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10 gigabit Ethernet 80 GHz point-to-point bridges

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Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#81

Post by amazon_not »

walrus01 wrote: post #50
madengr wrote: post #48

Earlier quoted context omitted.

Back in 60's AT&T make lots and lots of circular waveguide, intending to bury it across the country. One of the circular modes is dispersionless; then fiber was invented; lot's of money lost on circular waveguide. Interesting that mmWavguide is still rectangular. Wonder if one could do a mmWave fiber? Don't see why not.

millimeter wave waveguide on the rear of a parabolic antenna (30, 60cm dish) is actually circular (cylindrical), supporting dual polarity operation (opposite H and V). Individual radio heads like this russian radio or other 80 GHz radios are still single polarity. In certain scenarios you can mount two radio heads on a T-shaped waveguide on the rear of one dish antenna, one in H, one in V.

Is it a Russian company? I only found Estonian and Swedish contact details on their website. Both countries are very much not Russia.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#82

Post by zurn »

According to Nielsen's law of bandwidth, consumer gigabit last mile should be common by now and 10G would be a logical next step development, becoming ubiquitous in 2020 or so.

There's a huge number of houses with idle fiber installed 10+ years ago. Gigabit ethernet was introduced 17 years ago and carries 5 km over fiber. Cable is just waiting for providers to switch on 10 Gbps since years ago. Phone line copper has similar story..

Maybe something like this could jump-start the stalled development of last-mile consumer internet.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#83

Post by zokier »

walrus01 wrote: post #22

it's worth noting that this is just the first one publicly announced and not under NDA.. It's from a russian radar/microwave/millimeter wave manufacturer. All of the other much larger players such as Bridgewave also have 10 Gbps radios coming.

Its actually bit curious, they don't mention being Russian anywhere on their site and even their "Contacts" page refers the company being registered in Sweden.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#84

Post by cmiller1 »

ArkyBeagle wrote: post #39
cmiller1 wrote: post #21

Earlier quoted context omitted.

>higher sample rate ADCs and DACs becoming more viable Question, on optical networks doesn't this make dispersion more of a problem?

80 GHz isn't quite optical yet. It's a couple octaves down from infrared. SFAIK, it's still very much radio.

Sorry, I work in a photonics lab so in casual conversation more of the spectrum is "optical" to me. I just meant to ask if you just increase your sampling rate doesn't that mean you have to worry more about things like dispersion happening along the path of the signal?

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#85

Post by revelation »

zurn wrote: post #82

According to Nielsen's law of bandwidth, consumer gigabit last mile should be common by now and 10G would be a logical next step development, becoming ubiquitous in 2020 or so. There's a huge number of houses with idle fiber installed 10+ years ago. Gigabit ethernet was introduced 17 years ago and carries 5 km over fiber. Cable is just waiting for providers to switch on 10 Gbps since years ago. Phone line copper has…

You can put the savings into better bandwidth for consumers or lower cost for ISPs. With no competitive pressure for the former in the majority of the country, providers have happily pocketed the 3+ order of magnitude improvements while providing the same old 1990 speed.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#86

Post by jlgaddis »

cm2187 wrote: post #68
wrigby wrote: post #15

It'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)?

FWIW, I've got several similar point-to-point microwave links in my network, including the following setup:

  h1 - sw1 - ptp1a -/- ptp1z - sw2 - ptp2a -/- ptp2z - sw3 - r1 - h2

  h1    : Sun Fire server
  sw1   : Cisco 3560G switch
  ptp1a : 6 GHz point-to-point microwave transceiver ("A" end)
  ptp1z : 6 GHz point-to-point microwave transceiver ("Z" end)
  sw2   : Cisco 3560G switch
  ptp2a : 6 GHz point-to-point microwave transceiver ("A" end)
  ptp2z : 6 GHz point-to-point microwave transceiver ("Z" end)
  sw3   : Cisco 3560G switch
  r1    : Cisco 3945
  h2    : Sun Fire server
All connections are 1 GbE.

