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Architecture of wireless LANs In a wireless LAN (WLAN), the connection between the client and user exists through the use of a wireless medium such as Radio Frequency (RF) or Infrared (IR) communications. This allows the mobile user to stay connected to the network. The wireless connection is most usually accomplished by the user having a handheld terminal or a laptop computer that has an RF interface card installed inside the terminal or through the PC Card slot of the laptop. The client connection from the wired LAN to the user is made through an Access Point (AP) that can support. | Mobile Telecommunications Protocols For Data Networks. Anna Hac Copyright 2003 John Wiley Sons Ltd. ISBN 0-470-85056-6 8 Architecture of wireless LANs In a wireless LAN WLAN the connection between the client and user exists through the use of a wireless medium such as Radio Frequency RF or Infrared IR communications. This allows the mobile user to stay connected to the network. The wireless connection is most usually accomplished by the user having a handheld terminal or a laptop computer that has an RF interface card installed inside the terminal or through the PC Card slot of the laptop. The client connection from the wired LAN to the user is made through an Access Point AP that can support multiple users simultaneously. The AP can reside at any node on the wired network and performs as a gateway for wireless users data to be routed onto the wired network. The range of these systems depends on the actual usage and environment of the system but varies from 100 ft inside a solid walled building to several 1000 ft outdoors in direct Line of Sight LOS . This is of a similar order of magnitude as the distance that can be covered by the wired LAN in a building. However much like a cellular telephone system the WLAN is capable of roaming from the AP and reconnecting to the network through other APs residing at other points on the wired network. This allows the wired LAN to be extended to cover a much larger area than the existing coverage by the use of multiple APs for example in a university campus environment. A WLAN can be used independently of a wired network and it may be used as a standalone network anywhere to link multiple computers without having to build or extend a wired network. For example in an outside auditing group in a client company each auditor has a laptop equipped with a wireless client adapter. A peer-to-peer workgroup can be immediately established to transfer or access data. A member of the workgroup can be established as the server or the .