What is the significance of keeping empty APN?

What is the significance of keeping empty APN?

@akn

There isn’t a ‘significance’. it just means the unit will try to perform the initial LTE attach (or 3G data session) without an APN. If you don’t know the APN your SIM should be using it is the safest thing to do as more networks will reject an incorrect APN than no APN.

Regards

Matt

I am unable to activate the packet data connection with empty APN on EM7455. Do I need to perform some additional AT operations?

AT+CGDCONT?
+CGDCONT: 1,“IPV4V6”,“ims”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 2,“IPV4V6”,“vzwadmin”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 3,“IPV4V6”,"",“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 4,“IPV4V6”,“vzwapp”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 5,“IPV4V6”,“vzw800”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0
+CGDCONT: 6,“IPV4V6”,“vzwclass6”,“0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0”,0,0,0,0

OK
AT!GSTATUS?
!GSTATUS:
Current Time: 1873 Temperature: 34
Reset Counter: 1 Mode: ONLINE
System mode: WCDMA PS state: Not attached
WCDMA band: WCDMA BC3
WCDMA channel: 1249
GMM (PS) state:NULL —
MM (CS) state: IDLE LIMITED SERVICE

WCDMA L1 state:L1M_PCH_BPLMN LAC: D8F1 (55537)
RRC state: DISCONNECTED UTRAN Cell ID: 03518F7B (55676795)
RxM RSSI C0: -94 RxD RSSI C0: —
RxM RSSI C1: — RxD RSSI C1: —

OK
at+cpin?
+CPIN: READY

OK
at!scact?
!SCACT: 1,0
!SCACT: 2,0
!SCACT: 3,0
!SCACT: 4,0
!SCACT: 5,0
!SCACT: 6,0

AT!PCINFO?
State: Online
LPM voters - Temp:0, Volt:0, User:0, W_DISABLE:0, IMSWITCH:0, BIOS:0, LWM2M:0, OMADM:0, FOTA:0
LPM persistence - None

OK
AT!PRIID?
PRI Part Number: 9907469
Revision: 001.000
Customer: Generic-M2M

Carrier PRI: 9999999_9904780_SWI9X30C_02.33.03.00_00_VERIZON_002.079_001
Carrier PRI: 9999999_9904594_SWI9X30C_02.24.05.06_00_ATT_002.027_000
Carrier PRI: 9999999_9904609_SWI9X30C_02.24.05.06_00_GENERIC_002.026_000
Carrier PRI: 9999999_9904779_SWI9X30C_02.24.03.00_00_SPRINT_002.022_000

OK

AT+COPS?
+COPS: 0

OK
AT+COPS=?
+COPS: (1,"Verizon ","Verizon ",“311480”,7),(3,“T-Mobile”,“T-Mobile”,“310260”,2),(1,“313 100”,“313 100”,“313100”,7),(1,“Extended Network”,“Extended”,“310410”,7),(1,“Extended Network”,“Extended”,“310410”,2),(0,1,2,3,4),(0,1,2)

OK

AT+CREG?
+CREG: 0,2

OK

AT!BAND=?
Index, Name, GW Band Mask L Band Mask TDS Band Mask
00, All bands 0002000007C00000 000000000000101A 0000000000000000
01, Europe 3G 0002000000400000 0000000000000000 0000000000000000
02, North America 3G 0000000004800000 0000000000000000 0000000000000000
06, Europe 0002000000400000 0000000000000000 0000000000000000
07, North America 0000000004800000 000000000000101A 0000000000000000
08, WCDMA ALL 0002000007C00000 0000000000000000 0000000000000000
09, LTE ALL 0000000000000000 000000000000101A 0000000000000000

                                               0000000000001000 - B13
                                               0000000000000010 - B5
                                               0000000000000008 - B4
                                               0000000000000002 - B2
                              0002000000000000 - B8  (900)
                              0000000004000000 - B5  (850)
                              0000000002000000 - B4 (1700)
                              0000000001000000 - B3 (1700)
                              0000000000800000 - B2 (1900)
                              0000000000400000 - B1 (2100)

OK
AT!BAND?
Index, Name, GW Band Mask L Band Mask TDS Band Mask
00, All bands, 0002000007C00000 000000000000101A 0000000000000000

OK
at+cpin?
+CPIN: READY

OK
AT!CUSTOM?
!CUSTOM:
GPSLPM 0x01
IPV6ENABLE 0x01
UIM2ENABLE 0x01
SIMLPM 0x01
USBSERIALENABLE 0x01
DHCPRELAYENABLE 0x01
SINGLEAPNSWITCH 0x01

OK
AT!GETBAND?
!GETBAND: No Service

OK
AT!GSTATUS?
!GSTATUS:
Current Time: 2202 Temperature: 36
Reset Counter: 1 Mode: ONLINE
System mode: WCDMA PS state: Not attached
WCDMA band: WCDMA 850
WCDMA channel: 4385
GMM (PS) state:NULL —
MM (CS) state: IDLE LIMITED SERVICE

WCDMA L1 state:L1M_PCH_SLEEP LAC: D8F1 (55537)
RRC state: DISCONNECTED UTRAN Cell ID: 03518F7B (55676795)
RxM RSSI C0: -94 RxD RSSI C0: —
RxM RSSI C1: — RxD RSSI C1: —

OK

AT+CGCONTRDP
OK

ATI
Manufacturer: Sierra Wireless, Incorporated
Model: EM7455
Revision: SWI9X30C_02.33.03.00 r8209 CARMD-EV-FRMWR2 2019/08/28 20:59:30
MEID: A000005368D949
ESN: 12807986565, 8079DD85
IMEI: 359073061394304
IMEI SV: 20
FSN: LF833224780210
+GCAP: +CGSM

