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posted by martyb on Wednesday February 13 2019, @11:20AM   Printer-friendly
from the how-many-nanoseconds-is-50-meters? dept.

Cosemi Launches USB 3.1 Gen 2 Hybrid Active Optical Cable: Up to 50 Meters of USB

Cosemi has introduced the industry's first USB 3.1 Gen 2 hybrid active optical cables (hAOC), which enable USB connectivity over distances upwards of 50 meters. The cables will be available with various connectors and therefore will be able to address various applications.

As you might guess from the name, Cosemi's USB 3.1 Gen 2 hybrid active optical cables use fiber optics for data transfers, which is further paired with copper wires for control and power. The data portion of the cable is fully USB SuperSpeed+ capable, meaning it can transfer 10Gbps in each direction. [Notably], since hAOCs can power themselves, unlike other solutions they do not need any extension boxes or repeaters, making them simpler and more reliable. Using fiber for the data channel also means that the cables are more resistant against EM and RF interference, which is particularly important for medical applications.

The manufacturer plans to offer hAOCs with various types of connectors, including USB Type-A to USB Type-A, USB Type-A to USB Type-C, as well as USB Type-C to USB Type-C, with A-to-C cables being the first type out the door. And while the cables are best geared for high bandwidth applications, like copper USB 3.1 Gen 2 cables, the hybrid active optical cables are backwards compatible with the USB 2.0 spec.

I'd buy one for $5.


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  • (Score: 5, Funny) by RandomFactor on Wednesday February 13 2019, @11:35AM (1 child)

    by RandomFactor (3682) Subscriber Badge on Wednesday February 13 2019, @11:35AM (#800563) Journal

    and let slip the data on glass...

    --
    В «Правде» нет известий, в «Известиях» нет правды
    • (Score: 0) by Anonymous Coward on Wednesday February 13 2019, @01:10PM

      by Anonymous Coward on Wednesday February 13 2019, @01:10PM (#800578)

      you got mail. it's stored on a floating atoll ...

  • (Score: 0) by Anonymous Coward on Wednesday February 13 2019, @12:22PM (6 children)

    by Anonymous Coward on Wednesday February 13 2019, @12:22PM (#800569)

    Until you remember that it's 50 meters of fiber usb cord. That shit will stop working as soon as the first fool not paying attention trips over it and puts a kink in the fiber. Might be nice for some cheap and fast Ethernet-over-USB though?

    • (Score: 2) by isostatic on Wednesday February 13 2019, @02:05PM (3 children)

      by isostatic (365) on Wednesday February 13 2019, @02:05PM (#800590) Journal

      Might be nice for some cheap and fast Ethernet-over-USB though?

      It's not nice and won't be cheap. Run some cat5 for 50m, it'll cost you about $10. If you want 10G, run a 50m fibre, it'll still be cheaper than this.

      • (Score: 0) by Anonymous Coward on Wednesday February 13 2019, @06:55PM (2 children)

        by Anonymous Coward on Wednesday February 13 2019, @06:55PM (#800692)

        Won't be cheaper when you have to buy new NICs to use it. 10Gb Ethernet is crazy expensive, and fiber NICs are too.

        • (Score: 4, Informative) by RS3 on Wednesday February 13 2019, @08:02PM (1 child)

          by RS3 (6367) on Wednesday February 13 2019, @08:02PM (#800714)

          Not really- I see plenty of used 10GB Ethernet cards on ebay for $20-40, and new starting at $50. Obviously much more than a 100 or 1GB NIC, but if you need the speeds, you're probably doing something involved and expensive anyway.

          10GB switches get pricey- I see a 5-port Netgear for $390, but you might not need a switch if you're just doing point-to-point.

          Depending on many factors you might also do "trunking": parallel Ethernet runs. 4-port 1GB Ethernet cards exist and are cheap ($15-40), so 2 of them, 4 cables, and you're good to go.

          ** 4 cables if you don't need POE (Power Over Ethernet). Cat-5, etc. cable has 4 pairs, but only 2 are used for data, the other 2 for POE, but you can use them for data, so 2 Ethernet signals can be run in a single Cat-5 (or 6 or 7) cable, and yes, I've done it many times and have seen it done many times and it works 100% no errors or problems.

          • (Score: -1, Troll) by fakefuck39 on Thursday February 14 2019, @09:43PM

            by fakefuck39 (6620) on Thursday February 14 2019, @09:43PM (#801230)

            Classic RS3. So when these come out used and new on Ebay, then you'll have a valid comparison. Until then, the comparison is a 10Gb NIC from an enterprise vendor (~$800) to this cable. Should be obvious to anyone with half a brain. Just make sure and don't touch the power pin with a sweaty finger - your finger will dissolve from the formed lye and your head will explode from the produced hydrogen.

            Just to let you know, I won't be reading your reply.

    • (Score: 2) by TrentDavey on Wednesday February 13 2019, @04:38PM (1 child)

      by TrentDavey (1526) on Wednesday February 13 2019, @04:38PM (#800626)

      When I worked making optical combiners/splitters (you can't just screw two or three cables together under a shared screw terminal) as a demo I saw fiber tied in a tight knot and still perform fine. And this was single mode, very small core fiber.

