Skip to content

HaLow (802.11ah)

Experimental — actively under test

PugetMesh is beginning HaLow testing at Haystack. Treat everything here as evolving: AREDN's HaLow support is still maturing, and our local band plan and hardware picks will firm up as testing progresses. Coordinate on Discord before putting a HaLow node on the air.

What HaLow is

HaLow (IEEE 802.11ah) is a WiFi standard that operates in sub-GHz spectrum—including the 902–928 MHz ISM band, and amateur allocations near 900 MHz where permitted. Compared to 2.4/5 GHz microwave it trades raw speed for much longer range and far better penetration through foliage and terrain.

  • Throughput: roughly hundreds of kbps up to a few Mbps, depending on conditions
  • Channel width: 1, 2, 4, or 8 MHz—narrower channels mean a smaller spectral footprint and longer range
  • IP-native: it's standard WiFi/IP, so it drops directly into an AREDN mesh

That combination makes HaLow attractive for obstructed paths—forested valleys, terrain shadows, and sites where a clean 2.4/5 GHz line of sight simply isn't available.

Status in AREDN

HaLow support landed in AREDN's version 4 (Babel-only) production line for some 900 MHz radios. It is real, but still rough around the edges:

  • Support is limited to specific radios—verify your exact model against the Supported Devices list before buying.
  • Driver support in current Linux kernels is immature; expect occasional device restarts and some troubleshooting, and note that HaLow nodes may need a power cycle after a firmware upgrade.
  • Because it's v4, HaLow nodes are Babel-only and won't talk to legacy OLSR-only nodes.

Known-working hardware to date includes the Morse Micro MM-HL1-EX and Heltec HT-HD01 / HT-HD01 V2. More radios are being added over time—check the release notes and supported-devices list.

900 MHz coexistence

HaLow at ~900 MHz shares spectrum with our MeshCore and Meshtastic LoRa networks, which also live in the 900 MHz band. Before deploying HaLow:

  • Plan your frequency/channel to avoid stepping on the LoRa mesh (and vice-versa).
  • Keep channels as narrow as the link allows—a 1 MHz HaLow channel is far easier to fit around the LoRa mesh than an 8 MHz one.
  • Coordinate on Discord so we keep the band usable for everyone.

Local testing at Haystack

We're in the early stages of evaluating HaLow for PugetMesh at Haystack. Questions we're working through:

  • Which supported radios perform best on our regional paths
  • Realistic throughput and range on obstructed links
  • A band/channel plan that coexists cleanly with MeshCore/Meshtastic
  • How HaLow links best tie into the existing 2.4 GHz AREDN backbone

(Hardware under test, band plan, and results to be documented here as the Haystack testing develops.)

If you're testing HaLow, share your results on Discord—real-world regional data is exactly what we need right now.