In the previous articles of our technical sharing series, we introduced four types of LPWAN (Low Power Wide Area Network), including LoRa, NB-IoT, eMTC, and SigFox. In the following articles, the author will share content related to short-range wireless communication technology. Short-range wireless communication technology includes Wi-Fi, ZigBee, Bluetooth, and Z-Wave, which we are familiar with. Today, we will uncover the mysterious veil of Wi-Fi.
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For over 20 years, Wi-Fi has been carrying the ever-increasing network demand with just two frequency bands, 2.4GHz and 5GHz. According to ABI Research, Wi-Fi data traffic has already exceeded cellular traffic, and its upload traffic is expected to surge by 80% in 2022, making it the biggest contributor to traffic growth.
As ultra-high throughput and low-latency applications become increasingly prevalent, the seventh-generation Wi-Fi technology (Wi-Fi 7), also known as IEEE 802.11be, is under intensive research. Wi-Fi 7 is designed to provide devices with faster and more efficient wireless connections, ushering in a new era of data transmission.
Release Year: 1997
Defined the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol and the compatible interconnection of data communication devices in Local Area Networks (LAN).
Release Year: 1999
Also known as Wi-Fi 1 (First Generation Wi-Fi)
802.11b has a theoretical maximum data rate of 11 Mbps and utilizes the CSMA/CA media access technology of the original standard, which significantly increased throughput and reduced costs. It was widely accepted as a wireless LAN protocol.
Release Year: 1999
Also known as Wi-Fi 2 (Second Generation Wi-Fi)
The IEEE 802.11a standard adopted the same core protocol as the original standard, but operates at a higher frequency (5 GHz). Its theoretical data rate is 54 Mbps, with other data rates of 6 Mbps, 9 Mbps, 12 Mbps, 18 Mbps, 24 Mbps, 36 Mbps, and 48 Mbps. However, it is not interoperable with 802.11b as it operates in different unlicensed ISM bands.
Release Year: 2003
Also known as Wi-Fi 3 (Third Generation Wi-Fi)
802.11g has a theoretical throughput of 54 Mbps, and is the successor to the popular 802.11b standard, which has a maximum throughput of 11 Mbps. Both use the 2.4 GHz band, but 802.11g uses OFDM. It is backward compatible and supports 802.11b and 802.11g clients.
Release Year: 2009
Also known as Wi-Fi 4 (Fourth Generation Wi-Fi)
802.11n is the next IEEE 802.11 standard after 802.11a, 802.11b, and 802.11g. It supplements the 802.11 series of standards. 802.11n uses a technology called Multiple Input/Multiple Output (MIMO) and wider radio frequency channels. It also provides a mechanism called "frame aggregation" to reduce the time between transmissions and is backward compatible with 802.11b/g devices.
Release Year: 2014
Also known as Wi-Fi 5 (Fifth Generation Wi-Fi)
802.11ac has a theoretical maximum speed of 1300 Mbps (1.3 Gbps) - 2300 Mbps (2.3 Gbps), and builds on the features provided by 802.11n to increase throughput, bandwidth, and speed.
Release Year: 2019
Also known as Wi-Fi 6 (Sixth Generation Wi-Fi)
IEEE 802.11ax is the sixth generation Wi-Fi, building on the advantages of 802.11ac. It provides higher wireless capacity and reliability through the use of more dense modulation schemes, smaller subcarrier spacing, and schedule-based resource allocation. 802.11ax is a dual-band technology operating in the 2.4 GHz and 5 GHz frequency bands, and can provide speed upgrades even for the lower frequency band. It is expected to be fully compatible with 802.11a/b/g/n/ac clients.
Release Year: 2024 (anticipated)
Also known as Wi-Fi 7 (Seventh Generation Wi-Fi)
Wi-Fi 7 is the latest Wi-Fi technology for routers and modems, and is four times faster than Wi-Fi 6. This huge throughput supports Virtual Reality (VR), low-latency gaming, and higher-quality streaming. Although it will change the way you use the Internet, it will not be fully available until 2024. Certified Wi-Fi 7 devices are expected to become popular in the market by 2025.
Wi-Fi 7 will achieve speeds of up to 46 Gbps, with routers connecting to more devices, each using huge throughput and Orthogonal Amplitude Modulation (QAM) for more efficient wireless connections.
Wi-Fi 7 is much faster than Wi-Fi 6, with more data being transmitted through the pipeline to more devices, without affecting each other's user experience. When you want to watch a game upstairs, while your partner is playing a movie in the study, and your children are playing "Star Wars" with VR headphones in the bedroom, these synchronous operations will not have any buffering problems.
