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wifibroadcast

Gordon Haverland
 

I stumbled across this, perhaps this is old news.

https://befinitiv.wordpress.com/wifibroadcast-analog-like-transmission-of-live-video-data/

Nominally, this was a project to broadcast video over wifi to a
receiver from an elevated (drone) transmitter. Being elevated, the
transmitter has a good chance at line of sight. I have no idea of the
dates on any of this, the article is undated, and I don't see dates on
any of the comments.

What appears to be some common problems with people using this, is not
having a good enough power supply for the computer (usually a RPi type
things) and someone's software (the website is wordpress, so it could
be guilty or a web browser could be guilty) changing minus signs into
some kind of "dash". For command lines on Linux, they probably have to
be minus signs, not any kind of dash.

One person fairly early in the comments, thought about changing it so
that two video feeds were being sent, so that a 3D image could be
built. That was accomplished.

This project revolves around one way transmission. No acks, checksums,
retransmits, .... It puts the receiving NIC into promiscuous mode. It
may be the transmitting NIC into some different mode as well.

It starts with a warning, that this project may not be legal in various
countries. But it doesn't suggest any which are legal or any which are
not legal. I have no idea if Canada is. There are things which people
with a HAM license can do to the code, and others shouldn't (because it
is probably not legal).

There are a LOT of comments.

--

Gord

Gordon Haverland
 

On Tue, 3 Dec 2019 12:33:41 -0700
"Gordon Haverland" <ghaverla@...> wrote:

I stumbled across this, perhaps this is old news.
As I got through the comments, I realize some of my description is
wrong.

They are not accessing the wifi hardware as if it was some kind of IP
networking. They are accessing the wifi hardware at a lower level.
Hence, one of the modes they are talking about is MONITOR mode, which
I had assumed was PROMISCUOUS mode.

--

Gord