Appendix A: RF Troubleshooting
5. DOES THE PHONE HAVE A RELIABLE CONNECTION TO THE NETWORK (GSM)?
This section refers to a situation when the phone registers to the GSM-network and is capable to make a call, but
the call is not reliable even if the GSM-network field strength is strong. The phone call is maybe disconnected or
interrupted.
5.1 GSM receiver Bit Error Rate (BER) ok?
•
This test needs a GSM communication tester and if there is no that kind of tester available
continue troubleshooting in section 3.2
•
Attach the phone to the product specific test jig and a GSM communication tester to the
RF-coupler. Coupler attenuation should be also taken into account during measurements. This
measurement should be done in an RF shielded box.
Close the shield box hatch.
•
•
Make a GSM call against the tester
•
Settings to the tester have to be done according to the 3GPP specifications:
Set base station downlink power to -102 dBm
-
•
Bit Error Rate should be less than 2 %
5.1.1 Does the phone give realistic RSSI-values?
See section
•
5.1.2 Hinku (N7500) or RAP3G (D2800) faulty?
•
RAP3G is not possible to replace
5.2 GSM transmitter power levels and transmit frequency ok?
•
See section
5.3 GSM Transmitter phase error ok?
•
See section
5.4 GSM (GMSK) modulation spectrum ok?
•
See section
5.5 TX power vs. time ok?
•
See section
6. DOES THE PHONE HAVE A RELIABLE CONNECTION TO THE NETWORK (WCDMA)?
This section means situation when the phone registers to the WCDMA-network and is capable to make a call, but the
call is not reliable even if WCDMA-network field strength is strong. The phone call is maybe disconnected or
interrupted.
3.2. "Does the phone give realistic RSSI-values?"
3.1. "GSM transmitter power levels and transmit frequency ok?"
3.3. "GSM Transmitter phase error ok?"
3.4. "GSM (GMSK) modulation spectrum ok?"
3.5. "TX power vs. time ok?"
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"Does the phone give realistic
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RSSI-values?".
A-113