Technical data

376 Chapter 12
GSM and EDGE Analyzer
Interpretation of GSM and EDGE Analyzer Measurement Results
GSM and EDGE Analyzer
Interpretation of GSM and EDGE Analyzer
Measurement Results
This section contains expected result values and possible causes of error if the
expected results are not met.
Frequency Error
The GSM standard specifies very tight frequency error performance. In the GSM
900 band, the 0.05 ppm (parts-per-million) specification translates to only 45 Hz
error.
Frequency error measurements indicate synthesizer/phase lock loop performance.
This is especially important in a BTS with frequency hopping active. Poor
frequency error measurements can show, for example, that a synthesizer is failing to
settle quickly enough as it shifts frequency between transmissions. Poor frequency
error can cause a multitude of problems, for example, the target receiver may be
unable to gain lock, and the transmitter may cause interference with other users.
You will need to use an external reference or GPS (if available) in order to achieve
an accurate frequency error reading.
BSIC (Base Station Identity Code)
If the BSIC can not be decoded, dashes will be displayed. If it is not as expected,
check the base station settings against the plan.
TS Pwr (Timeslot Power)
Maximum Timeslot Power is the measure of in-channel power for GSM Systems.
The purpose of the Maximum Timeslot Power measurement is to determine the
power delivered to the antenna system in the radio frequency/channel under test.
The Maximum Timeslot Power measurement verifies the accuracy of the
transmitted RF carrier power.
If the maximum timeslot power is lower than expected, verify you have a good
connection to the RF output of the base station. Also, verify the cable you are using
to connect to the base station is not faulty. A low power may also indicate an issue
with the power amplifier.
Inaccurate channel power (high or low) may indicate an incorrect power setting at
the base station.