What is "Wi -Fi HT40"? --Because you can't hear it now, why is it?

You can select your favorite terminal from a wide variety of candidates, and you can customize it, which is the charm and strength of Android.However, on the other hand, it is not pointed out that it is difficult to understand.In this corner, I will explain such "I do not know this of Android" in an easy -to -understand manner.This time, I will answer the question, "What is" Wi-Fi HT40 "?"

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The Wi-Fi HT40 is an abbreviation of "Wi-Fi High Throughput 40" and is a type of high-speed technology that appeared in the wireless LAN standard "IEEE 802.11N".In simple terms, it is a technology that can twice the communication speed by bundling and communicating the two bandwidth, and is also called "channel bonding".

The conventional wireless LAN standard (IEEE 802.11a/b/g) communicates with 20MHz width per channel.Normally, it is not possible to communicate beyond this bandwidth, but IEEE 802.11N has set up two channels in one (20MHz+20MHz = 40MHz) to achieve high speeds.The communication speed of the 20MHz width is up to 75Mbps per channel, but if you use the 40MHz width, it reaches up to 150Mbps (all theoretical values).

Wi-Fi HT40/channel bonding is more effective in communication in the 5GHz band.Only three 40MHz channels can be secured in the 2.4GHz band, and it is difficult to avoid interference with the conventional wireless LAN (IEE 802.11b/g) flying around the neighborhood, but it is sufficient for 5GHz band.You can secure the number of channels.

By the way, in Japan, the maximum output of the wireless LAN is restricted, and when the bandwidth is expanded, the signal output is reduced (the output at 40 MHz is half at the time of 20MHz).If you communicate in a distance from the access point, the communication speed may decrease in the 40MHz width compared to the 20MHz width, so the 20MHz width that can earn a large output in places where the radio wave condition is unstable is more advantageous.It can be said.

(Article provision: AndroWire editorial department)