Signal Attenuation with Distance

Inverse Square Law

Radio waves, including Wi-Fi signals, spread out in a spherical pattern from their source. The inverse square law states that the intensity of a signal decreases with the square of the distance from the source. This means if you double the distance from your router, the signal strength will be reduced to one-fourth of its original intensity.

Signal Obstacles

Various materials can interfere with Wi-Fi signals, absorbing or reflecting them. Common household items like walls (especially concrete or brick), large metal objects (like refrigerators or filing cabinets), mirrors, and even water (like in fish tanks) can significantly weaken the signal. The more obstacles between your device and the router, the more the signal will degrade.

Environmental Interference

Other electronic devices operating on similar radio frequencies can also cause interference. Devices such as microwaves, Bluetooth devices, cordless phones, and even neighboring Wi-Fi networks can compete for airwaves, leading to a weaker and less stable connection.

Example:

Imagine a light bulb. When you are close to the bulb, its light is bright and concentrated. As you move further away, the light spreads out and appears dimmer. Wi-Fi signals behave similarly; they lose intensity as they travel further from the router.

Limitations and Edge Cases

The effectiveness of a Wi-Fi signal is also dependent on the router's power output and the sensitivity of your device's Wi-Fi receiver. Some routers are designed for wider coverage than others. Similarly, newer devices with more advanced Wi-Fi antennas might maintain a stronger connection at greater distances than older ones. High-frequency signals, like those used in the 5 GHz band, generally offer faster speeds but have a shorter range and are more easily blocked by obstacles compared to lower-frequency 2.4 GHz signals.