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
Would love to get some feedback for the next iteration
At $195 it's definitely not low cost.
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.
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.
I would be shocked if anyone has those. Maybe alarm wire I guess?
[1] Actually, it's 4 pair to an in-ground junction box, where it splices to 3 pair to the gate controller. For $350, I have maybe some other other options around the junction box (I've already got some passive 10baseT <-> single pair devices, but they don't work at the full distance. Probably would work at the junction box, if I had a powered ethernet switch there, but I need weatherproofing.
10Base-T1L may replace RS-485 in forms of process automation, but the length capability is not the particularly interesting feature there :)
Isn't that 80 cents/foot, or 0.80 dollars/foot?
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.
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.
There are reasons why copper and coax exists though, which is what I was pointing out.
Big infrastructure often orders the cables pre-terminated, eg an ISP will order their arial cable with built-in termination at certain intervals. No muss, no fuss.
You're right about single pair though. If you're putting in two strands might as well do 6. If you need 6 might as well do 24. Never hurts to have spares and extra capacity. Especially if it involves stringing poles or digging holes.
I will get pre-terminated for MTP runs, but not for anything else. Fusion splicing connectors just isn't slow (and if i need to go quick, i'll just splice a pigtail onto it until it fails)
I agree for redundancy, etc, better to just add more until loss-of-ROI occurs, but will say doing something for extra capacity for home users/even business users feels like massive overkill these days.
Even 2km 100G duplex transceivers for SMF are <$200 a piece now. Cost is dropping crazily fast. (bidi simplex ones now also exist on fs.com as of a month or two ago, but are still way too expensive)
Put another way - outside of being technically correct, why does it matter to the point at hand?
You can certainly spend more on other options: https://westwardsales.com/patton-cl2300e-ethernet-extender
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.
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.
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...
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.