Wireless networking has come on strong in the past few years. Wireless networking is defined by the IEEE 802.11 standard. Also known as Wi-Fi, 802.11 comes in three flavors: a, b, and g. The differences relate mainly to the operating frequency and the available bandwidth.

To utilize wireless networking in a permanent setting where a wireless network needs to exist full time, you need both a Wireless Access Point (WAP) and a wireless NIC in each computer. A wireless network that uses a WAP is known as an infrastructure network. All the devices must support the same standard of Wi-Fi; in other words, 802.11b NICs can only talk with 802.11b access points. It is not uncommon to find WAPs and wireless NICs that support multiple standards. When running in infrastructure mode, the WAP is hard-wired to the physical network. All wireless clients must connect to a WAP in order to communicate with other wired and wireless devices.

You can also create an ad hoc network using 802.11 wireless NICs. In an ad hoc network, several machines with wireless cards can communicate with one another without the use of an access point. Each machine in effect acts as both an access point and as a client. Ad hoc networks are great for small meetings or for transferring large files from one machine to another in an area where a network connection is unavailable.

In either type of wireless network, you need several key pieces of information in order to have your machine participate:

Service set identifier
The service set identifier (SSID) is basically the name of the wireless network to which you are connecting. Depending on the security of the wireless network, the SSID may be broadcast for anyone with a wireless NIC to see. In some cases, to provide a more secure environment, the SSID will not be discoverable, so you must already know the SSID to connect to the wireless network.

Security type
When wireless networks are set up, the administrator needs to decide whether to use security. With an unsecured network, any person in range of the access point can connect to the wireless network and the resources on the wired network beyond. In many cases, administrators of wireless networks will choose to utilize security to prevent unauthorized access. With the security also comes data encryption. Several kinds of wireless security are available; the kind your organization is using will be based on the capabilities of the WAP that is being used. We will discuss wireless security and the requirements to connect to each one in the next section.