New breakthrough! WiFi 7 coming soon...

Our innovative Wi-Fi 7 solution sets the standard for the next generation of Wi-Fi," reads the official Qualcomm website on 15 February. The expectations for WiFi 7 are high.

 

This is not the first time that WiFi 7 has made an appearance. In January 2022, MediaTek debuted WiFi 7, taking the lead as the first company in the industry to successfully complete a WiFi 7 technology demonstration. The latest WiFi standard on the market is WiFi 6E, however, it feels like WiFi 6E is not even fully popular, so is WiFi 7 a King card or a pie?

 

What is WiFi and WiFi 7?

Before we talk about WiFi, it is important to mention Hedy Lamarr, an actress and inventor who in 1941 invented FHSS (Frequency-Hopping Spread Spectrum) based on the principle of synchronised piano playing by musician George Antheil, which laid some of the foundations for future technologies such as CDMA, Bluetooth and Wi-Fi.

 

In 1985, the FCC released the ISM licence, which opened up three frequency bands, including 2.4GHz, allowing nodes to communicate using spread-spectrum technology. It is also considered to be the prototype of WiFi design, and from then on, the development of WiFi gradually started.

 

In 1993 the concept of Hotspot access was introduced. The concept of Hotspot access was introduced in 1993, where small base stations were constructed through wireless network protocols and then connected directly to ISP networks through the base stations. The hotspot concept was one of the key points in the eventual implementation of WiFi.

 

In 1997, IEEE, the American Institute of Electrical and Electronics Engineers, promulgated the IEEE 802.11 protocol, the first generation of wireless local area network (WLAN) standard, which requires WLANs to operate in the 2.4GHz band, a band defined by the Global Radio Regulations as the band for frequency expansion.

 

In 1999, the Wireless Ethernet Compatibility Alliance (abbreviated as WECA) was formed to promote the IEEE 802.11b specification, and in October 2002 it was renamed the Wi-Fi Alliance.

 

Since the release of IEEE 802.11, the Wi-Fi Alliance has changed its naming convention to WiFi+Number. 2009 marked a major turning point for the industry with the release of 802.11n, or WiFi 4, which changed the transmission rate from 54 Mbit/s to a maximum of 600 Mbit/s, introduced MIMO technology, and supported both 2.4Ghz and 5Ghz dual-band.

 

In 2013, WiFi 5 (802.11ac) technology was adopted, introducing MU-MIMO technology, which works only in the 5G band and can reach speeds of 6.9Gbps.

 

In 2019, WiFi 6 (802.11ax) introduces OFDMA technology and can reach speeds of up to 14Gbps.

  

In May 2019, the IEEE 802.11be Task Group (TGbe) was formed to work on the development of 802.11be (Wi-Fi 7). WiFi 7, the seventh generation of WiFi wireless networks, will introduce CMU-MIMO technology to support up to 16 data streams compared to WiFi 6. Wi-Fi 7 can handle at least 30 Gbps and possibly up to 40 Gbps. Secondly, in addition to supporting the traditional 2.4GHz and 5GHz bands, WiFi 7 will also add support for the 6GHz band, and all three bands will be able to work simultaneously.

 

What's new in Qualcomm's WiFi 7 announcement?

As seen in the previous WiFi 7 draft released in 2021, WiFi 7 is a significant breakthrough from WiFi 6, which used the unlicensed 2.4 GHz and 5 GHz bands and was subject to limitations and congestion. While Wi-Fi 6E greatly expands the use of broadband spectrum, multiple 160 MHz channels can be used in any area where 6 GHz spectrum has been allocated.

 

To achieve a maximum throughput of 30 Gbps, Wi-Fi 7 will support the 6 GHz band and expand with new bandwidth modes including contiguous 240 MHz, non-contiguous 160 + 80 MHz, contiguous 320 MHz and non-contiguous 160 + 160 MHz.

