nRF9160 DK - Unable to establish connection with nRF Cloud

[ChandraSR K]

I am using nRF9160 DK(PCA10090 0.9.0 2019.19) with Indian carrier LTE-M SIM and carried below steps to establish LTE-M communication with nRF Cloud:

1. Upgraded to latest firmware (nrf9160dk_fw_2020-04-29_bc7ade8b.zip)  using Programmer

Application firmware : nrf9160dk_asset_tracker_ltem_2020-04-29_bc7ade8b.hex

Modem firmware : mfwnrf9160120.zip

2. Generated certificates at nRF Cloud and updated to nRF9160 DK. ( ensured proper IMEI and HWID are supplied while generating certificates)

LED 3 keep on blinking and rebooting after displaying below messages in Link monitor terminal.

tried few times as well.

Appreciate any pointers on how to trouble shoot this issue.

+CEREG: 2,"FFFE","FFFFFFFF",7,0,0,"11100000","11100000"

[00:01:07.385,040] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 2

[0m

[00:10:00.412,139] 

[0m<inf> lte_lc: Network connection attempt timed out

[0m

+CEREG: 0,"FFFE","FFFFFFFF",7,0,0,"11100000","11100000"

[00:10:00.434,600] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 0

[0m

[00:10:00.442,901] 

[0m<inf> lte_lc: Using fallback network mode

[0m

[00:10:00.449,035] 

[0m<dbg> lte_lc.w_lte_lc_connect: Network mode: AT%XSYSTEMMODE=0,1,1,0

[0m

+CEREG: 2,"0094","00017718",9,0,0,"11100000","11100000"

[00:12:01.164,062] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 2

[0m

+CEREG: 2,"0094","00017718",9,0,11,"11100000","11100000"

[00:12:01.607,116] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 2

[0m

+CEREG: 4,"0094","00017718",9,0,11,"11100000","11100000"

[00:12:01.946,228] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 4

[0m

+CEREG: 2,"FFFE","FFFFFFFF",9,0,11,"11100000","11100000"

[00:14:06.065,155] 

[0m<dbg> lte_lc.parse_nw_reg_status: Network registration status: 2

[0m

[00:20:00.495,086] 

[0m<inf> lte_lc: Network connection attempt timed out

[0m

[00:20:00.502,044] 

[1;31m<err> asset_tracker: LTE link could not be established.

[0m

*** Booting Zephyr OS build v2.1.99-ncs1-1145-g13dc96f83bab  ***

[00:00:00.006,805] 

[0m<inf> mcuboot: Starting bootloader

[0m

[00:00:00.015,228] 

[0m<inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3

[0m

[00:00:00.028,594] 

[0m<inf> mcuboot: Boot source: none

[0m

[00:00:00.035,827] 

[0m<inf> mcuboot: Swap type: none

[0m

[00:00:00.440,887] 

[0m<inf> mcuboot: Bootloader chainload address offset: 0x10000

[0m

[00:00:00.448,608] 

[0m<inf> mcuboot: Jumping to the first image slot

[0m

*** Booting Zephyr OS build v2.1.99-ncs1-1145-g13dc96f83bab  ***

Flash regions

[Martin Lesund]

Hi Chandra,
The application first tries to search and connect on the LTE-M bands, but cannot find the network associated with the SIM card and then it tries the NB-IoT network and also fails.

First step, I would recommend that you make sure that this SIM card you have is registered, and that it actually support LTE-M and can give you access the given network.
(According to GSMA official deployment map there is no network in India that says they support LTE-M)

I would advice you to flash the AT Client sample and send some AT commands that may give some additional information about the situation using the LTE Link Monitor app in nRF Connect.

So before you turn ON the modem (AT+CFUN=1) I suggest that you select the mode it should start up in (either LTE-M or NB-IoT) AT%XSYSTEMMODE.

Then make sure to have the "automatic requests" checked in the settings (down right corner of the lte link monitor) then turn ON the modem and send the AT+CFUN? command.
This should prompt a script that sends additional commands to the modem and read out additional information which will update the GUI at the right hand side of the app.

First try LTE-M then turn off the modem (AT+CFUN=4) and switch to the other mode (nb-iot) + set the AT%XEPCO=0 since most likely the network does not support ePCO, then Turn On the modem again (AT+CFUN=1) and send AT+CFUN? to update all the GUI again.

Please send the log output after the test so we could take a look at what is happening at your side.

Best regards,
Martin L

[ChandraSR K]

at this moment our location doesn't support : LTE-M or NB-IoT. so for now I hold this.

[Martin Lesund]

Thanks for the update.
Just let me know if there is any questions you have than may come up.

[ChandraSR K]

closing for now.