In this video, we are going to discuss about frequency channel assigned to Wireless LAN.
We know that frequency is defined as the number of cycles per second, and we communicate using frequencies and I have discussed various frequency ranges and their applications in one of my other videos.
WLAN operates in two bands, namely 2.4 GHz and 5GHz. These bands also know as ISM band, ISM stands for Industrial- Scientific and Medical. In addition to WLAN these bands are also used in other wireless technologies like cordless phones, Bluetooth devices, near field communication (NFC) devices
So…. What is band? So the band is a range of frequencies - It mean 2.4 band is basically a range for frequencies which start from 2.400 to 2.4835.
This range is further divided into sub-bands, called channels and these channel are allocated to for communications between a WiFi devices like a laptop and the AP.
The first channel starts at 2.401 and ends at 2.423. this makes 22 MHz which means each WiFi signal occupies 22 MHz. The middle of this channel range is called the center frequency and channel is known by its center frequency as well as channel number, like this channel has got number 1.
The second channel starts after a gap of 5MHz, it means the second channel will start from 2.406 and ends at 2.428 and the center frequency will be 2.417 and the channel number would be 2. In the same way, third channel is defined by keeping a 5MHz gap from the previous one and we keep defining the channels. One important point to note is that these channel are overlapping with each other, it means communication taking place in these nearby or adjacent channel will interfere with each other.
But we will reach a channel, like channel 6, where there is no overlap between channel number 1 and channel number 6. It means if in the same BSS, if we use channel number 1 and 6 then there will not any overlap and communication will not be disturbed.
#wirelessbands
#ISMband
#WiFi
23 июл 2024
