WiFi is a set of standards governed by the Institute of Electrical and Electronics Engineers and describes the technical details of how wireless devices may communicate with each other and wireless access points. In this video, learn how WiFi networks function and provide network access for mobile devices.
- Wireless networking is everywhere. We use wireless networks to provide network access to our smartphones, tablets and laptop computers and to a wide variety of other devices, including televisions, thermostats and home automation systems. As the use of wireless networks continues to increase, the security of those networks becomes of critical importance. The most common wireless standard in use today is Wi-Fi technology. Wi-Fi is a set of standards governed by the Institute of Electrical and Electronics Engineers and it describes the technical details of how wireless devices may communicate with each other and with wireless access points.
The use of a standard for wireless communications is absolutely essential because, without a standard, wireless devices wouldn't speak the same language. Standardization is what allows any Wi-Fi device to work with any Wi-Fi network around the world. Wi-Fi works by replacing the wires and cables of wired networks with radio transmitters and receivers. Every device that supports Wi-Fi contains a radio transceiver that is capable of communicating on one or more standard Wi-Fi bands.
From smartphones and laptops and video game consoles to internet-connected smoke detectors, every Wi-Fi enabled device contains a small chip similar to the one shown here and an antenna used to transmit and receive Wi-Fi signals. Most Wi-Fi networks are also connected to local networks that are, in turn, connected to the internet. This allows wireless devices to not only communicate with each other but also communicate with wired devices and systems located anywhere on the internet.
This type of communication requires a connection between wireless networks and a wired network. Home and business networks use wireless access points, such as the one shown here, to perform that connection. These access points contain powerful antennas, transmitters and receivers that allow them to broadcast Wi-Fi signals over large areas. They are also connected with a cable to a traditional wired network. Wireless devices in the area can then communicate with the access point to connect to that wired network and the internet.
There are many different version of the 802.11 standard that use increasingly sophisticated wireless technology to provide higher bandwidth and longer-range coverage. The earliest version of Wi-Fi, 802.11, was released in 1997 and allowed communications up to two megabits per second. Two years later, the 802.11b standard more than quintupled that speed to allow communication at 11 megabits per second. 802.11g, released in 2003, bumped up the maximum bandwidth to an average throughput of 22 megabits per second.
While 802.11n brought a tremendous boost in bandwidth to 600 megabits per second in 2009 by using special antennas known as multiple-input multiple-output, or MIMO, antennas. The most recent version of the Wi-Fi standard, 802.11ac, allows communications at speeds over one gigabit per second. One of the important things to remember about Wi-Fi signals is that they are radio transmissions and, as such, they can be picked up by anyone with a suitable antenna and receiver.
Unlike wired networks, wireless signals travel out in many different directions. This introduces new security concerns, as network administrators must carefully protect against eavesdropping attacks. I'll examine some ways to secure wireless networks in the next few videos.
Note: This course is part of a series releasing throughout 2018. A completed learning path of the series will be available once all the courses are released.
- How IP addresses are assigned and managed
- Multilayer protocols
- VPNs and VPN concentrators
- Designing secure networks
- Firewall management techniques
- Maintaining network availability
- Software defined networking (SDN)
- Port isolation
- Network attacks
- How Wi-Fi networks function
- WPA, WPS, and propagation attacks
- Host-based network security control