[Hilo] Any link among <AT+CIND?>, <AT+CSQ> and <AT+KCELL=0>?


#1

[Hilo] Is there any link among result of <AT+CIND?>, <AT+CSQ> and <AT+KCELL=0>? How are the signal quality of <AT+CIND?> and <AT+CSQ> computed?

Answer: CIND and CSQ are computed based on “Field Strength level” whose possible values are [0-63, 0xFF]. They are just expressed in different manner and ranges.

The Signal quality of <AT+CIND?> is computed as follows:
<AT+CIND?> will returns 0 if Field-Strength is [0].
<AT+CIND?> will returns 1 if Field-Strength is in range of [1-10].
<AT+CIND?> will returns 2 if Field-Strength is in range of [11-20].
<AT+CIND?> will returns 3 if Field-Strength is in range of [21-35].
<AT+CIND?> will returns 4 if Field-Strength is in range of [36-63].

The RSSI of <AT+CSQ> is computed as follows:
<AT+CSQ> will return [0] (That is -113 dBm or less) if Field-Strength is [0].
<AT+CSQ> will return [1-30] (That is -111 to -53 dBm) if Field-Strength is in range of [1-59].
<AT+CSQ> will return [31] (That is 51 dBm or greater) if Field-Strength is in range of [60-63].
<AT+CSQ> will return [99] (not known or not detectable) if Field-Strength is [0xFF].

To check the Field-Strength level, you can use <AT+KCELL=0>.

For example:
AT+KCELL=0
+KCELL: 2,
2,43,39,64f000,247c,fc8,60, ---- Field-Strength 60 is in range of [0-63, 0xFF]
255,568,5,64f000,247c,e31,40
OK
AT+CIND?
+CIND: 2,4,1,1,0,0,0 ---- Signal quality 4 is in range of [0-4]
OK
AT+CSQ
+CSQ: 31,99 ---- RSSI 31 is in range of [0-31, 99]
OK