The Wi-Fi Alliance branded its next-generation 802.11ah wireless protocol as Wi-Fi HaLow. It is targeted at the Internet of Things(IoT), which includes the smart home, connected car, and digital healthcare, as well as industrial, retail, agriculture, and smart-city environments. Unlike the older and more familiar 802.11 protocols, which mostly use the 2.4 or 5GHz bands, 802.11ah is a sub-gigahertz protocol that uses the 900MHz band. It has an enviable combination of characteristics.
Wi-Fi HaLow can cover a greater distance than the 2.4 and 5GHz Wi-Fi protocols. While your home Wi-Fi network equipment can transmit up to 100 meters — a little longer than a football field — under ideal conditions, HaLow can transmit at reasonable rates up to 1 kilometer (a little less than two-thirds of a mile). The Wi-Fi Alliance, however, makes a more conservative and reasonable claim of it having a coverage range of nearly twice that of the Wi-Fi networks we have today.
Another characteristic of the 900MHz band HaLow is that it has better propagation (the ability to transmit in the presence of various kinds of interference) and penetration (the ability to go through walls and other obstructions). This combination of greater range, propagation, and penetration means that those Wi-Fi dead spots in your home or office that currently requires the installation of a wireless extender will be reachable by a single HaLow access point — critical if you plan to have IoT devices all around and in your home or business.
The third important HaLow characteristic is its ability to transmit a minimum 150Kbps transmission over 1 or 2MHz channels. This kind of short, bursty data means that the sensors of IoT devices only need to be on for a short time, thus conserving power and allowing for longer battery life.
That leaves transmission speed, and that’s where HaLow may disappoint. HaLow, focusing on IoT, is not intended as a high-speed general purpose wireless network solution for your home or office. As a result, HaLow speeds will be in the low tens of megabits per second rather than in the hundreds of megabits. This is perfectly fine for its intended IoT-related purpose, though. And, for many people, tens of megabits per second is sufficient for most activities. In fact, it probably describes most people’s current home network speed, if not the average ExtremeTech reader’s.
As with all new wireless standards, it will be a while before we see the first HaLow radio hardware in consumer products. However, when they do appear, it’s a good bet HaLow will begin to supplant Bluetooth in certain applications.
Leave a Reply