Wireless Data Networks

Wireless LAN Configuration

The simplest WLAN configuration is an independent LAN that connects a set of PCs with wireless adapters. Any time two or more wireless adapters are within range of each other, they can set up an independent network (as shown below). These on-demand networks typically require no administration or preconfiguration.

Independent WLAN

Access points can extend the range of ad hoc LANs by acting as a repeater, effectively doubling the distance between wireless PCs. In infrastructure WLANs, multiple access points link the WLAN to the wired network and allow users to efficiently share network resources. The access points not only provide communication with the wired network but also mediate wireless network traffic in the immediate neighbourhood. Multiple access points can provide wireless coverage for an entire building or campus.

 

 

 

Wireless LAN

Microcells and Roaming

Wireless communication is limited by how far signals carry for given power output. WLANs use cells, called microcells, similar to the cellular telephone system to extend the range of wireless connectivity. At any point in time, a mobile PC equipped with a WLAN adapter is associated with a single access point and its microcell, or area of coverage. Individual microcells overlap to allow continuous communication within wired network. They handle low-power signals and "hand off" users as they roam through a given geographic area.

Microcell/Roaming Configuration

 

           

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Copyright © 1997 Derek Mc Donnell.
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Last updated 07-Apr-1998.
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