Ercogener GenPro 25e - 5.5 Checking the quality of the GSM reception signal

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Descriptions and non-contractual illustrations in this document are given as an indication only.
ERCOGENER reserves the right to make any modification.
Dct_427_02
5.5 Checking the quality of the GSM reception signal
The modem will be able to make a call only if the received GSM signal is powerful enough.
The command AT+CSQ allows to know the reception level (rssi) of the signal sent by the closest GSM Base
Transceiver Station (BTS), as well as the reception error code (g).
When the SIM card is inserted and the PIN code entered, the command AT+CSQ allows to measure the
signal from the BTS of the subscribed operator network.
This command cannot be used without the SIM card.
To check the quality of the GSM signal, do the following operations:
Use communication software like HyperTerminal enter the command AT+CSQ.
The response is in the following format:
+CSQ : <rssi>, <ber> with:
<rssi> = indicates the reception level,
<ber> = receive bit error rate.
Check the returned value <rssi> with the help of the table below.
Table 42 : RSSI value
Value of <rssi>
Gain in dbm
Interpretation
Value of <ber>
Interpretation
0
-113 dbm
Insufficient
0 à 7
See Standards ETSI
GSM 05.08
1 à 10
-111 à -95 dbm
Insufficient
11 à 30
-93 à -53 dbm
Sufficient
31 (max)
-51dbm
Perfect
99
Unknown/not detectable
99
Unknown/not detectable
The GSM modem works normally with a minimum <rssi> between 11 and 15.
Below 10, the signal level is insufficient; the modem cannot work depending on the geographical situation or
the vehicle mobility. Above 15, the signal is sufficient..
For more information about the AT commands, see the document "u-blox_AT_Commands_Manual_xxx.pdf