WiFi 7

WiFi 7, also known as Wi-Fi 7, represents the next generation of Wi-Fi standards, corresponding to the IEEE 802.11's upcoming revision, IEEE 802.11be – Extremely High Throughput (EHT).

Wi-Fi 7 introduces technologies such as 320MHz bandwidth, 4096-QAM, Multi-RU, and multi-link operation on the basis of Wi-Fi 6, enabling Wi-Fi 7 to offer higher data transmission rates and lower latency compared to Wi-Fi 6. Wi-Fi 7 is expected to support a throughput of up to 23Gbps, roughly three times that of Wi-Fi 6.

Why WiFi 7 ?

With the advancement of WLAN technology, households and businesses have increasingly relied on Wi-Fi as the primary means of accessing the internet. In recent years, new applications have emerged with higher requirements for throughput and latency, such as 4K and 8K video streaming (which may require transmission rates of up to 20Gbps), VR/AR, gaming (with latency requirements below 5ms), remote work, online video conferencing, and cloud computing. Although the newly released Wi-Fi 6 has focused on enhancing user experience in high-density scenarios, it still cannot fully meet the demands of these higher throughput and latency requirements.

To address this, the IEEE 802.11 standards organization is poised to release a new revision, IEEE 802.11be EHT, also known as Wi-Fi 7.

Wi-Fi 7 vs Wi-Fi 6

Wi-Fi 7 New Features

The goal of the Wi-Fi 7 protocol is to further enhance the throughput of WLAN networks and provide low-latency access guarantees. To achieve this goal, corresponding changes have been made to the entire protocol at both the PHY layer and the MAC layer. Compared to the Wi-Fi 6 protocol, the main technological innovations introduced by the Wi-Fi 7 protocol are as follows:

Support for a maximum bandwidth of 320MHz

The unlicensed spectrum in the 2.4GHz and 5GHz frequency bands is limited and congested. Existing Wi-Fi systems inevitably encounter issues of low Quality of Service (QoS) when running emerging applications such as VR/AR. In order to achieve the goal of maximizing throughput, Wi-Fi 7 will continue to introduce the 6GHz frequency band and add new bandwidth modes, including contiguous 240MHz, non-contiguous 160+80MHz, contiguous 320MHz, and non-contiguous 160+160MHz.

Support for Multi-RU mechanism

In Wi-Fi 6, each user can only send or receive frames on a specific assigned Resource Unit (RU), greatly limiting the flexibility of spectrum resource scheduling. To address this issue and further improve spectrum efficiency, Wi-Fi 7 defines a mechanism that allows multiple RUs to be allocated to a single user. Of course, in order to balance the complexity of implementation and the utilization rate of the spectrum, the protocol places certain restrictions on the combination of RUs, namely: small-sized RUs (RUs smaller 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 and large-sized RUs is not allowed.

Higher-order 4096-QAM modulation technology

The highest modulation scheme in Wi-Fi 6 is 1024-QAM, where each modulation symbol carries 10 bits. To further increase speed, Wi-Fi 7 will introduce 4096-QAM, allowing each modulation symbol to carry 12 bits. With the same encoding, Wi-Fi 7's 4096-QAM can achieve a 20% increase in speed compared to Wi-Fi 6's 1024-QAM.

Multi-Link mechanism

To efficiently utilize all available spectrum resources, there is an urgent need to establish new spectrum management, coordination, and transmission mechanisms across 2.4GHz, 5GHz, and 6GHz. The working group has defined technologies related to multi-link aggregation, mainly including enhanced MAC architectures for multi-link aggregation, multi-link channel access, and multi-link transmission.