LHG 4G Kit unstable LTE connection

rushpro · November 18, 2019, 10:48pm

Hello Everyone

We have purchased a few Mikrotik LHG 4G Kit units for use with a 3.5Ghz Baicell basestation. The 4G Kit (With the R11e-4G card) supports Band 43 which is what we are using, and they seem to work great most of the time, however we are finding that the LTE has issues with locking up and winbox sessions continually disconnect (Without lossing LTE connectivity).

We are currently running 6.45.6 (Just updated to 6.45.7 for security patches) with the LTE firmware being R11e-4G_V007
Signal levels are RSSI: -72, RSRP:-86, RSRQ:-5, SINR: 28, CQI: 15.
This issue is on both 10Mhz and 5Mhz channel widths.
From what I know, the few Baicell clients we have on the sector do not have these issues and stay connected 24/7 with lower signal levels.

It seems the LTE locks up requiring a full reboot to get it functional again. We have mitigated it a bit by enabling the watchdog, however it’s still rebooting every 5-6 hours and causing service disruptions.

Because of the watchdog I haven’t been able to get any detailed logs from it. I am going to be setting up a test unit at the office with remote syslog running with LTE INFO enabled to see if I can get more data.

I am just wondering if there are some tweaks or something I am missing? I have seen quite a few form posts with similar issues, however they mostly seem to be resolved with patches from older versions.

ksthree · November 21, 2019, 1:17pm

Hi rushpro

I am having similar issues with SXTLTE and R11 LTE.

Are you able to connect into these devices via a public IP address?
Does the public IP address change with each new LTE session?
Do you have a stable RB in your office that has a buzzer that you can hear while you are working on other stuff?

I can share with you some of the ways I am debugging this, and maybe we can help each other.

BitHaulers · November 25, 2019, 7:22pm

Have you tried a factory reset and importing a config file?

I had an R11-LTE ROW link up, but not pass traffic, and the reset fixed it in <2 minutes. I think maybe the flash memory is not create in some of these, and something gets corrupted, and resetting seems to fix a lot of problems. I’ve had to factory reset devices straight out of the box to get them to work, but after that they spend a year in the field with no problems.

ksthree · November 25, 2019, 7:56pm

In our case, we have reset the units several times. We have even updated modem drivers as well as firmware. I have even written some scripts to monitor the connection and resolve issues as they happen, but yet we still have gremlins popping in through every way they can.

The one site we have has two SXT LTE units and they have a cross-connect on ETH2, but now Unit 1 says the cable is connected and Unit 2 says it has a short in the cable. Unit 1 can telnet into Unit 2 and carry out tasks, but Unit 2 can’t telnet into Unit 1.

So I am scratching my head right this minute…

uldis · November 26, 2019, 12:35pm

is it happening for only that device or also other 4g kits experience this problem?
Please contact support so we could get support output files and logs from the device.

ksthree · November 26, 2019, 9:18pm

where do I go for that?

SiB · November 26, 2019, 11:50pm

*) save logs to action=disk to check it after reboot.
*) watchdog create a suport.rif? You can read this file at mikrotik.com account and check latest logs!.
*) You can swap sim port to down/b and again to restore to up/a
*) You can grab lte info and send SMS when LHG is offline.
*) You can create own script action when you receive a specific SMS like reboot, 2xchange sim slot, disable/enable lte etc.

I hope I give you some ideas.

ksthree · November 27, 2019, 6:56am

All of the above done.

But here are two tricks I have learned.

Set watch dog to 10 mintutes with 600 seconds…

Also use a scheduled script that pings but on fail instead of reboot it just resets the LTE. This takes a lot less time than a reboot. (Bare in mind the time it takes for the device to reboot as well as regain in it’s connection.)

SiB · November 27, 2019, 8:15am

And what you see when networks is down?
LTE is up and running? Have signal? Ping’s to a nexthop works?
You activate a lte logs and?
What you learned, what is wrong?

Set watch dog to 10 mintutes with 600 seconds…

It’s just a one of way to do reboot. Re-power USB is faster. Disable/Enable or set lte parameter is more faster. Change by AT*Cell is more faster.

Also use a scheduled script that pings but on fail instead of reboot it just resets the LTE. This takes a lot less time than a reboot. (Bare in mind the time it takes for the device to reboot as well as regain in it’s connection.)

