What is an access point?

Let's talk some more about the central pivot point in your wireless network: the access point. Somewhat similar in function to a network hub, an access point in a wireless network is a special type of wireless station that receives radio transmissions from other stations on the wireless LAN and forwards them to the rest of the network. An access point can be a stand-alone device or a computer that contains a wireless network adapter along with special access-point management software. Most home networks use a stand-alone AP. Because many homes and businesses use wireless networking, a method is needed to distinguish one wireless network from another. Otherwise, your neighbor may accidentally send a page to the printer on your network. (That could be fun or that could be a little scary.) Three parameters can be used to uniquely identify each segment of a wireless network:

• Network name: When you set up your wireless network, you should assign a unique name to the network. Some manufacturers refer to the network name by one of its technical monikers - service set identifier (SSID) or perhaps extended service set identifier (ESSID). This can be confusing and comes up most often if you're using equipment from different manufacturers. Rest assured, however, that network name, SSID, and ESSID all mean the same thing. If the AP manufacturer assigns a network name at the factory, it assigns the same name to every AP it manufactures. Consequently, you should assign a different network name to avoid confusion with other APs that may be nearby (like your neighbor's). Note: All stations and the AP on a given wireless network must have the same network name to ensure that they can communicate. Assigning a unique network name is good practice, but don't think of the network name as a security feature. Most APs broadcast their network name, so it's easy for a hacker to change the network name on his or her computer to match yours. Changing the network name from the factory setting to a new name just reduces the chance that you and your neighbor accidentally have wireless networks with the same network name.

• Channel: When you set up your wireless network, you have the option of selecting a radio channel. All stations and the access point must broadcast on the same radio channel to communicate. Multiple radio channels are available for use by wireless networks, and some of the newer wireless APs use multiple channels to increase the speed of the network. The number of channels available varies according to the type of wireless network you're using and the country in which you install the wireless network. Wireless stations normally scan all available channels to look for a signal from an AP. When a station detects an AP signal, the station negotiates a connection to the AP.

• Encryption key: Because it's relatively easy for a hacker to determine a wireless network's name and the channel on which it's broadcasting, every wireless network should be protected by a secret encryption key unless the network is intended for use by the general public. Only someone who knows the secret key code can connect to the wireless network.