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Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

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Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#11
post #9

I vaguely remember some sort of stunt where they had got hold of two 3 meter dishes paired them with off the shelf wifi radios, mounted one on a pickup truck and drove out across a dry lake bed. 53 miles before signal loss is what I remember. I will probably never be able to find the source, and my poor memory probably inflated the range like any good fish story.

https://www.techmonitor.ai/technology/wifi_and_bluetooth_dis...

Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#12
post #8

Not about range, but speed. Wifi is surprisingly slow. I noticed downloading a model from the internet (Huggingface) to my Desktop (connected by LAN cable) is faster than copying it from said Desktop to the laptop in the same room via Wifi.

Latency seems higher, much higher sometimes, and variable. I need to complete the LAN cable runs I started long ago :-)

Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#15
"Ideal" isn't doing as much heavy lifting as I thought it would be in this article. This is a basic wardriving setup on flat ground.

Standard wifi is phy limited to ~1600m unless you can increase ack response time limit, otherwise retransmissions will be sent by the sender while ack's are being transmitted by the receiver.

Then, per friis equation, with enough power and antenna gain (it's the antenna gain that really matters) the limit is only obstructions/terrain. Get yourself high enough (mountains, planes, satellites, moons, etc), or bounce of an opportune reflector (planes, moon, aurora, meteors, ionosphere, rain, hail, etc), and there is no real limit, besides how big of an antenna you're willing to build in orbit :P

or just make the throughput really really really REALLY slow and ice your receivers with liquid He.

Hams make a game of it: https://www.arrl.org/files/file/WA50-Standings/Distance-Reco...

Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#16
post #8

Not about range, but speed. Wifi is surprisingly slow. I noticed downloading a model from the internet (Huggingface) to my Desktop (connected by LAN cable) is faster than copying it from said Desktop to the laptop in the same room via Wifi.

Depends on the WiFi, you can easily get 1Gbps on WiFi 7 as long as your modem + access point have the bandwidth

Yeah. I ran a hand crimped cat-5 Ethernet run to my office and speed tested it, and it turns out my wifi is faster, according to speed.cloudflare.com. Haven't had a chance to debug that yet, but there's a switch and some other wiring in the way.

Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#17
post #9

I vaguely remember some sort of stunt where they had got hold of two 3 meter dishes paired them with off the shelf wifi radios, mounted one on a pickup truck and drove out across a dry lake bed. 53 miles before signal loss is what I remember. I will probably never be able to find the source, and my poor memory probably inflated the range like any good fish story.

Yeah, I met Radio when he was at MIT. He got a black badge from Defcon for it.

Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#18
post #15

"Ideal" isn't doing as much heavy lifting as I thought it would be in this article. This is a basic wardriving setup on flat ground. Standard wifi is phy limited to ~1600m unless you can increase ack response time limit, otherwise retransmissions will be sent by the sender while ack's are being transmitted by the receiver. Then, per friis equation, with enough power and antenna gain (it's the antenna gain that really…

For discussion purposes just "WiFi" isn't doing much. I doubt typical APphone 802.11ac on 5GHz can achieve >1km let alone 802.11ax/be on 6Ghz carrier, even 802.11n can only reach a few hundred meters with line-of-sight, sunny day, and no interference

Long range WiFi is a "solved" problem with 802.11ah with sub-Ghz carrier and can reach more than a km depending on bandwidth requirements

All that assuming tx power is within regulation, no enterprise grade antenna, and all with commercially available parts

Re: Long Range Wi-Fi – Pushing 2.4 GHz Wi-Fi to the limits (2019)

#20

They address that they were looking at the maximum unlicensed power. In HAM circles some people do use WiFi in an arguably legal manner by making the SSID their callsign and either making the network open or putting the password somewhere public. This is because you are not allowed to use public bands for encrypted communications (with a carveout for satellite control, for obvious reasons). I'm unsure what ranges can…

> In HAM circles some people do use WiFi in an arguably legal manner by making the SSID their callsign and either making the network open or putting the password somewhere public.

And presumably also no SSL when browsing?

Part of why I never really understood the appeal to getting a ham license. Things like no encrypted communications really limits the utility.

Anything outside of talking to randoms on the open air, and you'll better served by the computer networking infrastructure where encryption is allowed, you can speak to anyone in the world anyway, and the medium (IE physical device) you're using is irrelevant.

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