The protocols supported by WiFi5 and WiFi6 are 802.11ac and 802.11ax respectively. At present, WiFi5 has begun to upgrade to WiFi6, and many users may have already adopted WiFi6.

       The main four key differences between 802.11ac and 802.11ax are as follows:

       1. Uplink MIMO

       802.11ac supports multi-user MIMO, but only in the downlink mode. On the contrary, 802.11ax adds uplink functionality, so multiple users can simultaneously upload videos.

       2. Modulation

       802.11ax features a more advanced modulation scheme, upgrading from 256QAM to 1024QAM. This enables a higher throughput, increasing the capacity by 25% and allowing 10 bits of data to be transmitted per symbol.

       3. Capacity and efficiency improvements

       802.11ax employs OFDMA (Orthogonal Frequency Division Multiple Access) modulation instead of OFDM (Orthogonal Frequency Division Multiplexing), which enables FDD (Frequency Division Duplexing), replacing TDD (Time Division Duplexing), and allows for resource unit allocation within a specific bandwidth. It can also reduce the subcarrier spacing to 78.125 kHz, which is only 25% of the 802.11ac spacing, and has a symbol length four times longer than the latter. All these changes combined mean that the system is more efficient, capable of simultaneously uploading or downloading multiple data packets instead of transmitting only one at a time.

       4. Based on scheduling rather than resource contention

       In 802.11ax, the access point determines when the devices will operate, thereby enabling more efficient handling of the clients. The resource scheduling also significantly reduces the energy consumption during sleep, thereby extending the battery life of the clients.

       The following table provides a simple summary of the two supporting protocols for easy distinction: