Wi-Fi
Wi-Fi is a wireless communication technology widely used to create networks that provide internet access and facilitate data sharing among devices. It allows users to connect to a network without the need for physical Ethernet cables, making it convenient for both personal and public use. Wi-Fi networks can vary in scale, from small home setups to extensive municipal systems, enabling a range of functionalities such as accessing shared printers, scanners, and internet resources.
Wi-Fi operates using radio waves at two primary frequencies—2.4 GHz and 5 GHz—which influence data transfer speeds and network performance. While the 5 GHz frequency supports faster data transfers, devices connecting to these networks require compatible wireless receivers, known as wireless cards.
However, Wi-Fi networks are not without vulnerabilities; they can be susceptible to cyberattacks if not properly secured. Network administrators play a crucial role in maintaining the security of these networks by implementing various protection measures, including the use of encryption protocols such as WEP, WPA, and WPA2. Each of these protocols offers different levels of security, with WPA2 being the most recommended for safeguarding sensitive information.
On this Page
Subject Terms
Wi-Fi
Wi-Fi is a form of wireless radio communication commonly used to create wireless computer networks. People use Wi-Fi networks to distribute Internet access from an Internet provider (IP) and to share photographs, music, and other important information. Wi-Fi networks may be as small as an apartment’s personal network or as large as a metropolitan city’s public Internet system.
Wi-Fi Basics
A network is any set of linked computers. Before Wi-Fi networks became common, most networks were connected via Ethernet cables. Ethernet cables connect each computer to a central network hub, also called a router. Routers sort and manage communication between computers on a network. In some cases, the router connects to a modem, which provides Internet access to every machine on the network.
Wi-Fi networks are used for a variety of purposes. They allow every user on a network to access a single machine, such as a scanner or printer. They allow all the devices in a building to access the Internet without installing wires. They also allow for files, programs, and applications to be distributed to every device on the network.
Wi-Fi networks require each computer on the network to have a specialized wireless receiver, also called a wireless card. While some computers come with preinstalled wireless cards, others require an external wireless card. Wireless networks also require a wireless router, which uses radio waves rather than Ethernet cables to transmit information.
Wi-Fi networks transmit radio waves at two frequencies, 2.4 gigahertz (GHz) and 5 GHz. Older wireless routers transmit at 2.4 GHz while many newer wireless routers transmit at both frequencies. Transmission at 5 GHz allows for the transfer of more data at once, leading to higher data-transfer speeds. Wireless routers that broadcast at both frequencies allow users to sort network traffic into each frequency. Tasks that require particularly fast transfer speeds should be sorted onto the 5GHz frequency while tasks that do not should be sorted onto the 2.4 GHz frequency.
Some devices other than wireless routers use radio waves to function. Cellular phones, walkie-talkies, audio radios, satellite television, and even microwaves use radio waves to fulfill their primary functions. In most cases, these devices are programmed to utilize only radio waves at specific frequencies to avoid interfering with other devices that use radio waves. In some cases, however, malfunctioning or outdated devices may transmit or receive radio waves outside their intended frequency range. This interferes with other devices that utilize that frequency range. For example, running an old or malfunctioning microwave near a wireless router may flood the router with meaningless data, drastically slowing the transfer of real data.
Network Security
Wi-Fi networks are vulnerable to attacks by cybercriminals if not properly secured. They suffer from many of the same drawbacks as traditional local area networks. If a virus, Trojan horse, rootkit, worm, or hacker gains access to one computer on a network, all of the other computers in the network become compromised. Moreover, unlike with a traditional local area network, a hacker does not need to physically connect to a Wi-Fi network to gain access to it. Instead, he or she just needs to be within range of the wireless router. The consequences of such an attack can be catastrophic. The hacker may gain access to personal information, such as names, birthdays, and social security numbers, to steal identities. He or she may steal credit card information and make fraudulent purchases. In some cases, the hacker may be able to hold all the files on the computer hostage until a large monetary sum is payed.
Wi-Fi networks are maintained by individuals called network administrators. Network administrators use a variety of tools to keep networks safe and secure. For example, they may set permissions for computers on the entire network. Permissions restrict the actions that non-administrator accounts may take. For example, on some networks, non-administrator users are not allowed to download or open executable files or install new software. This limits the chance of an ill-informed computer user accidentally allowing a compromised file onto the system.
Network administrators also are responsible for utilizing the built-in security features of the wireless router. Most wireless routers have four types of security: open, WEP, WPA, and WPA2. An open network is not protected by password or encryption. While an open network may make use of security features such as firewalls, a prospective intruder needs only to be within range of the wireless router to gain access to the network. Open networks may be convenient, but security experts generally advise against them.
Networks using WEP are more secure than open networks. They require a password, and information traveling over WEP is encrypted. However, WEP encryption is considered weaker than many other options. Free, specialized software can break WEP encryption in a short time.
WPA is very similar to WEP. It requires a password, and all data transmitted across the network is encrypted. However, the protocols utilize separate password requirements and different forms of encryption. WPA was specifically designed to patch many of the weaknesses of WEP. Its successor, WPA2, was designed to be even stronger. Most security experts recommend using WPA2 on any networks containing important or sensitive information. However, older devices may not be compatible with WPA2.
Bibliography
Brain, Marshall, Tracy V. Wilson, and Bernadette Johnson. "How WiFi Works." HowStuffWorks Tech. InfoSpace LLC. Web. 16 Feb. 2016. http://computer.howstuffworks.com/wireless-network.htm
Brandon, John. "How Does a Wi-Fi Signal Work?" Mental‗Floss. MentalFloss, Inc.. Web. 16 Feb. 2016. http://mentalfloss.com/article/57916/how-does-wi-fi-signal-work
CCM. "What Is WiFi and How Does It Work?" CCM. CCM Benchmark Group. Web. 16 Feb. 2016. http://ccm.net/faq/298-what-is-wifi-and-how-does-it-work
Escobar, Eric. "How to Set Up Your Home Wireless Security." Quick and Dirty Tips. Macmillan Holdings, LLC. Web. 16 Feb. 2016. http://www.quickanddirtytips.com/tech/home-theater/how-to-set-up-your-home-wireless-security
ETHW. "Wireless Local Area Networks (WLANs)." ETHW. Engineering and Technology History Wiki. Web. 16 Feb. 2016. http://ethw.org/Wireless‗Local‗Area‗Networks‗(WLANs)
Sophos. "Security Tips for Network Administrators." Sophos. Sophos Ltd. Web. 16 Feb. 2016. https://www.sophos.com/en-us/security-news-trends/best-practices/10-tips.aspx