Setting Up Wireless Adapters and Network Interface Cards

For your client computers to connect to your WLAN, each of them must have a wireless adapter or wireless NIC. These adapters are small transceivers (radio transmitter/receivers) that allow your PC to send and receive radio signals. There are three main types of Wi-Fi adapters available for your WLAN: USB wireless adapters, wireless NICs, and PCMCIA cards.

A USB wireless adapter connects to your computer through its USB port. It is simple to install and enables you to adjust the location of the adapter to improve signal reception. You install a wireless NIC in a PCI slot within the computer, just like an Ethernet card; a wireless NIC installed within a computer saves desktop space. For a laptop computer, the best choice is a PCMCIA card adapter that fits in the laptop’s PC card slot

Caution: Always turn off me Power to your computer when installing internal network adapters. You usually won’t need to turn off the computer to insert PCMCIA cards or USB devices, but you may have to reboot to finish the installation.

Any time you open the case of a computer you need to take special care. Always turn off the power and unplug the cord. Don’t force adapters into PCI slots, and be careful of dropping things like screws into the case. You also should wear an anti-static wrist strap to avoid damaging components with static electricity.

Wireless adapters have two modes of operation, infrastructure and ad hoc. Installation of adapters is usually very simple. Once you install or connect the adapter to the client PC, Windows (assuming you are using Windows) usually recognizes the new hardware and prompts you to insert a disk with the appropriate drivers.

Even if you aren’t using Windows, the configuration utility that comes with your adapter will lead you through the setup process and often automatically detects your access point and the channel that it is using. Manufacturers call the ability to automatically detect and select the channel frequency-agility.

Normally the software prompts you to select an SSID from a list of detected SSIDs. Assuming your AP is the only one in range, this will be a short list. You will then enter any other required information, such as encryption keys.

Note: Windows XP has a feature called Wireless Auto Configuration. This is a useful feature if your wireless adapter supports it Wireless Auto Configuration automatically configures your card to connect to a detected preferred network.

This means that you can have several saved configurations (home, work, coffee shop, and so on) and Windows XP automatically configures your card to connect when it detects those networks. It also can prevent your computer from accidentally connecting with another network (like your neighbor’s).

The software also may prompt you to select a data speed. This is the minimum speed required to connect to your WLAN. Usually your card performs this selection automatically, based on the signal strength that it detects. If your signal strength fluctuates you can set this speed manually to a signal level that your adapter can reliably detect. There also are good security reasons for setting a high minimum connection speed.

Adapter setup should be a relatively painless process. In the event that you do run into problems, review your documentation and visit the manufacturer’s Web site for updates and helpful troubleshooting tips.