      • (Score: 3, Informative) by bob_super on Wednesday February 13 2019, @06:16PM

        by bob_super (1357) on Wednesday February 13 2019, @06:16PM (#800679)

        Under 5cm bend diameter (1 inch bend radius for the challenged), off-the-shelf fiber will not like you and losses will happen exponentially as the radius shrinks (light leaks, plus core damage). Sure, you can make a knot, but that fiber won't ever work the same. Reliability depends on your optical budget and optical return loss requirements.
        Some specialty fibers can bend much tighter safely, but you wouldn't use those for multi-km links. Last I checked, they were also expensive.
        Tradeoffs...

  • (Score: 0) by Anonymous Coward on Wednesday February 13 2019, @12:24PM (12 children)

    by Anonymous Coward on Wednesday February 13 2019, @12:24PM (#800570)

    50.0 m/(299792458 m/s) = 167 nanoseconds. Probably a bit more than that but that's sort of the lower limit.

    • (Score: 5, Informative) by BsAtHome on Wednesday February 13 2019, @12:42PM (11 children)

      by BsAtHome (889) on Wednesday February 13 2019, @12:42PM (#800574)

      At a refractive index of ~1.5 it would be about 2e8 m/s (or about 250 ns for 50m). But you need to look at round-trip too. For optimal transfers, you will need some good windowed protocols.

      • (Score: 0) by Anonymous Coward on Wednesday February 13 2019, @02:59PM (10 children)

        by Anonymous Coward on Wednesday February 13 2019, @02:59PM (#800602)

        i can't believe that a serial connection is running over fiber. we've come a long way since rs-232 connectors were the common denominator across consumer platforms.

        • (Score: 2, Interesting) by Anonymous Coward on Wednesday February 13 2019, @03:23PM (9 children)

          by Anonymous Coward on Wednesday February 13 2019, @03:23PM (#800610)

          Cough, TOSLINK [wikipedia.org] 1983, cough, cough.

          • (Score: 2) by bzipitidoo on Wednesday February 13 2019, @04:06PM (8 children)

            by bzipitidoo (4388) on Wednesday February 13 2019, @04:06PM (#800617) Journal

            We've also taken big steps back. Twisted pair has been used for decades. Greatly increases the range by canceling out the interference that adjacent wires can produce in one another. It's why Ethernet can handle 100m, while USB can't swing more than a piddly 5m, if USB 2. (USB 3 is limited to just 3m.) But they wouldn't use twisted pair for USB. Costs a little more, so they wouldn't do it.

            • (Score: 0) by Anonymous Coward on Wednesday February 13 2019, @05:43PM (7 children)

              by Anonymous Coward on Wednesday February 13 2019, @05:43PM (#800663)

              USB specifications has mandatory differential twisted pair.
              Won't find many cables to use neither a twisted pair nor the mandatory wire gauge though.
              Then actual USB length problem most people have is due to the voltage drop.

              • (Score: 2) by bzipitidoo on Wednesday February 13 2019, @06:25PM (6 children)

                by bzipitidoo (4388) on Wednesday February 13 2019, @06:25PM (#800681) Journal

                Ah, my mistake. USB does indeed have twisted pair. It was the RS-232 serial port standard, with those ribbon cables, that was too cheap to use twisted pair.

                • (Score: 4, Informative) by pipedwho on Wednesday February 13 2019, @06:49PM (5 children)

                  by pipedwho (2032) on Wednesday February 13 2019, @06:49PM (#800690)

                  RS-422 and RS-485 were the balanced cable standards that made use of twisted pair. For low speed short range signalling between a terminal/computer and a modem, unbalanced signalling was fine and simplified the cabling that already needed to carry quite a few other ancillary signals like RTS/CTS/DTR/DSR/CD/RI/TX/RX/etc.

                  • (Score: 2) by PartTimeZombie on Wednesday February 13 2019, @07:52PM (3 children)

                    by PartTimeZombie (4827) on Wednesday February 13 2019, @07:52PM (#800709)

                    Good lord you guys are nerds!

                    I mean that in the kindest way possible, in case you weren't sure. ;-)

                    • (Score: 2) by pipedwho on Wednesday February 13 2019, @09:42PM (2 children)

                      by pipedwho (2032) on Wednesday February 13 2019, @09:42PM (#800747)

                      I can’t believe I even remember this stuff!

                      • (Score: 2) by PartTimeZombie on Wednesday February 13 2019, @10:08PM (1 child)

                        by PartTimeZombie (4827) on Wednesday February 13 2019, @10:08PM (#800752)

                        I'm impressed.

                        • (Score: 0) by Anonymous Coward on Thursday February 14 2019, @10:51AM

                          by Anonymous Coward on Thursday February 14 2019, @10:51AM (#800948)

                          I am getting flashbacks of uni.
                          Thanks guys. I just had those years of my life nicely buried under layers of alcohol and work.

                  • (Score: 2) by RS3 on Friday February 15 2019, @06:18AM

                    by RS3 (6367) on Friday February 15 2019, @06:18AM (#801438)

                    "Were"? They're still in use a lot. Besides industrial controls, RS-485 is used for stage lighting control, implemented as "DMX512" https://www.analog.com/en/analog-dialogue/articles/isolated-rs-485-in-dmx512-lighting.html [analog.com]. I might have guessed it could go 1000', but the Analog article says 4000' - pretty impressive.

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