this post was submitted on 06 Sep 2024
69 points (97.3% liked)
Technology
59038 readers
3862 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Any idea how they achieved it?
Ultra directional antennas with maximum allowable power?
Which frequency? 5-6 Ghz?
I can't find it in the datasheet.
But it says power consumption of 36 W (very high for just L2 Ethernet bridge).
The article says that it's six gigahertz and that they are putting one unit on each side of the wall they want to blast through. So the signal is extremely strong right at the wall and then goes through it weakening and hits the other device and then is re-transmitted or whatever. By putting the routers directly on the wall, next to each other, they have enough power to get through the obstruction. But if they were in the middle of the room, for example, they probably would not.
Source: A passion for wireless technologies and myself being a licensed amateur radio operator.
It's the medium transfer that always kills you, this minimizes that by limiting it to 1 medium (concrete) and not doing air-concrete-air.
You can do eq and compensation for 1 medium, 2 media are harder.
2 media is concrete air or.... Its 3 media when you have add another air gap. And each transition is orders of magnitude of power requirments
Well, air-concrete-air is 2 media but 3 transitions. You can re-use the model for the transition which makes the math easier, but you still have to re-do all the math with different numbers, some of which you have to determine by analyzing the transformation the signal channel underwent through the transitions.
I don't think it would be an order of magnitude more power for EM trying to go through a transition between air and concrete, it's not like the wave is actually moving the matter so much as its bouncing into it sometimes, and the change in propagation velocity and group delay coupled with frequency rolloff in the transition, but it adds a ton of noise, mostly as the group delay gives you effective multipath, and especially modern modulation relies on heavily phase measurement (PSK and QAM) which can make everything all really icky when the phase interference is that small, we designed our modulation for large phase interference like multipath reflections, etc, the assumption that going between media would cause the reflected/refracted component to heavily rolloff, which might not be the case here.
Maybe ultra low frequency somehow.
Now, it's six gigahertz according to the article. But by putting the routers close to each other, it doesn't matter so much.
Low frequency = lower bandwidth. But I had similar thoughts.
It's impossible to get gigabit speeds on ULF. The datasheet says it uses 5.925 GHz to 7.125 GHz.