BC68 operation in bad coverage

IoT Modules LPWA Module
1

Hi,

I have been trying to test NB-IoT connection in “bad coverage” conditions. But it seems that BC68 cannot register to network even tough conditions shouldn’t be too bad for NB-IoT. I used AT+NUESTATS to measure channel conditions and here are the average results during test:

kuva

I have also logs taken by UEMonitor but I guess I can’t attach those here.

Basic procedure is that I reset the module by using AT+NRB, then I set modem functionality by AT+CFUN=1 and PLMN selection to be automated by using AT+COPS=0. I also confirm that PDP context is what I want it to be with AT+CGDCONT?. I have earlier also set correct band by using AT+NBAND, which I still confirm by using AT+NBAND?. Finally I repeat AT+CEREG? for 300s (NUESTATS is checked every 15s), and check if +CEREG: 0,1 is received.
Problem is that it is never received in these conditions. +CEREG: 0,2 is received during whole 300s period. Is there anything I could try to do to improve modules operation in bad coverage or is these conditions beyond the limit of the BC68?

Br,
Niko

2

Hi Niko
The on-site network environment is too poor to meet the network access requirements. You can provide UEMonitor log, I will help analyze specific reasons.

3

Hi Abner,
Please find the UEMonitor logs from the follwing link: https://unioulu-my.sharepoint.com/:u:/g/personal/nkuisma_student_oulu_fi/EXvyyZGaZk1PldUqBDSLkEwB9IpUnkAaFN1uqJmeurVSOA?e=0wzg1L

4

Hi Niko

%E5%85%A5%E7%BD%91%E5%A4%B1%E8%B4%A5
%E5%85%A5%E7%BD%91%E5%A4%B1%E8%B4%A5837×942 62.5 KB

The root cause may be that the network environment is too poor.

3
399×643 1.96 KB

Solution: SNR> 0, RSRP> -110 recommended network environment.