User Guide

GSM Rx chain activation for manual measurements / GSM RSSI measurement
Context
RSSI signal measurement is the main Rx troubleshooting measurement. The test measures the strength of
the received signal.
I and Q branches can be measured separately. In GSM, the input signal can be either a real GSM signal or a
CW (Continuous Wave) signal that is 67.71 kHz above the carrier frequency.
Steps
1. Start Phoenix service software.
2. Choose Testing→GSM→RSSI Reading .
3. Set the RF signal generator for a channel frequency +67.71 kHz in CW mode with a –80 dBm signal level.
Alternatively set the cellular tester downlink channel to the appropriate channel. Make sure that the tester
is set to continuous mode, not to burst mode.
4. In the
RSSI Reading window, select the appropriate band and channel.
Figure 21 RSSI Reading window
5. To start the measurement, activate GSM Rx chain, click Start.
Results
RSSI reading values of the selected band and channel are displayed. The RSSI level must be the same value
as that which is set at the signal generator (-80 dBm).
Transmitter troubleshooting
General instructions for TX troubleshooting
Context
• Tx troubleshooting requires Tx operation.
• Do not transmit on frequencies that are in use!
• Transmitter can be controlled in the local mode for diagnostic purposes.
• The most useful Phoenix tool for GSM transmitter testing is "RF Controls".
RM-272; RM-273
RF Troubleshooting and Manual Tuning Guide
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