Hi everyone! I’m working on a mining project and we’re evaluating Wi-Fi HaLow (802.11ah) to improve connectivity inside tunnels (and possibly from tunnel entrance to surface infrastructure). Sub-GHz propagation/penetration seems like a perfect fit.
I’d love advice from anyone with industrial/mining experience (or general HaLow deployment experience) on the best path to maximize reliable range.
1) Higher-power HaLow modules / reference designs
Are there higher-TX-power HaLow modules you recommend for evaluation in industrial environments?
I’ve seen products described as ~1 W / 30 dBm modules (e.g., TD-HALOM “1W” module), and I’m trying to understand what’s realistic and what’s actually deployable/certifiable in the field.
2) Does “more RF power” actually mean more range?
In practice, how much range improvement do you typically see from more TX power (vs. being limited by receiver sensitivity / noise / interference)?
How often do you hit regulatory caps (conducted power / EIRP) before hardware limits? (Example: FCC 15.247 allows up to 1 W conducted for certain digitally-modulated systems in 902–928 MHz.)
3) Antennas & tunnel considerations
For tunnels, do directional antennas (Yagi/panel) at each end help a lot, or do reflections/multipath dominate?
Any best practices for antenna placement, cable losses, and using repeaters/mesh nodes to “walk” signal down the tunnel?
4) Long-range claims (10–66+ miles)
Morse Micro describes a ~15.9 km (~10 mile) theoretical maximum based on 802.11ah slot timing (52 µs slot time / time-of-flight constraints).
Teledatics reports a 106 km (66 mile) HaLow link using a 1 W module and directional antennas in a line-of-sight test.
Is that realistic with standard-compliant timing, or does it require non-standard timing changes + extreme line-of-sight + high-gain antennas + very low data rates?
If helpful, I can share more details about tunnel geometry, spacing constraints for repeaters, and target data rates.
Yes, there is a potential ‘great fit’ in such an environment.
Sounds good, will be happy to compare notes. We are a ISP/NSP/WISP, and currently working with a couple of ‘mining’ clients to solve communication issues. Our clients are involved in ‘Surface’ and ‘Strip’ mining .. (no digging tunnels).
Higher power in most cases not a good solution. To give you an example , consider Audio.. Just by cranking up the Volume to reach farther is not the best solution, since the ‘quality’ starts to get distorted and needless to say the near client starts to go deaf !
That is based on the FCC limits for the 900mhz (unlicensed) operation, it is pretty good limit to work with . Keep in mind that for communication systems, the key is Signal to Noise Ration and an adequate receive level signal .
more RF power = More Range .. maybe yes, maybe no .. again go back to the example of a loud speaker, turning up the volume … e.g. if the speaker is blasting in one direction, and you are going to be standing some distance behind the speaker .. well you get the idea !
Not sure what is the context of the question.. after all the system is going to based on your choice of power, antenna gain and desired SNR.
Even signal coverage inside a tunnel is always a challenge ..In many cases for a desired uniform coverage, typical antennas are not ideal, and as such Tunnels use “leaky cable” / “leaky feeder” for antennas Look them up..
Well, all of that is going to be determined by your desired functionality parameters .. : )
Take all of that with a grain of salt .. Kind of like 'how far can you pull chewing gum before it beaks
(in outer space, I am sure Wifi Halow can do 1000mile links )
There is no ‘gps’ or ntp based timing sync with the Wifi Halow protocol. Designing for extreme LOS is a very different use case, vs yours (in the tunnel).
The key question you have to answer is , how exactly your users will be using WifiHalow . Are you using it as a middle pipe to connect WIFI ? are you using to to tie control equipment ? Sensors ? .. In my use case the end users are either using WIFI or we are deploying Private LTE , and looking at WIFI Halow as a quick adjhoc Mesh ‘middle pipe’ connection for sensors and OOB communication systems.
(Keep in mind, I am pretty sure your Mine is already using some 900mhz stuff , so you need to make sure you are not going to be trampling over another comm system (rf wise).
That could be a fun exercise. Keep in mind that it is highly likely that one would have to ‘develop’ . integrate , assemble the ‘working product’ for such a deployment. Right now Wifi Halow exists in modules that can be used to create functional systems.
I’m very interested in your HaLow implementation. I’m actually working with @josefeliuf on the mining project mentioned in this thread.
To give you some context on our current progress: I’ve personally tested Anjielo repeaters and successfully maintained a stable video call through three levels of underground concrete. It was a great result, but now we want to take it to the next level: achieving a 1 km link inside a tunnel.
Could you share more details regarding the maximum range you’ve achieved and the actual data throughput (speed) at those limits?
Specifically, I’d like to know:
Were your results achieved in a Line-of-Sight environment or an obstacle-heavy scenario (like a tunnel or building)?
What was the TX power and antenna gain (dBi) used for that specific link?
Based on your experience, do you think a 1 km link with enough bandwidth is realistic in a tunnel environment?
