Wi-Fi 7 vs Wi-Fi 6
Based on the Wi-Fi 6 standard, Wi-Fi 7 introduces many new technologies, mainly reflected in:

New features supported by Wi-Fi 7

The goal of the Wi-Fi 7 protocol is to further improve the throughput of WLAN networks and provide low-latency access guarantees. To achieve this goal, the entire protocol has made corresponding changes in the PHY layer and MAC layer. Compared with the Wi-Fi 6 protocol, the main technical changes brought by the Wi-Fi 7 protocol are as follows:

Supports a maximum bandwidth of 320MHz

The unlicensed spectrum in the 2.4GHz and 5GHz bands is limited and crowded. When running emerging applications such as VR/AR, existing Wi-Fi will inevitably encounter low QoS problems. In order to achieve the goal of maximum throughput improvement, Wi-Fi 7 will continue to introduce the 6GHz band and add new bandwidth modes, including continuous 240MHz, non-continuous 160+80MHz, continuous 320 MHz, and non-continuous 160+160MHz. Wi-Fi 6 supports up to 2 continuous 80MHz channels bundled into a 160MHz channel.

Support Multi-RU mechanism

In Wi-Fi 6, each user can only send or receive frames on the specific RU assigned to it, which greatly limits the flexibility of spectrum resource scheduling. To solve this problem and further improve spectrum efficiency, Wi-Fi 7 defines a mechanism that allows multiple RUs to be assigned to a single user. Of course, in order to balance the complexity of implementation and the utilization of spectrum, the protocol imposes certain restrictions on the combination of RUs, namely: small-sized RUs (RUs less than 242-Tone) can only be combined with small-sized RUs, and large-sized RUs (RUs greater than or equal to 242-Tone) can only be combined with large-sized RUs. Mixing small-sized RUs and large-sized RUs is not allowed.

Introducing higher-order 4096-QAM modulation technology

The highest modulation mode of Wi-Fi 6 is 1024-QAM, in which the modulation symbol carries 10 bits. In order to further improve the rate, Wi-Fi 7 will introduce 4096-QAM, so that the modulation symbol carries 12 bits. Under the same coding, Wi-Fi 7's 4096-QAM can achieve a 20% rate increase over Wi-Fi 6's 1024-QAM.

Introducing Multi-Link multi-link mechanism

In order to achieve efficient utilization of all available spectrum resources, it is urgent to establish new spectrum management, coordination and transmission mechanisms on 2.4 GHz, 5 GHz and 6 GHz. The working group defines technologies related to multi-link aggregation, including enhanced multi-link aggregation MAC architecture, multi-link channel access, and multi-link transmission.

Support collaborative scheduling between multiple APs

Currently, within the 802.11 protocol framework, there is actually not much collaborative relationship between APs. Common WLAN functions such as automatic tuning and intelligent roaming are all vendor-defined features. The purpose of collaboration between APs is only to optimize channel selection, adjust the load between APs, etc., to achieve efficient utilization and balanced distribution of radio frequency resources. The collaborative scheduling between multiple APs in Wi-Fi 7, including coordinated planning between cells in the time domain and frequency domain, interference coordination between cells, and distributed MIMO, can effectively reduce interference between APs and greatly improve the utilization of air interface resources.

There are many ways to coordinate scheduling between multiple APs, including C-OFDMA (Coordinated Orthogonal Frequency-Division Multiple Access), CSR (Coordinated Spatial Reuse), CBF (Coordinated Beamforming), and JXT (Joint Transmission).