Signal Quality

With Online AT Command Tester tool, you can get the signal level of the device. The response for the AT+CSQ comamnd is also interpreted for teh corresponding dBm value.

To find out what signal qualities are supported,
AT+CSQ=?
+CSQ: (0-31,99),(0-7,99)
OK

The first part of the response is RSSI (Received signal strength indicator) and the possible values are,
0 -113 dBm or less
1 -111 dBm
2…30 -109… -53 dBm
31 -51 dBm or greater
99 not known or not detectable

The second part of the response is the Bit Error Rate (BER) and the possible values are,
0…7 as RXQUAL values in the table in 3GPP TS 45.008 [20] subclause 8.2.4
99 not known or not detectable

Now to get the signal level,
AT+CSQ
+Csq: 25,99
OK

The RSSI values returned by the CSQ command is mapped to dBm value in the table below. In the above example, rssi value of 25 corresponds to -63 dBm which implies an excellent signal condition.

Value RSSI dBm Condition
2 -109 Marginal
3 -107 Marginal
4 -105 Marginal
5 -103 Marginal
6 -101 Marginal
7 -99 Marginal
8 -97 Marginal
9 -95 Marginal
10 -93 OK
11 -91 OK
12 -89 OK
13 -87 OK
14 -85 OK
15 -83 Good
16 -81 Good
17 -79 Good
18 -77 Good
19 -75 Good
20 -73 Excellent
21 -71 Excellent
22 -69 Excellent
23 -67 Excellent
24 -65 Excellent
25 -63 Excellent
26 -61 Excellent
27 -59 Excellent
28 -57 Excellent
29 -55 Excellent
30 -53 Excellent
Keywords: Module signal quality, M2M signal quality, GPRS signal quality, 3G signal quality, signal quality through AT commands,