OpenWrt Forum Archive

Topic: 4G / LTE USB Modem Setup (Huawei E3276 & R215/E5372)

The content of this topic has been archived on 7 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

So i have a TP-Link router with OpenWRT installed (of course) and i have been trying to get these particular 3G dongles to work however after hours of scouring Google and the OpenWRT wiki i haven't had much luck. The documentation i have found is either incredibly confusing or ill relevant to my hardware.

So far i have had the E3276 detected by OpenWRT but have not been able to have it connect to the network, the R215 i have not been able to communicate with at all.

I am very confused with the different communication modes QMI RDIS NCM there was something else i read about.

Any tips anyone? please??

Please check following...and use google translate to understand. commands are same smile

http://eko.one.pl/?p=openwrt-3g

http://eko.one.pl/forum/viewtopic.php?id=7236

Generally, when configuring new USB 3G/4G dongle, i start with Linux and check, if Linux works. Recommended is to disable PIN if possible. When linux is working, then SIM+DONGLE is OK and you can proceed on openwrt part.

Each mode has some plus/minus, so you can read A LOT about each...

Bye

I'm also trying to get some clarity on the best way to use these dongles. I agree the info out there is confusing or incorrect or even contradictory. I've sent an email to devel@ and contacted some of the contributors - hopefully they'll provide some guidance and I'll post back here and update the wiki with the currently accepted way of getting these dongles operational.

I have successfully installed E3276 on several routers.
Dongle works very well when used in 'ncm' mode (use ncm protocol in interface settings). To install it, look for kernel modules containing 'huawei' in the name.

Yep - I've had one running for over a year on a remote router. However, there are niggles. Some of the posts to the devel list indicate the NCM protocol is provided by a couple of packages (ie wwan I think) and that if that is used configuration through Luci should be possible. An extension of this is that signal strength information etc should also be available.

Key for me is this last part - getting signal strength info and perhaps operational mode (LTE / 3G etc) in an easy to use form. Yes, I can issue the AT command but sometimes that doesn't work or even something like "comgt sig -d /dev/ttyUSB0" or "comgt sig -d /dev/cdc-wdm0".

[As an aside, I need something that returns signal strength so I can power cycle the dongle when it 'jumps' to a further away cell tower giving a worse connection. Power cycling of the USB is achieved using a YKUSH board. I could monitor pings and do a power cycle when they are > a set value, but this seems a bit of a dangerous way of doing things. My test setup performs a cycle via a cron job every 24 hours - so the longest the remote location will have super-slow access is 24 hrs.]

But I still think it would be useful to have the process and capabilities documented on the wiki.

tristanc wrote:

I need something that returns signal strength so I can power cycle the dongle when it 'jumps' to a further away cell tower giving a worse connection.

It seems something changed between my old trunk build (r44497) and the CC 15.05 release (r49007). Issuing

comgt -d /dev/cdc-wdm0 -s /etc/gcom/getstrength.gcom

on both systems gives no response on r44497 and +CSQ: 9,99 with r49007. Hopefully this behaviour isn't a one-off or quirk of current set-up.

There used to be unofficial NCM Luci plugin for BB that had all the info about mobile network state. It didn't make it to CC. Try to find it - may be it will work with minimal changes.

Yeah - I've tried patching CC luci with the patch available, except Luci has changed somewhat since it was written... I've given up & botched together a commandline alternative using the Luci Custom Commands app which sort of works some of the time.

tristanc wrote:

Yeah - I've tried patching CC luci with the patch available, except Luci has changed somewhat since it was written... I've given up & botched together a commandline alternative using the Luci Custom Commands app which sort of works some of the time.

I'm looking to build something very similiar to what you did (remote router connected over LTE, power cycling modem on "bad reception" events) and I'm looking at this particular LTE stick as a modem option. I'd really like to see your command-line hackjob, if you would be so kind to share smile

xon wrote:

I'm looking to build something very similiar to what you did (remote router connected over LTE, power cycling modem on "bad reception" events) and I'm looking at this particular LTE stick as a modem option. I'd really like to see your command-line hackjob, if you would be so kind to share smile

A bit has changed since this post - I ended up using a HiLink dongle, so behind double NAT. I VPN out to get a static IP and make it connect on boot and maintain that connection via OpenVPN’s config. I use a cron job to turn the dongle off (completely unpowered) for a minute or so each morning at 3am. The system gets reasonable ‘up’ time - 79days at last check, but I have seen it get to 100. Our electricity goes off fairly regularly so it’s limited by that...

Anything clever / complex just didn’t work as support for the signal strength reporting / NCM / LTE doesn’t seem to coincide which is a shame.

tristanc wrote:

Anything clever / complex just didn’t work as support for the signal strength reporting / NCM / LTE doesn’t seem to coincide which is a shame.

It really is. Was hoping for an elegant solution but looks like I'll be going for something like a script pinging Google's DNS to determine quality of reception then. I've just gotten the dongle in the post so I'll start experimenting. I'll probably end up experimenting with a couple more modems before I'm happy. This now is #2 after an interesting bout with a Samsung GT B3740, which has more than a few quirks but that I'll likely keep to toy around with.

Guess hostless would be my next step up as well.

If you still have it available, I'd still like to see your script for reference, but either way many thanks for letting me know that this particular rabbit hole I need not go down.

(Last edited by xon on 5 Jan 2018, 13:39)

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