Path Loss Considerations; Calculating Path Loss; Adaptive Modulation - Motorola PTP 48600 User Manual

Path loss considerations

Path loss considerations
Path loss is the amount of attenuation the radio signal undergoes between the two
ends of the link.

Calculating path loss

The path loss is the sum of the attenuation of the path if there were no obstacles in the
way (Free Space Path Loss), the attenuation caused by obstacles (Excess Path Loss)
and a margin to allow for possible fading of the radio signal (Fade Margin). The
calculation of
can be installed.
Equation 2-1 Path loss
Where

Adaptive modulation

Adaptive modulation ensures that the highest throughput that can be achieved
instantaneously will be obtained, taking account of propagation and interference.
When the link has been installed, web pages provide information about the link loss
currently measured by the equipment, both instantaneously and averaged. The
averaged value will require maximum seasonal fading to be added, and then the radio
reliability of the link can be computed.
2-10
Equation 2-1 needs to be performed to judge whether a particular link
+ +
L L L
_
free space excess fade
L
Free Space Path Loss (dB)
_
free space
L
Excess Path Loss (dB)
excess
L
Fade Margin Required (dB)
fade
Seasonal Fading (dB)
L
seasonal
L
Equipment Capability (dB)
capability
UNDER DEVELOPMENT
Chapter 2 Planning considerations
+ <
L L
seasonal capability
phn-0896_009v003
Feb 2010