User's Manual

• Security—The 802.11 wireless networks use encryption to help protect your data.
Wired equivalent privacy (WEP) uses a 64-bit or 128-bit shared encryption key to
scramble data. Before a computer transmits data, it scrambles the data using the secret
encryption key. The receiving computer uses this same key to unscramble the data. If
you are connecting to an existing network, use the encryption key provided by the
administrator of the wireless network. If you are setting up your own network you can
make up your own key and use it on each computer.
Identifying a Wireless Network
Depending on the size and components of a wireless LAN, there are many ways to identify a
wireless LAN:
• The Network Name or Service Set Identifier (SSID)—Identifies a wireless network. All
wireless devices on the network must use the same SSID.
• Extended Service Set Identifier (ESSID)—A special case of SSID used to identify a
wireless network that includes access points.
• Independent Basic Service Set Identifier (IBSSID)—A special case of SSID used to
identify a network of wireless computers configured to communicate directly with one
another without using an access point.
• Basic Service Set Identifier (BSSID)—A unique identifier for each wireless device.
The BSSID is the Ethernet MAC address of the device.
• Broadcast SSID—An access point can respond to computers sending probe packets
with the broadcast SSID. If this feature is enabled on the access point, any wireless
user can associate with the access point by using a blank (null) SSID.
Surveying the Site of Your Wireless LAN
Conducting a site survey for your wireless LAN is the most crucial step in the process of setting
up a wireless network. It greatly reduces the amount of troubleshooting you will have to do once
you have the wireless LAN set up and ready for connection testing. To conduct a site survey,
you will need the following tools:
• An access point (or laptop computer) that is set up to be the transmitter. It should be
mounted near and at the same height as the designated location of your wireless LAN.
• A laptop that will act as the mobile receiver. It must contain your site survey software.
• An area or building map, which will be used to plot the strength of your signals.
Once you have the tools you need, you are ready to survey the inside of the building. Launch
the site survey software on the mobile receiver laptop and carry it around in the intended
wireless LAN area to test the signal strength. Be sure to also check the signal strength of each
intended access point location. If you encounter problems while surveying the site, make sure
your transmitter laptop is not located on a wall containing metal, such as an air-conditioning
duct, which will interfere with the range of your signal. Simply move the transmitter and test the
signal strength again. For users to have seamless coverage when moving from access point to
access point, the signal levels at each point must overlap. There is software available that will
seamlessly hand off changing signal levels from one access point to another.
Your building's infrastructure can sometimes interfere with the microwave signal, but finding the
location and cause of the interference will allow you to figure out the best place to mount your
access points for optimal area coverage. Microwave signals travel in all directions, which means
there is one access point for a multi-floor building. However, the range is highly dependent on
the material used to construct the flooring, especially metal materials. Once your signal strength
is strong inside the building, you are ready to check the strength outside the building. To do so,