AT^SMONI vs AT+CSQ for EHS6 signal strength detection | Telit Cinterion IoT Developer Community
January 20, 2015 - 6:37pm, 10975 views
For our application, using the EHS6, we report back the signal strength when our device connects. The release notes for the EHS6 state that AT+CSQ is not the correct commnad for 3G networks and that AT^SMONI should be used.
Can Gemalto provide guidance on how best to get the signal strength value for both 2G and 3G networks? Our device may be operationg on either at any given time so we want to know the strength of the signal that is being used.
Which output parameters are equivalent to the AT+CSQ output for 2G and 3G networks, using the AT^SMONI command?
If I read the AT command documentation correctly then is the Rxlev(Receiving level of the BCCH carrier in dBm in decimal). So the third parameter in the output. But I am not 100% sure, so it's better to wait for someone from Gemalto to respond or you can connect to 2G and test responses for both commands.
Output:
^SMONI: 2G,BCCH,Rxlev,MCC,MNC,LAC,CI,C1,C2,NCC,BCC,GPRS STATUS<,PWR><,ACC MIN
RXLev><,Hoping,TS,timAdv,rxlevfull,Qual,ChMod><,Service>
Thanks. I agree that we need someone from Gemalto to chime in here with the correct way to do this. From the AT command set doc, it appears there is two sets of output depending on which type of network the device is registered on (2G or 3G). It also appears there is different output if niether a 2G or 3G network is available.
This is critical for my device because we don't waste power trying to make a connection if there isn't reception.
The AT command datasheet shows this for 2G Networks:
Syntax:
^SMONI: ACT,ARFCN,BCCH,MCC,MNC,LAC,cell,C1,C2,NCC,BCC,GPRS,ARFCN,TS,timAdv,dBm,Q,ChMod
Example:
^SMONI: 2G,71,-61,262,02,0143,83BA,33,33,3,6,G,NOCONN
The AT command datasheet shows this for 3G Networks:
Syntax:
^SMONI: ACT,UARFCN,PSC,EC/n0,RSCP,MCC,MNC,LAC,cell,SQual,SRxLev,PhysCh, SF,Slot,EC/
n0,RSCP,ComMod,HSUPA,HSDPA
Example:
^SMONI: 3G,10564,296,-7.5,-79,262,02,0143,00228FF,-92,-78,NOCONN
I'm trying to figure out which parameter is the correct parameter to record when ACT=2G or ACT=3G.
I use the following code to detect which network is used.
First init the module with:
SyncATCommand atc = SyncATCommand.getInstance();atc.send("at+creg=2\r");
public String getNetworkAccessType() {
try {
SyncATCommand atc = SyncATCommand.getInstance();
int tech = Integer.parseInt(StringUtils.split(StringUtils.split(StringUtils.split(atc.send("AT+CREG?\r"), "\r")[0], ":")[1], ",")[4].trim());
switch (tech) {
case 0:
return "GPRS";
case 2:
return "UMTS";
case 3:
return "EDGE";
case 4:
return "HSDPA";
case 5:
return "HSUPA";
case 6:
return "HSDPA + HSUPA";
}
} catch (Exception e) {
Debug.getInstance().error("Ehs6SIMDriver::getNetworkAccessType() --> Cannot read network access type" + e.getMessage());
}
return "unknown";
}
Hi,
In 3G you need to care care of two values to know your signal streng/quality
The best way is to look at the signal streng with the RSCP(Received Signal Code Power) value using the at^moni/at^smoni command; and the CPICH Ec/No (The received energy per chip divided by the power density in the band).
RSSI= Receiver Signal Strength Indicator. dBm measurement of the incoming signal before gain for internal processing
RSSI= RSCP-EC/io
Ec/No= energy per chip over noise (quality of signal)
RSCP= Energy after processing
RSCP: RSSI +EcNo
you need to measure the two parameters (EC/No and RSCP) to check the CPICH
values RSCP > -100 dBm and Ec/No > -14 dBm can be considered like the acceptable conditions
Values RSCP > - 47 and Ec/No > -4 dBm can be considered like optimal conditions
Values outside these two vectors can be considered not acceptable.
Regards
ALopez
Somewhere over the rainbow!!! Looking for the Oz Land!!!
From AT^SMONI, we can get below response detail,
^SMONI: ACT,UARFCN,PSC,EC/n0,RSCP,MCC,MNC,LAC,cell,SQual,SRxLev,PhysCh,SF,Slot,EC/
n0,RSCP,ComMod,HSUPA,HSDPA
From above response which RSCP and EC/n0 is useful to measure signal strength?
Generally for signal quality monitoring it's better to use serving cell parameters.