Perfect. When you detect the offline state then you can do a diagnostic staff. e.g. check if lte device exist in USB magistral etc. grab logs, do some re-enable stuff.

rushpro · November 27, 2019, 6:47pm

Unfortunately I have been really busy. We currently only have 10 LHG 4G Kit Radios in stock.

I have just got the radio setup in the office today with it logging lte to my work computer. I have disabled the watchdog on it so I will see what it does when the LTE crashes. When it crashes next I will grab the support.rif file and pass it on

rushpro · November 27, 2019, 7:03pm

I will give that a try once it starts crashing reliably. There is a chance that the issue is location dependant, so I want to rule that out first.

SiB · November 27, 2019, 10:04pm

Hello,

First stuff, The “Passthrough” is used by you?
If YES then please not do it at ether1 but use vlan-s like this (at SXTR I have 2xFastEth then I have bridge):

In my scenario LTE APN do passthrough to vlan-br_lan-v0003-lte and SXTR haven’t a internet for itself.
At second vlan id 2 I use dhcp-client to reach internet from remote router.

This way SXTR/LHGR can be accessible from LAN by telnet/ssh/romon/winbox from inside LAN (vlan id 2).

If NO then this is easy, you just use this as classical CPE Router with WAN as LTe and ether1 as LAN.

In Both answers. Please connect by WinBox via IP Address (not MAC) or by RoMon who have got a good stability but WinBox via IP is winer.

Please enable logs:
[admin@MikroTik] > system logging add topics=lte action=memory prefix=LHGR
Please use all this command to check if all are properly when problem exist

Detection connected modem into USB bus - the same parameters like “1-1” at normal and bad work ?

[admin@MikroTik] > system resource usb print detail where name~“R11e-”
0 device=“1-1” vendor=“MikroTik” name=“R11e-LTE6” serial-number=“000000000000” vendor-id=“0x2cd2”
device-id=“0x0004” speed=“480” usb-version=" 2.00"

IRQ on USB modem should increasing with any communication with modem. What is happend when a problem exist and this counter is inc. at any lte info command ?

[admin@MikroTik] > system resource irq print where users~“usb”
or enter new terminal and do loop by
[admin@MikroTik] > do while=(true) command={delay 1; system resource irq print where users~“usb”}
Flags: ro - read-only

IRQ USERS CPU ACTIVE-CPU COUNT

0 3 usb1 auto 0 7 692 711

interface is still running at problem exist? One of posters writey YES.

[admin@MikroTik] > interface lte print
Flags: X - disabled, R - running
0 R name=“lte1” mtu=1480 mac-address=AC:50:43:1A:EE:FD apn-profiles=sim_a allow-roaming=yes
network-mode=lte

Please be sure that modem firmware is update, MTK wiki not give us changelog and verion fw per every modem. This is only at forum.

[admin@MikroTik] > interface lte firmware-upgrade 0
installed: R11e-LTE6_V020
latest: R11e-LTE6_V020

When problem exist please do scan and info and cell-monitor, what effect you reach? Logs show AT command? USB Counter increase?

[admin@MikroTik] > interface lte scan 0 duration=10s
Flags: C - current, A - available, F - forbidden
OPERATOR MCC-MNC ACCESS-TECHNOLOGY RSSI RSRP RSRQ
Plus 26001 Evolved 3G (LTE) -75dBm -108dBm -12dB

[admin@MikroTik] > interface lte cell-monitor 0 duration=10s
PHY-CELLID BAND EARFCN RSRP RSRQ RSSI
16 B8 -94dBm -12dB
280 B8 -100dBm

[admin@MikroTik] > interface lte info 0 once
pin-status: ok
registration-status: registered
functionality: full
manufacturer: “MikroTik”
model: “R11e-LTE6”
revision: R11e-LTE6_V020
current-operator: 26001
lac: 11009
current-cellid: 3623426
enb-id: 14154
sector-id: 2
phy-cellid: 485
access-technology: Evolved 3G (LTE CA2)
session-uptime: 17h3m6s
imei: ******************
imsi: *********************
uicc: ***********************
subscriber-number: +CNUM:
primary-band: B3@20Mhz earfcn: 1300 phy-cellid: 485
ca-band: B8@5Mhz earfcn: 3526 phy-cellid: 16
rssi: -75dBm
rsrp: -108dBm
rsrq: -12dB
sinr: 3dB
cqi: 8

Please try send a SMS from LTE1 what give you a answer that modem is still woriking with signal/operator.

