LTE router, external antenna, guest wifi, outdoor

[alfredo]

Hello,
for a volunteer project, I am solving an Internet connectivity problem for a school in a small community of about 30 people located in the Andes. In short, in a larger village that is at a higher altitude on the mountain than the community, there are some 4G cellular network repeaters, but due to the distance and the lay of the land, the signal cannot reach the school and the village square where coverage is limited to 3G. Unfortunately, this connection is too slow, we are talking about less than 1 Mbit/s in both upload-download directions and is therefore insufficient even for opening a web page, only communication applications such as Telegram "work". Moving up a hill about 1.5 km as the crow flies from the village, there is a 4G signal from various telephone operators and speeds in the order of 10 Mbit/s in both upload-download directions can be achieved, which would be sufficient for almost all the activities of the school and the village. Moving to another area at the same altitude as the village, but free of obstacles (trees, houses, etc.) about 800 m as the crow flies from the village, speeds in the order of 5 Mbit/s in both upload-download directions can be achieved.
To solve the problem, I came up with two solutions:

1. Buy 1-2 4G routers and install 1-2 antennas on a mast.
2. Buy 1-2 satellite kits.

In the first case I have to choose whether to buy 1-2 omnidirectional or directional antennas and with the help of the locals install them on top of a mast at least 10 metres high, preferably 20 metres so as to reduce the height difference between the repeaters and the receiving antenna. In the second case, I have seen several companies offering ready-made solutions complete with everything.
In addition, the first solution requires a higher initial investment for the purchase of the devices and installation, but is more flexible as it allows you to vary the subscription and the telephone operator, and to obtain higher performance (transmission speed and delays), especially in the event of possible future expansion of the 4G cellular network. The second solution is initially cheaper and easier to implement, but more expensive and less flexible in the long run as you are tied to an operator and generally provides lower performance and more limited traffic for the same cost (I need to look into this part for starlink, but I don't think it works wonders).
Besides the two scenarios above, do you have any others in mind? If it were possible, I would like to use a 4G router compatible with openWRT both because it is a free operating system and because it guarantees greater longevity. I think an outdoor router is preferable to avoid long cabling, but I also have to weigh up the cost against an indoor solution. In addition, the router must have the ability to control and limit the transmission speed in the 2 open and reserved WiFi networks that will be created to avoid congestion problems by a few users (probably the best solution is to use a guest wifi, I have not yet checked if there is an option in the GUI or if some light app like is needed).

I've never faced a problem like this before, so I'm asking you for advice on various models of routers and antennas. I have already done some research, but only found commercial products of more or less well-known brands.
Thank you very much in advance also on behalf of the community.

P.S. I have already read this thread and created a comparison table with the models listed. I will later add the others that you point out to me.

[mk24]

I lean toward the LTE approach, as satellite tends to be more expensive and satellite networks always get over-sold and slow down, while the capacity of terrestrial LTE is expanding.

The project can be divided into four parts. Each one is likely going to be a separate piece of equipment.

1. Receiving the LTE service
2. Link from the LTE receiver site to the village
3. Central router, with bandwidth control
4. User access via WiFi

For the LTE link, a unitized device with integral directional antenna intended for outdoor use would be better than cobbling together something with separate antennas and an indoor router mounted in some sort of weatherproof box. The NR7101 is nice but it is Europe bands and has become expensive as the supply of used ones left by a defunct service operator has been used up. I use the Mikrotik LHG-R-LTE6 it suits my usage but I'm not saying it is the best thing out there. It is not expensive and doesn't use a lot of DC power, but it is not (yet) OpenWrt and the dish has basically nil gain on the sub 1 GHz bands, which is the physics of a dish that size. They also make the LDF-LTE to retrofit to any old satellite dish. This will require some fabrication since the mount of a typical satellite dish is not made to aim the beam to zero elevation needed for terrestrial links.

For part 2 I would use 5 GHz CPE equipment. The link distance of 1.5 km is well suited for that if the path is not obstructed. If there is unavoidable multiple obstructions you could consider fiber optic cable.

Part 3 is where OpenWrt shines as you can do things like multiple networks with limited bandwidth. LTE speeds don't require particularly high performance hardware. MT7621 would be sufficient.

And for part 4 you're very likely going to use a mesh as this is a good way to distribute around a small village. This would likely be indoor routers running OpenWrt placed inside houses.

[alfredo]

Hello,
first of all thank you very much for your reply. Actually your idea is very good even if it requires more devices.
To see if I got it right, we could get a 4G LHG LTE6 kit or LHGG LTE6 kit modem (supports gigabit ethernet although with 4G connection it doesn't saturate fast ethernet, but it's future-ready. Will it support openWRT?) combined with LHG 2 (supports openWRT) or LHG XL 2 (might support it) to reach the centre of the country. Do you recommend 5 GHz because it allows better transmission speeds? For example, the LHG XL 5 ac model supports WiFi 5 up to 867 Mbit/s. Do I need 2 of these devices one on the 4G modem side and one on the router side in the centre of the village?
After from the village centre a simple router with SoC MT7621 you recommended with openWRT, band control and dual WiFi like GL-MT1300 or maybe I have an old BT HomeHub 5 router or if you have any suggestions. Finally, what about routers/access points for mesh networking?
Thanks again.