Page 126 - Integrated Wireless Propagation Models

104 C h a p t e r T h r e e

1-mile intercept
-60 - P0 = -61.7 dBm
E'
� -70 -
.r:
"&
c -80 -
�
UJ Path loss slope
� -90 - y = 38.4 dB/dec
C)
i:7i -100 �

0 2 3 4 5 6 7 8 9 1 0
Distance to mobile (miles)
FIGURE 3.1.2.1.1 Path loss reference curve (suburban).

i
path from the base station to the mobile. The 1-mile intercept value s based on the given
ERP at the base station and the antenna heights of both at the base and at the mobile.
The slope and intercept values, which can be adjusted by the user, are defined as
follows:
• The slope indicates signal path loss along the radio path in decibels per decade
(dB I dec). The suburban curve uses a default value of 38.4 dB I dec for the path
loss slope over land.
• The 1-mile intercept indicates the signal level (dBm) received, under the
standard conditions as shown below, at a distance of 1 mile from the transmitter.
The reference value for this 1-mile intercept is -61.7 dBm.
The predicted signal strength (P,) from the area-to-area path loss of the model is
given by one component of Eq. (3.1.2.1) as follows:
P, <area-to-areaJ = P, - Y log (_!__) - A 1 + a (3.1 . 2.1)
o r0
where P = the received power at the intercept point in dBm
'o
y = the slope of path loss in dB per decade
r = the distance between the base station and the mobile in miles (or kilometers)
r0 = the distance between the base station and the intercept point in miles
(or kilometers)
A1 = the frequency-offset adjustment from 850 MHz in dB
= 20 log( ) (3 1 .2.2)
{
.
8 0
a = �gb + �g m + �g + �g h,
lt,
= ( g� - gb) + (g:, - g",) + 2 0 log (� ) + 10log(�: ) (3.1.2.3)

where gb, g"', h1, and h 2 are described below with their standard values shown. Those g;,
g,�, h;, and h� are the values different from the standard ones.