How to organize wifi with different frequencies in a private house?

Question

WiFi

The situation is as follows:
There is a house with two floors.
More precisely, the first floor and basement.
On the first floor (where the provider's cable is pulled), I want to put a router with 4 antennas, at 2.4 GHz, this should be enough to cover the entire floor and the area above.
On the second floor, a cable will already be pulled, where I want to put a second router, but with different antennas (for 2.4 and 5 GHz). Because on the basement floor there will be the main devices for watching videos via the Internet, etc., I would like there to be a frequency of 5 GHz.
Actually the question is the following: can there be such an order for connecting routers - the first router (receiving the Internet) has a frequency of only 2.4 GHz, and the second router is already at frequencies of 2.4 and 5 GHz? Well, and accordingly, so that the second router would have all the frequencies working at the output. I remind you that they will be connected by cable to each other.
Or will you have to take routers with a frequency of 5 GHz both on the first floor and on the basement?
Thanks for answers.

Answer 1

Take dual-band routers, and then resolve them with settings. There will be no problems.
In normal routers, the ranges are independent of each other, you can even assign different grids to them. And you can one and resolve where to connect at the device level (not everyone really knows how to do this).

Answer 2

There is a house with two floors. More precisely, the first floor and basement

On the second floor

Yeah, besides the first and basement, there is also the second. Or did I misunderstand something? Or have you formulated it in such a way that it is impossible to understand otherwise? Be careful.

second router

There should not be a second router, you signed an agreement with your provider for one access channel. Or even two? If two, then a second router is needed. If on one, then instead of the second, put an access point, Access Point, AP.

I would like it to be 5GHz.

I warn you right away that this will greatly reduce the coverage area on this floor, because at 5 GHz, penetration through walls is much worse, and in neighboring rooms the signal level will be much lower.

can there be such an order for connecting routers - the first router (receiving the Internet) has a frequency of only 2.4 GHz, and the second router is already at frequencies of 2.4 and 5 GHz?

Yes, such a choice of channels is possible, but on the 2.4 band, both WiFi devices can interfere with each other. To reduce mutual interference, I would advise you to choose different channels for them, and from such a list - channel 1, or 6, or 13 (that is, the maximum frequency separation). For the 5 GHz band, you can leave the automatic channel selection - there are a lot of them, they won't interfere.

Answer 3

The provider does not care how many routers you have, what they write from above is nonsense. The provider gives the Internet to the first router, and he already distributes it to everyone else. The second and subsequent routers can work both as routers (a separate local network with its own internal IP addresses) and as an access point (one local network with the first router). It is only important that you take into account one point when setting up: two devices in router mode (not an access point, but a router / gateway) cannot be inside the same local network (usually yellow ports). And also: a router cannot have two identical networks on the external WAN (blue) port and internal LAN (yellow) ports. In such cases, you need to manually change the IP addresses of routers and their networks. For example, 192.168.1.1 (the first router) and 192.168.2.1 (the second router). The subnet mask 255.255.255.0 indicates that the last digit is the address space within the network, and the first three digits are the network number. There cannot be two identical network numbers!
Phew, I sort of explained this in detail.
Better make the names of the WiFi network different (passwords can be the same). The only exception where a network can be named the same is when the router supports special mode. For example, a ZyXel router and a ZyXel access point can coordinate with each other and roam seamlessly within their WiFi networks, but this is not certain. MikroTik routers definitely know how to seamless roaming, but it still needs to be tormented to set it up so that it works as it should. Therefore, it’s better not to worry, just name the WiFi networks differently. For example "Floor_0", "Floor_1", "Floor_2".
Where to put the only 5GHz router is up to you. I would put it where they use WiFi more often. 5GHz has less penetration but higher speed.
At the expense of power, there in the settings you can reduce it. It is better to turn off the power on all routers to the minimum possible values ​​at which the final coverage of the zone by all routers suits you. For example, if it doesn’t catch in the far corner near the cat’s toilet, then to hell with it with a cat, it will do without Wi-Fi. The lower the power of the transmitters, the less your routers will interfere with your other devices to transmit data, which means the final speed will be higher. And yes, you may be pleasantly surprised - the number of "wifi sticks" with a transmitter power of all routers of 25% may turn out to be the same as in the case when the power at all is turned up to the maximum! [You can drive 40km/h in first gear and use 30l/100km, or you can shift to 3rd gear and drive the same 40km/h with 10l/100km by slowing down]
And lastly, do not save on yourself, buy normal routers with support for both bands each, it is better to have all the same than a zoo from different companies and models. If you really want to save money, it’s better to buy a Chinese router in China (on Ali) than the same router is 2-3 times more expensive from local outbids. A budget two-band Mi3 router with Ali costs less than an average 2.4 in a local dns.