Not everyone has Wi‑Fi 5 yet, but Wi‑Fi 6 is already available for some

You have probably noticed that there was no such thing as “Wi‑Fi 5”. For the average user, the naming convention was maybe not that easily understandable: first, there was 802.11 format and then some additional symbols, like a, b, g, n, ac, or ax.

The developers finally decided to fix this problem, giving the new standards user‑friendly names. So, the fourth generation of the 802.11n standard is now called Wi‑Fi 4, ac is Wi‑Fi 5, and the new ax standard is Wi‑Fi 6. The Wi‑Fi Alliance has renamed the standards to eliminate confusion in the device market and make it easier for users to move to the next Wi‑Fi versions.

The Wi‑Fi 6 technology was tasked with improving the efficiency of the wireless network. In real life, wireless networks struggle to cope with these tasks, not only because of low data transfer rates, but also because of the large number of devices that interfere with each other, having to wait until the transmission medium becomes free. And over time, the problem only gets worse.

Maximum theoretical speeds that Wi‑Fi standard can achieve.

Frequency range

The 2.4 GHz band makes a comeback in the Wi‑Fi 6 standard, unlike Wi‑Fi 5. This band will support the OFDMA modulation type, allowing for simultaneous data transmission/reception by multiple clients. Nowadays, another method is used, which will be briefly discussed in this article, too.

It is also planned to use the 6 GHz frequency (1…7 GHz possibly) to expand the bandwidth. The picture below shows the non‑overlapping channels that can be grouped for parallel operation of several networks without interference and delays.

But increasing the signal frequency has a drawback, too: the shorter the wavelength, the worse the wave overcomes obstacles in its path, such as external and interior walls. However, Wi‑Fi 6 can improve the performance of overlapping networks in a different way, like a friend‑or‑foe system.

Coloring data packets: BSS Coloring

Today, Wi‑Fi 5 routers cannot distinguish between data packets of their own network and packets of a neighboring network. If your router uses the same channel as your neighbor’s, your router will have to wait until the neighbor’s router frees the radio channel. Wi‑Fi 6 solves this problem with BSS Coloring: now, every data packet is digitally signed by a specific network. It can be said that data packets now have different colors, which will significantly improve the performance of networks in the 2.4 and 5 GHz bands.

Transferring data to multiple devices simultaneously

The 802.11 protocol uses the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) method, in which wireless stations first check the communication channel and only try to transmit data when the channel is inactive. Thus, they try to avoid collisions when transmitting data packets. When a Wi‑Fi station detects other active devices in a channel, it waits for a certain amount of time before checking the channel again and trying to transmit the packet. When the channel is found to be free, the Wi‑Fi device tries to transfer its data. Clearly, this means that the more devices in one network, the longer you must wait for the packet to be transmitted.

To transmit data via radio, a Wi‑Fi device generates a radio signal at a certain frequency. Previously, Wi‑Fi devices transmitted data using OFDM (Orthogonal Frequency Division Multiplexing) technology. Its operating principle is simple: let’s say there is a certain frequency band in the radio channel, in which data is being transmitted for some time. Instead of transmitting data on a single carrier in this band, data is transmitted on multiple subcarriers. It looks as if we have several transmitters instead of one. The subcarrier division allows to increase the data transfer rate. But OFDM technology does not work well when there are a lot of devices. Multiple devices must wait for others to receive their data.

However, Wi‑Fi 6 supports OFDMA (Orthogonal Frequency Division Multiple Access) technology. The principle of its operation is almost the same, but now the channel is divided into several parts. The parts are allocated into separate resource units (RU). A set of several resource units can contain data for not just one but several users. OFDMA has increased the efficiency of data transmission, working simultaneously with up to 74 users.

Data encoding and compacting

To transmit data in digital form (0s and 1s), the analog radio signal needs to be changed in a special way, i.e. modulated. Wi‑Fi 6 adds support for signal modulation with more bits: previously, 8 bits were used, and now 10. Wi‑Fi 5 technology used 256QAM modulation, while Wi‑Fi 6 technology uses 1024QAM, which increases the data transfer rate by 25 %.

There are never too many antennas: MU‑MIMO and Beamforming

Using the Wi‑Fi 5 standard, it was possible to work simultaneously with four streams (data transfer directions), but only in the direction from the router to the client. This type of transmission was carried out through MU‑MIMO (Multi User Multiple‑Input Multiple‑Output) technology. MU‑MIMO routers have multiple antennas and look like spiders. In fact, the technology allows to form a separate beam of the antenna directional pattern (Beamforming) for a separate direction, allowing the signal to be amplified towards the user and attenuated in other directions.

In Wi‑Fi 6, this technology has been improved to MU‑MIMO 8 × 8. Now you can work simultaneously with 8 streams in both directions: receiving and transmitting data.

Sleep mode will increase the energy efficiency of the Internet of Things

In the future, autonomously powered IoT devices with Internet connection via wireless networks will become widespread. Therefore, Wi‑Fi 6 features a specialized function that reduces the power consumption of devices while also reducing the number of competitors for the transmission medium at any given time. This mechanism is called TWT (target wake time). It allows IoT devices to transmit data on a timer and sleep during the rest of the time, switching to power saving mode to conserve battery power.

WPA3 and improved security

The most common Wi‑Fi security standard now is WPA2 (Wi‑Fi Protected Access). WPA2 defines the protocol that a router and Wi‑Fi client devices use to communicate securely. Unlike the original WPA standard, WPA2 requires AES encryption, which is harder to crack. This type of encryption ensures that a Wi‑Fi hotspot (such as a router) and a Wi‑Fi client (such as a laptop or phone) can communicate securely wirelessly and no one can intercept the data.

Unfortunately, a vulnerability was found in the WPA2 protocol that allows outsiders to connect to a Wi‑Fi network. WPA3 has a different mechanism of operation and is not susceptible to this attack. Also, WPA3 has strengthened data encryption with 192 bits, instead of 128 bits for WPA2.

Upgrading to Wi‑Fi 6: is it worth it?

In conclusion, we can say that Wi‑Fi 6 will allow building networks with a higher device capacity than Wi‑Fi 5. A fourfold increase in theoretical capacity will help build new networks in places with a high consumer density, such as public areas, business centers, facilities with a high density of IoT sensors. The process of upgrading from previous standards to Wi‑Fi 6 will take several years. Therefore, if you do not need high speeds and connecting many devices, you probably should not hurry to switch to Wi‑Fi 6 yet. But Wi‑Fi 6 will certainly eventually replace all other Wi‑Fi standards — it’s only a matter of time. Therefore, when creating promising projects, keep in mind the Wi‑Fi 6 standard.