Wi-Fi is a wireless LAN technology based on IEEE 802.11 standards. Devices that can use this technology include personal computers, game consoles, phones and tablets, digital cameras, some TVs, audio players, and modern printers.
Wi-Fi enabled devices can connect to the internet via WLAN and wireless hotspot. The latter has a range of about 20 meters indoors and much more outdoors. Access point coverage can be small (a single room with radio blocking walls) or very large (several square kilometers), achieved by using multiple overlapping access points.
What is this?
The name of this wireless network - Wi-Fi - began to be used in August 1999. It was created by the consulting firm Interbrand with the goal of creating a name that would be easy to remember.
The Wi-Fi Developers Alliance used a nonsensical advertising slogan for a short time after its trademark creation, which sounded like "The Wireless Standardprecision." It was soon changed to WirelessFidelity.
How does it work?
Basic information about Wi-Fi networks is as follows.
The IEEE 802.11 standard is a set of media access control (MAC) and physical layer (PHY) specifications for computer communication over a wireless local area network (WLAN) in frequency bands 2, 4, 3, 6, 5 and 60 GHz. They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802). The basic version of the standard was issued in 1997 and has been subject to subsequent amendments. They provide the basis for wireless networking products using the Wi-Fi brand. Although each amendment is officially repealed when it is included in the latest version of the standard, the corporate world tends to sell changes because they succinctly define the capabilities of their products. As a result, each change tends to become its own standard.
Wireless Wi-Fi networks most often use the 2.4 GHz (12 cm) UHF and 5.8 GHz (5 cm) UHF radio frequency bands. Anyone within range of the modem can attempt 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 networks. Security features are constantly evolving to provide stronger protection and new methods.
How do I set up a wireless Wi-Fi network?
To connect to Wi-Fi LAN, your computer must be equipped with a wireless network interface controller. The combination of a computer and a controller interface is called a station. For all stations that use one radio frequency communication channel, transmissions on it are received within the range. Signal transition is not guaranteed and is therefore a best effort delivery mechanism. A carrier wave is used to transmit data. These waves are organized into packets sent over an Ethernet link.
Internet access
Modern Wi-Fi technology can be used to provide Internet access to devices within signal range. The coverage of one or more interconnected access points can range from a small area to a considerable number of square kilometers. Coverage over a larger area may require a group of APs with overlapping coverage.
Wi-Fi provides services in private homes, businesses, and public hotspots that are installed either free of charge or on a paid basis, often using a specific web page to provide entry. Organizations and businesses such as airports, hotels, and restaurants often provide free connections to attract customers.
Routers include a digital subscriber or cable modem and a Wi-Fi hotspot. They are often installed in residential buildings.and other buildings and provide Internet access and interconnection to all devices connected to them wirelessly or via cable.
Portable routers
Setting up Wi-Fi wireless networks can also be done on portable devices. Battery-powered routers may include a cellular internet radio and Wi-Fi hotspot. When subscribed to a cellular data carrier, they allow neighboring stations to access the Internet via 2G, 3G or 4G networks using bonding technology. Many smartphones have this type of capability built in, including those based on Android, BlackBerry, Bada, iOS (iPhone), WindowsPhone, and Symbian, although carriers often disable this feature or charge a fee to enable it, especially for customers with unlimited data. Some laptops with a cellular modem card can also act as mobile Internet hotspots.
Ad-hoc connection
Wi-Fi networks also allow you to communicate directly from one computer to another without an intermediary point. This is called special signaling. This Ad-hoc wireless networking mode has proven popular in multiplayer handheld game consoles such as the Nintendo DS, PlayStation Portable, digital cameras, and other consumer electronics devices. Some devices can also use their Internet connection in adhoc mode, becoming "hotspots" or "virtual routers".
Another way to communicate directly over a Wi-Fi network is Tunneled Direct Link Setup (TDLS), which allows two devices on the same network to communicate directly instead of through an access point.
Hardware
Wi-Fi makes it cheaper to connect local networks. In addition, wireless connections can be placed where cable cannot be used (such as open areas and historic buildings). However, building walls made of certain materials (such as stone with a high metal content) may block Wi-Fi wireless LAN signals.
Modern manufacturers create such network adapters in most laptops. The price of the Wi-Fi chipset continues to drop, making it a budget networking option included in more devices.
Different competing brands of access points and client network interfaces can interoperate at a basic service level. Products designated as "Wi-Fi Certified" by the Wi-Fi Alliance are backwards 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 nearby 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. itallows all connected devices to communicate with each other.
Wireless adapters allow devices to connect to the Web. They synchronize with 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 an access point, an Ethernet switch, and internal router firmware that provides IP address forwarding, NAT, and DNS forwarding through the built-in WAN interface. This device allows you to connect wired and wireless Ethernet LAN devices to a regular WAN device (such as a cable or DSL modem).
The wireless router allows you to configure all three components (mainly access point and router) through one central utility. It is typically an integrated web server accessible to wired and wireless LANs, and often to WAN clients. This utility can also be an application that runs on a computer, as in the case of Apple's AirPort, which is controlled using AirPort Utility on macOS and iOS.
A wireless network bridge connects a wired network to a wireless network. 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 twocable networks over its own line, which is useful in situations where a wired connection may not be available, such as between two separate homes or remote locations.
The Dual Band Wireless Bridge can also be used to provide a 5GHz network on a device that only supports 2.4GHz wireless and has an Ethernet cable port. In addition, range extenders or repeaters can extend the range of an existing Wi-Fi 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 transmit data through it. This allows you to create simple control devices. An example would be a portable ECG device monitoring a patient at home. With Wi-Fi support, it can communicate with a remote computer over the Internet.
These modules are designed by OEMs, so device makers need only minimal knowledge of Wi-Fi information to enable their products to connect.
Network Security
The main problem with wireless network security is that it is easier to access than traditional wired networks (such as Ethernet). With a wired connection, you must either gain access to the building (physicallyconnect to an internal network), or break through an external firewall. To turn on Wi-Fi, you just need to be within signal range. Most corporate networks protect sensitive data and systems by attempting to deny external access. Enabling this technology reduces security if the network does not use encryption.
Wi-Fi Security
A common measure to prevent access by unauthorized users is to hide the access point name by disabling SSID broadcast. While this is effective against the casual user, it is unreliable as a security method because the SSID is transmitted explicitly in response to a client request. Another way is to allow computers with known MAC addresses to connect to the Wi-Fi network, but there is also a vulnerability here. Certain listening devices can join the network by spoofing an authorized address.
Wired Equivalent Privacy (WEP) encryption was designed to protect against accidental snooping, but 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 implementation of Wi-Fi Protected Access (WPA), which uses TKIP. This protection method was specifically designed to be applied to older hardware, usually through a firmware update. Despite being more secure than WEP, WPA also discovered a vulnerability. Further security measuresallowed to update this technology.
The more secure WPA2 method using Advanced Encryption Standard was first introduced in 2004. It is supported by most new Wi-Fi devices and is fully WPA compliant. In 2017, a flaw was discovered in this protocol as well. The vulnerability concerned attacks using a key repeat known as KRACK.
