Would like to see the environmental impact and public health studies done with this
240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
41–50 of 67 posts
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#42While it looks like they got lower phase noise using the optical LO than the traditional source, there are better conventional sources, like the LNS Series from NoiseXT.
I applaud their novel optical based system of generating the RF to then transmit via the antenna. The world is getting quite interesting, where you can actually buy test equipment these days that will tell you the frequency (down to the Hertz!) of Blue Laser Light.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#43Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#44Earlier 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
If I may ask, what is your hardware setup like if you're achieving consistent 1.6Gbps? Is that a reproducible, every day speed? Is that only for LAN or both LAN+WAN?
> what is your hardware setup
U6 Enterprise AP, Hasivo ethernet switch from aliexpress (used as a media converter from the AP's 2.5G copper to 10G fiber), MikroTik RB4011iGS for NAT (router on a stick), 56G Mellanox SX6036 for wired LAN. 56G optics from eBay and 10G optics from fs.com
>only for LAN or both LAN+WAN?
Wired LAN is 56gbps nominal.
Wireless LAN is 1.6gbps actual throughput.
WAN is 1.4gbps actual throughput (limited by Comcast DOCSIS)
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#45I'm curious about the use cases for 275 ghz wireless communication, are microwave links still common? it's almost far infrared
My ISP actually uses microwave links! I get consistent gigabit speeds with them.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#46Earlier quoted context omitted.
That's the scene. Says it's from 1994. After that, I'm sure the Owner's Manual that comes with your new Enterprise-class Starship now has a "DO NOT DISPLAY YOUR SHIELD FREQUENCY" in the "Warnings" section
I mean I get that series like Star Trek rely on technobabble and suspension of disbelief, but surely an enemy can just... detect the frequency, or rapidly adjust their own like tuning in until it matches?
Yes. It happens every third episode.
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#47I'm curious about the use cases for 275 ghz wireless communication, are microwave links still common? it's almost far infrared
From the PDF:
> Requirements for 6G include extremely high data rates (>100 Gbit/s), ultra-low latency (> For the wireless communication of the 6G era, new radio frequency bands in sub-THz, ranging from 100 GHz to 300 GHz, have been identified as one of the most promising bands.
> There is also a technical challenge for seamlessly connecting wireless communication systems with fiber-optic communication networks
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#48Guessing that needs line of sight & stable environment?
Re: 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver
#49They make a big point of using HD-FEC rather than SD-FEC. To me, that makes no sense - the extra power usage of SD-FEC can be tiny, even at high data rates. The FEC problem can be parallelized (if the protocol is designed for this) so it doesn't need to run at line rate too. (SD-FEC lets you get substantially more data throughput in a given channel).
I can think of a number of cases where using a hard decision decoder can be a better choice. Power would be one factor and I would strongly disagree that the power delta between soft and hard codes at these data rates is small. Unfortunately, I can not find any public data to back up that claim for what appear (based on coding gain and overhead) an HD-FEC using RS and a SD-FEC using braided BCH or LDPC.
Other factors can include reduced routing complexity and area requirements of HD since you have to shuffle around soft information. Extra die space is expensive so you want to avoid it if possible.
However, I think the most likely is the latency reduction you get when using HD-FEC. I know that some applications of microwave links are extremely latency sensitive, could be that this research is targeting one of those applications.