As the various LPWAN protocols have tussled for market position, the WiFi story has been the quietest, even though the IEEE has defined a standard for this market – 802.11ah – and the collective weight of the WiFi community completely dwarfs that behind any other connectivity option, even NB-IoT. The first arrival of 802.11ah silicon may start to change all that.
There are many supporters of the idea that WiFi, and the IEEE 802.11 standards on which it is based, should cover all the connectivity bases from personal area to wide area; from low to high power; from sub-1 GHz to millimeter wave spectrum; and from low to multi-gigabit data rates – and therefore support almost any use case. That clearly takes WiFi well beyond its roots in the local area network, but a common standard would, of course, drive massive economies of scale and a rich ecosystem.
It has made significant progress – the 60 GHz WiGig technology supports very fast data rates with a WiFi-like standard for mmWave bands; high power WiFi variants underpin fixed wireless services in the USA and elsewhere; of course WiFi dominates indoor wireless broadband access in the home and enterprise. The 802.11 standards lie beneath technologies like DSRC for intelligent vehicle communications and other specialized vertical market implementations. The upcoming 802.11ax standard, the basis of ‘WiFi 6’, will add high levels of density and multi-gigabit rates as well as improved latency, emulating some of the advances made by 5G.
So the gap has been in the LPWAN segment, and therefore markets like smart city or intelligent transport, where 4G-based standards have started to fight it out with LoRA and other unlicensed spectrum systems, mainly in 900/868 MHz.
There has been an unusual delay, given the size of the WiFi ecosystem, in pushing commercial silicon into 802.11ah, so that WiFi can assert its role in this market.
The IEEE’s 802.11ah process started – initiated by Qualcomm – in 2014. The WiFi Alliance announced the HaLow branding at the Consumer Electronics Show (CES) three years ago. The Alliance’s brand and certification announcements is usually, in the WiFI market, the trigger for product launches, even before the standards are finalized (that pre-standard activity is already being seen in the 802.11ax space). But even when the 11ah standards were completed two years ago, there was a deafening silence. To date, only one company, Korean start-up Newracom, has shipped a chip (in use in a Korea Telecom gateway).
Some have blamed the nascent state of commercial LPWAN applications for the apathy – an addressable market that may be attractive to a start-up technology, or as an extension of a 4G model, but is tiny for WiFi vendors and service providers.
Others have said 802.11ah is a step too far in extending the reach of the WiFi technology, and HaLow (the WiFi Alliance brand for this standard) will not be fit for purpose. In particular, they question whether it entails too many compromises compared to technologies which were designed from scratch for the Internet of Things. HaLow, at least in its current specification, will not be as low cost and low power as LoRA or Sigfox, though it is likely to be cheaper (once the huge ecosystem moves into action) and lower power than NB-IoT and certainly LTE Cat-M. Supporters hope that delivering up to a few Mbps over distances up to a kilometre, with support for thousands of nodes per access point, will prove a sweet spot. Critics believe it will fall between two stools, with neither the ultra-low power needed for some M2M applications, nor the relatively strong data performance needed for others.
A more realistic sense of the truth of this will be easier to achieve with commercial offerings. This year, at last, there will be several commercial chips launched, though mainly from start-ups rather than the WiFi heavyweights like Broadcom. According to EETimes, four start-ups, at least, will sample HaLow silicon this year. They will help to test the market, and if it looks good, the giants are sure to follow, especially as they will have completed their early work on 11ax – a far more certain market opportunity – and will have more bandwidth to pursue 11ah. Another catalyst will be the start of WiFi Alliance certification in August, following a series of plugfests starting this month – always an important milestone to build confidence in a new standard.
One of the start-ups is Australia’s Morse Micro, which believes it will sell millions of units before the end of this year, into networks for use cases such as agriculture, utilities and video surveillance. Its implementation of HaLow will deliver about 160Kbps over at least 100 meters (longer with line of sight), and will support more than 8,000 nodes per access point, according to co-founder Michael De Nil.
Morse has its eye on the huge. potential of the Chinese market, where it will open an office and sample chips in July. De Nil expects Chinese OEMs to take 6-8 months to get into production, whereas US or European vendors will often take over a year.
The five start-ups aiming to launch HaLow chips this year:
Newracom of Korea, the only company with a commercial HaLow chip (used in a Korea Telecom gateway).
Morse Micro of Australia, considered the most developed of the pre-commercial start-ups, aiming to sample silicon around mid-year.
Methods2Business of The Netherlands, which has IP for a HaLow media access controller (MAC) based on a Tensilica digital signal processor.
Adapt-IP of the USA, which has developed an FPGA version of a HaLow baseband and is considering a partnership to design a complete HaLow chip this year.
Palma Ceia SemiDesign (PCS), which has IP blocks for NB-IoT and HaLow transceivers and aims to raise funds to create its first chip level product for HaLow this year.