Hey everyone, thanks for coming back to Wi Fi fundamentals with location and analytics. This course will help you to muster the air. In the first part of frequencies we have mentioned that the 2.4 gigahertz band is narrow, it is narrow and it is used widely in many products. And there are symptoms. One of them is co channel interference. What is it?
Well imagine that you're in an area where two access points operate in 2.4 gigahertz under the same channel. Let's assume that is channel one. What happens well think of the stations on each access points BSS. They sent the air remember csma ca on Channel One Although the stations on the second IP is not on their BSS, they hear the transmissions and have to wait. So the two access points area have become one which makes airtime much smaller for each station. One co channel interference happens all stations as we know listens to the direction value in a channel area.
When deploying access points to share the same channel, you should have at least a minus 20 dBm or greater of separation to minimize the same channel interference. Plan your channels effectively. Another vet symptom of the 2.4 gigahertz band is a Jessen channel interferes, though not on the same channel. We have to add Access Point each operate under another channel. Let's see with channel one and channel three. adjacent channel interference is one of the worst interferences out there.
Imagine trying to talk in a coffee bar in a table near a rock band who plays the music very loud. Their noise will make your voice garbled and not understood. The same happens when two Wi Fi access point transmit their noise will make frames damage. In return we will have more retransmissions which means a slower data rate. The third symptom is that it is just crowded. 2.4 gigahertz is all over.
Bluetooth microwaves cordless. phones, wireless camera baby monitors, all uses 2.4 gigahertz band and interferences can come from nan 802 11 devices, non Wi Fi devices which would make eventually your signal to noise ratio low. Let's try to recap. Frequency is our highway, the more wider the more capacity it is splitted into roads we call them channels. The way we deliver goods on it is crucial. Is it on a semi trailer at DSS or a racing car and OFDM and last Be aware that the highway roads are not overlapping?
Next part moving to five gigahertz See you there