Hi there,

First, thank you for your work maintaining 'smsd'! I've been using it for several years now, and it's been rock solid.

Recently, with 2G GSM being retired in my area, I've had to switch to an LTE modem which does not support sending messages with the AT+CMGS command that 'smsd' exclusively uses. Instead the modem only understands sending messages using the AT+CMGW, AT+CMSS and AT+CMSD commands. It turns out that this is more and more common with recent hardware...

I'd love to see a future version of 'smsd' capable of handling this alternate sending method and I'd like to hear your thoughts on this.

Thanks & best regards,
-F.

Thanks for using this software.

What is the model and manufacturer of your LTE modem? Do you have a link for it's manual of AT commands? It would be very important.

Sending through the storage would be useful with older devices too, when the same message is sent to the large number of recipients. Sometimes it has been asked, but there has not been a major reason to create support for that in the past.

Hi keke,

Thanks for the quick response

The modem in question is a 4G LTE Huawei E397u-53 (a.k.a Huawei BOLTZ 4G LTE modem).

Unfortunately, I have not been able to find an exact link to the manual for this modem.

However, I have found one for another Huawei modem which works the same way with regards to the CMGW, CMSS and CMSD commands: here

Alternatively, you can also see how these commands are being used here as they're standard.

I hope this helps.

Thanks,
-F.

Thanks for the information.

With CMSD you likely meant CMGD, which is used when stored message is not needed anymore. Developershome talks about text mode which is not and will not be supported by smsd, because the mode is too limited. However it is clear that modems, at least some like the one in your link, support PDU mode too. Usage of stored messages might be slightly complicated, when multiple recipients are defined and the message contains more than single part. I will check and test these issues later when I have some more time.

I believe that the 2G perhaps is not the point in this case, because SMS is GSM related and the same PDU's still work for sending and receiving. Also HUAWEI ME909u 521 LTE LGA Module supports traditional CMGS, so I have to ask how have you detected that in your case CMGS does not work anymore? Okay, it stopped working when you replaced the device, but is anything else changed at the same time?

Yes, I meant to write 'CMGD'. Sorry.

The 2G modem that I used previously (a Huawei E303) used to work with smsd 'out of the box'. When 2G stopped being supported by my local carriers, I upgraded to the Huawei E397u-53 as mentioned earlier.

When I realized that smsd could receive messages but could not send them with the new hardware, I investigated the issue with a dumb terminal: when attempting to use AT+CMGS, the modem returns "COMMAND NOT SUPPORT". Nothing else about the system changed.

I validated that the E397u-53 modem could successfully send a simple SMS message in TEXT mode using AT+CMGW/CMSS/CMGD commands. I didn't try this in PDU mode, even though the modem supports both modes.

I hope this helps clarifying things a bit.