Question

I know how to select which frequency band to use with the gsmctl -A 'AT+QCFG=<bandval><ltebandval><tdsbandval>' command but how can I choose to not use any band at all in one category? I tried using a space instead of a number or hex value but that didn't work.

Answer 1

Hi,

You can specify which bands the device can use, meaning that it will not use any others. Take a look at these LTE bands:

0x1   - LTE B1
0x4   - LTE B3
0x10 - LTE B5
0x40 - LTE B7
0x80 - LTE B8
0x80000 - LTE B20

If you take multiple bands from this list and add up their hexadecimal values, the modem will only use these. For example, to exclude LTE B1, you just add up all the others:

0x4 + 0x10 + 0x40 + 0x80 + 0x800000 = 0x800134

Then you would use this to set it up:

ifdown ppp
gsmctl -A 'AT+QCFG="band",0,800134,0,1'
ifup ppp

Comments

So there is no way to disable all lte bands like there is from the webui? I mean I could just use a band that isn't available where I am but that seems really weird.

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You can disable all of them if you use 1A0000800D5 as <ltebandval>. But this will not work if the selected service mode is Auto. Change it via the WebUI, Network → Mobile page. There are also two ways to do this via command line:

1. AT+QCFG="nwscanmode"[,<scanmode>[,<effect>]] - this specifies a single type of network that the module will try to connect to. Possible parameter values are:

• <scanmode>
  • 0 - AUTO
  • 1 - GSM only 
  • 2 - WCDMA only
  • 3 - LTE only
  • 4 - TD-SCDMA only
  • 5 - UMTS only
  • 6 - CDMA only
  • 7 - HDR only 
  • 8 - CDMA and HDR only
• <effect>
  • 0 - Take effect after UE reboots
  • 1 - Take effect immediately

For example, to use only WCDMA:

gsmctl - A 'AT+QCFG="nwscanmode",2,1'

2. AT+QCFG=“nwscanseq”[,<scanseq>] - changes the sequence of preferred network type. Possible parameter values are:

• <scanseq>
  • 00 - Automatic (LTE/ WCDMA/TD-SCDMA/GSM)
  • 01 - GSM
  • 02 - TD-SCDMA
  • 03 - WCDMA
  • 04 - LTE
  • 05 - CDMA

For example, to connect to WCDMA first, GSM second and exclude everything else:

gsmctl - A 'AT+QCFG="nwscanseq",0301'

/etc/init.d/modem restart

Note: in order for nwscanseq to take effect, the module has to be rebooted (as seen in the example above).

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If you take multiple bands from this list and add up their hexadecimal values, the modem will only use these. For example, to exclude LTE B1, you just add up all the others:

0x4 + 0x10 + 0x40 + 0x80 + 0x800000 = 0x800134

You are absolutely wrong, case it will be : 0x800d4

And final command will be:

gsmctl -A 'AT+QCFG="band",0,800d4,0,1'