Long distance Wireless   Communicatoin   using 802.11b

Objective :  Measurement, Analysis & Modeling of Path-loss for    Long- distance 802.11b Networks

        IEEE 802.11b protocol is being primarily meant for indoor wireless networks. The range normally being used  with this protocol is around 200 meters; typically within the campus or building.  However, based on this protocol, an attempt has been made to use technology over longer distances using directional antennas. The objective of my thesis is to work out the "Path Loss" for links with various distances & find out a general formula applicable to such links. For this purpose various links are being set up & then the signal strength measurements are done. The setting up of various links is being done in association with  the on-going project of "Media Lab Asia" known as "Digital Gangatic planes" for setting up of rural internet connectivity.

There are different  Channel Models available for the analysis of wireless links.

Various long distance experiments conducted so far:

Finding Path Loss:   

Finding exact "Path Loss" is not a straight forward issue. As we are not having any power meter to measure the power at 2.4 GHz at the receiving end, we have to rely on the WLAN cards. These cards give signal strength in "%". The mapping from '%" to dB is not given in documentation of the cards & it was required to be established accurately. For this purpose, Calibration of WLAN Cards was done & mapping from "%" to dBm was found out for "ORINOCO" & "CISCO" WLAN cards.