[admin@MikroTik] > tool sms send lte1 phone-number=+48987654321 message=“test”
At logs you can see AT commands with a delivery report?
If this works then you can enable receiving SMS and create scripts to do action when SMS have got a message=“MyPassword+reboot”

Now you can do a support file
[admin@MikroTik] > system sup-output
created: 100%
Try do a reestablish internet connection by

THIS IS THE FAST RESTART CONNECTION in my device, it’s disable cell lock in normal way but I use it to do reconnection with ISP (7 ping loss).
[admin@MikroTik] > interface lte at-chat lte1 input=“AT*Cell=0”
In this mode I have some timeout and I work with cell lock who give me a stability.

Do a Cell Lock via AT command. In my scenario this create me a super stability at my new SXTR rev2 with R11e-LTE6 even if I use the same band and only one band without secondary ca-band.

[admin@MikroTik] > interface lte at-chat lte1 input=“AT*Cell=2,3,$earfcn,$phy-cellid”
I recommend use it even if your modem is LTE cat.4

Disable LTE1 interface and enable it

Change APN to worng and to correct one

SIM slot, change it 2x to comeback and reinitialize it without reboot

[admin@MikroTik] > system routerboard modem print
sim-slot: a
[admin@MikroTik] > system routerboard modem set sim-slot=a
[admin@MikroTik] > system routerboard modem set sim-slot=b

Restart USB Power itself is faster then reboot RB

[admin@MikroTik] > system routerboard usb power-reset duration=5s

Yes, I know that this one works:

[admin@MikroTik] > system reboot

I hope I can help you both to debug and found sth new in the fast time consuming way. I do it in Copy-Paste style. I hope it helps you.

rushpro · November 28, 2019, 4:43pm

Looks like I have made a little bit of progress. Our LTE base station got rebooted due to power issues and it seems the Mikrotik won’t attempt to reconnect. It is currently stuck with Registration Status: “denied”. Here is the raw output:
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: sent AT%MEAS=“8”
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd Signal Quality: RSRP = -101, RSRQ = -8, SINR = 11, RSSI = -85
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: sent AT%PCONI
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd duplexing mode: TDD
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd Transmission mode: Open loop MIMO
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd Bandwidth: 5
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd EARFCN: 43715
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd Global Cell ID: 006F4101
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd Physical Cell ID: 1
Nov 28 09:30:49 192.168.2.130 lte,async,raw lte1: rcvd HNBN: N/A
Nov 28 09:30:52 192.168.2.130 lte,async,raw lte1: sent AT%MEAS=“7”
Nov 28 09:30:52 192.168.2.130 lte,async,raw lte1: rcvd CQI: 8
Turning on the scanner doesn’t show any available networks (Even though there are at least two) This is during the scan:
Nov 28 09:31:51 192.168.2.130 lte,async lte1: sent AT+COPS=?
Nov 28 09:32:35 192.168.2.130 lte,async,raw +CEREG: 3
Nov 28 09:32:35 192.168.2.130 lte,async lte1: rcvd +COPS: (1,“31198”,7),(0,“302131”,7),(0-4),(0-2)
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: sent AT%MEAS=“7”
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd CQI: 8
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: sent AT%MEAS=“8”
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd Signal Quality: RSRP = -89, RSRQ = -6, SINR = 24, RSSI = -75
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: sent AT%PCONI
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd duplexing mode: TDD
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd Transmission mode: Open loop MIMO
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd Bandwidth: 2
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd EARFCN: 44360
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd Global Cell ID: 040B8F06
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd Physical Cell ID: 52
Nov 28 09:32:35 192.168.2.130 lte,async,raw lte1: rcvd HNBN: N/A
Now the unit can see our network, but it is not attempting to register or connect at all
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: sent AT%MEAS=“8”
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd Signal Quality: RSRP = -91, RSRQ = -7, SINR = 25, RSSI = -73
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: sent AT%PCONI
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd duplexing mode: TDD
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd Transmission mode: Open loop MIMO
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd Bandwidth: 2
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd EARFCN: 44360
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd Global Cell ID: 040B8F06
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd Physical Cell ID: 52
Nov 28 09:36:30 192.168.2.130 lte,async,raw lte1: rcvd HNBN: \0x18d\0xae*
It seems to me like the Mikrotik and the LTE card are not on the same page, or when a registration failure happens it just gives up all hope.

rushpro · November 28, 2019, 6:57pm

Forgot to mention, thanks for the write up SiB, very useful! I was unaware of the passthrough mode.

