TP-LINK TD-W8151N modem and is it possible to limit Wi-Fi speed?

Question

Computer networks

Good day gentlemen. The question is this: There is a TP-LINK TD-W8151N modem and a speed from a 4/1 provider. The problem is that when someone at home connects to Wi-Fi by phone and starts watching movies online, then it’s impossible to do anything on the computer at all, all the speed goes to the phone. That is, it is impossible to play more than one online game, since the ping immediately increases from 60-70 to 300 and above.
If anyone understands whether it is possible to somehow limit the speed given to the phone via Wi-Fi, let's say to give 1 mb or 0.5 mb to the phone.
Thank you in advance.

Answer 1

In the standard firmware - hardly.
See if you can put openWRT on it, flash and configure it.

Answer 2

A quick google showed that this tplink can't do that. And there are no alternative firmware for it.