  ptp1a to ptp1z : 12.80 miles (20.60 km)
  ptp2a to ptp2z : 05.01 miles (08.06 km)
From h1 to h2:

  --- x.x.x.x ping statistics ---
  20 packets transmitted, 20 received, 0% packet loss, time 19305ms
  rtt min/avg/max/mdev = 0.955/0.995/1.157/0.049 ms
Each of the two microwave links are advertised as being capable of 761 Mbps full-duplex.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#87

Post by amazon_not »

zurn wrote: post #82

According to Nielsen's law of bandwidth, consumer gigabit last mile should be common by now and 10G would be a logical next step development, becoming ubiquitous in 2020 or so. There's a huge number of houses with idle fiber installed 10+ years ago. Gigabit ethernet was introduced 17 years ago and carries 5 km over fiber. Cable is just waiting for providers to switch on 10 Gbps since years ago. Phone line copper has…

> There's a huge number of houses with idle fiber installed 10+ years ago.

Do you have a source for that? Verizon may have passed 18 million homes, but only the homes which have placed an order for Fios were ever connected. So, no or very little idle fiber.

> Gigabit ethernet was introduced 17 years ago and carries 5 km over fiber.

Wrong. You can buy off the shelf SFPs with 200 km reach. Use amps if you want longer reach.

> Cable is just waiting for providers to switch on 10 Gbps since years ago.

You don't just switch on 10 Gbps on cable. First your vendor needs to release DOCSIS 3.1 equipment and you need to test it. Then you need to upgrade your CMTS to DOCSIS 3.1 and swap out any cable modems that don't support 3.1 and dedicate spectrum to DOCSIS 3.1 downstream channels.

And it's not since years ago. DOCSIS 3.1 was released a bit over two years ago. Comcast will start rolling out commercial DOCSIS 3.1 service this year.

> Phone line copper has similar story...

What?! G.fast can theoretically give you 1 Gbps, but only if you already have fiber to your driveway. There aren't even any commercial deployments yet and all vendors don't even have products yet.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#88

Post by amazon_not »

revelation wrote: post #85
zurn wrote: post #82

According to Nielsen's law of bandwidth, consumer gigabit last mile should be common by now and 10G would be a logical next step development, becoming ubiquitous in 2020 or so. There's a huge number of houses with idle fiber installed 10+ years ago. Gigabit ethernet was introduced 17 years ago and carries 5 km over fiber. Cable is just waiting for providers to switch on 10 Gbps since years ago. Phone line copper has…

You can put the savings into better bandwidth for consumers or lower cost for ISPs. With no competitive pressure for the former in the majority of the country, providers have happily pocketed the 3+ order of magnitude improvements while providing the same old 1990 speed.

Some of those savings are needed in order to be able to provide 100M/1G to the consumer: - 10G in the distribution - 100G in the core

So, even with competitive pressure, consumers can't expect to receive the latest and greatest for peanuts.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#89

Post by madengr »

wrigby wrote: post #55
madengr wrote: post #51

Earlier quoted context omitted.

Thanks for the info. I got to mess with W-band stuff years ago, but I'm mostly Ku and below now. Would love to tear down some 80 GHz hardware. Have you seen anything come of the "angular momentum" polarization discovered a few years ago? Seemed specific for P2P microwave.

I would love to hear more about that - have any links? From a quick google, all I can dig up makes it sound like it's normal circular polarization, which is used quite often in satellite. Not sure why it wouldn't make it into terrestrial, since it has some interesting advantages (no x-pol alignment issues!)

Google "angular momentum antenna". IEEE had a write up a few years ago, but details still lacking. It was simple as twisting the dish surface into a helix, but they didn't say how many modes could be generated.

Re: 10 gigabit Ethernet 80 GHz point-to-point bridges

#90

Post by rfdave »

tzs wrote: post #75
wrigby wrote: post #15

It'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. [1] http://www.ti.com/product/ADC12J4000/description

The digital hardware to handle the output of a 4 GSPS ADC is beefy as hell. This part has integrated DDC's if you're happy with downsampling, but if you want full nyquist data coming out of this, you need to handle 6 Gbyte/Sec.
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