How are wireless networks organized in parks?

Question

WiFi

A question from a teapot, but there is almost no information to be found on the Internet. In the past few years, public wireless networks have become increasingly common on the streets. Let me take Moscow Gorky Park as an example. How are these networks organized in practice?
I can guess that in the administration building from the router there is a switch for the Nth number of ports to connect all workstations and organize a local network.
How did you deploy such a large seamless network throughout the territory? The length of the cable for normal operation of Fast Ethernet should not exceed 100m, while there are many points placed over several kilometers? Does each point need to be connected to a switch? It seems to me that using a router or access point in WDS mode or a repeater is inappropriate, since there is a load on one channel.
I know everything I've tried to describe looks pretty silly, but if possible, please describe in detail the construction of such a network. Thank you.

Answer 1

There are three more or less fashionable strategies for deploying large, but not heavily loaded networks:
1. We build a network from many access points. They can be small or large, with brains or not, controlled by a controller or not. The main thing is that each point receives its own copper wire and connects to the main network through it. All top vendors have solutions to such issues, and recently even Huawei wrote a little more on Habré.
2. We make one large antenna, distribute it in some way (wifi in the subway) and connect to its end N the number of broadcast trunks (one, two, ten) in this way, we are distributing the radio path, not transmitting nodes. It is possible to make several such points, but the main pattern is to increase the coverage area of ​​​​one point in order to minimize the negative effects of a lack of channels. These are usually solutions from a highly specialized area of ​​​​tasks, and, most often, are designed for sudden load jumps. It is important to clarify here that we are not making a huge single antenna with a huge radiator, but we are making the area (length, width) of the antenna larger, for example, a long cable is laid in the metro, very well shielded, where small pins come out of it at a great distance - antennas. Formally, the antennas themselves are not large,
3. We build any network of the Mesh structure. When there are one or more edge points connected to the access network and there are access points created only to expand coverage. These solutions are easy to deploy. The problem here is the use of a larger number of channels or a drop in speed in the far sections of the network (in distance from the nearest boundary access point to the network).
To guess (i.e. having just a laptop and a signal from a point) what strategy is possible in a given place - just scan the air. If there are many points with different BSIDs, then either the first or the second strategy. If there are many different busy channels on other frequencies that look like technical lines (for example, like Ross telecom Wi-Fi), then this is the third strategy.
Strategies for building loaded networks are slightly different, but not significantly. Those. they can also be attributed with some stretch to one of the above.

Answer 2

There are many implementation options. From the dead that comes to mind: a backbone wifi network and a network for clients, optics from switching to access points. And the network does not have to be seamless (it is very expensive on such a coverage). Most likely, all points just have the same SSID.

Answer 3

Of the fresh solutions, this is the ubiquity network mesh. It can be implemented like a tlink. We send a passive to the port and send it further on the second port. Optics for data transmission and a wire inside for power. Tons of options