Reposition your router or access point (AP) to avoid obstructions and radio interference. Both reduce the range of Wi-Fi network equipment. Common sources of interference in residences include brick or plaster walls, microwave ovens, and cordless phones. Additionally, consider changing the Wi-Fi channel number on your equipment to avoid interference.
upgrade the antenna on your router or access point. Wi-Fi antennas on most wireless base stations can be removed and replaced with more powerful ones.
add another access point (or router). Large residences typically require no more than two APs, whereas businesses may employ dozens of APs. In a home, this option requires connecting your primary wireless router (access point) to the second one with Ethernet cable; home wireless routers and/or APs don't normally communicate with each other directly.
add a bi-directional Wi-Fi signal amplifier to wireless devices as needed. A Wi-Fi signal amplifier (sometimes called "signal booster") attaches to a router, access point or Wi-Fi client at the place where the antenna connects. Bi-directional antennas amplify the wireless signal in both transmit and receive directions. These should be used as Wi-Fi transmissions are two-way radio communications.
add a Wi-Fi repeater. A wireless repeater is a stand-alone unit positioned within range of a wireless router or access point. Repeaters (sometimes called "range expanders") serve as a two-way relay station for Wi-Fi signals. Clients too far away from the original router or AP can instead associate with the same local wireless network through the repeater.