Hello, everyone!
Today, I will write about WiFi standard evolution. This is a very popular theme.
WiFi networks are based on IEEE 802.11 standards. To date, a number of standards have been developed. Currently, the latest standard is IEEE 802.11ax or WiFi 6. And the development of the WiFi 7 is underway.
The first version of the standard was published in 1997. This version defined the access control layer and the physical layer for media access. The maximum theoretical transmission rate was about 2 Mbps.
IEEE 802.11a
IEEE 802.11a is developed in 1999. 802.11a used 5 GHz and physical layer developed for maximum theoretical transmission rate 54 Mbps. This standard used orthogonal frequency division multiplexing encoding scheme – FHSS or DSSS.
IEEE 802.11b
IEEE 802.11b is developed in 1999, like 802.11a. This standard used 2.4 GHz, with a maximum theoretical transmission rate of up to 11 Mbps. 802.11b used orthogonal frequency division multiplexing encoding scheme – DSSS.
IEEE 802.11g
802.11g is developed in 2003. This standard uses 2.4 GHz with a channel bandwidth 20 MHz. The maximum theoretical transmission rate up to 54 Mbps. 802.11g was compatible with 802.11b.
IEEE 802.11n – WiFi 4
IEEE 802.11n or WiFi 4 was developed in 2004 but began to be used in 2009. This standard uses multiple channels (channel bandwidth 20/40 MHz) and frequencies – 2.4 GHz and 5 GHz. WiFi 4 uses 64 QAM modulation, MIMO systems (4x4 MIMO) and OFDM. The maximum theoretical transmission rate is about 600 Mbps. 802.11n is compatible with all previous standards – 802.11a/b/g. Most user devices still use this standard.
IEEE 802.11ac – WiFi 5
IEEE 802.11ac or WiFi 5 was developed in 2013. The frequency band is 5 GHz and channel bandwidth can be 20, 40, 80, or 160 MHz. This standard uses 256 QAM modulation, MU-MIMO antennas systems (8x8 MIMO), and OFDM. The theoretical transmission speed up to 7 Gbps. WiFi 5 is compatible with previous standards. This is one of the new standards, which enables high speeds and serves a large number of users (airports, e-classrooms, restaurants, etc).

Figure 1. WiFi standard evolution
IEEE 802.11ax – WiFi 6
IEEE 802.11ax or WiFi 6 was developed in 2019. Frequency bands are 2.4 and 5 GHz and channel bandwidth can be 20, 40, 80, or 160 MHz. This standard uses 1024 QAM modulation, OFDMA, and MU-MIMO (8x8 MIMO). It offers a theoretical transmission speed of up to 9.6 Gbps. WiFi 6 is compatible with previous standards. This is the latest standard. It enables high transfer speeds and service to a large number of users (restaurants, airports, cafes, e-classrooms, etc).
WiFi technology is still evolving. This allows voice and video transmission over WiFi, with very low latency. Today, Huawei offers ONT that supports WiFi 6 and enables the transfer of all services via WiFi.
Thank you!
For more information, please click:
WiFi Basics(2) - Wi-Fi Standards

