The Wi-Fi Alliance has announced plans to develop HaLow, a new version of the Wi-Fi standard optimised for IoT applications.
HaLow will be based on the IEEE 802.11ah standard, will operate in the 900MHz band, giving better in-building penetration than current Wi-Fi operating in the 2.4GHz and 5GHz bands and over twice the range of current Wi-Fi technologies. However, it is at least two years away from commercial availability during which time proprietary LPWAN technologies like LoRaWAN and Sigfox are expected to gain significant traction, along with new variants of 3GPP standards Narrowband Cellular IoT (CIoT) Narrowband Cellular IoT (CIoT) Narrowband Cellular IoT (CIoT) and Narrow-Band (NB-LTE).
802.11ah is a Wi-Fi variant for sub-1GHz band, expected to be finalised by IEEE in January 2016. (According to the IEEE web site board approval is scheduled for August 2016. No date is indicated for approval by ANSI).
According to Wikipedia, “a prominent aspect of 802.11ah is the behaviour of stations that are grouped to minimise contention, use relay to extend their reach, use little power thanks to predefined wake/doze periods, are still able to send data at high speed under some negotiated conditions and use sectored antennas.”
802.11ah uses the 802.11a/g specification down sampled to provide 26 channels, each of them able to provide 100kbps throughput. It can cover a one-kilometre area and aims to provide connectivity for thousands of devices from a single access point.
802.11ah is seen as being particularly well-suited to M2M applications where wireless traffic from large numbers of sensors is consolidated for transfer to a central control point. An IEEE technical paper from October 2014 offers “a performance assessment of IEEE 802.11ah in four common M2M scenarios such as agriculture monitoring, smart metering, industrial automation and animal monitoring.”
According to the Wi-Fi Alliance “Wi-Fi HaLow will broadly adopt existing Wi-Fi protocols and deliver many of the benefits that consumers have come to expect from Wi-Fi today, including multi-vendor interoperability, strong government-grade security, and easy setup.”
The organisation also says: “Many devices that support Wi-Fi HaLow are expected to operate in 2.4 and 5GHz as well as 900MHz, allowing devices to connect with Wi-Fi’s ecosystem of more than 6.8 billion installed devices.”
Further advantage touted are: “support for IP-based connectivity to natively connect to the cloud, which will become increasingly important in reaching the full potential of IoT” and “ Dense device deployments will also benefit from Wi-Fi HaLow’s ability to connect thousands of devices to a single access point.”