SiB · November 28, 2019, 10:37pm

Thanks for that.

I understand that next reboot fix a problem as always? Please confirm.
Please check and report a MAC Address of your LTE1 device and it’s always are the same or change every reboot / reenable lte1 interface / repower-usb ?
You see the lte1 interface but without connection by R=running status of lte1 interface? Or you see the R but no IP from ISP? Please give this info.
You are sure that you have a latest of lte modem firmware ? Please be sure of this.
You have a full functionality of modem and your ISP is registred as registration/login into ISP?

I try to add some light to this log’s but I’m not expert of them.

scan without any operator

rcvd EARFCN: 43715

Please check this value at https://www.cellmapper.net/arfcn?net=LTE&ARFCN=43715&MCC=0
decoding this “43715” = TDD Band 43 and 3612.5 MHz is a start freq of your ISP

rcvd Bandwidth: 5

width of band is 5Mhz means from 3612.5 to 3617.5
This is a theoretical speed too, http://anisimoff.org/eng/lte_throughput_calculator.html give me a table

rcvd Global Cell ID: 006F4101

006F4101 hex = 7291137 decimal by https://www.rapidtables.com/convert/number/hex-to-decimal.html
This 7291137(d) give information about YOUR Tower Antenna to what you are connecting. It’s your target in LTE.

In LTE we have got formula that:
eNBID * 256 + CLID = E-CID = 7291137 decimal
a) Number eNBID is a identificator of ISP at tower. Multiple it by 256.
28481 * 256 + 1 = 7291137 (check this https://www.cellmapper.net/enbid?net=LTE&cellid=7291137 )
b) CLID it’s a number of antena and counting start from 0 by step +1. 0 it’s a first antena of your ISP and he can have few of them on different Band’s, 3 x sectors of one Band and 4x sectors of other Band .
c) Final Cell ID = e-CID is your ISP ID *256 = 7291136 + CLID=0 for first sector antenna

You should check your goverment webpage about “spectrum allocation of bands”.
I in Poland have the UKE.gov.pl and deep in website are PDF with this sllocation of bands by all ISP in my country, I add the width of band 3 = 1800Mhz.

rcvd Physical Cell ID: 1

This is truly a physical antenna ID at tower and this number can be see at many ISP who share the same physical antenna.

All this I write because you can now understand more about your ISP and CellID etc.

Please do a this command next time:
[admin@MikroTik] > interface lte at-chat lte1 input=“AT*Cell=2,3,43715,1”
where earfcn = 43715 = B43 TDD starting from 3612.5 MHz
where phy-cellid = 1

scan with operator detected

rcvd EARFCN: 44360 → TDD B43 starting from 3677 MHz
rcvd Bandwidth: 2 → 2Mhz means slower
rcvd Global Cell ID: 040B8F06 → hex to dec = 67866374 and eNBID is 265103 (THIS IS OTHER TOWER!)
rcvd Physical Cell ID: 52

You can select this antenna to lock at it
[admin@MikroTik] > interface lte at-chat lte1 input=“AT*Cell=2,3,44360,52”

Please do a scanning your area via (Band + earfcn + phy-cellid) by
[admin@MikroTik] > interface lte cell-monitor 0 duration=10s
you should grab results like, example form wiki mikrotik because my R11e-LTE6 not give me a EARFCN and this scan is useless for me.

[admin@MikroTik] > interface lte cell-monitor lte1
PHY-CELLID BAND                                  EARFCN                                          RSRP         RSRQ          RSSI
        11 B3                                    1300                                         -107dBm       -175dB
       306 B1                                    150                                          -115dBm       -195dB
       373 B3                                    1300                                         -111dBm       -195dB
       374 B3                                    1300                                         -111dBm       -195dB
       384 B1                                    150                                          -106dBm       -120dB
       384 B7                                    2850                                         -115dBm       -175dB
       384 B20                                   6300                                          -97dBm       -195dB

rcvd HNBN: N/A

I haven’t idea

rcvd HNBN: \0x18d\0xae*

HNBN: \397\174* → by converting hex>dec
google not give me any clue for “lte hnbn”
Maybe it’s stg like “Home (e)NodeB DF” and HNB Name indication. I think it’s not important.

