Cost of fiber run between neighbouring office buildings

William Herrin bill at herrin.us
Tue Oct 2 17:49:15 UTC 2012


On Tue, Oct 2, 2012 at 9:01 AM, Nick Hilliard <nick at foobar.org> wrote:
> On 02/10/2012 13:35, Hank Disuko wrote:
>>  - 2 x 6-Strand 50/125u multimode, Tight Buffered, Armoured, Laser Ultra-Fox Fiber cables
>>  - Distance of run is approx 520 meters
>
> For that length, go with single-mode.  10G-LR will happily run on 10km of
> SMF, but 10G-SR flakes out at ~300m even on OM3.  Laying outdoor MMF plant
> like this is totally pointless.  Using MMF for anything outside your
> cabinet / small cage is creating a legacy deployment on day 1 which will
> bite you in future years.


I second what Nick said. Single mode for anything longer than a few meters.

*IF* you have existing conduit, consider just buying an AMP Lightcrimp
Plus kit, picking up some single mode from ebay and doing it yourself.
Each Lightcrimp Plus termination is expensive so you wouldn't want to
use it for a large job or a large set of jobs, but they've reduced the
difficulty level to about what you're used to for RJ45. You could end
up in a break-even situation that leaves you with a tool set for next
time.

You can also buy pre-terminated fiber assembly with a pulling eye and
cable netting at one end for pulling it through the conduit. But
you'll probably have to go with new fiber; not much in the way of long
preterminated cables show up in the used market.

If you don't have conduit already, consider:

Conduit requires trenching and repair of surfaces afterwards. Big
dollars and God help you if you get an amateur because Home Depot
doesn't stock the right pipe.

Direct burial is cheaper for single installations but you have to keep
paying the whole price if you add to it later. Worse really, because
each new installation has to carefully avoid cutting the ones before.
Conduit, once installed, can support lots of additional cable.

Microduct is a happy medium between the two. It's about as easy to
install as direct burial cable and once installed you can both blow
new fiber through unused ducts and remove obsolete fiber from existing
ducts. Microduct even installs well across roadways with a machine
that looks like a four-foot circular saw. They can seal the road
overtop with tar instead of having to patch or repave which is a major
cost savings. Unlike conduit, microduct really only works for fiber.
If you also want to run some copper lines, you can't do it.

Regards,
Bill Herrin


-- 
William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004



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