1. Wireless Networking

2. Wireless Networking • Wi-Fi or 802.11 • Uses radio waves (like cell phones, tv and radio). • Just like wired networking except without the wires. • A hot spot is a place where wireless networking is available • Hot spots need access points to propagate signals.

3. Access Points • Each access point has a service set identifier (SSID) which is its name to distinguish it from other access points. All access points come with a default SSID. If you install a home network you should change its SSID to something more cryptic. • Access points also have channels (1 to 11) which allows multiple access points to operate in the same area for different networks. The default channel is typically 6. Changing the channel on your home access point may improve your network’s performance since it will be less likely to interfere with your neighbor’s network.

4. Wireless Security • Wireless networks need more security than wired networks because anyone with a computer with wireless service can connect to your network if they are within range. • There are three types of wireless security: • Broadcast • MAC Filtering • Encryption

5. Broadcast • If your access point has broadcast turned on then it will continuously broadcast its identity and availability. • For example, if your access point has an SSID of NetFred, then it will broadcast its identity. “Hi! I’m NetFred, would you like to join my network?” This will allow your computer to detect that there is a hot spot and try to join it. • If broadcast is turned off then your computer can still connect to it if it knows its name. “I’m looking for NetFred. Are you around?” • So turning broadcast off on your home network will make it more difficult for a passerby to find it and use it.

6. MAC Filtering • Each network interface card has a MAC address. This address is a hardware address associated with a particular network controller. All controllers have unique addresses. • The address is a six byte hexadecimal number. • So if you turned mac filtering on in your access point and specified the MAC address of each of your wireless computers then no other computer could join your home network (unless they could spoof the MAC address of one of your computers.)

7. Encryption • Encryption is the process of coding your messages so that they cannot be understood. • WEP, wired equivalency privacy, uses an encryption key, which some vendors (I’m looking at you Apple) misname as a password. WEP is not very secure from a dedicated attack • WPA, wi-fi protected access, is a better method of protection which uses a username and password to allow one to log on to a network. There are several modes of WPA currently available. The curious can look them up.

8. Wireless Signal Strength • Like your cell phone. • Your computer will change access points (If one is available) when the signal on the current connection becomes sufficiently weak. • It will not always use the strongest signal but only change when its current signal degrades to a significant degree.