RSSI reported in AT+CSQ vs AT + QENG="servingcell"

Technical Subjects Software General Function
1

Hello,

We are using EC200T module and connecting to network in LTE mode.

We see a difference in RSSI value reported by using following two AT commands

  1. AT +CSQ or AT +QCSQ
  2. AT+QENG=“servingcell”

Through AT + CSQ - we get result as 26/31 → indicating RSSI value of about -61dBm as below

AT+CSQ
+CSQ: 26,99
OK

AT+QCSQ
+QCSQ: LTE ,61,-93,120,-14
OK

Through AT+QENG=“servingcell” - we get result of around --79dBm as below

AT+QENG=servingcell
+QENG: servingcell , NOCONN , LTE , FDD ,404,45,18790C,254,1301,3,4,4,232A,-95,-14,-79,-2,28

Which one is correct ?

Can you please clarify ?

3

hi, Jitender_Kumar_Misra:
RSSI only serves as a rough reference value, and RSRP and RSRQ are needed as reference values for terminal network selection. Meanwhile, SINR is also an important reference value as an interference evaluation index.

4

Hello,
I’ve got an follow up question exactly on this topic.

We observed that there is also a difference in the RSSI reported by the AT+CSQ command to the QENG command on a MC60 which does only support GSM (where there is no RSRP).

Example:
AT+CSQ returned -51 dbm
AT+QENG? returned -33 dbm for the serving cell

BR,
Sebastian

5

Well, the reason probably is that the best RSSI that CSQ can return is -51 dbm. Therefore i’d assume that the value returned from QENG is more accurate in this case?

6

GSM can refer to semaphore Rxlev; LTE can refer to the semaphore RSRP