In theory, Wi-Fi signals are capable of passing through walls and other obstacles relatively easily. However, in reality, some walls are thicker or use reinforced concrete and may block some of the signals. Materials such as drywall, plywood, other kinds of wood and glass can be easily penetrated by wireless signals.
Wi-Fi signals will usually reach about 150 feet or over 45 meters for a 2.4Ghz frequency. Using a 5Ghz frequency, you will get about 50 feet or about 15 meters of reach.
Having to go through physical objects can weaken Wi-Fi signals, which means walls can affect Wi-Fi. A common cause of reduced Wi-Fi performance is dense walls and furniture in between routers and wireless devices.
Concrete, with and without metal reinforcement, is one of the worst building materials for wireless signals to pass through, but masonry block and bricks can also be serious barriers for Wi-Fi. Plywood and drywall come close to zero signal loss in tests.
If you do have a properly designed electrical circuit in your house, then connecting two powerline adapters, one near the router and the other next to your access point (yes, the same concept as at the number 2 in this list), will indeed deliver a good wireless performance past a few thick walls.
Jeremy comments that while there is currently no scientific evidence to suggest that it is harmful to sleep with your Wi-Fi on, some experts recommend turning it off at night to reduce exposure to the low levels of electromagnetic radiation emitted by WiFi routers.
Reach longer distances - 2.4 GHz offers a longer reach and can easily cover larger areas. Universally compatible - Almost all Wifi devices are compatible with 2.4 GHz. Easily pass through walls - This frequency can penetrate through walls and other surfaces easily.
If you're getting slow or delayed WiFi in your home, it could be because your neighbors are using the same channel as you. While you're not on the same network, those other devices can still interfere with yours.
To get the best signal, put your router in a central, elevated location away from concrete/brick walls, electronics, water and microwaves. These days, getting a strong Wi-Fi signal throughout your home at any given moment is expected, yet not always guaranteed.
Routers tend to spread signal downward, so it's best to mount the router as high as possible to maximize coverage. Try placing it high on a bookshelf or mounting it on the wall in an inconspicuous place.
Physical obstructions such as walls, doors and even furniture can cause WiFi interference. Materials such as concrete, metal and plaster can significantly reduce the range of WiFi signals. The solution is to strategically place routers in areas where they can provide optimal coverage.
While EMF emissions from different routers vary, for most home WiFi routers, a distance of 40 feet (ideally, or 10 feet at a minimum) will help your body and shouldn't impact your WiFi connection too much.
Move the router or other access point high up and in front of any obstacles. Preferably high up on the wall. Place your devices and access points with as much of a clear line of sight between them as possible.
Put simply, walls are just as transparent to WiFi signals as glass windows are to visible light, which is why WiFi signals can easily pass through most walls and ensure you stay connected!
Re-locating your router to a more central location in your home. Updating your router firmware to the latest version. Switching between the two WiFi frequency bands (2.4 GHz is ideal for coverage; 5 GHz is ideal for speed) Choosing a better WiFi channel (Here's a guide on how to find the best WiFi channel)
Wi-Fi uses radio waves to transmit information between your device and a router via frequencies. Two radio-wave frequencies can be used, depending on the amount of data being sent: 2.4 gigahertz and 5 gigahertz. What does that mean, though?
With proper line of sight, you can extend your WiFi signal outside of your building to another using a wireless bridge . A wireless bridge uses a microwave or infrared transmission to span a single Internet connection across two or more buildings.
Obstacles, like thick walls and distance can affect how well your WiFi signal performs. Sometimes the signal can only reach so far and needs a boost. The likely reason for your poor connection upstairs is that your router is placed too far away in your home or it is blocked by some obstacle.
The “Best” place in the house for a router if you're only worried about signal strength would be a central location with limited obstructing walls. However, the “Safest” place for a router in the home would be to keep it as far away from the places you spend the most time, especially the bedroom.
Considering the Wi-Fi chip consumes so little power, it doesn't really make sense to do this. It's true that turning off Wi-Fi can cause some predictable localised connectivity problems in your house.