Codan Radio P25 Training Guide - Manual (Page 50)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 3: P25 Technical Information Page 42
Since the RF power output levels of current FM analog and P25 digital equipment are equal, it would
seem that digital coverage and analog coverage are equal. This is not true, as much more of the
covered area is usable when sending a P25 digital signal. The signal-to-noise ratio in the subscriber
unit is a critical element of analog systems. P25 signals attempt to correct for noise-induced errors,
with the built in error correction, so that fringe areas that were not clearly audible in analog systems
have a good chance of being loud and clear with P25 digital.
Figure 3-2: Analog vs. Digital Audio Quality
Audio Quality
Radio Signal Attenuation (dBm)
-30 -120 -130 -110 -100 -90 -80 -70 -60 -50 -40
40 dB
0 dB
-20
5 dB
10 dB
15 dB
20 dB
25 dB
30 dB
35 dB
45 dB
0%
5%
15%
12 dB
Digital = BER
Analog = SINAD
Digital
Analog