Nowadays, in the field of information
Communication is everywhere
A universe of stars
Networking devices come in all shapes and sizes
Whether wired or wireless
Behind the scenes lies a mysterious and important rule
It's called network protocol.
Wherever you can communicate without plugging in.
Without plugging in a wire, it's all about wireless protocols.
Mainstream wireless communication protocols
The birth of wireless communication protocols can be traced back to the end of the 19th century, and with the development of radio technology, wireless communication protocols were gradually formed and developed. Wireless communication protocols can be categorized into three types, i.e. long distance, medium distance and short distance. As the name suggests, the difference between the three is the distance covered. Long range is measured in miles, while medium range is measured in tens to hundreds of feet, and short range is usually defined as distances less than 10 feet apart.
Some of the more popular wireless communication protocols are Wi-Fi, Bluetooth, ZigBee, LoRa and MQTT.
Wi-Fi has become a ubiquitous technology in today's world and is the preferred method of Internet access for more and more users, and has gradually replaced wired access. Wi-Fi is now available at home, in the office, in restaurants and even on high speed trains, and has entered the fast lane with Wi-Fi 7.
Wi-Fi 7 enhances WLAN performance in the 2.4 GHz, 5 GHz, and 6 GHz bands to provide higher data throughput and support deterministic latency.
▲Selected Wi-Fi operating bands and transmission rate references
Frequency bands and channels
In Wi-Fi, what do we often refer to as a frequency band (Band)?
A Wi-Fi band refers to a specific frequency range of radio waves that is allocated for wireless communication. Different wireless communication technologies use different frequency bands to avoid interference with each other.
The most common WiFi bands include 2.4GHz and 5GHz.
2.4GHz
The 2.4G operating band ranges from 2400~2483.5MHz, each channel occupies about 20M, dividing 2.4G into 13 channels.
The 2.4G operating band is mainly based on IEEE 802.11b and other technical standards, and the supported modes include 802.11b, 802.11g, 802.11b/g, 802.11b/g/n/ax, with a bandwidth support of 20MH and 40MHz, and the operating band is 2.4GHz.
5GHz
The 5G operating band range is 5150MHz~5825MHz, and the larger band range allows it to have 13 (of which 100~140 channels are not available domestically) non-overlapping channels.
The 5G operating band is mainly based on the IEEE 802.11ac technology standard, and the supported modes include 802.11a, 802.11a/n/ac, 802.11a/n/ac/ax, with bandwidths of 20MHz, 40MHz, 80MHz and 160MHz, and an operating band of 5GHz.
6GHz
If we compare the spectrum to the oxygen of the communications industry, then 6GHz is the “less cultivated and extremely clean” pure oxygen. 6GHz refers to the frequency range of 5925 MHz to 7125 MHz this spectrum, the bandwidth of 1.2G. The higher the frequency, the faster the speed. 6GHz combines the advantages of low-frequency coverage and high-frequency capacity, and can “reject” more interference.
The higher the frequency, the faster the speed. 6GHz combines the advantages of low-frequency coverage and high-frequency capacity, and can “reject” more interference.
We can loosely understand the frequency band as a highway between two places, 2.4 GHz and 5 GHz, 6 GHz is a different road, each has a different working channel. It's like a car on a highway and a subway on an underground track, each with its own characteristics.
The frequency band specifies the frequency range in which the wireless communication system operates. In practice, the transmission of data does not necessarily require the entire frequency band, and at the same time, in order to avoid competition between many devices, the concept of channel bandwidth is generated. That is, in the fixed frequency band, a number of different channel bandwidth can be flexibly allocated.
That is, the channel is further divided on the basis of the frequency band.
Why don't we have more channels?
First of all, the more channels, then the width of each channel is very narrow, the probability of conflict between terminals in the channel becomes greater, if you want to avoid or reduce the conflict, then you need to spend more time to monitor the conflict, and if there is a problem, you need to retransmit the packet, so the speed is certainly not up.
What else do you have to add about Wi-Fi bands and channels, welcome to interact with us~!
