Wireless security
A site survey can determine where to place access points within a building to create a map of the areas (cell structures) that will require wireless LAN access. The data transfer rate for each wireless client will be determined by its location within the cell structure.
Locations closer to the centre of an access point radius will experience higher throughput than those that are closer to the outside of the cell coverage area. This is facilitated by auto shifting, which allows the data rate to downshift based on distance from access point. Again, this functionality will vary depending on the product and 802.11 standard used.
One of the greatest benefits to roaming mobile users is the ability for one access point to hand off communication to the next access point in the roaming cell.
Known as seamless roaming, this allows the user to move from cell structure to cell structure without losing connectivity to the network.
Wireless bridges enable high-speed long-range outdoor links between buildings (Figure B). The high-speed links between the wireless bridges deliver throughput several times faster than T-1 lines at distances up to 25 miles.
Based on line-of-sight, wireless bridges are not affected by obstacles such as freeways, railroads, and bodies of water, which typically pose a problem for copper and fibre-optic cable.
Wireless bridges are often the ideal choice for campus environments where the cost of multiple T-1 lines or fibre runs can be very costly.
Wireless can also be used for building-to-building connectivity.
The question of wireless security
No wireless project should be implemented without a lengthy discussion of security. Over the past year, much has been written about the vulnerabilities of 802.11 wireless LANs. Older forms of security on WLANs included the SSID, which was not really a security method at all, since the SSID can easily be retrieved by sniffing the network.
Authentication based on MAC filters was found inappropriate because they, too, could be sniffed on the network, and the allowable MACs could be spoofed. Newer 802.11 security uses 128-bit Wireless Encryption Privacy (WEP) for data encryption, along with shared key authentication. Unfortunately, researchers have recently identified holes in WEP that let attackers learn the keys used to encrypt 802.11b traffic.
Summary
As changes are in the works to establish new 802.11 standards and improve security, wireless LANs are moving into corporations at an increasing rate. Who knows? In a few short years, wireless networks may be as commonplace as their wired counterparts.
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Thanks for your article, it cleared up some of the questions I had and was very informative.