Structured wiring: fiber optic or not?

How about some big conduit and some fish lines, so anything can be added later?

John

If you are going to run fiber, use single mode. The optics are getting cheaper and at some point will displace MM fiber entirely.

tm

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Hadn't thought of that. It's a great idea.

Thanks!

Second that. Fiber has been around for decades and never really caught on for internal communications. It's great for moving lots of data over really long distance, but within a building there is just not much advantage over copper and a lot of disadvantages.

Yes - always do 2 (or more) of each so you can do loopback tests.

Put in some lines in the attic and to the roof for satellite, antenna on the roof, and antenna in the attic.

Cat 6E might be for real now, so try for it instead of Cat 6. The cables I put in in 2004 say "CAT6E", but it certainly wasn't an official specification then.

See if you can find out what the cable company runs to your house. It would either be better than RG-6 or better than RG-6 that you choose at random. Also, get the kind that has a separate wire for DC.

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Single mode. The stuff I put in 2004 works with the 1Gb/s interfaces that I got 6 years ago that were made for the larger diameter multimode stuff [wouldn't work over kilometers, does work over 100 meters] Single mode interfaces are still till expensive, but coming down in price. Multi-mode won't handle much over 1Gb/s; single mode should hit more than 1Tb/s over 100 meters in a while.

There probably is a specific type of connector that you should use for the fiber-optics, but I never figured out what it was.

When we did our building, we put runs of rectangular plastic downspout pipe into the walls and floors.

John

Fibre needs it's own conduit. It is still fragile, limited bend radius and subject to shock. Secondly, it will be corning glass so thin that it bends. Plastic fibres have too much opacity, went out with hooped skirts and is limited to toys and lamps now.

If you damage it you may not realize it until you wonder why the bandwidth is so bad. Stick with copper inside a buiding as James stated.. The fibre optic providers do. Glass fibre has never been faster than the copper circuits that feed it.

Bob E. wrote:

Recommend any system that allows easy upgrades, such as conduit with pull cords installed. Then he can pull through whatever the current cool stuff he wants.

Jacketed fiber is tough. One trick is to blow it into existing underground gas pipes, with a little parachute/umbrella sort of thing. A quarter inch bend radius has no effect on the stuff we use.

But shock?

John

nd

There are companies that make data and RF bundled cable. Just a thought.

I'm not so sure running RF is all that useful these days. I own a few boxes that pipe video over either data cabling . Silicon Dust for TV and a USB satellite box. But there are satellite boxes that support data cables directly these days.

All glass fibre optics need a large radius for the bends. 1/4" radius will definitely break any of the corning glass products we used to build a four city wide MAN fibre optic network.

I was warned of this bend problem early in my installation training and thought it was bunk. I was using electrical tape boxes (about 4.5" dia.) to store spare flexible jumper leads for usage in the field instead of making two trips from the site to warehouse each time. It took a few months to a few years for the fractures to show up in the glass and become problems for customers once they achieve high bandwidths and cannot attain them, due to data errors...fractured glass strands = reflected light and bad light conduction.

One day a contract cross country fibre optic company we used to do all our splices, showed me, with his laser light indicator, what happens when you bend the stuff too sharply. Red light spills out the sides at the fractures and you can see it right throuygh the jackets too. Most strands never recover but still work fine, depending on tolerable light losses. We stopped storing the flex jumpers in small round boxes from then on. Behind the scenes I began seeing all our installed jumpers being replaced due to data errors (light impedance)....ooops!

Check the specs and although these jacketed outdoor cables with many strands looks tough they cannot make the sharp bends. Most specs will tell you to use no smaller than 2-3" conduit to enforce slow turns.

Shock? A few incidents where cables between poles were hit, one by a dumptruck, and a pole hit in an accident (IIRC), shattered some (or all) of the strands in

50 or 100 strand aerial cables. The contractors started cutting back cable sheaths to find the start of the good glass sections and make a splice there. One fracture from the dumptruck with dumper up, stretched the cable so badly before snapping, the inside the fractured strands when over 1 km in one direction and almost 1/2 km the other, due to longitudinal mechanical shock. The injuries are restrung back to the nearest splice box now, without test, and it it takes a few km of new cable it is faster and cheaper. The drivers not looking pay big time for those ones.

But shock?

John

Do you mean Cat. 6A? I've never heard of 6E.

I think OM-1 is 220m with Gigait, 1000 base SX. OM-3 laser optimised fibre will do 10 Gb, 10G base SR, at several hundred metres, I think it's 300 m.

The longer wavelength optics normally used with single mode fibre are significantly more expensive. It is possible to run 1000 base LX over OM-1 and OM-2 multimode fiber using special mode conditioning patch cords, but you'd probably only do this if you already had existing older fibre installed.

As for connectors, ST were the most common at one time, but later equipment tended to be SC. In more recent times the smaller LC connector has become very common, and is probably the most popular. It is also the recommend standard for use with OM-3 fibre. We've found all of these connector types to be reliable, and MTRJ to be very unreliable.

none of this matters.

nobody is going to be hooking up fiber devices in their home, no matter what's in the walls already.