It seems to me like the MikroTik and the LTE card are not on the same page, or when a registration failure happens it just gives up all hope.

You should try scan your area towers and try connection to particular antenna, maybe you discover that your ISP at some tower give you internet every time and on some not every time, maybe.
Final step is create a support file and send it to support@mikrotik.com and in e-mail you can give URL to this post.

Good Luck !

rushpro · November 29, 2019, 4:44pm

Hello SiB
Thanks again for all the information!

Yes, a Reboot or toggling of the LTE interface does solve the problem. The “R” indicator does disappear while it is stuck in the Registration Denied State, so worst case I can quickly write a reset script based on that.

We are our own operator as we own the Baicell LTE basestation we are connecting to. Here in Canada, we get access to the band 43 as long as we register our equipment.
We currently have it set to EARFCN: 44360 or 3677Mhz with a 5 Mhz channel width (Although the AP is now operating at a 10Mhz channel width as of yesterday as we brought some old Ubiquiti M365 gear offline and freed up some spectrum)

The EARFCN: 43715 is a competitor, however we were also getting this same issue with another Baicell basestation that doesn’t have any other providers near by (well as far as I can tell)

I also wasn’t aware it was possible to lock frequency on the Mikrotik’s. It would be nice if this was a sub menu on the LTE interface. I am going to lock it down and see if it helps

Here is where it gets really strange. At this time, it isn’t possible to scan with both cell-monitor and scan
[admin@LTE Test Radio] > interface lte cell-monitor 0 duration=10s
failure: cell-monitor not supported!

[admin@LTE Test Radio] /interface lte> scan 0
Flags: C - current, A - available, F - forbidden
OPERATOR MCC-MNC ACCESS-TECHNOLOGY RSSI RSRP RSRQ
– [Q quit|D dump|C-z pause]

Log File During Scan:
Nov 29 09:34:22 192.168.2.130 lte,async lte1: sent AT+COPS=?
Nov 29 09:34:22 192.168.2.130 lte,async lte1: rcvd +CME ERROR: PLMN busy
Nov 29 09:34:23 192.168.2.130 lte,async lte1: sent AT+COPS=?
Nov 29 09:34:23 192.168.2.130 lte,async lte1: rcvd +CME ERROR: PLMN busy
Nov 29 09:34:24 192.168.2.130 lte,async lte1: sent AT+COPS=?
Nov 29 09:34:24 192.168.2.130 lte,async lte1: rcvd +CME ERROR: PLMN busy
As a test, I turned on the Band 7 which is the same band my phone is running on (yet another provider) and it still can’t scan that either.

Considering the fact that it can both connect to our basestation and get stuck attempting to connect to a different provider yet not scan any of them, something is not working properly.

EDIT:
And it looks like I can’t lock it down even if I wanted to…
[admin@LTE Test Radio] > interface lte at-chat lte1 input=“AT*Cell=2,3,44360,52”
output: +CME ERROR: operation not supported

ksthree · November 29, 2019, 6:58pm

When my units go dow,n I get a log entry that reads LTE Unregistred State 0 or LTE Unregistred State 11. And yes, that is how the log depicts Unregistred. I have been trying to find a list of the State codes and what they mean, as I finally have the radios semi stable, but if I knew what they state code meant it would lead me to my path of enlightedment.

I do have the following running as a scheduled script every 2:30minutes

/interface lte info lte1 once do={
:log info "RSRP:= $"rsrp" RSRQ:= $"rsrq" SINR:= $"sinr""}

And the following running every 5:00 minutes

:local i 0; {:do {:set i ($i + 1)} while (($i < 2) && ([/ping 8.8.8.8 interval=1 count=1]=0))};
        :if ($i=2) do={:log warning "LTE Lost"; 
/interface lte at-chat lte1 input="AT+reset";
:log info "Script Reset LTE1"}

mkx · November 29, 2019, 8:16pm

EARFCN actually defines centre frequency of LTE carrier. So in example above (EARFCN 43715 and 5MHz bandwidth the used frequency band is between 3610 MHz and 3615 MHz.

Both fields (eNbID and CID) are fully operator configurable and there are no constraints other than that eNbID must be unique inside MNO and that CID is unique within single eNodeB. Meaning that CID can be whatever and doesn’t have to start from 0 (however that seems to be customary).

