Cat NB1 & M1 band frequencies

Hello forum,

I’m developing a product to be deployed all across the globe using BG96, every country will use a local SIM card with NB1 or M1 technology support.
During the configuration I’ve used the following commands to test a setup where I’m looking for NB1 and if it doesn’t get signal I’ll move to GSM:
Then I block until I have a valid AT+CSQ value.

About these steps I have a few questions:

  • Do I really need need the AT+CFUN=0?

  • I’ve verified that if I use AT+QCFG=“band” to limit the bands that are searched, the module will skip to GSM much faster in situations where the SIM card doesn’t have support for NB1, where it blocks waiting for signal for a longer time than desired. Taking in consideration that the device can be deployed into multiple countries, can I limit this search to a few bands? I’ve noticed that the most commonly used are 3, 5, 8 and 20 for NB1. Do you have any recommendation on this?

  • When signal is acquired and after querying the registration status (CREG/CEREG/CGREG) I configure the APN using AT+QICSGP and activate the context with AT+QIACT. I’ve noticed some people using AT+CGDCONT and AT+CGACT. What is the recommended way?

Hope someone can help!

Can someone help with this question?

  1. AT+CFUN=0, AT+CFUN=1 is not necessary as far i know, because 3th parameter of nwscanmode automatically does this.
  2. You can limit 2G, CAT M1 and NB bands using just at+qcfg=“band” command. See AT command datasheet for more info. We are using only band 20 in Turkey. its enough.
  3. I prefer AT+QICSGP because this command has more features than CGDCont such as setting IP version and APN username, password, auth type etc. AT+QIACT is common way to activate PDP context to connect internet in all networks.(2G,NB, M1 etc.). In BG95 and EG91, we are using only qiact. You can check. QIACT also activating cgact automatically when u use 2G.

use CEREG for NB networks, use CGREG for 2g networks. Its will be fine.

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