And here I am with 12MbS down/800KbS up
10 gigabit Ethernet 80 GHz point-to-point bridges
71–80 of 94 posts
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#72It's interesting to see the huge channel bandwidths they're using to attain this. Advances like this are largely driven by higher sample rate ADCs and DACs becoming more viable in recent years. Edit for clarity: channel bandwidths in the datasheet are up to 2 GHz. Need to close the link at 32 QAM to hit 10 gb before error correction overhead at that bandwidth, which is certainly doable. Also, it's interesting to note…
What sort of latency would you expect with a system like this (I mean the link in this submission, not satellites)?
Point to point wireless links like these usually have low latency, some under a millisecond.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#73Earlier quoted context omitted.
Not really, 80 GHz is definitely difficult to aim, the very center of the beam is quite small. The mounts for the most popular antennas accommodate this and have very fine adjustments for the azimuth and elevation. Keeping them aligned long term? Not a problem as long as the mounts the radios are on (whether non penetrating or bolted to a wall/structure on a building roof) are done properly.
I'm wondering how the natural motion of some taller buildings affects this kind of deployment. Lots of buildings swing and twist in the normal course of the day. We found this out with some of the free space optical solutions available.
It can have some effect but at the distances aimed (max 3km for a high reliability, high Tx power 80 GHz link) it doesn't affect much. A link that is a nominal -34 RSL on a clear sunny day might drop to -36.5 as a result of building sway (such as if one end is on top of a 60 floor tower). Weather is the main issue not heat expansion/contraction or sway.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#74Earlier quoted context omitted.
That's the nature of 80 GHz, design the links for your climate and don't try to go more than 2-3km. You can achieve five nines. And yes, run a 5.x GHz backup path in parallel.
> You can achieve five nines. As long as nobody pilots a drone in the path.
It'd have to be a big ass drone, I have links that stayed up when a Canada goose was sitting 2 ft directly in front of the 60cm antenna on one end.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#75It's interesting to see the huge channel bandwidths they're using to attain this. Advances like this are largely driven by higher sample rate ADCs and DACs becoming more viable in recent years. Edit for clarity: channel bandwidths in the datasheet are up to 2 GHz. Need to close the link at 32 QAM to hit 10 gb before error correction overhead at that bandwidth, which is certainly doable. Also, it's interesting to note…
> Advances like this are largely driven by higher sample rate ADCs and DACs becoming more viable in recent years.
I'm looking forward to what these will do for SDR. I salivate over the thought of an SDR using something like the TI ADC12J4000 [1] which has a 4 GSPS sampling rate.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#76Crap, now I need to go buy a couple of these and lobby the nearest data center for some rooftop space. That is the short way of saying I had no idea you could get antenna this effective for wireless data transmission. I'd seen the 5mbps ones but nothing close to a gigabit much less 10 gigabits. Time to draw a 10km radius circle around my home address :-)
Metrolinq has a 1GE product using unlicensed 60 Ghz which is like $500 a pop.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#77Do these products require a clear line of sight to work?
Yes.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#78Interesting. There has been a huge effort in the UK for mobile carriers to add fiber to as many cell towers as possible. Do people think this would undo this trend? I'm sure that 10gbit would be more than enough to carry the backhaul of 3G+4G with plenty of room to spare?
not really, fiber is still greatly preferred (For example: it's impossible to do 40Gb by microwave/millimeter wave, but a CWDM 4-channel 4x10GbE passive mux/demux on two strands of singlemode is trivial and very very cheap), or just a pair of 40Gb QSFP 10km reach optics using a single 1550nm wavelength between two routers or metro-E switches. But wireless can reach small cells, rooftops and towers that might be a ver…
Plus there's the reliability factor. With fiber you only have to worry about backhoe fade. Wireless has all kinds of fun failure modes.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#79Earlier quoted context omitted.
Do you have any recommendations for current products for line of sight?
I know some people who have successfully used Ubiquiti's airFiber for point-to-point links. I think those run on the order of $5 grand for a complete installation (two radios, mounts, etc) of a faster-than-gigabit link.
We run some between offices across the street from each other. We were lucky as we didn't understand the minimum distance was probably more important than the maximum distance for this type of setup! They have run flawlessly at about 800Mbps for the last year.
Re: 10 gigabit Ethernet 80 GHz point-to-point bridges
#80It's interesting to see the huge channel bandwidths they're using to attain this. Advances like this are largely driven by higher sample rate ADCs and DACs becoming more viable in recent years. Edit for clarity: channel bandwidths in the datasheet are up to 2 GHz. Need to close the link at 32 QAM to hit 10 gb before error correction overhead at that bandwidth, which is certainly doable. Also, it's interesting to note…
The specs sound very similar to what the BCM8500 can do. Add an analog frontend and an antenna, and that's basically it.
https://www.broadcom.com/products/Microwave-%26-Mobile-Backh...