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So I built a tiny single pair Ethernet bridge (10BASE-T1L) that can transmit 10mbps over a kilometer on a single pair of twisted copper wires. Would love to ge

So I built a tiny single pair Ethernet bridge (10BASE-T1L) that can transmit 10mbps over a kilometer on a single pair of twisted copper wires. Would love to get some feedback for the next iteration

Aloha 4y ago
What are the limits on cable characteristics? Capacitance, foreign voltage, etc?
zakki 4y ago
Is this full duplex?
- yosheli123 4y ago
  Yep full duplex
yetihehe 4y ago
> Any application requiring a simple, low cost, robust connection between physically disparate devices At $195 it's definitely not low cost.
- silviot 4y ago
  What's the difference in price between 1km of fiber vs 1km or single pair wire? It might play a role in this solution being cheaper than immediately apparent.
  - eru 4y ago
    I don't think the wire itself would be the expense, but the laying of it?
    - voakbasda 4y ago
      The cost of laying wire is virtually the same as laying fiber, so the difference really comes down to the material costs. The only good reason to use wire would be existing installations, as you sidestep that cost entirely.
      - eru 4y ago
        Whatever EUROCARE said about existing installations applies. Though what I had in mind was that when I was handling optical fibre as a layman (we have fibre to the living room here in Singapore), that fibre is a lot more delicate, so would require a bit more care to handle than copper. But I guess that's probably not a major cost factor, if eg you have to dig a trench for your cable.
      - EUROCARE 4y ago
        But perhaps the wire is already there. I don't think anybody advocates for building entirely new datalinks using this. Laying another 1km of cable is much more expensive than 2x200 USD to reuse existing cable.
  - DannyBee 4y ago
    The fiber is much cheaper because it's so much more common. For example: I/O fiber is about 0.10 cents a foot or less for 2 fiber cable. (12 fiber is only 20 cents a foot). OSP gel-filled direct burial is 0.55 cents a foot or less for 2 fiber cable. (12 fiber is only 65 cents). This is micro-armored OSP cable, resistant to chewing/damage as well. Basic 18 awg single pair shielded direct burial wire is about 0.80 cents a foot. Can't even find a non-expensive armored version 10km single fiber transceivers at 10gbps are 40 bucks. 10km dual fiber transceivers at 10gbps at 29 bucks. It would be much cheaper, more effective, and a better result to just use fiber for 1km here. You could easily bury 12 fiber cable and use it for the price you will pay to use single-twisted-pair.
    - p1mrx 4y ago
      > 0.80 cents a foot Isn't that 80 cents/foot, or 0.80 dollars/foot?
    - Aloha 4y ago
      When everyone prices fiber, they fail to include the termination costs. How much are the termination costs on that fiber, per run? Also, you'd never install single pair direct burial, and almost never shielded (unless its audio and not phone type) - it'd be 4/6/12 pair direct bury gel-filled cable.
      - DannyBee 4y ago
        Termination is basically a non-cost anymore. The price a pack of 10 sc/apc field terminations (IE that a random DIY'ers could do) is <20 bucks, and to your question, the same as a price of a pack of 10 ez-r45 connectors. The loss and ease of mechanical connectors has gotten good enough (0.15 db or better) that most of the folks i know will only fusion splice when they really have to. I agree it wouldn't make sense to do single pair or single fiber, but that's the actually the comparison at which 10baset-1l is at all competitive. I have buried a lot of fiber, and a lot of network cable over the years :) I was just trying to be fair and present the best case for 10baseT1L In practice you can do 12/24 strand fiber (or 6 strand fiber + power + whatever) for less than the price of whatever particular set of 18 awg twisted pair (which is what the spec requires at 1km) + other things you wanted. The cable would be smaller, and if you use A3 or B3 fiber, it would be more flexible/support a lower bend radius than the 18 awg twisted pair. By far. IT's not even close.
  - rkangel 4y ago
    It comes down to whether the cable is there already. If you were laying it, you'd probably go for fibre. But if you've got 1km of some poor quality cable there already, then spending $200 to get usable bandwidth might be a lot cheaper than laying something new.
  - withinboredom 4y ago
    A copper wire can be bent in just about every which way (such as tangled when being tethered to an underwater drone), while fiber cannot.
- deleted 4y ago
  [deleted]
- kube-system 4y ago
  “Low cost” is relative. For parts in the industrial/robotics space, $195 is not expensive. You can certainly spend more on other options: https://westwardsales.com/patton-cl2300e-ethernet-extender https://westwardsales.com/patton-cl2300e-ethernet-extender
  - jeroenhd 4y ago
    You can get full products that do higher speeds over longer distances at lower cost, search term "vdsl repeater". It's possible that this product handles bad wiring better as it's ethernet rather than VDSL2, but I think those devices are a much better fit. One thing that might be better with an ethernet based standard is the ability to add multiple stations to the same link, relying on ethernet's error correction.
chriscjcj 4y ago
Definitely cheaper than StarTech's offering. That's appealing. https://www.startech.com/en-us/networking-io/110vdslext https://www.startech.com/en-us/networking-io/110vdslext However, with StarTech's product, you have a shot at faster speeds if you're going a shorter distance. It can do 75 Mb/s at 300 meters and up to 100 Mb/s at shorter distances. I would really like to find a similar box that can bond multiple pairs for faster speeds but I haven't found such a device yet.
- tyingq 4y ago
  >Definitely cheaper than StarTech's offering There are other brands of VDSL extenders. This board seems to be $300 for a pair. This product, for example, is ~$271 a pair if you buy them at the same time: https://www.netsys-direct.com/products/vdsl2-ethernet-bridge-nv-202 https://www.netsys-direct.com/products/vdsl2-ethernet-bridge... And they come with an enclosure and power supply. And a better sort of "step up / step down" bandwidth based on distance...see the chart at the bottom.

