The network connected by telecommunications must be connected to the bus (home information box), you are right. Then you can install a wired or wireless route in this place, and the network cable of each room is connected to this route, so that there will be a network on the network cable interface of each room in your home. If you use wireless routing again, you can plug it into the port of any room without worrying about where the signal is bad.
If you can't solve this problem according to the above, there is another way to solve the problem of poor wireless WIFI, that is, buy another repeater and expand the use of this WIFI through wireless expansion. Now all major brands have this kind of equipment, and the price is tens of dollars. The picture above shows you this kind of equipment.