Does the GSM1400 support the 2100MHz band

Official Hardware MKR Family MKR GSM 1400
1

We are using the GSM1400 as the data connection for our outdoor counters, for the most part everything works as it should. We are using a universal 2/3/4G SIM card that has no problem connecting to EE, O2, Vodafone (we are in the UK).

The issue is when the module connects to the Three network (UK) or recently to Airtel (Jersey). The only difference I can see is that they only use the 2100MHz band. The modem seems to connect (it can be seen on the network providers portal) but I can not open a data connection.

I'm using one of the examples that I have modified for my needs. The unit fails to connect in the gsmAccess.begin/gprs.attachGPRS functions.

Looking at the Arduino documentation and product page 2100MHz is not mentioned, When I look at the band management application it does include UTMS 2100MHz band and the SARA-U201 documentation also mentions 2100MHz support.

I have tried to use the band management utility sketch to change the band but if I run the sketch again it always shows the default 'GSM_MODE_EGSM_DCS' as the current band. The U201 documentation does mention it is an NVR parameter but I'm not sure if it is saved or reset each time the module is started.

The board does have a good 5V supply that is only enabled when data needs to be sent (to save battery), we have used this for the last couple of years will no issues, it just seems to be the 2100MHz band that is causing issues.

My questions are:

  1. Does the GSM1400 support the 2100MHz band.
  2. Is the band management setting stored in the U201 modem or is it something that needs to be set each time The U201 documentation does mention it is an NVR parameter

Any words of advice or suggestions would be most appreciated.

2

The specifications of the GSM1400 are to be found at:
https://store.arduino.cc/collections/boards/products/arduino-mkr-gsm-1400.

I don't see 2100MHz mentioned.

3

Thanks John, with you 100%, this is my cause of concern, the product page says no but the band management sketch and the U201 documentation say yes.

The problem I have is that it is connecting to the 2100MHz band (Airtel only use this band) but the connection does not seem to work, it is very odd. Unfortunately there is no way of steering away from the 2100MHz band as the SIM is universal so will connect to anything (that the supplier has a deal with).

4

Some operators (like Orange) were using 2 frequency bands for 3G: 2100 MHz and 900 MHz. In 2021they walked away from the 2100 MHz frequency band keeping only 900. (they resold the band to other operator who probably do some 4G stuff there and support mobiles that do not have access to the 800Mhz band)

I'm not familiar with the capabilities, but would there be a way to force a 2G connection?

5

Thanks,

I can force the GSM1400 into 2G only mode (not remotely, unfortunately), but I'm not sure what the 2G coverage is in Jersey - proving difficult to find out!

6

Seems like Airtel Jersey switched off their 2G in 2018! :frowning_face:

7

:frowning:

too bad