So I built a tiny single pair Ethernet bridge (10BASE-T1L) that can transmit 10mbps over a kilometer on a single pair of twisted copper wires. Would love to get some feedback for the next iteration

Aloha 4y ago

What are the limits on cable characteristics? Capacitance, foreign voltage, etc?

zakki 4y ago

Is this full duplex?

yosheli123 4y ago
Yep full duplex

yetihehe 4y ago

> Any application requiring a simple, low cost, robust connection between physically disparate devices At $195 it's definitely not low cost.

silviot 4y ago
What's the difference in price between 1km of fiber vs 1km or single pair wire? It might play a role in this solution being cheaper than immediately apparent.
- eru 4y ago
  I don't think the wire itself would be the expense, but the laying of it?
  - voakbasda 4y ago
    The cost of laying wire is virtually the same as laying fiber, so the difference really comes down to the material costs. The only good reason to use wire would be existing installations, as you sidestep that cost entirely.
    - eru 4y ago
      Whatever EUROCARE said about existing installations applies. Though what I had in mind was that when I was handling optical fibre as a layman (we have fibre to the living room here in Singapore), that fibre is a lot more delicate, so would require a bit more care to handle than copper. But I guess that's probably not a major cost factor, if eg you have to dig a trench for your cable.
    - EUROCARE 4y ago
      But perhaps the wire is already there. I don't think anybody advocates for building entirely new datalinks using this. Laying another 1km of cable is much more expensive than 2x200 USD to reuse existing cable.
- DannyBee 4y ago
  The fiber is much cheaper because it's so much more common. For example: I/O fiber is about 0.10 cents a foot or less for 2 fiber cable. (12 fiber is only 20 cents a foot). OSP gel-filled direct burial is 0.55 cents a foot or less for 2 fiber cable. (12 fiber is only 65 cents). This is micro-armored OSP cable, resistant to chewing/damage as well. Basic 18 awg single pair shielded direct burial wire is about 0.80 cents a foot. Can't even find a non-expensive armored version 10km single fiber transceivers at 10gbps are 40 bucks. 10km dual fiber transceivers at 10gbps at 29 bucks. It would be much cheaper, more effective, and a better result to just use fiber for 1km here. You could easily bury 12 fiber cable and use it for the price you will pay to use single-twisted-pair.
  - p1mrx 4y ago
    > 0.80 cents a foot Isn't that 80 cents/foot, or 0.80 dollars/foot?
  - Aloha 4y ago
    When everyone prices fiber, they fail to include the termination costs. How much are the termination costs on that fiber, per run? Also, you'd never install single pair direct burial, and almost never shielded (unless its audio and not phone type) - it'd be 4/6/12 pair direct bury gel-filled cable.
    - DannyBee 4y ago
      Termination is basically a non-cost anymore. The price a pack of 10 sc/apc field terminations (IE that a random DIY'ers could do) is <20 bucks, and to your question, the same as a price of a pack of 10 ez-r45 connectors. The loss and ease of mechanical connectors has gotten good enough (0.15 db or better) that most of the folks i know will only fusion splice when they really have to. I agree it wouldn't make sense to do single pair or single fiber, but that's the actually the comparison at which 10baset-1l is at all competitive. I have buried a lot of fiber, and a lot of network cable over the years :) I was just trying to be fair and present the best case for 10baseT1L In practice you can do 12/24 strand fiber (or 6 strand fiber + power + whatever) for less than the price of whatever particular set of 18 awg twisted pair (which is what the spec requires at 1km) + other things you wanted. The cable would be smaller, and if you use A3 or B3 fiber, it would be more flexible/support a lower bend radius than the 18 awg twisted pair. By far. IT's not even close.
- rkangel 4y ago
  It comes down to whether the cable is there already. If you were laying it, you'd probably go for fibre. But if you've got 1km of some poor quality cable there already, then spending $200 to get usable bandwidth might be a lot cheaper than laying something new.
- withinboredom 4y ago
  A copper wire can be bent in just about every which way (such as tangled when being tethered to an underwater drone), while fiber cannot.
deleted 4y ago
[deleted]
kube-system 4y ago
“Low cost” is relative. For parts in the industrial/robotics space, $195 is not expensive. You can certainly spend more on other options: https://westwardsales.com/patton-cl2300e-ethernet-extender https://westwardsales.com/patton-cl2300e-ethernet-extender
- jeroenhd 4y ago
  You can get full products that do higher speeds over longer distances at lower cost, search term "vdsl repeater". It's possible that this product handles bad wiring better as it's ethernet rather than VDSL2, but I think those devices are a much better fit. One thing that might be better with an ethernet based standard is the ability to add multiple stations to the same link, relying on ethernet's error correction.

chriscjcj 4y ago

Definitely cheaper than StarTech's offering. That's appealing. https://www.startech.com/en-us/networking-io/110vdslext https://www.startech.com/en-us/networking-io/110vdslext However, with StarTech's product, you have a shot at faster speeds if you're going a shorter distance. It can do 75 Mb/s at 300 meters and up to 100 Mb/s at shorter distances. I would really like to find a similar box that can bond multiple pairs for faster speeds but I haven't found such a device yet.

tyingq 4y ago
>Definitely cheaper than StarTech's offering There are other brands of VDSL extenders. This board seems to be $300 for a pair. This product, for example, is ~$271 a pair if you buy them at the same time: https://www.netsys-direct.com/products/vdsl2-ethernet-bridge-nv-202 https://www.netsys-direct.com/products/vdsl2-ethernet-bridge... And they come with an enclosure and power supply. And a better sort of "step up / step down" bandwidth based on distance...see the chart at the bottom.