PCI has nothing to do with physical antenna (unless it’s beam-forming antenna it is truly passive piece of equipment). This acronym is indeed stands for what you wrote. However its significance is in “quick and dirty” identification of a cell mainly for mobility reasons when decoding of full cell info (eCI is broadcast and takes time and energy to decode) is not feasible (nor needed). It is used to distinguish different cells operating with same EARFCN (could be different operator on border of network, e.g. near country borders) - for performing a handover station has to report PCI of non-serving cells to the serving eNodeB and that’s usually enough. PCI can be between 0 and 511, which in dense network might not suffice … if different celks with same PCI overlap, then mobility in that area might be problematic. If same antenna transmits several LTE cells on different EARFCNs, then those different cells may be configured with same PCI (makes PCI planning easier).

SiB · November 29, 2019, 11:38pm

@ksthree: “reads LTE Unregistred State 0 or LTE Unregistred State 11”

Q: This “Registration Denied State” it’s a message in this place?
LTE Unregistred State 0 or LTE Unregistred State 11

[admin@LTE Test Radio] > interface lte info 0 once
pin-status: ok
registration-status: registered <— here ?
functionality: full
.

interface lte cell-monitor 0 duration=10s
failure: cell-monitor not supported!

But this is response when the modem have not a FULL Functionality.

[admin@LTE Test Radio] > interface lte info 0 once
pin-status: ok
registration-status: registered
functionality: full <— here ?

We are our own operator

WOW, Then you know more then me. You can reach a log’s from opposite devices “LTE basestation” ?

I also wasn’t aware it was possible to lock frequency on the Mikrotik’s. It would be nice if this was a sub menu on the LTE interface. I am going to lock it down and see if it helps

I just read all book’s at MikroTik, do certification from MikroTik, read a wiki when I configure stg. new and before I helps few persons with scripting to LTE devices and I buy SXTR with R11e-LTE6 to check this device. My primary WAN’s are two E3372 with custom firmware connected by USB HUB and I use both ISP at the same time. SXTR have a good antenna and works 4days for now.

Lock to CellID is write at wiki>LTE but you know, MikroTik have got many settings only inside CLI and only the most common are in WinBox. Thats way you must read mtk wiki !.

Here is where it gets really strange. At this time, it isn’t possible to scan with both cell-monitor and scan

I understand that in problem situation, the LTE logs are not give you any logs with “crashing modem” etc. and you see the new log LTE entry when you do scan/cell-monitor ?
That it’s a problem in hardware or firmware of modem. It’s like you write before… modem hangs and not work anymore until you reset power/reboot/re-enable interface etc… but he never register into network by himself.
You are sure that you use a latest firmware? You not answer me and I ask again. My result of CLI:
interface lte firmware-upgrade lte1
installed: R11e-LTE6_V020
latest: R11e-LTE6_V020

First the modem have got what a functionality, if not FULL then you must try register manual by AT command.
Second, you should register in your ISP and APN etc. are not important here.

Please disable lte1.
log print file=lte-startup.txt follow-only where topics~“lte”
enable lte1
CTRL+C
This way you record all AT command what are used in normal operating modem and you can compare to this bad ones or repeat them when problem happens.

And it looks like I can’t lock it down even if I wanted to

https://wiki.mikrotik.com/wiki/Manual:Interface/LTE#Using_Cell_lock
“It is possible to lock R11e-LTE International version modem and R11e-4G equipped devices to exact LTE tower.”
What you have a modem? R11e-LTE-US? You not provide me a full a “lte info” message.
At wiki you have example for R11e-4G who have differ syntax and works only one time, until device will be disabled/rebooted. Proper syntax can be added to “modem-init” who is like autostart :).

I hope I give some new information.
Please upgrade modem firmware, record logs from proper start of lte1, contact with support@mikrotik.com (now they use a new Request Ticket “Atlassian JIRA Service Desk” with a GUI at URL: https://help.mikrotik.com/servicedesk

Good Luck!

SiB · November 30, 2019, 7:46am

One more debug stuff…
Get R11e-(YourVersion) into USB adapter, outsite RouterBoard, and when problem happend then use WireShark USB…

But this is hard way and just insted you should use warranty, other modem mPCIe like my favourite EP06-E but now I use sxtr with r11e-lte6 and i must do cellid lock to reach stability data transfer.

You both do you do a support rif and send it to support@mikrotik.com ?