Hello, everyone!
Today, I will continue to write about WiFi. In this article, I will explain the problems with WiFi.
There are a lot of problems with WiFi technology. I mentioned these problems in the first article on WiFi technology, now I will go into detail about them. The problems are coverage, data transmission rate, and security.
The first two problems are greatly affected by the distance from the WiFi device, obstacles, and whether there are wireless devices operating nearby in the same frequency range.
During the trip, the signal attenuation is in all transmission media (copper or optical cables, or wireless). Particular attenuation is expressed in wireless signal transmission. The signal strength decreases exponentially with the distance from the WiFi device. For example, at 1 m from the device the signal strength is 100 mW (+20 dBm), at 5 m - the signal is 4 mW (+6 dBm), at 10 m - the signal is 1 mW (0 dBm), ... and at 100 m - 0.01 mW (-20 dBm).
Figure 1. Wi-Fi path loss
(https://arstechnica.com/gadgets/2020/04/remote-work-lagging-if-you-cant-plug-it-in-upgrade-to-mesh/)
The main reasons for attenuation of WiFi signal are metal objects, large furniture, walls (especially if they have metal elements), etc. Metal objects or elements fully reflect the WiFi signal. Water completely absorbs the WiFi signal. Other objects introduce attenuation, e. g. window - from 2 to 4 dB, wooden doors - from 3 to 5 dB, wooden furniture from 2 to 15 dB, etc.
Today, there are many devices that operate in the frequency range as well as WiFi devices - at 2.4 GHz and 5 GHz. These devices are microwave ovens, wireless mice, some wireless phones, Bluetooth/ZigBee devices, wireless cameras, drones, motion sensors, your neighbor's network, separate wireless networks in our home, TV, baby monitors, and many other wireless devices. The microwave oven has the highest power - about 800 W, other devices have less power: some cordless phones have about 3 W, cordless cameras - from 0.5 to 1 W, Bluetooth devices about 1 mW, etc. The presence of these devices leads to interference. The problems are the reduction of coverage and data transfer speed.
In the next article, I will continue to explain WiFi >> WiFi (4): MIMO technology
Thank you!
