Lte stability and band

[lampra]

I have connection to a tower 9.4 km away. I use a mimo antenna with 15dBi gain to connect either using gsm or lte (B20 @ 800).
When the queqtel ec20 is in gsm mode, the connection is rather stable but almost unusable due to very low speed. When in Lte mode the connection is unstable but if there is a constant transfer (at least 1 ping every 6 seconds with ssh remote execute from a second connection) then the connection is stable and very fast.
I am wondering if an antenna with higher gain eg 21 dBi would stabilize the connection (eg this one) or if I should leave it as is and automate my pings!!
Any suggestion?

`Lte signal:
root@turris:~# qq --nas-get-signal-info
[/dev/cdc-wdm0] Successfully got signal info

RSSI: '-46 dBm'
RSRQ: '-12 dB'
RSRP: '-74 dBm'
SNR: '0.8 dB'`

[lampra]

So nevermind, I managed to solve the stability issue.
Today I saw that the modem was unstable and looking at the output of
root@turris:~# qmicli -d /dev/cdc-wdm0 --nas-get-cell-location-info
I realized that I was connected to a cell serving other than B20 lte band.
After some trial and error i managed to lock the modem to B20 lte band and it is now stable. Here is what I used for the EC20 modem

#Stop the connection
ifdown Lte

#conect to modem through serial
socat - /dev/ttyUSB2,crnl

#Get the original BANDS
AT+QCFG="band"
+QCFG: "band",0xdf,0x800d5,0x3f

#Lock to B20
AT+COPS=0
AT+QCFG="band",0,80000,0,1

#Get the new BANDS
AT+QCFG="band"
+QCFG: "band",0xdf,0x80000,0x3f

#Start the connection
Ifup Lte