Support for gsm-r (railway) band?

Good afternoon,

I was wondering if it would be possible with any of the Quectel mini-pcie GSM modules to scan (preferably without SIM) the 2G gsm-r railway band. Downlink is between 921 and 925MHz and uplink is between 876 and 880MHz. My goal would be to measure and map both gsm-r and UMTS 900 (E-GSM) base stations and determine potential interference locations.

Open to any suggestions, looking forward to your replies.

BR.

Ed.

Hi all,

Been sifting through the manuals and found the following:

“AT+QSCANF=? //Test mode of QSCANF. +QSCANF: (0-3),(0-1023,9999)
This command can scan the specified frequency or a certain band, and then show the list of ARFCN and RxLevel from the strongest signal level to the lowest when CFUN is 0 or 4.”

So, since gsm-r starts at ARFCN 955 and ends 19 channels higher at 974, i should be able to scan gsm-r channels as well, right? Seeking confirmation!

Now i only need to get +QSCANF to work, since it returns ERROR with UC20-G and EC25-E.

Open to suggestions!

BR.

Ed.

Good afternoon,

Allright, there were some learning moments here and there. So AT+QSCANF is not supported in the EC25-E, but i found out that the QuecCell commands that are available should be sufficient for me.

This is what i have for now:

AT+QCFG=“BAND”,1,0,0,1

OK
at+qcops=1,1

+QCOPS: “2G”,“T-Mobile NL”,“20416”,“GSM 900”,111,408,C481,59,-56,50,1
+QCOPS: “2G”,“T-Mobile NL”,“20416”,“GSM 1800”,860,408,2409,0,-56,50,1
+QCOPS: “2G”,“T-Mobile NL”,“20416”,“GSM 900”,101,408,C480,29,-63,43,1
+QCOPS: “2G”,“T-Mobile NL”,“20416”,“GSM 900”,111,408,C481,59,-63,43,1
+QCOPS: “2G”,“NL KPN”,“20408”,-,-,-,-,-,-63,-,-
+QCOPS: “2G”,“vodafone NL”,“20404”,-,-,-,-,-,-83,-,-

OK

AT+QENG=“servingcell”

+QENG: “servingcell”,“LIMSRV”,“GSM”,204,16,408,C481,59,111,-,-56,255,255,0,50,50,1,-,-,-,-,-,-,-,-,-,"-"

OK
AT+QENG=“neighbourcell”

+QENG: “neighbourcell”,“GSM”,204,16,408,C480,29,101,-63,43,43,0,0
+QENG: “neighbourcell”,“GSM”,204,16,408,56B5,40,114,-64,42,42,0,0
+QENG: “neighbourcell”,“GSM”,204,16,408,6919,9,119,-65,41,41,0,0
+QENG: “neighbourcell”,“GSM”,204,16,408,691A,33,123,-81,25,25,0,0
+QENG: “neighbourcell”,“GSM”,204,16,408,C482,31,115,-78,28,28,0,0

OK

The QCOPS command varies in time it takes to perform, from 40 seconds up to 120 seconds. I want this timeperiod to be as short as possible. So, since i have no business in the GSM 1800 band i want to leave that band out. The QCFG=“BAND” command is helpfull, i can leave out almost all other bands, but not the GSM 1800 band. Anybody any suggestions on how to scan GSM900 only? I intend not to use a SIM card so i can not force to lock on a particular operator.

Planning to go onsite this weekend for the moment of truth and see if i can detect GSM-R activity.

BR.

Ed.

Hello all,

So, the trip to the gsm-r base station turned out to be a bit disappointing. The QCOPS command listed all operators, except for the gsm-r operator. I asked a colleague why the command is so slow and why his results were always quicker. He hinted that the QCOPS command is old and that the QOPS command is now the way to go.

After digging into some docs i also found the QOPSCFG command and for the first time i see the EGSM band mentioned in the documents. Perhaps this will bring me further. Fingers crossed.

I’ll redo the onsite test. Let’s see what happens.

BR.

Ed.

Well, not so quickly,

The Quectel docs mention E-GSM band and this is what i found for that band:

“The extended GSM 900 band ranges from 880 - 915 MHz and from 925 - 960 MHz.”

If this is really correct, than that says it all, because GSM-R NL ranges from 921-925MHz in the downlink.

Any Quectel engineer interested in answering this one? Would it be possible, with perhaps a firmware upgrade, to scan the whole GSM band including the 921-925MHz band? I really need this to do spectrum analysis.

BR.

Ed.

Hello sir,

Sorry for the late reply,
Currently we don’t have module support GSM-R.
GSM-R cannot be supported by firmware upgrade.

Thanks!