 

Wi-Fi 7's multi-connectivity features provide clients with multiple options for using these channels, most effectively by leveraging the higher band's greater capacity, higher peak speeds and lower congestion levels. In Qualcomm's WiFi 7 solution, the terminal connection can alternate between bands. In this solution, the terminal uses the first available band for each transmission, and once the previous transmission is complete, it can select any band for the next transmission. This approach avoids congestion on the connection links and reduces latency.

 

Alternating multiple links, where devices alternate between available bands to reduce latency

 

Currently, some regions can support three 320MHz contiguous spectrum channels, some regions support one, and some regions do not support them at all. For the 5GHz band, there are no contiguous 320MHz channels, so only regions that support 6GHz can support this contiguous mode. Multi-connection parallelism in the HF band provides a wider effective channel by aggregating the two available channels. This means that by combining two 160MHz channels in the high band, a 320MHz active channel is created.

 

In China, 240MHz active channels can be achieved using high-band multi-connectivity concurrency, which takes advantage of the ultra-high throughput of Wi-Fi 7 even when no 6GHz spectrum is allocated. It can run simultaneously on each band, so it is even better at avoiding congestion to reduce latency.

 

High-band synchronous multi-link, where the high bands are aggregated to provide the highest throughput and lowest latency

 

In some scenarios, users will occupy a portion of the bandwidth in a free contiguous channel (e.g. 20MHz or 40MHz), which often prevents AP access points from using that spectrum. In this case, Qualcomm's Wi-Fi 7 technology brings an innovative solution called "Preamble Puncturing", which allows devices to operate on multiple bands simultaneously to avoid congestion and reduce latency. Supporting AP access points makes it possible to use this continuous channel without the interference mentioned above. Although the amount of punching reduces the overall bandwidth, a wider channel can still be achieved than would otherwise be possible.

 

Leading code piercing allows for wider channels

 

The highest level of modulation supported by Wi-Fi 6 is 1024-QAM, which allows up to 10 bits to be carried per modulation symbol. Wi-Fi 7 introduces 4096-QAM so that each modulation symbol can carry 12 bits. Using the same encoding, 4096-QAM in Wi-Fi 7 achieves a 20% speed increase compared to 1024-QAM in Wi-Fi 6. This allows for better 8K video playback and extended reality (XR) applications.

 

There are two major changes that distinguish WiFi 7 from WiFi 6. The first is a major upgrade to the WiFi uplink, which will feature Uplink Multi-User Multiple Input Multiple Output (UL MU-MIMO) technology. This new technology creates multiple paths between the router and the WiFi connected devices. WiFi 6 allows 8 paths to be transmitted simultaneously, WiFi 7 increases this to 16 paths.

 

WiFi 7 will also bring another improvement marked as Coordinated Multi-User MMO (CMU-MIMO), which will allow home devices to connect to multiple WiFi routers at the same time. This harmonisation should result in faster connections, lower latency and the ability to provide high bandwidth to every corner of the home with multiple WiFi access points. This is the most complex challenge of the WiFi 7 specification.

 

 

Why do we need WiFi 7?

WiFi is now an integral part of our daily lives, and as mentioned in "With 29% compound annual growth, China's Wi-Fi Internet of Things is taking off", the Chinese Wi-Fi Internet of Things market will continue to grow at a compound annual growth rate of 29%, from 252 million connections in 2021 to 916.6 million in 2026. The demand for WiFi is huge, and the number of indoor IoT connections will continue to grow, with businesses and users demanding even more low latency and fast transmission speeds.

 

WiFi 7 is already a repertoire of technological innovation, introducing new features that will significantly increase data transfer rates and provide lower latency, and will be a core network for industries such as video/voice conferencing, cloud gaming, smart home, industrial IoT, metaverse and telemedicine. It is highly anticipated that it will be available for commercial use by 2024.

 

But a key part of WiFi 7's fate will be the policy announcement of the 6 GHz spectrum, as modern high-speed Wi-Fi devices demand increasingly higher performance from WiFi transmissions, and some emerging industry applications cannot demonstrate their best quality of service in the congested 2.4 GHz and 5 GHz bands. The allocation of the 6 GHz spectrum will be an important message to the WiFi industry in the coming years.

 

Responsible Editor: Hua Hin

Source: IOT Media