WLAN Standards and Basic Knowledge

Wireless Local Area Network, called WLAN, means technology that allows you to build wireless data networks. It can have satisfactory parameters and quite low cost. Moreover, the advantage of this technology is also a short time of implementation.

What does WLAN give you?

1. Wireless access to local network at home, office etc.
2. Wireless access to the Net in public space, for example at the airport or Main Market Square (hotspot)
3. Wireless point-to-point links (connecting LAN networks, telemetry, remote control, remote monitoring)
4. Wireless access to the Internet (in your garden for ex.)
5. Emergency communications link (duplication of wired network)

Mainly used standards are:

- 802.11a - in 5 GHz band, transfer rate up to 54 Mbps;
- 802.11b - in 2.4 GHz band, transfer rate up to 11 Mbps;
- 802.11g - in 2.4 GHz band, transfer rate up to 54 Mbps;

But there are also more: 802.11f, 802.11i, 802.11n (up to 300 Mbps), 802.11e, 802.16.

There should be also a consciousness about some external factors that influence wireless transfer. These are for example: output power, cable attenuation, antennas' gain, sensitivity of devices, attenuation between antennas, physical barriers such as buildings, walls and trees (Fresnel zone), interference from different devices.