In the semiconductor industry driven by Moore's Law, it is quite rare that a technical standard can last for several years without updating. The IEEE 802.11 protocol that dominates the wireless networks around us is such a strange standard: from the first wireless router supporting 802.11A to the present, it has only been updated three times: 802.11g, 802.11n, and the latest 802.11ac. Now, a brand-new Wi-Fi wireless network protocol has stood in front of us. It is expected to allow overwhelmed wireless networks to keep up with the times and achieve rapid development. Its name is IEEE 802.11ax (the IEEE prefix is ​​omitted below).

What is 802.11ax?

The 802.11 protocol suite is a standard established by the International Institute of Electrotechnical and Electronic Engineering (IEEE) for wireless local area networks. 802.11ax is the latest revision of this standard. You can think of it as the successor to 802.11ac.

The easiest way to understand 802.11ax is to think of it as an enhanced version of 802.11ac. It works in the 5GHz frequency band like 802.11ac. The difference is that 802.11ax uses MU-MIMO (Multi-User Multiple-Input Multiple-Output) Technology, the signal is divided into four different "signal channels" in multiple dimensions such as time domain, frequency domain, and space domain. Each "signal channel" can communicate with a device alone, which looks like a high-speed The highway is divided into four different lanes, and the communication efficiency is doubled.

In addition, 802.11ax has an extremely important innovation. It introduces OFDMA (Orthogonal Frequency Division Multiple Access), which is the core technology of the next generation of high-speed wireless communication networks. Our existing wireless network standard essentially uses complex algorithms to modulate electromagnetic wave signals, so that the signal presents a certain pattern to carry 0 and 1, so that data can be transmitted. OFDMA is a brand-new signal modulation and coding algorithm. It can divide a signal channel into tens or even hundreds of smaller orthogonal sub-channels, and then closely superimpose these sub-channels together and then distribute them to different users. The efficiency of data transmission in the same time is greatly improved.
 

last year.

On the other hand, as a transition plan before 802.11ax, 802.11ac will enter the second life cycle from 2015 and 2016, the so-called 802.11ac 2.0 standard. The landmark change of 802.11ac 2.0 is the introduction of MU-MIMO technology to improve network congestion. Version 1.0 of 802.11ac only supports up to 3 spatial streams. In version 2.0 of the standard, this number will be increased to 8.

A large wave of new routers will begin to support this vital over-standard. Before 802.11ax really enters into practical use, 802.11ac 2.0 should be a good stopgap measure.