RLAN (WLAN)

A Radio LAN (RLAN), or wireless lan (WLAN) is a radio access system used to provide wireless access between computer devices. Originally it is used in an existing Local Area Network (LAN) to give location-indepent wireless access to the resources of a corporate network. Today, a RLAN is also used as a wireless access system to the Internet. This can be an access point at home, to have wireless access to a broadband internet connection. It can also be an access point at a hotspot, such as an airport lounge or a cafe, or a hotzone.

A radio LAN is composed of the following components:

• Access point(s),
  A radio LAN can be built around one or more access points. The typical range of an access point is in the order of 10-20 m (30-60 ft.). Above this range the througput will dramatically drop off. For home applications, this range is usually enough. For a home network the wireless access point can be integrated with a router and/or an ADSL or cable modem. For a corporate network a number of access points might be needed.
• Wireless LAN PC card,
  For each computer that is to be connected to the wireless network an wireless adapter is needed. This can be an internal PC card or an external USB or PCMCIA card.

Most wireless LANs operate in the unlicensed 2.4 GHz band using the IEEE 802.11b or 802.11g standard, more commonly known as Wi-Fi. In this band , the radio LANs have to share the spectrum with a lot of other applications. There is also a more exclusive band available for RLANs, ranging from 5150-5350 and 5470 - 5725 MHz. Expectations are that the wireless LANs will gradually migrate to the 5 GHz range.