Important update regarding LTE modem updates

[Xykon]

In regards to band 8, I was informed now that, while the hardware supports all bands (1,2,3,4,5,8,12,13,18,19,20,28), the Sequans firmware currently only supports a maximum of 6 bands so we chose the ones that gave us the best support at the time of launch. I have a call with Sequans later today to discuss this limitation and provide a firmware that can be used with band 8 as soon as possible. I hope to have an update on that within 24 hours.

[tuftec]

@xykon thanks

[tuftec]

@xykon I have been advised that for future compatibility with Vodafone's Australian network, all devices should support bands 5, 8 & 28. Currently only band 8 is supported.
If there is only a limitation in the modem firmware for only 6 bands, then maybe there should be a special version for Australia that will provide support for Vodafone, Telstra & Optus/Singtel.

[robert-hh]

@xykon How do I have to understand the answer. I read, that the set of bands the firmware can support is 6, but which bands are in this set of 6 can be freely chosen. If that is true, then there should be not problem, unless in a certain region more than 6 bands are used simultaneously.

[mfalkvidd]

@robert-hh with 12 bands to choose from, covering all possible combinations of 6 bands would require pycom to make 665,280 different firmwares available (12 * 11 * 10 * 9 * 8 * 7). I think that would be troublesome.

[robert-hh]

@mfalkvidd That is not required. Since lte.attach w/o parameters only send AT commands like:
AT!="RRC::addScanBand band=20"
to the device for the 6 supported bands, an user could also manually send these commands, or would call lte.attach(band=xx). It's only important, that the Sequans firmware could deal with that. And obviously, the should be a link the the docs to a table, where users could find the frequencies of interest.

[kevin]

@robert-hh The problem is that the underlying modem firmware from Sequans (e.g., NB1-38729) only supports bands 3/4/12/13/20/28. Operations involving other bands silently fail at the modem level, with no effect and no error messages.
Pycom was aware of this from the beginning, but it is still not resolved:
https://forum.pycom.io/topic/2496/gpy-readiness/8
Not sure if it is a lack of support from Sequans, or concerns over certification, or a deliberate strategy to control roll-out with selected partners. In any case it goes against the principle of "open development" that motivated many of us to choose Pycom/Sequans.

[kevin]

@xykon Pycom was looking into a "test" firmware from Sequans, supporting all 12 bands:
https://forum.pycom.io/topic/2496/gpy-readiness/18
That was 8 months ago, I guess it didn't work out? Can you look into that option again? Even if not fully calibrated/certified, it would work for lab testing.

[robert-hh]

@kevin So it seems that the decision for Sequans was not a lucky choice.

[Redferne]

Just tried upgrading a FiPy to Stable v1.18.1.r1 and LTE firmware NB1-38729. Seems to attach fine using Telia NB-IoT, however it will not let me connect due to this:

>>> lte.send_at_cmd("at+cops?")
'\r\n+COPS: 0,2,"24001",9\r\n\r\nOK\r\n'
>>> lte.send_at_cmd("at+cereg?")
'\r\n+CEREG: 2,5,"03F4","01A7561C",9\r\n\r\nOK\r\n'
>>> lte.isattached()
False
>>> lte.connect()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: modem not attached

Sequans

+CEREG: <n>,<stat>[,[<tac>],[<ci>],[<AcT>[,<cause_type>,<reject_cause>]]]

Without digging in the code, is <stat> 5 properly handled as registered, roaming?

[robert-hh]

@redferne See thes post of @Xykon below, which try to address this:
https://forum.pycom.io/topic/3549/important-update-regarding-lte-modem-updates/84
and
https://forum.pycom.io/topic/3549/important-update-regarding-lte-modem-updates/86

[JoseDLopez]

@stsiafak Thanks for you answer!

Did you make that test in Chile? If it so, wich operator? I am trying with telefonica/movistar

Finally i am trying with Huawei Node and after:
.
.
lte.send_at_cmd('AT+CFUN=1')
.
.
lte.send_at_cmd('AT+CGATT=1')

I receive:
error +CEREG: 4

It seems to be a problem with freq band selected. Can you guide me about what does that error mean?

Maybe? Error Code: 4 -> Operation not supported

Best regards,

[tuftec]

@xykon please advise when we can expect a response to the band 8 problem.
I was surprised to discover that this issue has been known about for 8 months now.
This is a critical stop point for our project. We have already eaten up precious time that we have arranged with Vodafone Australia for system trials.
Peter.

[danielm]

I performed successful tests in NB-IoT network of Slovak Telekom with Sequans FW NB1-38729 and Pycom FW 1.18.1.r2 provided by @Xykon .

As suggested by @peterv it was possible to reduce the code to:

lte = network.LTE()
lte.send_at_cmd('AT+CGDCONT=1,"IP","nbiot.telekom.sk"')
lte.attach(band=20)

Issues which remain unsolved from my point of view are:

• working DNS over NB-IoT connection
• support of PSM and eDRX

[danielm]

There is one more issue. Test application was sending MQTT message once per minute. After approx. 5 hours MQTT client returned exception [Errno 113] EHOSTUNREACH and each following attempt to reconnect to MQTT broker was unsuccessful.
The application also checks lte.isattached() and lte.isconnected() in each loop and if there is a change of state it prints out notification. There were no notifications therefore I assume that state of both lte.isattached() and lte.isconnected() remained True.

[serafimsaudade]

Hi,

I'm from Portugal, and I doing some testing the MEO NB network with 2 modems.
1 - Mangohred WP7702
2 - Pycom Gpy

I can connect with wp7702, and send data to our cloud server over UDP, MQTT. I also check the band use by the modem to connect, and is using the band 20.

With pycom, I try this code:

lte = network.LTE()
lte.send_at_cmd('AT+CGDCONT=1,"IP","internetm2m"')
lte.attach(band=20)
lte.isattached()

And the response is always False.
I update the sequans modem Firmware, but the result is the same.

I came to the conclusion that the sequans fw is not ready for the portuguese network. Or I'm doing something wrong?

cumps,
Luís Santos

[robert-hh]

@xykon Today I got the information that T-Mobile Germany uses band 8 for NBIoT (900 MHz band). So it would be useful to know, if this band is supported by the Sequans firmware is the attach is requested by the command AT!="RRC::addscanband band=8"
Trying to do that did not succeed even after 2 hours waiting.
At least, AT+CSQ tells me, that a cell is seen and a good signal can be received. But I have to go through a hard reset to get that.

[tuftec]

@robert-hh still wait on a response to band 8 support.
It appears that it is currently not supported.
This has put a halt to our developments at present.
Peter.

[robert-hh]

@tuftec What is your source of the missing band 8 support? Doers it tell that the Sequans firmware, or the Pycom firmware, not passing the request to the Sequans firmware.
If I compare the behavior between band 20 and band 8, it looks pretty similar. All commands are accepted, and then the Sequans modem is reporting alternating CEREG 2 and CEREG 0 on its TX line, only the period is different. For band 20, the period is 45 seconds, for band 8 it is 225 seconds.

[tuftec]

@robert-hh suggest you read the other posts in this thread. Particularly those from @Xykon.

It appears that the Sequans modem is not currently configured for band 8 support. A new firmware update is required.

Peter.