Next generation Wi-Fi: Wi-Fi 6
2020-09-02

The new generation of Wi-Fi wireless connectivity standard is already here. This is the sixth version, well-known as Wi-Fi ax or 802.11ax. Since 2013, the year of creation of Wi-Fi fifth generation (802.11ac), there has not been a release capable of adapting to the drastic evolution of wireless connectivity.

The new challenges of wireless connections such as higher Internet connection speeds, a greater number of connected devices and new high-demand services, among others, have led to the creation of this new release, which proposes a series of access mechanisms that aim to provide the best user experience.

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Figure 1: Evolution of Wi-Fi standards. Source: Techstage

Wi-Fi 6 will provide better connectivity for all the devices, independently from their nature, carrying out more efficient connection management and satisfying the speed and consumption needs. This is a new approach that tries to increase the efficiency of devices with different traffic profiles located at the access point at different distances.

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Figure 2. New Wi-Fi 6 approximation. Source: Calix

Wi-Fi 6: Improvements and main characteristics

We could say that capacity, efficiency and performance are the keys to this new release, a bunch of features that lead to a series of important benefits for User Experience:

  • Higher data transmission rates.

  • Network capacity growth.

  • More efficient energy consumption.

  • Better performance in environments with high device      density.

  • Support for both bands (2.4 and 5 GHz) and backward      compatibility.

How do we achieve this? Well, thanks to the implementation of a series of advanced features that increase spectral efficiency and adapt to the nature of the device. There are more than 50, but the following should be noted:

  • OFDMA DL/UL

Orthogonal Frequency-Division Multiple Access (OFDMA) is a system of access to the medium, which is already present in mobile communications. It is an enhanced version of the existing Orthogonal Frequency Division Multiplexing (OFDM), which splits the spectrum into subcarrier signals for better efficiency. Furthermore, OFDMA combines or multiplexes both in time and in frequency, and creates small transmission units (RUs) that adapt to the bandwidth requirements of each device.

Thus, more efficient transmissions are achieved with lower latency and it allows full integration of IoT (Internet of Things), preventing devices with a lower transmission rate from hindering access to the medium.

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Figure 3. OFDM vs OFDMA. Source: Xataka

  • 8×8 MU-MIMO & Uplink      MU-MIMO

The spatial transmission and reception capability for multiple users simultaneously (MU-MIMO) was already present in the latest revisions of Wi-Fi 5 (802.11ac), however it only allowed to send a maximum of 4 streams (live data transmissions). With the arrival of Wi-Fi 6, it is now possible to send up to a maximum of 8 streams and serve up to 8 simultaneous users at the same time (8×8).

WiFi 6 also allows the access point to receive different data streams from different users at the same time (UL MU-MIMO), achieving better performance, especially for the use of high-demand streaming services, such as Netflix.

  • Quadrature amplitude      modulation: 1024-QAM

With higher order modulation, more bits can be transmitted in the same time interval, as long as the conditions of radio signals are good enough. With the inclusion of 1024-QAM, it is possible to increase both the peak speeds and the spectral efficiency by around 25% in relation to 256 QAM.

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Figure 4. 256 QAM vs 1024-QAM. Source: Naseros

  • Reduced energy      consumption

Reducing energy consumption is a key factor, especially for smart devices, which remain connected for long periods of time and transmit little information less frequently. To this end, Wi-Fi 6 implements a functionality called TWT (Target Wake Time) that allows devices to remain in power saving mode until there is transmission or reception of data, prior negotiation with the access point, so battery life increases.

  • Narrow channels 

Wi-Fi 6 supports narrow channels of 2 and 5 MHz, very useful for smart devices or low-power IoT, which transmit small amounts of information. The use of this type of channels increases the transmission range, allowing communication of devices located in difficult access areas.

  • BSS (Basic Service Set)      coloring

This feature optimizes data transmission in dense and interference environments. An identifier is added in the Wi-Fi communication between the access point and the device, which allows it to just attend the packets that have such identifier, ignoring the packets from the nearby and interfering access points and, thus, avoiding collisions and high response times.

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Figure 5. BSS Coloring. Source: Tp-Link

The near future of Wi-Fi 6

The Coronavirus crisis (COVID-19) that we are currently experiencing worldwide is exponentially increasing the use of Internet at homes, so enjoying a more fluid wireless experience, in a responsible way, becomes increasingly essential.

Nowadays, there are already numerous devices certified by the Wi-Fi Alliance to operate with this new technology. Basically, we are talking about routers, phones and computers from companies such as Samsung, Broadcom, Asus, ZTE, Sagem, Qualcomm, Cisco, etc. In the case of Apple and its iPhone 11, the device supports Wi-Fi 6 but is not certified by the Wi-Fi Alliance.

Convergence with 5G networks will be another key aspect of the near future. Wi-Fi 6 and 5G do not have to be exclusive technologies, but the opposite. In fact, it is expected that service providers will offer both technologies that complement each other according to the needs and location of the end-user. Both have several common features: higher speeds, lower latencies, operation in denser environments, IoT support and indoor coverage.

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Figure 6. Convergence diagram 5G vs.Wi-Fi 6. Source:pxosys

Regarding service providers, Wi-Fi 6 promises a series of benefits that will probably begin to be exploited during 2020, since compatible and certified devices already exist. Being at the forefront of technology before competitors, providing the best User Experience, managing the growing demand for bandwidth and increasing revenue are just some Wi-Fi 6 strong points.

 

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