The champion of consumer connectivity, Wi-Fi’s latest version further boosts user accessibility and throughput. But the changes also were made with one eye on wireless sensor networks.

What you’ll learn:

• Wi-Fi was borne of several wireless innovations dating back to the 1970s.
• Wi-Fi 6 brings technical advantages to IoT deployments.
• The technology is poised to become the foundation of future smart homes.

Wi-Fi has a complex history. That’s perhaps not surprising since the radio technology represents a melding of many innovations, four of which stand out. The first was the development of a pioneering packet-radio network in Hawaii during the 1970s. ALOHAnet connected seven campuses on four islands across the archipelago, ensuring that they could all communicate with each other through a central computer on Oahu.

Second, in 1985, the U.S. Federal Communication Commission (FCC) formalized the use of the 2.4-GHz spectrum (among other allocations) for unlicensed industrial, scientific, and medical (ISM) use. The move encouraged commercial organizations to consider how they could make use of this new radio resource.

Then, in the 1990s, radioastronomy scientists at Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) worked out a way to overcome the multipath problems that afflicted indoor, high-throughput radio communications. The invention formed the basis of wireless local-area networks (WLANs) and paved the way for widespread Wi-Fi deployment.

Finally, an Institute of Electrical and Electronic Engineers (IEEE) standards committee was formed and tasked with defining the physical-layer (PHY) and media-access-control (MAC) specification for a WLAN protocol dubbed IEEE 802.11. The target application was “wireless Ethernet,” using RF technology to link computers together in the fashion pioneered by wired networking.

The committee’s work resulted in the first version of the Wi-Fi specification, IEEE 802.11-1997, which was published in June 1997. Then a 1999 amendment to the standard introduced the technology upon which today’s versions of Wi-Fi are largely based. The Wi-Fi Alliancewas formed to commercialize the technology.

Power and Deployment Challenges

Now there’s a fifth key event influencing Wi-Fi’s evolution—the Internet of Things. It’s a phrase that was still two years away from being coined—the term was dreamt up in 1999 by Kevin Ashton, an executive working to promote RFID—when the first version of Wi-Fi was officially adopted. Today, connecting billions of devices (or "things") to the established internet is largely being achieved by wireless technology.

For short-range IoT networks, Bluetooth Low Energy (BLE), Thread, Zigbee, and other protocols are shouldering the load. For the IoT’s wide-area networks (WANs), LTE-M/NB-IoT (cellular IoT) and LoRaWAN are proving good options. But what of Wi-Fi? At first glance, it would appear to be the perfect option for wireless networks needing greater range than that provided by the short-range, low-power protocols, but not the kilometer-plus range of the WAN technologies. However, closer inspection reveals Wi-Fi has some considerable drawbacks for IoT applications.

The first problem is power consumption. Wi-Fi was primarily designed for good throughput, which costs battery power. In contrast, IoT wireless technologies typically try to limit on-air time to extend battery life and hence minimize maintenance. The tradeoff is lower throughput, but this is hardly an issue for sensors and actuators that only infrequently send small amounts of data.

Second, Wi-Fi struggles in dense deployment scenarios. Many of us are familiar with patchy service when accessing public hotspots in busy malls and libraries. It’s annoying, but consumers can typically afford to be tolerant. Industrial networks comprising hundreds of sensors are a different matter.

Built for the IoT

Now a version of Wi-Fi, technically named IEEE 802.11ax and marketed as Wi-Fi 6, promises to address the deficiencies that have hampered the technology’s widespread adoption for the IoT. Approved by the Wi-Fi Alliance earlier this year, Wi-Fi 6 was specifically designed to meet the requirements of dense deployments, both public and industrial. The new version offers several enhancements, but the headline features are improvements to throughput and spectral efficiency, which allow for more network connections while still maintaining good service.