What is Path loss? Indoor Propogation Models? Multi-floor model? Partition attenuation model? Empirical path loss model? ITU Model for Indoor Attenuation/ Wall and floor factor model? FRIIS MODEL? Log-distance path loss model?

1. Presented By:-Arvind Sahu.

2.  The path loss is the difference (in dB) between the
transmitted power and the received power.
 Path loss may be due to many effects, such
as:-
 Free space loss.
 Refraction.
 Diffraction.
 Reflection.
 Absorption.

5.  Base station antenna located inside building.
 Indoor radio channel differs from traditional mobile radio
channel in:
◦ Distances covered are much smaller.
◦ Variability of the environment is greater for a much
smaller range of T-R separation distances.
 It is strongly influenced by specific features such as:
◦ Layout of the building.
◦ Construction materials.
◦ Building type.

6. 1. Empirical path loss model.
2. ITU Model for Indoor Attenuation/ Wall and floor
factor model.
3. FRIIS MODEL.
4. Log-distance path loss model.

7.  Propagation within buildings.
 Irregular terrain, like in cities, doesn’t lend
itself to simple analytical path loss models.
 Empirical path loss models based on
extensive measurements.
 Okumura Model: Empirical model for irregular
terrain.
 Hata Model: Analytical approximation to
Okumura model.

8. Path loss(L)= L1 + 20log r + nf af + nw aw
 af = attenuation factor per floor.
 aw = attenuation factor per wall.
 L1 = reference path loss at r =1 m

9.  Models have poor accuracy (15-20 dB STD
error).
 Not easy to analyze.
 Widely used to study cellular and WiFi
performance via simulation.

10. I. Multi-floor model.
II. Partition attenuation model.

15.  The ITU indoor propagation model, is a radio
propagation model that estimates the path
loss inside a room or a closed area inside a
building delimited by walls of any form.
 Suitable for appliances designed for indoor use,
this model approximates the total path loss an
indoor link may experience.

16.  This model is applicable to only the indoor
environments.
 Typically, such appliances use the lower
microwave bands around 2.4 GHz.
 However, the model applies to a much wider
range.
 Frequency: 900 MHz to 5.2 GHz

18.  It is used to model the LOS path loss incurred
in the channel.
 It is based on the inverse square law of
distance.

20.  It predicts that the RSS decreases logarithmically
with distance.
 Log distance path loss model is a generic model
and an extension to Friis Free space model.
 It is used to predict the propagation loss for a
wide range of environments.
 whereas, the Friis Free space model is restricted
to unobstructed clear path between the
transmitter & the receiver.