Huawei B310 Router: External Antenna Options, Comparing to B618, Improving LTE & WiFi Signals

Hello,
I have a subscription at Play with a home internet and for this I received the Huawei B310 router.
I wanted to choose a better one but the lady in the living room insisted that this one is enough because she is very good ... of course she is not.
As I was able to set it in a place where it catches the LTE signal, wifi does not break through to the second floor
In addition, LTE also works ok once, then jumps and sometimes disconnects.

I am thinking about two options:
1. I leave this router and buy an external dual antenna - here a request for help in matching the appropriate antenna. I have already looked around and they differ in parameters and I do not know what would be the best.
2. I will try to replace this router with a better one - B618. If it works, I will either leave it alone or buy an external antenna - here too a request for help in choosing.

I don't have any high speed requirements. I am aware that it will be difficult to find super speed in my area. Earlier I had a highway and it was barely 2.5 MB
Now, as I tested, LTE with B310 is different - depending on the time of day: 2MB / 4MB / 6MB / 16MB

My town is Wisłowiec near Zamość.

I am asking for advice on which antenna to choose and which solution would be better.
Thanks!

A subscription to Play with B310 is a serious mistake. First of all, in the subscription service for 59.90 PLN / month there is 100GB and immediately a funnel 1Mb / s. In Play for LTE without a subscription and equipment you can have a minimum of 100GB for a possible 2Mb / s funnel for 5/15 PLN per month and a B310 / B315 router to buy yourself for 250 PLN. B310 in subscription is for 1 PLN + 24x10 PLN = 240 PLN. (the difference between subscription 59.99 with equipment and 49.99 is the same without equipment). Router without LTE-A. But this is nothing compared to the operator's choice because this is just a mistake. Ms. Play should not sell the internet service at all for this location at all because the town lies on the border of LTE900 range with BTS Play at Okrzeja 32 in Zamość. Weak offer, equipment too, operator without coverage, it looks like this, total resignation is the basis. This is a cruise area where T-mobile or Orange are used, which each will have their LTE800 in Wierzba. Unlimited T-mobile offer for PLN 49.59 per month with B525 for PLN 49 is optimal.

Yes, as I have already started reading the forums in this topic, I already know it ...
I always check everything and now we rushed everything and failure along the whole line.
Unfortunately, I cannot unscrew the subscription and I cannot replace the router - subscription wifi house + 3 numbers for two years.
At the moment I can't buy a better router and I need to improve it temporarily.

Is buying an antenna for this modem anything pomorze help ?
If I chose the Internet in Orange or Tmobile, will their card work in this B310 model and will it have better performance, or should I immediately take it with another router?

The idea for Play in such a location is a failure, practically no voice coverage on the Play home network, coverage only in domestic roaming, e.g. Orange on 2G./3G/LTE with BTS NetWorks Wierzba on GSM900 / UMTS900 and LTE800. In this offer only voice cards have access to national roaming and with DL / UL 3 / 1Mb / s. The internet card works only on the Play home network and is practically useless in this location unless you improve the range. It is not the router that is the problem but the Play range Check if it works with LTEwatchH http://www.lte-anbieter.info/ltewatch/count_huawei.php?Datei=ltewatch_h or http://www.mediafire.com/file/1yz26m6u8gfl16n/E5186_Toolbox_latest_v0.9.zip Log in to them on B310 and show BTS signal and CID parameters. They allow you to force specific LTE bands. You force LTE800 and LTE1800 and LTE2100 in turn. You show the DATA tab, home and outdoor test. For this speed test. The LTE800 has the widest range but it is only 5MHz in MIMO2x2 and DL band up to 37.5Mbps. On LTE1800 twice as much but range smaller. The purchase of an external antenna depends on the tests.

It was only in the evening that I could take care of it - I send screenshots of info:


Added after 2 [minutes]:

And here are screenshots from the phone - where I did not have wifi to test on a desktop computer:

And we have a surprise. at home, better signal parameters on all LTE bands, the B4310 does not show CID BTS, so it is difficult to say which connection. Generally, as if some BTS was from the north but it is not on the maps. Speeds are still weak DL

I was also surprised that the results were worse outside.
Maybe it is the fault of frost and wind?
So there is hope that something can be learned from it?

We will see outside there was a weak signal on LTE1800 and LTE2100 from Zamosc. Better at home but the lack of CID does not allow BTS to be identified. This is puzzling on the phone with LTE1800 coverage, at -99dBm. Play is now launching new BTSs and it is possible that one has appeared somewhere in the area. I verify it.

The second BTS is a chimney on Hrubieszowska, all LTE bands in Play operate on it. Such signal parameters on LTE1800 with over 10 km is a big surprise.

Fortunately, you can see Hrubieszowska from my home in a straight line without any obstacles. There are only meadows, no forests or hills. Chimneys are also very well visible. In the evenings the speed is ok but slightly jumps and can hang up for a moment. During the day, unfortunately, the signal weakens. Is there a chance that if I buy a directional antenna then this signal will get stronger and won't jump like that?

Of course, this is done with an antenna that stabilizes the connection. You set the area code to a specific BTS. You have visibility with BTS and the area is favorable from here.

Cool!
Do I have any specific parameters to choose? Because I saw that they differ, e.g. in the size of dBi ... does it affect anything?
I found such, for example: Dualna LTE / 4G 15dBi MIMO for Huawei B315, B310. Is it better to buy some that has more of these dBi?

Checked on LTE1800, LTE2100 is http://www.cybertech.com.pl/p140,antena-dualna-lte-4g-15dbi-mimo-do-huawei-b315-b310.html, cable as short as possible, max 10m. A newer version for the 1800-2600 band is http://www.cybertech.com.pl/p173,antena-dualna-lte-a-4g-17dbi-mimo-1800-2600mhz.html, cable as above and SMA connector on the cable .

I come back after tests.
I bought this 1800-2600 antenna and I already installed it so that it catches the signal from BTS on the chimney in Zamość. So far, everything is going well I set it to 2600 because in the tests it reaches the highest speeds but it has a higher ping and I don't know if it is better to set a different frequency - does it bother?
Thank you for your patience and help!
2 years subscription I would not forgive myself, as if it worked as at the beginning: /
I send today's screenshots: