Wi-Fi Signal and Potential Interferences

Wireless data transmission relies on electromagnetic waves.
Electromagnetic waves are categorized based on their wavelength (e.g., radio waves, visible light, X-rays, gamma rays).
Wi-Fi utilizes radio waves, a specific portion of the electromagnetic spectrum.

A band is a range of frequencies.
- Example: The 2.4 GHz band ranges from 2.4 GHz to approximately 2.482 GHz.
Bands are divided into sub-bands called channels.
Each channel is identified by its central frequency.
The 2.4 GHz band consists of 14 channels; availability varies by country.

Adjacent Channel Interference: Occurs when wireless devices operate on closely spaced channels.
- To minimize, use non-overlapping channels.
- Default non-overlapping channels: 1st, 6th, and 11th.
Co-channel Interference: Occurs when multiple devices use the same channel.
The 2.4 GHz band is congested with:
- Wi-Fi devices.
- Other wireless technologies (Bluetooth, Zigbee, cordless phones).
- Household appliances (microwaves, washing machines).

24 non-overlapping channels.
Offers more flexibility compared to the 2.4 GHz band.
Channel bonding: Channels are combined to increase bandwidth.
Less crowded than the 2.4 GHz band.
Vulnerable to interference from radar systems.
- Examples: Military radars, satellite communication, weather radars.

Radio waves are susceptible to physical phenomena that impact data transmission.
Absorption: Wave energy is absorbed by materials.
- Examples: Thick walls, windows, water-filled aquariums weaken the signal.
Reflection: Certain materials (like metals) cause wave reflection.
- Wi-Fi signal is often poor in elevators due to metal.
Obstruction: When a radio wave encounters an obstacle such as furniture, the Wi-Fi signal can bend around the object, creating a dead zone behind the obstacle.