LTE extension board and NB-IoT

[odi.odi 2 4 4 0 3 4 1 1 1 0 1 1 1 6 4 5 4 5 4 6 3 3 1 1 1 1 1 0 5]

Hi,
there is a RAT selection possibility within the sample Arduino sketch LteScanNetworks:
https://developer.sony.com/develop/spresense/docs/arduino_tutorials_en.html#_get_network_status

At point 3. - if you select NB-IoT (LTE_NET_RAT_NBIOT) I do not get a network attach.
My used SIM is able to connect to NB-IoT network 262-01 with other devices.

Which LTE bands are activated by default on the LTE extension board with ALT1250 chipset?
What are the possibilities to adapt NB-IoT parameters used from the module?
Any chances to send at-cmds to the ALT1250?

Thank you for some answers

[CamilaSouza]

Hello, @odi-odi-2-4-4-0-3-4-1-1-1-0-1-1-1-6-4-5-4-5-4-6-3-3-1-1-1-1-1-0-5
Spresense product specification webpage (https://developer.sony.com/develop/spresense/specifications) talk about the bands for LTE extension board: US Band 2, 4, 12, 13 EU Band 3, 20
In order to send at-cmds, please take a look at lte_send_atcmd_sync on the API reference for LTE (https://developer.sony.com/develop/spresense/developer-tools/api-reference/api-references-spresense-sdk/group__lte.html#gad2dd35c2d1a79446cea10bc694680a0f=

[gendor 0 1]

@odi-odi-2-4-4-0-3-4-1-1-1-0-1-1-1-6-4-5-4-5-4-6-3-3-1-1-1-1-1-0-5 Did you manage to get NB-IoT to work? It looks like I may not have LTE-M coverage in my area, and was hoping to use NB-IoT instead.

[odi.odi 2 4 4 0 3 4 1 1 1 0 1 1 1 6 4 5 4 5 4 6 3 3 1 1 1 1 1 0 5]

@gendor-0-1
With the setting of the EU Band 3, 20 I will not be able to connect to NB-IoT here (band 8).

I was able to set the band via: AT%SETCFG="BAND","8"

..and then startet it via:
lte_sysctl -a <apn> -r NB start
ifup eth0

AT+CEREG?
+CEREG: 5,5,"C37A","019BC807",9
|_ 9: NB-Iot