Like most people who cannot get wi-fi internet unless they sit next to the modem, you have probably purchased devices that boost or extend the wi-fi range into other rooms. And like most people you wish you had not wasted your money.
There are hundreds of “Wi-Fi Range extenders“, “Wi-Fi boosters“, “POE (Power over Ethernet)” devices available at your local electrical retailer and although many do help, they do not provide a complete solution that provides full-strength, secure, multi-user, wi-fi access over a wide area (including outdoors)
A properly configured WAP (Wireless-Access-Point) network provides seamless Wi-Fi access throughout buildings large or small by automatically switching to the WAP with the strongest signal, no need to keep manually switching between different wi-fi networks as you move from room to room. Some people try to get around this by configuring the extenders/boosters with the same name (SSID). This works as long as the signal from the modem and the extender do not overlap, if they do, network conflicts can occur and you can do more harm than good.
The following articles show how: