I'm starting on a project that will involve digging a long (roughly 150-200 meter) trench from my house down to the road. The trench itself will be a considerable expense and so while the ground is open, I plan on laying additional conduit(s) containing any telecom links we may ever want, both for connecting to services currently available and ensuring we can use any services that might become available later. Currently only phone and cable are available at the road, but fiber-to-the-home has become available in other areas around us recently and I would hate to lose out by not being ready for it should it become available here.
Based on the distance, multimode fiber seems the best general option (vs CAT5/6 or singlemode fiber). POTS/DSL and cable are also available at the road currently.
To the specific questions:
- Is MMF really the correct choice, vs SM fiber or CAT6? Should I run both MM and SM?
- How many fiber lines is it reasonable to run for redundancy/backup? Should I include 2 or 3 lines from the outset?
- Is it safe/reasonable to run fiber, coaxial cable and POTS all in the same conduit over this distance?
- In principle, laying a second, empty, conduit with a strong comealong wire seems reasonable, but actually using it would certainly require a winch of some kind to pull it through over this distance, and I don't know if it is even practical. Any thoughts on this welcome.
- What additional cabling besides fiber, POTS and coax should I consider for future proofing this run?
I've done in-premises CAT5 installs before and played with fiber a bit at work but am not a network engineer so I suspect there are some unknown unknowns and would appreciate any comments or insight you may have. Thanks.
Best Answer
Empty conduit is your best bet here. No point in guessing what (if anything) you may get, and guessing wrong. While you can leave a pull string in it, you can also just vacuum a pull string into it when the time comes (that's what is normally done to install it in the first place). If you do leave a string, don't worry about how big/strong it is: it can be used to pull in one big/strong enough when the time comes. Do make sure it won't rot while it's waiting. And CAP THE ENDS of the empty conduit, or it may not be as empty as it should be when you need to use it.
Speaking from personal experience, assuming you don't need more than one for excessive bends/sweeps (and do use long-radius sweeps when you do need to make a bend, not the short radius stuff from home centers) you will be much happier with a pull box/hand hole/access at the halfway point.
I have hand pulled (no winch) fiber over 600 feet. It was not much fun. With correct technique (pulling on the Kevlar, not the fiber or the jacket), possible, but no fun. 330 feet/100m it should be easy (was for us) if the conduit is configured correctly (large-radius sweeps, no more than 360 degrees of bending between access points.)
Enter (and leave) the pull box with 45s, not 90s. Leave some extra cable coiled up in the pull box in case of any future need for more at either end due to damage. Before pulling cable in, see figure 8 coiling and use it so you can pull the cable in, figure 8 coil the other half, flip the coil and pull it the rest of the way - no tangles.
For political/turf (rather than electrical) reasons, it's often best to keep cable, telephone and "whatever is next" in separate conduits. It's also much less practical (or more difficult) to pull into a conduit with a cable in it - often best to remove the original cable and pull the new cable and the original cable back in together, rather than trying to pull a new cable in next to the original - but best if you can just pull the new cable in its own conduit and leave the original cable/conduit alone.
Additional suggestions -