Indoor Radio Propagation at 900 MHz and 2.4GHz Frequencies

Abstract

Radio frequency signal dispersion for indoor wireless areas is highly distributed than the outdoor one. This makes the reflection, diffraction, and scattering of the RF signal is more complex and difficult to predict , so in WALAN and cellular phone networks a small change in the receiver position relative to the transmitter may result in wide variation in the signal strength , indoor coverage is also supported by GSM and may be achieved by using an indoor picocell base station, or an indoor repeater with distributed indoor antennas fed through power splitters, to deliver the radio signals from an antenna outdoors to the separate indoor distributed antenna system. These are typically deployed when a lot of call capacity is needed indoors , for example, in shopping centers or airports, however , this is not a prerequisite, since indoor coverage is also provided by in-building penetration of the radio signals from any nearby cell. The main problem that exists for indoor environments is that the signal propagated from the transmitter antenna will experience many different signal transformations and paths with a small portion reaching the receiver antennal (1) pages 1.so one of our main attentions of this project is to assist the user to understand the radio performance limitations. Not only the radiated power and the transmitter / receiver reparation ( transmission rate) but there is also the effect of the surrounding physical environment such as room dimension, obstructions, material, etc