OK
AT+ICCID
ICCID: 89148000001635942450

OK
AT+COPS?
+COPS: 0

OK
AT^SYSCONFIG?
^SYSCONFIG: 2,0,1,0

OK
AT!IMAGE?
TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID
FW 1 GOOD 132 0 0 ?? 02.24.05.06?
FW 2 GOOD 1 0 0 ?? 02.24.03.00?
FW 3 GOOD 133 0 0 ?? 02.33.03.00?
FW 4 GOOD 127 0 0 ?? 02.32.11.00?
Max FW images: 4
Active FW image is at slot 3

TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID
PRI FF GOOD 0 0 0 002.027_000 02.24.05.06_ATT
PRI FF GOOD 0 0 0 002.026_000 02.24.05.06_GENERIC
PRI FF GOOD 0 0 0 002.022_000 02.24.03.00_SPRINT
PRI FF GOOD 0 0 0 002.079_001 02.33.03.00_VERIZON
Max PRI images: 50

OK
AT!IMPREF?
!IMPREF:
preferred fw version: 00.00.00.00
preferred carrier name: AUTO-SIM
preferred config name: AUTO-SIM_000.000_000
preferred subpri index: 000
current fw version: 02.33.03.00
current carrier name: VERIZON
current config name: VERIZON_002.079_001
current subpri index: 000

@akn

You aren’t attached to the network as per the +CREG: 0,2 response hence you cannot start a session. Assuming you have a Verizon SIM in (implied by the fact that the unit is in auto SIM mode and it has selected Verizon as the operator) then the config looks fine and you can see the Verizon network (as per the COPS? response) then there is nothing stopping it attaching.

Last thing to check is the state of your SIM subscription as from what I can see there is nothing wrong.

Regards

Matt

The SIM is working , but it requires setting the APN manually (it is dynamic IP SIM)
AT+CGDCONT=3,“IPV4V6”,“vzwinternet”

There is another SIM with static IP and it uses different APN setting
AT+CGDCONT=3,“IPV4V6”,“WE1.VZWSTATIC”

The verizon firmware has default class-3 APN set to vzwinternet.

I am trying to find a generic way to avoid “manually setting” this APN on SIM hotswap.

@akn

The Verizon spec (so the order and name of the APN’s in this case) is what we comply to, there isn’t a way to change this as it is set in the PRI file and there is no way to distinguish between SIM ‘types’ or at least what services SIM’s are subscribed to.

Regards

Matt

Verizon also uses the following APNs for Static IP SIM (depending upon a specific USA region)

Midwest: MW01.VZWSTATIC
Northeast: NE01.VZWSTATIC
South: SO01.VZWSTATIC
West: WE01.VZWSTATIC

The Static IP SIM does not work with APN “VZWINTERNET”.

So I tried with empty APN but it also have no effect.

How do I enable auto switching of the APNs in this case?

Verizon open development portal has a Over-the Air Device management requirement document https://opendevelopment.verizonwireless.com/open-access/article/OA-LTE-Req-OTADM

Please confirm if this is implemented in the Verizon firmware or It needs to be developed by application.

FYI: Auto selection of the correct APN is also one of the Class-3 apn test case in Verizon certification.

@akn

So yes ‘class 3’ (I hate the term as class implies a specific behaviour or characteristic where it is actually only referring to the CID number on the UE) is part of the certification and it works (obviously as we have passed Verizon certification). There is nothing active that you do on the unit to enable this, it is ALL network driven, since, as I have pointed out, the unit cannot tell one SIM from another or in what region it is in.

Assuming all of the network settings are correct in that the IMEI is not associated with anther IMSI, its not set in a different region, etc, there are a huge number of settings on the network that are not visible to the UE and also over which it has no control then the APN switch will just happen as per signaling coming from the network. The UE does not and cannot compel or request this as it is at the mercy of the network.

Regards

Matt

Thank you for your prompt response.

We have received the feedback that the “UE is not initiating the OTA-DM process to fetch the APN and other relevant information once the Static SIM is attached”. OTA-DM will use CID-2 (APN vzwadmin) to perform provisioning (APN fetch and setup).

Please confirm if this is performed by EM7455 UE or the mobile application need to perform this provisioning.

If application need to perform the OTA-DM then please share the procedure to request APN information.

@akn

This is between the SIM and the server at the other end, they make it sound like the UE’s fault by saying it is not initiating the connection but in actual fact it is the SIM that commands the unit to start the connection, the UE will never start a connection unless it is commanded to do so by something i.e. microprocessor, Legato application (in the case of WP), SIM card, etc.

Regards

Matt

This test case is failing in the certification Lab.

I was under impression that the OTADM feature is prebuilt inside the EM7455. Please confirm if this is correct.

Please let me know if I need an additional application to perform the Automatic APN setup.

@akn

The setup for this test case is highly complex, and all do with things outside of the UE, namely the pairing of IMEI’s and IMSI’s on the network to make sure they are totally clean so it then triggers the mechanism to change the APN, if it is not clean it will not trigger it.

Its next to impossible to tell you how to do it over a forum posting.

Regards

Matt

Is there any sample code and a simplified document to perform the Automatic APN management with Verizon Network?

Please provide your inputs to proceed further.

We need to resolve it anyway otherwise the Certification of the product with EM7455 will fail.

@akn

There isn’t anything from Sierra as it is well outside our area of responsibility. This either needs to come from Verizon (as its their test and their systems) or from the test house in that they should be able to set the test up and run it being aware of the pit falls, after all you are paying them (probably quite a lot) for the service to get the unit to pass.

Any documentation we generated could easily be made inaccurate by changes on the system that we are neither in control or aware of hence it has to fall to the above parties.

Regards

Matt