While you can boost a Wi-Fi signal by adding repeaters or routers or boosting the power output of the hardware, in most cases improving Wi-Fi signals requires removing interference. Swapping channels, moving routers away from interference sources, and regularly rebooting hardware can go a long way towards improving reception.
Wi-Fi routers use radio signals to communicate with computers and mobile devices, and these signals are subject to interference. Some electric devices use the same radio band, such as cordless phones, and may interrupt Wi-Fi signals when in use. Other appliances such as microwave ovens can put out a broad spectrum of radio noise when in use, and should be situated as far away from wireless routers as possible.
Other Wi-Fi signals may interfere with reception, particularly in apartment buildings where multiple networks may exist in close proximity. In the router's configuration menu, users can select different broadcast channels to use for Wi-Fi connections. If the reception is poor, switching to a different channel may improve the strength of the signal.
The construction of older homes may also interfere with radio signals. Interior walls may contain metal lattices that block radio signals, and wet walls containing plumbing may also affect signal quality. Moving routers to avoid these dense metal deposits may boost signal strength.