R11e-LTE6 CA issue

Hardware MikroTik hardware general
1

Hi all,
I’ve bought a new MikroTik LHG kit with the R11e-LTE6 modem preinstalled.
I’ve an issue with the CA: I’m not able to use the carrier aggregation with band 7: for example, I can do b3+b20, but whenever the modem tries b7+b3, the connection is lost. The modem get disconnected from the BTS and a new connection have to start: then the modem tries again the b7+b3, and the connection get lost, and so on…
I can use band 7 without issue, but not with the CA enabled.

Also, I can use the CA b7+b3 using other modems from other vendors on the same cells. Note that I can replicate this issue trying with different BTS.

Does anybody have the same issue?

Thanks.

2

Hi, you should post the “info” feature here when you works at B3 and B7 to see all parameters.
I know that B3+B7 can not works when B7 have ~105 and worse RSRP…

You can enable only band=3,7 to try force that.
You can do Freq or Cell Lock to force B3 be primary or to B7 be primary.
You can do /interface lte at-chat 0 input=“at+eemginfo?” and check if BTS send to you SIB with inter band.

3

Hi, I’ll get back to you with this infos. I know that my signal is bad, I have a good RSSI (between -55 and -60), I’d say a mediocre RSRP (from -90 to -95) but a very bad SINR (~0) and RSRQ (~-14). Of course, I’ve different router with worst data (the LHG is the one with the best RSSI and RSRP) that can connect in CA to that BTS with a speed of 30mbps/50mpbs download/upload.
With the LHG, when I’m connected to only B7 I get this info, when I try the CA it gets disconnected so the ‘info’ command does not return any usefull data (but I’ll get back to you with the actual screen).

Already done this, I only use cell lock and band lock to work with the BTS I’m working on.

I’ll let you know about this soon.

4

Hi, here some data.
Note that I’m using the latest RouterOS beta, theare are no differences in this behaviour. I wanted to test the new updates to see if something was changing.
When I’m connected to the BTS with CA enabled (I’ve removed info like the IMEI):

[admin@Huawei] > interface lte monitor lte1    
           pin-status: ok
  registration-status: registered
        functionality: full
         manufacturer: "MikroTik"
                model: "R11e-LTE6"
             revision: R11e-LTE6_V020
     current-operator: 22288
                  lac: 24372
       current-cellid: 61994765
               enb-id: 242167
            sector-id: 13
           phy-cellid: 143
    access-technology: Evolved 3G (LTE CA2)
       session-uptime: 3s
                 imei: 
                 imsi: 
                 uicc: 
         primary-band: B7@20Mhz earfcn: 3350 phy-cellid: 143
              ca-band: B3@20Mhz earfcn: 1650 phy-cellid: 359
                 rssi: -54dBm
                 rsrp: -91dBm
                 rsrq: -12.5dB
                 sinr: 1dB

After some seconds, the connection is lost and:

[admin@Huawei] > interface lte monitor lte1    
	pin-status: ok
  registration-status: not searching
        functionality: tx and rx rf circuit disabled
         manufacturer: "MikroTik"
                model: "R11e-LTE6"
             revision: R11e-LTE6_V020
       session-uptime: 18s
                 imei: 
                 imsi: 
                 uicc:

This is the output of the command you asked:

[admin@Huawei] > interface lte at-chat 0 input="at+eemginfo\?"
  output: +EEMLTESVC: 546, 2, 136, 24372, 143, 3350, 21350, 7, 20, 45, 242, -3, 2, 10, 0, 1, 0, 65001, 48, 4064677188, 61994765, 255, 0, 3, 46, 47,  17, 19, 65, 5, 108, 0, 0, 0, 0, 0, 0, 0, 13556, 0, 0, 0, 1, 0, 0, 218, 0, 0, 0, 0 +EEMLTEINTRA: 0, 148, 3350, 45, 9

I’ve noticed that I’ve the same issue using CA with band 7 and 20. I can work without issue with B1+B20, for example.

5

First, upgrade the modem firmware to v25, checking is via
/interface lte firmware-upgrade lte1 upgrade=no ;

About 2CA:
primary-band: B7@20Mhz earfcn: 3350 phy-cellid: 143
ca-band: B3@20Mhz earfcn: 1650 phy-cellid: 359

You can do a Freq/Band Lock via /interface lte at-chat lte1 input=“at*cell=1,3,3350” ; ← 3350 is a earfcn from B7, you can try the 1650 to force B3 as primary.

/interface lte at-chat 0 input=“at+eemginfo?”
You results just show some one intra band, and you lost registration… this is like a BUG and that’s why I recommend to do modem firmware upgrade, this is separate of ROS version !.

6

Hi, I have to thank you!

I’ve upgrade the firmware to the latest version, V025, and now I’m able to work with CA without issues. Both with band 7 or band 3 as primary.
Thank you very much!

7

Im facing similar issue but r11e-LTE6 v25 didnt fix it.

I have LHG-LTE6 pointed at cell tower with bands 3 and 20. When first connected it come up with band 3@15Mhz as primary and band 20@5Mhz. Speeds are good. [SNIR/CQI 17db/15] R11e-LTE6_V025

After a while I loose the primary band and it drops to the B20@5Mhz so we loose significant speed.

In this state, if I use cell monitor it shows only band 20. If I reboot or at*reset I get the two bands back again for a short time and cell monitor shows both bands. If I lock it to band 3 it comes up on band 3 only and cell monitor shows only band 3.

Ive emailed support but does anyone have any clues? Its really spoiling what is otherwise an excellent product.

8

example of connecting to B3@20Mhz earfcn: 1650 phy-cellid: 359

I recomend to try FreqLock who lock band and ca B20/7 can be additional band, the Tower and sector can re-connect and give differ speeds.
/interface lte at-chat lte1 input=“at*cell=1,3,1650”

or a CellLock to specific tower with his specific antenna
/interface lte at-chat lte1 input=“at*cell=2,3,1650,359”

Try them !

You can use a Track LTE parameters script what is publish here: http://forum.mikrotik.com/t/sxt-lte-4g-cat6/134468/1