Question

Hi,

Have RUT955V03XXX (EG25) with RUT9XX_R_00.06.08.3 and the LTE band lock does not appear to work.  Regardless of UI selection gsmctl for <AT+QCFG="BAND"> always returns LTE band bitset 0x1e00b0e18df (FW default?) and indeed the modem uses undesired LTE bands.

It is possible to adjust this manually using the same <AT+QCFG="BAND"> command, but one would expect that UI configuration should do the trick.  Also, obviously any CLI changes do not survive across boots without further work, which I would not like to do.

Answer 1

Hello,

Thank you for contacting.

May i know what bands you want to use ?

What is the country  you are in ?

I have tried it on my side on the latest firmware 

Make sure service mode is auto.

https://community.teltonika-networks.com/?qa=blob&qa_blobid=13646318128140263976

I have tested in it on my side and its working fine.

Check if the band you are selecting is supported by the ISP. 

Thanks.

Regards,

Ahmed

Comments

My /etc/config/simcard looks like this (uninteresting parts omitted). Service mode is auto and I've selected my bands 1, 3 and 7 which result as bitmask 0x45; The bitmask is correct but it does not get updated when I query the modem using gsmctl. So, I must manually set the band lock value using gsmctl.

Yes, the bands I'm using are provided by my ISP. However, when demand is low ISPs turn off many bands that support wider bandwidth and only offer bands that do narrow bandwidth. This obviously costs less money for ISPs. When band lock is not correct and there is no CA support the modem never returns to more speedy bands.

---

config sim1 'sim1'
        option reconnect '5'
        option ifname 'wwan0'
        option proto 'qmi2'
        option pdptype '1'
        option mtu '1500'
        option pincode <my pin>
        option auto_apn '0'
        option force_apn '-1'
        option apn <my apn>
        option auth_mode 'none'
        option device '/dev/cdc-wdm0'
        option roaming '1'
        option method 'pbridge'
        option passthrough_mode 'dynamic'
        option service 'auto'
        option leasetime '30'
        option letter 'm'
        option ltebandval '45'

config bands 'bands'
        option auto_sim1 'disable'
        option lteb1_sim1 '1'
        option lteb3_sim1 '1'
        option lteb7_sim1 '1'

---

Hello,

We have upgraded the RutOS of the Rut9xx devices.

Please try to upgrade device to the newer one without keeping settings as it includes a lot of major fixes.

https://wiki.teltonika-networks.com/view/RUT955_Firmware_Downloads

Further have you tried to use the bands individually if it works?

Thanks.

---

If I recall correctly, once I manually set the band lock it appeared to work via UI, too (i.e. via configuration).  I did however upgrade to RUT9_R_00.07.00 pretty much on the day it was released and at least now band lock can be configured via UI.  Band configuration configuration keys seems to have changed, and the previous configuration keys were not removed - did not bother to clean those up.

With band lock enabled I run into a problem where the modem would re-connect (presumably when locked bands were not available) but with a wrong APN.  The software seems to configure many PDP contexts (AT+CGDCONT) with default / unset values and there's only the primary PDP with the proper (custom) APN set. Perhaps when the modem does not see any enabled bands it attemps to use another PDP context.  In my case, it will fail, since I must a use specific APN to bypass CGNAT.

Anyway, I enabled all bands that my ISPs use and then set <AT+QCFG="lte/bandprior">.  It seems to work.  The modem stays on priorized bands when those are available and when priorized bands are not available it will choose some other (locked) band.  There are no connectivity losses during band switchovers and especially APN remains the same, meaning that the device is reachable.

It would be nice if one could set band priorization via UI since attempting to set something like this thru initialization scripts is always a hazzle (due to possible timing issues since there are no callbacks e.g. when modem is ready).

---

Hello,

For the band prioritization unfortunately its not available in WEBUI be default.

But yes its possible with custom developments. You can contact your sales Manager for this.

Or you can do it yourself , SDK is available here:

https://wiki.teltonika-networks.com/view/GPL

Instructions could be seen here:

https://wiki.teltonika-networks.com/view/RUTX_Software_Development_Kit_instructions

Thanks.