GL7500 Network Interface Configuration

IoT Modules Development tools
1

Hello,

I’m trying to connect an embedded setup (NVIDIA Jetson Nano + Ubuntu 18.04 + Airvantage SIM) via a GL7500 to the Internet (using NCM mode) in the US.
I was following the instructions in this SWIR technical note (paragraph 4).
I tried the other day in Europe with a GL7600 (GL7600 Network Interface Configuration (linux)), there the steps in the instructions worked fine, except the modem reset itself after a few seconds, what was fixed by doing a Firmware update.
With the US Modem I can not get that far with Firmware (GL7500.A.2.13.151600.201802201800.x7160_1). I’m hitting a “CME 133 Error”, when trying to activate the PDP context (step 4.4 in the Instructions).
“CME Error 133” translates to “Requested service option not subscribed”, which doesn’t tell me much.
The particular setup (SIM/Modem/Jetson PC) worked fine with ModemManager, therefore I don’t expect any SIM/Contract related problems.
I run a bunch of diagnostic at-commands and the first two at commands from the instructions. Find attached the log.
I also tried to use another PDP context ID (=), what did not help.

Any help is much appreciated! Please let me know If I can provide more details to track down the problem.

Dominik

AT-Commands-log:

at
OK
ati
GL7500

OK
at+creg?
+CREG: 2,5,"AB78","08A07542",6

OK
at+COPS?
+COPS: 0,2,"310260",2

OK
at+csq?
+CME ERROR: 3
at+csq
+CSQ: 20,2

OK
at+cgdcont?
+CGDCONT: 1,"IPV6","na.internet.swir","0:0:0:0:0:0:0:0",0,0,0,0,0,0

+CGDCONT: 2,"IPV4V6","na.internet.swir","",0,0,0,0,0,0

+CGDCONT: 3,"IPV6","na.internet.swir","0:0:0:0:0:0:0:0",0,0,0,0,0,0

+CGDCONT: 4,"IP","na.internet.swir","0.0.0.0",0,0,0,0,0,0

OK
AT+CCID
+CCID: 89332401000013631086

OK
AT+CPIN?
+CPIN: READY

OK
AT+CREG?
+CREG: 2,5,"AB78","08A07542",6

OK
AT+CGREG?
+CGREG: 2,5,"AB78","08A07542",6,"04"

OK
AT+CEREG?
+CEREG: 2,0

OK
ATI9
GL7500.A.2.13.151600.201802201800.x7160_1
GL7500
GL7500.A.2.13
x7160
FUSED
2018-02-20 18:20:46
r12350

OK
at+kusbcomp?
+KUSBCOMP: 0

OK
AT+XDNS=1,1
OK
AT+CGACT=1,1
+CME ERROR: 133
2

Hi dominik1,

It appears the device is registered on a 3G network:
AT+CGREG?
+CGREG: 2,5,“AB78”,“08A07542”,6,“04”

With the imminent 3G turn down in the U.S. it is possible that data services are not available on 3G.

Can you verify the RAT setting in the GL7500? Use AT+KSRAT? command. The default is 7 (Search LTE first, then 3G).

You could ty to force LTE only using AT+KSRAT=5. Then reboot the GL.

Also, due to the 3G turndown, please see this application note on changes need to be done on the GL7500 to continue operation after the 3G shutdown.
https://source.sierrawireless.com/resources/airprime/application_notes_and_code_samples/3g-network-sunset-plan---application-note/#sthash.vanTsl3E.dpbs

3

Hey bte,
Thanks a lot for the hint! I’ll check.

4

You were right, must be a 3G/Network access issue.
I set the modem to LTE only (at+ksrat=5) - but with that I got a registration denied error.
I’ll ping my network operator (sierra wireless) about it.

5

I found the at+kcell command.
It gives me:

at+kcell=0
+KCELL: 1,2,9712,130062,ab78,8a07542,402,77,4,255
+KCELL: 0

Using the AT-Command reference I would translate it as followed:

1 -> count of UMTS cells,
2 -> cell type UMTS
9712 -> DL UARFCN OF SERVING CELL IN DECIMPAL FORMAT
130062 -> mcc and mnc 3 byte hex
ab78 -> location area in hexadecimal format
8a07542 -> UMTS Cell ID
402 -> scrambeling mode
77 -> Recieved signal power 0 .. 91
4 -> cell quality / RSSI 0..24
255 -> pathloss (not available)

2nd line 0 -> No LTE Cells

So I guess I’m just not seeing an LTE Network from my current location?

6

Dominik1,
It appears so. Can you issue AT+COPS=? and what is the response? (It may take a minute or two for the response to appear as this triggers a full network scan)

7

AT+COPS=?
gives me:

+COPS: (1,"","","003300310032003500330030",7),(3,"","","003300310033003100300030",7),(1,"","","003300310030003800330030",7),(3,"0041005400260054","0041005400260054","003300310030003400310030",7),(3,"","","0033003)
OK

I guess the 7’s are LTE networks?