Trouble Shooting Guide, Advanced
4/00021-3/FEA 209 544/25 C
Ericsson Mobile Communications AB
36(78)
11 Phase and Frequency Error
11.1 What is ”Phase and frequency error”
Phase and frequency error is a measurement in the Go/No Go – test where you check how big
the phase and frequency variations of the transmitter are during a connected call.
The phase and frequency fault is measured during 20 bursts.
For EGSM 900 use power level 5 and low channel (anyone between 975 and 980).
For GSM 1800 use power level 0 and low channel (anyone between 512 and 521).
The phase fault is presented as RMS and peak. RMS is the average value during the 20 bursts
and peak is the largest phase divergence measured at anyone of the 20 bursts.
The tables below show the limits for phase and frequency fault Table 11.1 and Table 11.2.
EGSM 900
Parameter
Value
Unit
Max RMS
phase error
5
deg
Max peak
phase error
20
deg
Max frequency
error
90
Hz
Table 11.1
GSM 1800
Parameter
Value
Unit
Max RMS
phase error
5
deg
Max peak
phase error
20
deg
Max frequency
error
170
Hz
Table 11.2