I'm curious about the use cases for 275 ghz wireless communication, are microwave links still common? it's almost far infrared
Satcom downlinks for laser connected sats
240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
51–60 of 67 posts
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#52I'm curious about the use cases for 275 ghz wireless communication, are microwave links still common? it's almost far infrared
Seems useful as a cable-replacement for e.g. uncompressed video; DisplayPort tops out at 10.8 Gbps, so even allowing a 19x reduction for "real world" limitations, you could send DP over 20 meters with this.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#53I'm curious about the use cases for 275 ghz wireless communication, are microwave links still common? it's almost far infrared
The same use as optical wireless like LiFi. Higher speed over short distances. Optical has the advantage to bouncing off walls, but EHF may have bandwidth advantages. This wouldn't be useful for microwave links since it is absorbed by the atmosphere and has short range. 275 GHz is one the edge of EHF. Terahertz is 300 GHz to 3 THz. Above that is infrared.
> This wouldn't be useful for microwave links since it is absorbed by the atmosphere and has short range.
Nit-pick; 275GHz isn't terrible for atmospheric absorption. What gets you is the phase dispersion when the humidity is high.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#54When incorporated into Wifi 18 in the year 2046, it will prove to realistically get around 500 MB/s, and have a hard time getting through most walls.
They are only transmitting 30 mm, when they moved to transmitting 20 meters it had to drop from 64QAM to 32QAM and lost some throughput. It's also laser generated so I don't believe it's omnidirectional, just point to point.
The transmitted signal is diode generated, not laser-generated, and it's coupled with a typical EHF horn antenna.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#55Earlier quoted context omitted.
Jokes aside, I get a consistent 1600mbps over wifi 6E which is good enough for me. Of course you need an AP in every room to get consistent performance, but wifi has always been like that. And unless your applications use forward error correction wifi will always have latency spikes from L2 retransmission if there's even one wall between the AP and device
> wifi has always been like that not for me
Nor for me; I have a 3000 square-foot house and run a single access point; I ran Ethernet to a very central place (we have a centrally located open stairwell between the two floors, which helps) and got a PoE WAP that covers essentially the whole house (if you hold your phone in the very corner of the corner rooms, you can get it to drop).
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#56Apropos of absolutely nothing, but IIRC a "Star Trek" movie where a screenshot of one of the displays on some ship or another had the Shields Frequency up which allowed the enemy to match it and disable it, and back in the 80s(?) when this came out I remember thinking "237GHz" (or something like that) was an insanely high frequency and doubted it could ever be reached with any degree of stability. Physics: HMB
I thought it might be Generations, but that was 257.4 MHz https://www.youtube.com/watch?v=6A9IZHWz45Q&t=20s
That's the shield modulation frequency though, so the actual frequency of whatever field the shield consist of is unknown. It's also entirely possible the numeric strings displayed in the bottom part of the image constitute the secret key to a pseudorandom binary sequence that is overlaid onto the useful shield signal, and that's what the Klingon actually use to penetrate them.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#57When incorporated into Wifi 18 in the year 2046, it will prove to realistically get around 500 MB/s, and have a hard time getting through most walls.
They are only transmitting 30 mm, when they moved to transmitting 20 meters it had to drop from 64QAM to 32QAM and lost some throughput. It's also laser generated so I don't believe it's omnidirectional, just point to point.
IIRC there are modern enterprise wi-fi APs that sit in the rafters, and form star-topology laser relays between devices.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#58When incorporated into Wifi 18 in the year 2046, it will prove to realistically get around 500 MB/s, and have a hard time getting through most walls.
Jokes aside, I get a consistent 1600mbps over wifi 6E which is good enough for me. Of course you need an AP in every room to get consistent performance, but wifi has always been like that. And unless your applications use forward error correction wifi will always have latency spikes from L2 retransmission if there's even one wall between the AP and device
Consider: the faster the packets go, the faster the channel gets free to let other TDMA stations talk. A big office with a lot of computers still experiences QoS losses over 6E when someone starts watching a 4K video. Get those bursts of video-buffer-filling done faster, and other traffic will stay smooth.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#59I'm curious about the use cases for 275 ghz wireless communication, are microwave links still common? it's almost far infrared
> are microwave links still common?
Yes, they have their purposes. I work in finance and we use microwave links to talk between systems in Chicago & New York. Fiber links are the backup, here! The reason is purely latency as the bandwidth of the fiber links is orders of magnitude higher. The major downside is the microwave links drop quite frequently as they're sensitive to the totality of the weather between data centers (e.g. any sort of precipitation as a crow flies between NYC & CHI and there's potential for dropped links).
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#60Earlier quoted context omitted.
And fitted with six hydrocoptic marzlevanes to the ambifacient lunar waneshaft to effectively prevent side fumbling.
go home, Scotty, you are drunk!
For those who have never had the oportunity to learn of the marvels of the Turbo Encabulator: https://www.youtube.com/watch?v=Ac7G7xOG2Ag