BC660K-GL - how to speed up registration process?

IoT Modules LPWA Module
1

Hello everyone!

In our projects we use the BC660K-GL module and I would like to ask how can I speed up the process of registering to the network?
So far the following has been done:

  • manual operator setting using the at+cops=1,2, “26001” command
  • forcing scanning of only band 8 at+qband=1,8

However, in poor conditions the times of logging into the network after starting the modem are very different:

  • optimal - about 4 seconds from starting the module (energy cost is about 50uAh)
  • pessimistic - even 50 seconds! (energy cost in this case is over 1200uAh!!!)

The problem for us is the significant power consumption in the pessimistic scenario.

Using the at+qeng=0 command I noticed that the <sc_ECL> attribute in the case of a longer login to the network is usually 2 - does this affect the extended registration time? Is it possible to manually set the ECL value?

What parameters/at commands can I use to determine if there is a chance for faster registration?

We have problems with energy balance due to a small battery in the device, so we would like to be able to control the network registration time and, in the event of a longer time, be able to react (e.g. try to start the modem after some time)

Please give me some advice, best regards!

2

ECL can also be used to evaluate network coverage, but I recommend using rsrp to evaluate the strength of the signal coverage and snr to evaluate the interference of the signal coverage
If you want to speed up your radio network search, you usually need to lock your band and PLMN (mainly for roaming SIM cards)
Quectel_For BC660K&BC950K Development and Application Process in Power-off and PSM Mode.pdf (1.8 MB)

3

Hello @herbert.pan-Q! Thanks for your reply!
As mentioned in first post i already locked band and PLMN:

  • at+cops=1,2, “26001”
  • at+qband=1,8

But still got very various registration times - device is in the same place and registration duration is sometimes 3-4 seconds, but in some cases it takes around 40s

4

What you describe may be a normal phenomenon, BC660K search network and registration network time is not fixed, may be due to signal instability or insufficient channel resources related,If you need to know why, you need to get the debug log
Quectel_EPAT操作指导与参考(CN&EN)_BC260Y&BC660K&BC28F&BC95GF&BC300Y&BC950K&BC280E&BC95GE.pdf (2.1 MB)

5

Hello team from support,

Do you have “Process in Power-off and PSM Mode” Documentation also for the BG600 or the BG77x? I found some Commands (AT+QCSEARFCN, AR+QRST), that seem important for reliable function, but are not present on the BG600/77x.
We noticed some problems with these e.g. while crossing country borders (in Europe)

Thank you very much!
Jo

6

BG600L clean the historic EARFCN,run
GSM: AT+QNVFD=“NV/item_files/modem/geran/grr/acq_db”
CATM: AT+QNVFD=“/nv/reg_files/modem/lte/rrc/csp/acq_db”
NB: AT+QNVFD=“/nv/reg_files/modem/lte/rrc/csp/acq_db”

BG770x
image

7

Thank you very much!

8

Hello @herbert.pan-Q i`ve got another question but maybe related to the topic:
Im considering change LTE protocol version from 13 to 14.

  • at+qcfg=“relversion”,14

Could you please tell me if this action can change registration process?

This action also automatically changes the “NBcategory” to the NBIOT2, yes?

9

yes,However, in practice, the radio network needs to support NB2 to work properly