WIFI and WLAN 2

WLAN configuration

WLAN device consists of 2, namely:

* Wireless Station (WAS): desktop, laptop or PDA equipped with a wireless NIC
* Access Point (AP): function as a bridge between the LAN network and the conventional WLAN

There are 2 kinds of WLAN operation modes, namely:

* Infrastucture Mode, consisting of
o Basic Service Set (BSS), there is only one Access Point
o Extented Service Set (ESS), two or more BSS form one subnet

* Ad-hoc mode, consisting of some of the wireless station to communicate directly (peer-to-peer) without using the AP.



Connection in the BSS

The process of WS terbentuknya connection to AP in a BSS is as follows:

* AP send a signal beacon which contains the SSID (Service Set Identifier). SSID is a setting that is used in the AP group WAS in a segment of the network. WAS only know the SSID can join in the network. SSID can be considered as a shared password.

* When the WAS is in a coverage area or some of AP, the WAS will select one of the AP based on the strong signal and the error rate is received. WAS will periodically monitor the signal to find out the most powerful. If found WAS will then choose a new AP.

* To join the network, the WAS must connect to the AP. WS SSID should mention that according to join the AP that have been selected. Some of the AP that has the same SSID will form ESS.

* Some WAS NIC can set it with the SSID Any or * (asterik) so he can join the AP which the stronger the signal regardless of SSID.

WLAN signals

WLAN uses radio signals at a frequency of 2.4Ghz. In the implementation of the WLAN, AP location is set so that only have a coverage area that is operating the WLAN such as a valid one floor in a particular building. But radio signals can penetrate walls and vine-storey building, although a weak signal. Thus, these signals may be very out of the coverage area of operation. Luberan signal can be spread out to a few hundred meters from the building especially when placed AP luberan without considering the problem for example, this signal is placed near a window facing outside the building.
By using the effective antenna (directional) and the need to brace signal using radio signals (RF amplifier) then the radio signals that may have been weak earlier arrested again on a relatively remote place.