Low-Power Wi-Fi Extends Signals Up to 3 Kilometers
spectrum.ieee.org
spectrum.ieee.org
It’s not entirely unrealistic to get several and replace the LNB’s with Wifi adaptors, and set up multi diferectional internet spongeing setup.
Of could it would look ridiculous.
Put it on a camper, and it'll look like yet another old hippie tinfoiler from movies/TV shows.
There is hardware advertised for 1Gbps for 100+km links!
Select example:
> Next, Paul et al. [62] reported on their observation of the WLAN link performance in open outdoor networks. The deault packet size was 1470 B for all reported measurement campaigns. They achieved a maximum range of 1800 m LOS at 148 Mbps with IEEE 802.11n links in outdoor locations for back-haul connection among WLAN APs.
I'm sure there are things here making the actual tech impressive, presumably biggest thing being power consumption and size. But just saying that the demo is not doing much when they don't provide any details of the setup.
Deploying License-Free Wireless Wide-Area Networks:
https://www.ciscopress.com/store/deploying-license-free-wire...
For long distance terrestrial wireless communication on sub GHz wireless frequency, now people normally use Low Power Wide Area Network (LPWAN) solutions like LoRa, SigFox or ELTRES, but SigFox has been out of business, and ELTRES being Sony mainly limited to Japan at the moment. That leaves majority of the LPWAN installation based on LoRa.
LoRa however is not without its problem namely the spreading factor (SF) between 8 and 12 limitations, if you want to go further you really want to use the highest SF but the bandwidth goes down exponentially and instead of Kbps you have merely lowest bits/bytes speed transmission even with clear Line-of-Sight (LoS). We have tested LoRa transmission over the sea (island to mainland) and it even works for more than 20 km. That's OK if you have only IoT systems where the job is turning some remote switch or relay to be on or off.
There is a real need for efficient low power higher bandwidth transmission (Mbps range not Kbps) and this how HaLow by IEEE as inside this post come into the picture, and another cellular based Reduced Capability (RedCap) standardized in 5G release 17 standard by competing organization 3GPP. These new standards has more higher bandwidth than the existing LoRa and existing 4G/5G standards for examples NB-IoT and LTE-M but the facts the latter standards use existing 4G/5G infrastructure is a big plus and the latest RedCap standard want to capitalize on that.
I am excited about any kind of new network topologies because the current state of US Broadband is abysmal.
Foolishly, I am still hopeful that Artemis Networks will pull rank. We'll see.
It's _omnidirectional_. You don't need to point it.
source: had the only wifi point for hundreds of km in Afghanistan.
https://www.mouser.com/catalog/specsheets/MorseMicro_142024_...
Previous long-range WLAN deployments were pretty much limited to point-to-point fixed links using high-gain directional antennas. Being able to move around in arbitrary orientations opens up dozens of new use cases.
One particular application I'm interested in is tracking location data and athlete performance during rowing regattas. The course is over 2km long and over 150m wide, which makes it unsuitable for regular wifi without deploying a dozen specialized APs, and directional antennas are tricky due to all the movement involved.
Being able to put a single omnidirectional antenna at the halfway point and having it Just Work would be a absolutely amazing.
of course the protocol is not the same, but it's not very different either
4g/5g might also have techniques to improve connectivity in a 3km radius when you have buildings and so many other problematic things, while wifi was designed for building interiors.
I don't know how expensive is a cheap 5G antenna, but seems like it's a tech designed for longer distance, so why use wifi?
I remember reading somewhere that it has a lot on common with phased array radar systems.
Here is a Wikipedia link: https://en.m.wikipedia.org/wiki/Smart_antenna
What I can't square away is I also remember learning about beamforming in my Wireless engineering course, and I thought WiFi had some similar too.
But for some reason my brain is telling me 5G can beam really narrow "spotlights" of signal to the client devices.
Sorry for the vagueries but it's all I can recall.
> This paper demonstrates the use of Unlicensed National Information Infrastructure (UNII-3), 5.725-5.825GHz, Wi-Fi frequencies, in the IEEE802.11a/n standard ... A link distance of 24.3 kilometers, the longest so far, has been achieved. An average peak throughput of 98.4Mbps has been observed ... using a TDMA based Wi-Fi radio overcomes the fundamental challenges associated with the use of the off-the-shelf Wi-Fi radio whose Media access layer is based on CDMA/CA MAC protocol.
2021, "Open-source private LTE and 5G networks", 600+ comments, https://news.ycombinator.com/item?id=27946947
Then need a non-profit provider. Let's anyone sign up and manage cells. It runs in the CBRS bands. It is open to anyone. Although, might be commercial opportunity to restrict access for businesses and households.
That's not actually true. You can get a private 5G network from AWS for just $4000 a month ( https://aws.amazon.com/private5g/pricing/ ). It operates in the unlicensed band.
You can also buy a local frequency license for your campus. They can be surprisingly cheap, around $500 a month.
This is out of range for home users, but very attractive for some large industrial customers who want to add reliable connectivity for large warehouses or factories. Mostly because WiFi reliability sucks in many environments, and it's not getting better.
We also have other systems for unlicenced long-range communications (eg. LoRa), but once that becomes (more) popular, the spectrum will be full of that too.