The following figure is a timeline of different Wi-Fi standards since 1997, shared by the Wi-Fi Alliance:
Wi-Fi 7 specific advantages:
① Faster speed
It is hard to imagine such a big speed upgrade for Wi-Fi 7. The jump from a theoretical maximum speed of 9.6 Gbps to 46 Gbps, which is four times the speed, is extreme. In addition, Wi-Fi 6 is relatively able to meet the current transmission needs, so why launch such a high-speed version of wireless technology?
The table below shows the speed difference between Wi-Fi 6 (2019) and Wi-Fi 7 (2024). This extra speed will open up new ways of using the Internet. For example, you can virtually try on a pair of shoes or wear glasses, which will give you a "real" feel, saving you a lot of time and money in the shopping process.
② Lower latency
Compared with Wi-Fi 6, Wi-Fi 7 has much lower latency. Although doubling the speed is a big leap, the improvement in speed has a significant domino effect on latency, which is the delay you encounter when you are in a meeting, playing games, and streaming. According to Microsoft, you will see a general delay reduction of 100 times, and the delay of VR devices will be reduced by 15 times, greatly reducing loading and buffering times.
The significant drop in latency has far-reaching practical applications, creating incredible immersive web experiences. Wi-Fi 7's wider 320 MHz channel and unlicensed 6 GHz frequency band will give you a richer (less faulty) reality gaming, remote work, healthcare, and educational experience than you are used to.
③ Multi-link function
Although Wi-Fi 6 can provide services to multiple devices such as laptops, mobile phones, and tablets at the same time, this signal sharing is convenient, but it will cause delay problems. Wi-Fi 7 does a better job in this regard. This is because Wi-Fi 6 uses MU-MIMO technology, which supports up to four devices at a time. The MU-MIMO technology splits a single signal into smaller signals, which means that multiple devices share the same signal.
In contrast, Wi-Fi 7 uses multi-link operations with multiple signals to support multiple devices. Therefore, Wi-Fi 7 routers will prioritize unused channels. As you add more and more devices to the network, the wireless router will fall back on MU-MIMO technology to share channels.
④ Higher data transmission quality
Wi-Fi 6 relies on 1024-QAM to send and receive more data more efficiently using radio signals. This 1K QAM architecture makes Wi-Fi 6 25% faster than Wi-Fi 5. In a large-scale upgrade, Wi-Fi 7 uses 4K QAM, which is four times faster than Wi-Fi 6E.
As a user of Wi-Fi 7 modems, the higher QAM does not bring you additional benefits, but it is the "reason" behind the faster speed standard.
Omdia stated in its observation of LTE/5G private networks in 2023 that "in the private network field, 2023 will be a year of vigorous development of Wi-Fi 6 (not 5G)," and 40% of enterprises choose or consider using Wi-Fi to replace private networks, far exceeding public cellular networks. Wi-Fi 6 will not completely replace 5G, but will only play a substitute role in specific scenarios. In the 5G era, the competition of Wi-Fi 6 in the private network field is already apparent, and Wi-Fi 7 (expected to be released at the end of 2024) will continue to compete with 6G (expected around 2030).
The Wi-Fi Alliance predicts that by 2024, billions of people and 18 billion devices worldwide will rely on Wi-Fi connections to the Internet, and Wi-Fi device shipments will increase to 4 billion units per year. The actual landing of Wi-Fi worldwide is related to ITU's spectrum allocation and local spectrum policies.
Wi-Fi has two frequency range bands, 2.4GHz and 5GHz, but the non-authorized spectrum in these two frequency bands is limited and crowded. Some countries and regions have begun to expand the Wi-Fi frequency bands to 6GHz, which can provide larger bandwidth, faster speed, and more capacity. Wi-Fi 7 requires 320 MHz continuous channel support and urgently needs to expand the frequency band range. However, different countries have different attitudes towards whether to allow Wi-Fi access to the 6GHz frequency band as an unauthorized frequency band. The United States, Canada, South Korea, and other places explicitly allow the use of the entire 6GHz frequency band for Wi-Fi. The European Union, Russia, and other places use the 6GHz frequency band in segments. China, Asia, and some African regions have not yet clarified their 6GHz allocation policies.
Currently, China's 5G development is leading globally, and 5G and 6G development are also seeking more spectrum resources support. Since spectrum resources are scarce, it is not yet clear whether Wi-Fi 7 can obtain 6GHz frequency band support for large-scale commercial use in China in the future. Therefore, it is particularly important to handle the coordination relationship between Wi-Fi 7 and 5G/6G.