What we have been using in the last 2 years for backhaul is Ubiquiti Litebeam AC Gen 2 for links up to 15km ($50 x 2). Ubiquiti Rocket AC Lite + 31db Dual Polarity 5Ghz dish ($100 x 2) for links up to 30km. (They do work maybe up to 7km further than that, but then there really can not be any other wireless noise in the air, and it will be more difficult to get the connection to be stable.) They are all compatible with each other.
These are great for single networks or networks that are very rural and you can comfortably carry 100Mbps on a network like this.
You can also use the Litebeam on the tower (smaller antennas have a wider coverage area), and the bigger antennas for clients that are further away (the bigger the antenna, the narrower the beam.) Near urban areas it is better to use more expensive sector antennas because it allows you to use more channels and to connect more clients to a high site because the radiation pattern is much cleaner - the radiation pattern from the Litebeam is quite messy so if you can afford to use bigger dishes, always do it - but bigger dishes on the tower means you have to put a lot more radios on the tower.
Here is a good guide for the Ubiquiti equipment: https://help.ubnt.com/hc/en-us/articles/205197750
There are some cheap equipment that works, but it only works if you make very few connections. The best value for money equipment at this point seems to still be Mikrotik and Ubiquiti - both allow you to make connections as good- or better than other equipment that costs 5x - 10x as much.
But just because these ones are the best today does not mean that they will always the the best, that is why I keep testing a lot of equipment. I am trying to generate enough revenue so that I can pay for someone to document in detail all the equipment we test so that everybody can contribute and learn from that.
If there are enough enough people and urban development in an area that there is a case to be made to build a shared backbone that can carry 5 or more different independent networks, and in that case it is recommended to put your efforts together so that you can build licensed frequency backbone on 900Mhz, 3Ghz, or 6Ghz - 40Ghz - for which you need to find specialized brands - and then each link will cost maybe $1000 - $2000 - but if you split the costs, it will be same as the slower backbone - but it will give you reliable 1Gbps+ connection to share, without eating up the limited, cheap, 5Ghz space which you will need to connect from your towers directly to buildings, hotspots and busy areas.
Again, be careful to use what they say as your basis for planning - the figures that they give are for lab conditions - if there is no interference and nobody else using any other equipment in the area where you build this. The real world does not look or work like their lab - soon there will be 2 or 3 other networks - and they might think that they know better and that they don’t have to work with you. (There is a lot of value for all of you if you can help them to see the size of the market, and force them to make their calculations so that they can realize that they can’t do all the work themselves, and then to see that it will actually help them a lot to cooperate with you.) Near urban areas with lots of development, like for example in areas around Cape Town today there are more than 100 different companies putting up equipment - and almost nobody coordinates channel use - so I might put up a link on a channel that works, and tomorrow someone else who doesn’t understand Wi-Fi puts up another link on the same channel, and because his antennas are closer together than my antennas, my antennas can only hear his antennas, and my link stops working - then my monitoring system tells my my connection is down, and then I have to log in and find another channel that works better… and every time I have to do this it takes a lot of time, and during that time people can’t use their connection and they become more and more frustrated. You can set the equipment to automatically change the channels when that happens, but sometimes it still results in down time of minutes to hours… and this almost never works in a busy area. This is why it is super important to understand how antennas work, and to plan your antenna positions very carefully - so that they are in areas where they will be unlikely to see too many other antennas. Like in instead of on a tower or on a roof, rather put it in the middle of a wall, or in a corner between 2 walls, if you can.
They will say that you can get 1Gbps on a 50Mhz channel… but maybe your antennas are a bit too far apart, so you only get 500Mbps, and then maybe there are not any 50Mhz channels available any more at some point in time after you installed the equipment, so you can only get a 20Mhz channel, and only 150Mbps. So you might as well have just installed the much cheaper 150Mbps equipment because you can’t get more than that anyways and you wasted your money to buy more expensive equipment - and you also wasted your time. All the equipment, cheap and expensive, just use the same “road” - the spectrum - but specifically, the frequency band. If that road is congested, then nobody can drive on it, no matter how fancy or expensive their car is.
Licensed frequency is like a private road or lane that nobody else is allowed to drive on except you. It is like a bus or taxi lane in the cities and only the bus or taxi is allowed to drive on that road or lane. Where 5Ghz and 2.4Ghz (the license exempt frequencies) is like the normal road - 2.4Ghz only has 3 lanes, and 5Ghz only has 10 lanes - licensed bands have another 30 or so lanes and you have to pay a yearly license fee so that your regulator can afford to police them for you. Although in Africa you have to police them yourself - but usually it is not a problem because the equipment is so expensive that the people who can afford to buy it will also be able to buy the license. The lanes are like “Channels” - there are more channels, like in 2.4Ghz some equipment shows 13 channels, but the way that the settings work is that it is like you have a truck that takes up 4 lanes… so you can only fit in 3 trucks next to each other in the 13 channels, that is why I say 3 lanes. Different networks can not share these lanes so only cars from one network can drive on a lane at the same time, meaning only network traffic from one network - unless you coordinate with other networks so that you all use the same network and equipment that is compatible with each other and then you separate your networks with just settings.
I think it is important to explain things in a way that anybody can understand it by using images that everybody can see - if we use all the technical terms, then some of the people who really need to understand it just thinks it is too difficult and then they don’t even try, when in fact it is a simple concept that anybody can learn if you give them a chance.