS, PlayStation Portable, digital cameras and other consumer electronics devices. Some devices can also use their adhoc Internet connection, becoming “hot spots” or “virtual routers”.
Another direct Wi-Fi connection is Tunneled Direct Link Setup (TDLS), which allows two devices on the same network to communicate directly, rather than through an access point.
Hardware
Wi-Fi makes it cheaper to connect local networks. In addition, in places where the use of cable is not possible (for example, in open areas and in historical buildings), wireless connections can be placed. However, building walls made of certain materials (such as stone with a high metal content) can block the signals of a wireless Wi-Fi network.
Modern manufacturers create such network adapters in most laptops. The price of the chipset for Wi-Fi continues to fall, which makes it a budget network option included in even more devices.
Various competing brands of access points and client network interfaces can interact at a basic level of service. Products designated as “Wi-Fi Certified” by the Wi-Fi Alliance are backward compatible. Unlike mobile phones, any standard device will work anywhere in the world.
USB adapters
A wireless access point (WAP) connects a group of wireless devices to a neighboring wired LAN. It resembles a network hub relaying data between connected devices in addition to one (most often) wired connected gadget, most often an Ethernet switch. This allows all connected devices to communicate with each other.
Wireless adapters allow devices to connect to the network. They sync to devices using various external or internal interconnects such as PCI, miniPCI, USB, ExpressCard, Cardbus and PC Card. Since 2010, most of the latest laptop computers have built-in adapters.
Wireless routers integrate the access point, Ethernet switch, and internal router firmware, which provides IP address routing, NAT, and DNS forwarding through the built-in WAN interface. Such a device allows you to connect wired and wireless Ethernet Ethernet devices to a regular WAN device (for example, cable or DSL modem).
The wireless router allows you to configure all three components (mainly the access point and the router) through one central utility. It usually is an integrated web server available for wired and wireless LANs, and often for WAN clients. This utility can also be an application that runs on a computer, as is the case with Apple's AirPort, which is controlled using the AirPort utility on macOS and iOS.
A wireless bridge connects a wired network to a wireless. It differs from an access point: the latter connects wireless devices to a cable network at the data link level. Two wireless bridges can be used to connect two cable networks over their communication line, which is useful in situations where a wired connection may not be available, for example, between two separate houses or remote devices.
A dual-band wireless bridge can also be used to provide a 5 GHz network on a device that supports only a 2.4 GHz wireless network and has an Ethernet cable port. In addition, range extenders or repeaters can expand the range of an existing Wi-Fi wireless network.
Embedded systems
Recently (especially since 2007), built-in Wi-Fi modules are being introduced more and more. They include a real-time operating system and provide an easy way to wirelessly connect any device that has a serial port and transmits data through it. This allows you to create simple control devices. An example is a portable ECG device that controls a patient at home. Thanks to Wi-Fi support, it can communicate with a remote computer via the Internet.
Such modules were developed by OEMs, so device manufacturers only require minimal knowledge of Wi-Fi wireless network information in order to connect their products.
Network security
A major security concern for a wireless network is its simplified access compared to traditional cable networks (such as Ethernet). With a wired connection, you must either access the building (physically connect to the internal network) or break through the external firewall. To enable Wi-Fi, you just need to be within the signal range. Most corporate networks protect sensitive data and systems in an attempt to block external access. Enabling this technology reduces security if the network does not use encryption.
Wi-Fi Wireless Security
A common measure to prevent access by unauthorized users is to hide the access point name by disabling broadcast SSID. Although it is effective against the casual user, it is not reliable as a security method, since the SSID is transmitted in clear form in response to a client request. Another way is to allow computers with known MAC addresses to connect to a Wi-Fi wireless network, but there is also a vulnerability. Certain listening devices can join the network by spoofing an authorized address.
Wired Equivalent Privacy (WEP) encryption was designed to protect against accidental tracking, but it is no longer considered secure. Tools like AirSnort or Aircrack-ng can quickly recover WEP keys. For this reason, the Wi-Fi Alliance has approved the introduction of Wi-Fi Protected Access (WPA) technology, which uses TKIP. This protection method has been specifically designed for use on older equipment, usually with a firmware update. Despite being more secure than WEP, WPA also discovered a vulnerability. Further security measures allowed updating this technology.
The more secure WPA2 method using Advanced Encryption Standard was first introduced in 2004. It is supported by most newer Wi-Fi devices, and is fully compatible with WPA. In 2017, a flaw was found in this protocol. The vulnerability concerned attacks using a key replay known as KRACK.