In December 2009, ideas arose for the first time to operate WLAN alias Wi-Fi in the license-free range below 1 GHz. Compared to operation in the established 2.4 GHz band, this idea promised a good 9 dB less path loss, which should result in large ranges and good coverage in buildings in order to integrate smart refrigerators, vacuum robots and the like into the Internet of Things (IoT) .
The standardization project 802.11ah of the international standardization body Institute of Electrical and Electronics Engineers (IEEE) started work on WLAN for the IoT in October 2010. Within the large group of WLAN standards (IEEE 802.11), 11ah developed into an almost 600-page hodgepodge of ideas, functions and property rights. The tussle culminated in 2015 in a dispute over the new IEEE licensing rules and the question of whether or not the radio chip giant Qualcomm would commit to them how to throw Qualcomm’s ideas out of the ordinary.
Ultimately, however, the working group was wasting valuable time. Because Qualcomm found a legal loophole to apply the old license rules, which are cheaper for patent holders, for all eternity. The standard was only published in December 2017. Not least because of the next big thing – IEEE 802.11ax aka Wi-Fi 6 – IEEE 802.11ah got pretty quiet. The hubris widespread in the IEEE 802.11 working group, that the regulatory requirements of the world regions are already being adapted to their own standards once the latter are ready, made things even more difficult.
Fell on your face
In Europe, however, it failed. Even the regular transmission of the beacons (presence signal from the access points) takes so long with 802.11ah that the maximum duty cycle permitted for these applications in the European sub-1 GHz band (863 to 868 MHz) is exceeded. There would be no more time for user data packets. The EU was only convinced in 2017that a slightly higher duty cycle would not unduly disrupt the existing systems (garage door openers and the like).
Since 2016, the manufacturers’ association Wi-Fi Alliance (WFA) has been trying to obtain certification for IEEE 802.11ah internally. Due to a lack of interest from members the HaLow program, which was finally presented on November 2, 2021 so far only saved from being hired by new exceptions from the WFA Board of Directors.
Now the WFA announces the start in December 2021 whipped six HaLow-certified products, most of which are developer boards and feasibility studies. Rumor has it that Qualcomm has an 11ah design up its sleeve, but will not implement it until a market develops. Nothing of the kind is known from the other large WLAN chip manufacturers (Broadcom, NXP, MediaTek, Infineon).
100% growth annually?
Market research companies predict an annual doubling of the HaLow units sold. According to this, 1.6 percent of the total of 5,000 million WLAN devices sold annually should be certified for HaLow by 2026. It is doubtful whether these predictions will come true: Wi-Fi 6 HaLow could just as easily make it superfluous. Thanks to the support for smaller channel widths down to 2 MHz, the current WLAN standard can achieve higher ranges relevant for the IoT mass market. The advantage of mature and optimized chip designs should not be underestimated. While all currently available HaLow components have been redesigned from the ground up, Wi-Fi 6 chips benefit from twenty years of experience in mainstream WLAN.
Ultimately, HaLow will foreseeably continue to suffer from not having a globally harmonized spectrum: The areas that can be used for HaLow are regionally tattered and offer very different bandwidths. HaLow …….