This could be pretty intense. Using the below tool I had a play and found that you could have about 1.1 million people within 3km of you when in Cairo.
If anything it makes more amazed that regular wifi works as well it does between the house and garden, and I'll try to remember that next time I'm bemoaning its magic.
I’m in New Zealand and at that density you could fit our entire population in just over 2 of these 3Km circles.
I feel irritated when people stand too close to me, but at the Cairo density there must be tens of people within a stone throw.
Maybe if they formed a mesh network that prioritized signals of a certain power level and had dynamic power levels to avoid losing touch with the mesh while avoiding blocking close + strong signals.
I think that's one of the reasons why unlicensed (ISM in the case of WiFi) spectrum is best used where the natural cell size (due to attenuation) is small.
http://docs.arednmesh.org/en/latest/arednGettingStarted/ared...
https://www.instructables.com/Wifi-Signal-Strainer-WokFi/
At some point people were trying to set the record for the longest range wifi signal.
Ah, the joyful age of high school. No money or power to do things "the right way", but ample free time to skill up and hack your way around.
11p and 11bd are more generally V2X comms of which there are a cellular variants (C-V2X and NR-V2X)
Such a centralised system could also do some sanity checks. But in a peer to peer system how would one guard against malicious actors shouting false information?
Using localised peer to peer comms also eliminates some of the privacy concerns with directly sharing this info with a centralised authority as well as removing the need for any global persistent identification for this info. They also eliminate any reliance on the cellular network/internet which cannot be guaranteed to function normally for safety critical communications.
There are also alternate cellular standards for vehicle to vehicle comms called C-V2X and NR-V2X so it's entirely feasible one cellular radio could do general data comms and the P2P safety standards.
But they are being used to build systems that are advisory or are closed systems.
Here is an article on their project and they have published a book on the what they're building in Detroit. It is a charity that I personally support.
https://medium.com/read-write-participate/connecting-the-unc...
That's... not why your AP signal is weak.
It's because of laws that limit your broadcast strength.
Saturates fully.
2.4ghz is still too crowded in urban environments, but every smart device on it has enough bandwidth to function.
I've given up trying to improve this after spending a decent amount of time and money.
The allowed broadcast strength in the 2.4GHz band is so high that in a (sub)urban environment you won't just receive your own network, but also those of literally a dozen neighbors around you - and there are plenty of areas in your house where you can receive your neighbor's network better than your own so you end up in a shouting match.
And of course many people "solve" their poor wifi connection by adding a repeater or increasing the transmission power, which fixes the symptoms for them but makes the overall problem worse for everyone around them.
5Ghz has essentially solved the problem, simply because the signal gets killed real quick by things like walls - especially exterior ones. Your signal won't make it much beyond your house so you don't get in a shouting match with your neighbors, and adding a repeater (mostly) does what you'd expect it to.
But it isn't so much an issue of power, I don't think: If we erased all of the existing 2.4GHz devices from the world and replaced them with devices that only transmitted 1/10th of the previous power (a 10dB reduction), then: We'd still have to contend with our neighbor's neighbors' 2.4GHz background noise.
Like in a room where everyone is shouting all at once: You can't understand what the guy across the room is shouting because of all of the noise.
But we still have the same problem in a room where everyone is carefully talking quietly all at once: You still can't understand the guy across the room because of all of the noise. The problem hasn't changed. (Sure, the noise is reduced, but the desired signal is also reduced by the same magnitude)
Signal-to-noise ratio doesn't necessarily scale with overall amplitude.
In theory you could indeed all shout at once, but that breaks down when your conversation partner is way closer to the other shouter - no matter how loud you shout, your message will always be overpowered and will only get through when you wait until the other shouter is silent. That's why wifi chooses to listen first.
Relatedly, hypothetically increasing the transmit power of all 5GHz devices can never make it behave like 2.4GHz does.
Walls will still attenuate the higher frequency more than the lower one, and this function of a wall is independent of transmission power.
And Wifi devices are nowhere near as polite as you proclaim. They walk all over eachother all the time, for all kinds of reasons.
(CCA improves this, but it isn't a magical antidote.)
Furthermore, not all 2.4GHz transmitters are Wifi at all. There's (still) a ton of stuff in use on that ISM band, much of which has nothing at all to do with computers or Ethernet.
A 2.4GHz video feed doesn't care about neighboring Wifi networks, for instance. It doesn't even have the ability to care. It just transmits video, using whatever modulation it uses to do that, without any regard at all for other users.
There's a lot of reasons that 2.4GHz is completely trashed in many areas -- including such offenses as leaky microwave ovens. That's just how it is, and how it is likely to remain.
Which sucks, but here we are anyway...
Unlikely to be caught doing it, unless you live in the urban core. And for an apartment, a directional antenna likely would have sufficed for many uses, prior to MiMo ubiquity.
[1] "Sensor-Free Soil Moisture Sensing Using LoRa Signals" (2022) https://news.ycombinator.com/item?id=38768950
- Kreosan English's modded lunar rover WiFi antenna videos: "100s of km" https://youtu.be/Nk-nj_BwoBE?si=0iwpQBFs9ZqFP0p8 ... 10x: https://youtu.be/GWq6L94ImX8?si=V2R8hpa3vAosbhvi