Recently I faced the problem with 4G connection to be A LOT slower than the actual LTE link capacity can stand. So, many people complained about this on the forum, I've read many threads. Touched by some ridiculous, let's say, malfunction I made some tests with several USB modems and 3 different routers:
3. x86 intel powered router
and two different LTE modems:
1. Alcatel L850V (HiLink)
2. ZTE MF821 (non-HiLink)
and one android phone to compare the results.
First test was made with hAP and it gave the worst results. Not over 25 Mbps in download and not over 28 Mbps in upload.
Here is now the screenshot of speedtest results measured with an android phone over wifi connected to RB951G:
All measurements were made in the same place.
1. The white mark is ZTE MF821 (PPP connection, we can see that it is lightly faster in download but this is not something to pay attention much)
2. The blue one is Alcatel L850V (LTE interface)
3. Orange is phones mobile connection (far away better than with router)
Now, as You can guess, LTE interface will NOT speed up Your 4G connection. PPP 4G can also reach high speeds but in different conditions! This is for all those who think that LTE interface will solve the low speed problem... save Your money.
Here are some tests with x86 router and Alcatel L850V (NO SPEED LOSS):
This was also the highest speed for LTE in the place were it was measured! With x86 router there were no drops, not slower... full link capacity used (for the current LTE signal in the place were it was measured)
I would like to add also that LTE speed on hAP and RB951G was higher for 4-5 Mbps if the WIFI is OFF !
What can be the problem?
Well, in my opinion this is the problem of interference! Turning OFF WIFI can make us think like this, too. This is not the processor problem (at least I think it is not) as the resources show below 45% load. This interference is caused by high frequencies of the LTE signal. It either interfere the board of the router or the USB interface itself.
Possible solutions of the problem:
We can try to use USB extension cable to separate the modem from the router. Better way would be also to use some USB interference filter between the router and modem.
LTE interface with ethernet port.
Since this problem does not exist on x86, I also think that mikrotik devices should be designed better. LTE and mobile internet generally is not a small thing because it is in use more and more. For example, my mobile data plan is 250 GB monthly. I would like to use it on more than one device...