How Does WiFi Work?

Laptop's Wireless Adapter Signals

Overview

Wi-Fi works using radio waves.

Signal Transmissions

Wi-Fi stands for "wireless fidelity," which is a nod to "high fidelity," or "Hi-Fi," which is instead associated with sound. A Wi-Fi connection makes use of radio signals, much like the ones used by cell phones and other similar devices. A computer's wireless adapter card translates the data into radio signals that the antenna transmits. These binary code signals are then received and decoded by the router, which send the information to the Internet using a wired Ethernet or LAN (Local Area Network). A wired Ethernet service is typically hosted on a DSL or cable network connection. A Wi-Fi connection is bi-directional, meaning the process just described also works in reverse. In the reverse process, the wired Ethernet device supplying the Internet connectivity sends the information to a wireless router. The router then translates the signals and transmits them to the computer's wireless adapter card.

Wi-Fi Radios

Think of Wi-Fi as a two-way radio communication that sends and receives radio signals in a form of radio waves.The radios used for Wi-Fi communication convert radio waves into binary code and then convert the binary code back into radio waves. They are quite similar to the radios used for cell phones and walkie-talkies. However, Wi-Fi radios can transmit at a higher frequency of 2.4 GHz or 5 GHz. Because of their high frequency, they can deliver more data. A Wi-Fi uses 802.11 IEEE (Institute of Electrical and Electronics Engineers) standards. The 802.11 standards has multiple types; however, the 802.11g and 802.11n are the most commonly used ones.

A Wi-Fi radio can transmit to three frequency bands. It can use any of the three frequency bands and can hop between them to help reduce interference. This is the reason why in a wireless network multiple devices can connect to the same wireless connection at the same time.

Basic Requirements

A mobile device such as a laptop should have a wireless card or built-in adapter to be able to take advantage of using Wi-Fi. Newer laptops have built-in wireless cards; however, in older models you can use a wireless adapter to hook into a USB port or a wireless card that plugs into a PCI card slot. Desktop computers and printers that do not have wireless cards can also get USB wireless adapters to connect to the USB (Universal Serial Bus) ports. A desktop computer usually also has a PCI slot where a wireless card can plug in.

A wireless router acts as a gateway to the main access point. This wireless router connects to a wired Ethernet that provides the Internet connection; therefore, a router should have a port that can connect to a cable or DSL modem.

Configure the wireless router with the default or basic settings required. An SSID (Service Set Identifier) is the name of the network. This has a default setting with the manufacturer's name. You can opt to keep that name or change it any way you want. You would also need to configure the router with the channel, which is typically channel 6 by default. You can change this setting to prevent interference if you live in a multi-unit building.

You will also need to configure the router's security option. You can opt to use the standard or publicly available sign-on; however, doing so may raise the risk of hacking or network intrusion. It is therefore beneficial to use a user name and password to help protect your wireless network.

Hotspots

Mobile computing is becoming more popular than ever thanks to available public Wi-Fi hotspots that people can use. When you turn on your computer or other Wi-Fi-enabled device, it will show the available network connections. You can choose the one with the strongest signal and connect to it. In a public hotspot you can often just connect without using a password, although this is a very insecure method of connecting that allows malicious individuals to easily monitor wireless transmissions. Some hotspots, however, require a user to enter the password in order to connect. This usually happens when the host charges for the usage.

Resources

• Read this Article in Spanish
• Broadbandinfo: Broadband Information