Wi-Fi HaLow, Explained: Low Power and Necessary Bandwidth Meet Extreme Range

This post will briefly explain Wi-Fi HaLow, a new standard that extends the use of Wi-Fi to low-bandwidth devices.

Since its beginning, Wi-Fi has evolved to be "faster" by increasing the frequencies and bandwidth. That approach comes at the expense of high hardware costs, shorter ranges, and more energy consumption. An extreme example of this trend is WiGig, which uses the super high 60GHz frequency and has proved to be the most short-lived standard in real-world usage due to its extremely limited range.

In more ways than one, Wi-Fi HaLow is the opposite. And it might just be the right choice for many applications.

Dong's note: I first published this post on July 19, 2023, and updated it on April 15, 2024, with up-to-date information.

What is Wi-Fi HaLow?

The name is the friendly moniker for the IEEE 802.11ah wireless networking standard.

First published in 2017 by the Wi-Fi Alliance, Wi-Fi HaLow (HEY-Low) uses a sub-Gigabit frequency—900MHz—compared to the much higher frequencies of traditional Wi-Fi 4/5/6/7 standards, that include 2.4GHz, 5GHz, and 6GHz.

It's worth noting that, in the US, Wi-Fi HaLow uses unlicensed bands. As a result, it's easier to adopt and deploy since there are no regulatory barriers.

Wi-Fi HaLow: Extreme range, low power, and enough bandwidth for IoT needs

The way radio waves work, the lower frequency generally means:

• longer the signal range,
• less bandwidth,
• lower power required on the broadcasting end, and
• less energy consumption on the receiving end.

And that's the purpose of Wi-Fi HaLow. The new standard is designed to deliver signals over a vastly more extensive range. Specifically, its range can reach over a mile with sustained rates of around 150Kbps. Shorter distances generally yield higher bandwidth, but it will still not be more than a few tens of megabytes per second. The point is that Wi-Fi HaLow is limited in bandwidth, and it's supposed to be slow.

The extensive range is great, but why would anyone want such sluggish connection speeds? It's simple. Range and speed can play two distinctively different roles depending on the applications.

IoT devices and bandwidth

Faster is not always better or even necessary. Many networking devices, particularly those within the Internet of Things (IoT) crowd, don't need a lot of bandwidth.

For example, a gate sensor generally has a few simple possibilities in terms of action—open, closed, locked, or unlocked—and those commands or statuses only need a few kilobytes of data to transfer. Similarly, the on, off, or dimming management of a light bulb doesn't require much data.

And on the more demanding end, a security camera only needs a few Mbps to deliver live footage. That's especially true with modern video compression methods.

The point is that in certain applications, high bandwidth is irrelevant. On the other hand, range is crucial since these low-bandwidth devices need to be connected somehow. And they are often scattered over a large area—the gate can be hundreds of feet from your main residence.

Wi-Fi HaLow: The much better alternative to existing low-power wireless standards

Currently, we have two different approaches for low-bandwidth (IoT) connectivity:

The first is to use traditional Wi-Fi with them, often on the 2.4GHz band. In this case, apart from the short battery life, these devices can also burden the existing network. They slow it down significantly—as detailed in this post on the subject.

The second, and also recommended, approach is to use special low-power wireless standards—such as Zigbee, Thread, or Z-Wave.

In this case, the particular standard's hub is the only networking device that connects to the network—via traditional Wi-Fi or a network cable—with an IP address. While these wireless standards help with performance and battery life issues, low-bandwidth devices themselves are hard to manage since they are not part of the IP network—they don't even support the IP protocol natively.

And then there's the lack of resilience: if your Z-Wave hub stops working, all its connected IoT devices become useless. In other words, the hub itself is the single point of failure.

And that's where Wi-Fi Halow comes into play. It's a combo solution that simplifies connectivity. With it, all device types can use Wi-Fi and be part of the overall IP network without adversely affecting one another's connection speed or having to use more power than necessary. That's the idea, anyway.

Wi-Fi HaLow (vs. Wi-Fi 6E): General specifications

As a Wi-Fi thing, Wi-Fi Halow's range and sustained rates change depending on specs, environment, and specific hardware. The table below shows how this standard differs from Wi-Fi 6E, the first "normal" standard that uses the highest 6GHz frequency band.

Wi-Fi 7 uses all three bands (2.4GHz, 5GHz, and 6GHz).

	Wi-Fi HaLow	Wi-Fi 6E
Wi-Fi Band	900MHz	6GHz
Maximum Frequency Width Available (the band's total width)	26MHz (from 902MHz to 928MHz)	1200MHz
Channel Width (the portion of the band's width used at a particular time)	1/2/4/8/16MHz	20/40/80/160MHz
DFS Channel Use	No
OFDMA Support	Yes (narrow bands)	Yes (wide bands)
Highest QAM	256-QAM	4K-QAM
Maximum Bandwidth per Stream (ideal conditions and range)	From: 4Mbps @ 1MHz To: 86.7Mbps @ 16MHz	From: 150Mbps @ 20MHz To: 1200Mbps @ 160MHz
Wi-Fi Security	WPA3
Native IP Support	Yes
Power Consumption	Extremely low with multiple power-saving modes (coin battery-operated device can last for months or years)	High with TWT (suitable for handled or plugged-in devices only)
Effective Range (within line of sight)	≈ 1 mile (1.61 km)	≈ 75 feet (23 meters)
Wall/Object Penetration	Excellent	Mediocre
Intended Usage	IoT and low-bandwidth devices	General network devices

Wi-Fi HaLow follows the same general Wi-Fi rules:

1. The narrower the channel (in MHz) means:
   • the less information it can carry—the lower the speed.
   • the more stable the connection is.
   • the longer range and the better object penetration.
2. Not all hardware will support all the channel widths, QAM, or other options available.
3. Susceptible to interference caused by devices sharing the same band. For example, ham radios and Z-Wave devices use the same frequency as HaLow.
4. The performance of a particular device is always that of the lowest denominator involved and depends greatly on the environment.

Realistically, we can expect Wi-Fi HaLow to deliver a solid bandwidth of around a few megabits per second (Mbps) over hundreds of feet in range. And that's good enough for the standard's target applications. You can use it to deliver general Internet access fast enough for simple applications such as text-based emails or light web surfing.

Availability and usage

Just like Wi-Fi 6E or any new Wi-Fi standard, to take advantage of Wi-Fi HaLow, we need entirely new hardware.

On the broadcasting side, this standard can be added to any existing network via an access point, similar to hardware upgrades on the broadcasting end. Eventually, routers with Wi-Fi HaLow built-in might be available.

Currently, there are only a few Wi-Fi HaLow broadcasters worldwide, but that's slated to change starting in 2024. Ultimately, it's the support on the clients' side that will drive the adoption of the new standard. In most cases, these are new generations of outdoor devices that, for the first time, become "smart" thanks to their easy connection to the IP network. And that will take a while.

This Wi-Fi HaLow kit can supposedly extend your network up to 2600 feet (≈750 meters) in range. While that range might be true, keep in mind the limited bandwidth.

The takeaway

Wi-Fi HaLow completes the Wi-Fi family by delivering the much-needed-yet-so-far-underrated portion of connectivity: the combo of extensive range, long battery life, and low bandwidth.

When widely available, Wi-Fi HaLow will gracefully solve the problem with the increasingly common use of "smart" devices, which have been fragmented between multiple wireless standards, including traditional Wi-Fi, where things get problematic.

As a new standard, Wi-Fi HaLow will eventually become common. When you need it, know that, in principle, it'll work just like any existing Wi-Fi device you've had for years—and that's part of its beauty.