WiFi as of Today

The  number of WiFi devices in the world would be in the range of 10 – 12  billion now if we extrapolate the estimation by WiFi Alliance from a couple of years ago [2]. It has taken a couple of decades to reach this number [1]. These WiFi devices can be classified by various criteria as below:

  1. Specification supported (802.11 b/g/a/ac & ax)
  2. Band supported (2.4 GHz, 5 GHz) and frequencies restricted by various countries
  3. Sizes (Connected Home devices which are tiny to mobile phones to laptops and Access points)

It’s not clear if there is an estimate of devices by category for any of the above. However, it helps to keep in mind where the growth would come from. Mobile Phones & Connected Home devices would be the key drivers for WiFi Chipset market.

The introduction of 802.11ax (called WiFi 6 by WiFi alliance) is a step in the right direction to address these market segments.

Standardization Status

Wireless LAN Working Group of IEEE (WG802.11), that is working for the definition of the 802.11ax specification released a draft version in Feb 2019 (IEEE P802.11AX/D4.0). The final version is to be published in June 2020 [3].

WiFi Alliance has announced that the certification program would be ready by 3rd quarter of 2019.  This looks a little challenging considering the fact that the specification would be ready for approval by Dec 2019. It is possible to infer from these that the early MAJOR 802.11ax deployments would be in Q1 2020.

Motivation for 802.11ax

As pointed above, the market segments where the growth of WiFi devices would be prominent are Mobile Phones & Connected Home Devices (previously called “IoT” devices).

The key feature that is addressing the mobile phone market is OFDMA (DL & UL). This would help APs to handle large number of devices simultaneously, which is the use case of Public WiFi (Ex: high density of users in a stadium or airport with mobile phones, see slide 19 [7])

OFDMA coupled with TWT (target wake time) would be the driver for implementing 802.11ax in connected home devices as these features improve power efficiency.

We would also need to consider the economic incentives for various manufacturers to move to 802.11ax chipsets in future.

  • Public WiFi operators would like to maximise users per AP to drive down their deployment cost. Together with the increased throughput provided by 1024 QAM, the operators have a need to move to 802.11ax and consequently push AP manufacturers.

 

  • Mobile phone manufacturers currently using 802.11ac/n chipset have very little economic reason to move to 802.11ax chipsets other than marketing claims. Since these are WiFi client devices, as backward compatibility is always assured by the specification, the devices would work with 802.11ax APs as good as any 802.11ax client in most scenarios (1024 QAM is probably not going to make that good a case). This would work to disadvantage of Public WiFi operators as the overall bandwidth efficiency gets reduced. It is also not known, if the new power save mechanisms would have a significant impact on battery life of mobile phones.

 

  • Manufacturers of Connected home devices that are battery powered may have a sound economic reason to move to 802.11ax chipsets as this would improve battery life. There are some open issues as mentioned in [8] for evaluation of this feature. If there is a significant order of magnitude improvement in battery life, the new technology would be deployed.

Expected Deployment Timelines

Conclusion

802.11ax / WiFi 6 is a good step forward for the advancement of WiFi. Everything from PCs/Laptops, and mobile phones to IoT devices in future are likely to be significantly enhanced by next generation WiFi technology. Probably, the initial deployment would be little slow due to the above reasons. It would be interesting to see how the planned features play out in real life during this phase.

References

  1. Wi-Fi Alliance® celebrates World Wi-Fi® Day 
  2. Facts and stats Wireless Broadband Alliance
  3. IEEE P802.11 – TASK GROUP AX – GROUP INFORMATION UPDATE
  4. Wi-Fi CERTIFIED 6 Wi-Fi Alliance
  5. Wi-Fi CERTIFIED 6â„¢ coming in 2019
  6. Wi-Fi CERTIFIED 6â„¢: Highlights
  7. Usage models for IEEE 802.11 High Efficiency WLAN study group
  8. A Tutorial on IEEE 802.11ax HighEfficiency WLANs