What is the difference between dual-frequency WiFi and single frequency WiFi?

Dual-frequency WiFi refers to the simultaneous transmission of 2.4g/5g band of dual-frequency terminal equipment. Double frequency. Maybe the users are still foggy about WiFi dual-band WiFi, and we're going to take you today to see what a dual-band WiFi is.

Let's start with a history of WiFi, the 1999 802.11a defines a physical layer with a data transfer rate of up to 54mbit/s on the 5GHz ISM band, 802.11B defines one on the 2.4GHz ISM band but the data transfer rate is as high as 11mbit/ The physical layer of S. The 2.4GHz ISM Band is universal for most countries in the world, so 802.11b is the most widely used. Then the development of WiFi went through the 802.11 a,b,c,d,e,f,g,h,i,n. Such a stage of development. At this stage, we generally use the 802.11n.

--Single and dual-frequency WiFi

At present, there are two types of devices using 802.11n, only single frequency and dual frequency support.

Because microwave ovens, Bluetooth, cordless phones and so on in the 2.4Ghz this band work, and support single frequency WiFi network card, only support 802.11b/g/n, That is, only support in the 2.4Ghz this band work, that is, and the above description of the three situations will have a conflict, because 2.4Ghz this band only 3 do not overlap with the 20M channel, mutual interference is very serious.

Dual-frequency WiFi adapters can support 802.11a/b/g/n (sometimes identified as supporting 802.11a/g/n). Can work in the 5Ghz band, this band is much cleaner, this band, in China has 5 not overlapping 20M channels, can easily avoid mutual interference.

--how to differentiate between single and dual frequency WiFi

We compare these two logos, (802.11b/g/n and 802.11a/b/g/n) obviously see a difference between the two "a". Although this "a" is no use, the 802.11a is basically eliminated, but we can see from the history of WiFi is defined in the 5GHz band, so This "a" indicates that the network card can work on 5G. The difference between running on the 5G band and running on the 2.4 band

802.11n that can work in the 2.4G band, can also work in the 5G band, so the single look "n" is not sure whether this network card is a dual-frequency network card. And "A" can only work in the 5G band, so have this logo, must be double frequency.