Many people in third world countries suffer from infrequent wireless networks, so regardless of the size of the residence, expanding the wireless network is important. The reasons may vary (concrete walls, interferences, many “curves,” mirrors, glass or even the physical size of the space), but the complaint, after all, is the same.
There is no shortage of repeaters and new Wi-Fi kits in the market that are made up of two, three or more units already designed to be scattered around the house, precisely to avoid the weak signal problem at some points. But the idea here is to focus on a very common scenario: people who have, for example, more than one AirPort Time Capsule/Extreme or even a set consisting of an AirPort Time Capsule/Extreme and an AirPort Express.
Many people make the mistake of expanding the wireless network by opting to expand the Wi-Fi signal. The problem is that by positioning one router in the room and the other in a room, for example, connected wirelessly (without a cable) it is quite possible that the second unit amplifies a signal that is already quite weak. This way, you do not solve the problem because the signal will continue to be bad. The best option, in this case, is to do what Apple calls the roaming network.
How to Create a Roaming Network
The key to this is to connect the AirPort units with an Ethernet cable. Many times this isn’t possible because you did not predict this scenario and did not pass the cable through the wall and simply do not have a network point in the room (using the scenario described above). But that makes all the difference, believe me. It is worth striving to have this cable physically linking the two routers.
Remember that expanding the reach of your Wi-Fi network by connecting the Wi-Fi base stations together (using Ethernet) is always the best option and will provide the best transfer rates. The Ethernet connection offers much faster rates than wireless and is immune to radio frequency interference. Also, you can consider ECS as it provides swift communication and data sharing.
Only then did I solve the connectivity problems here at home, putting an AirPort Time Capsule in the room (primary station) and an AirPort Express in the room.