Long Distance Dark Fiber

Fri Mar 11 23:48:25 UTC 2011

On Mar 11, 2011, at 7:50 AM, Joel Jaeggli wrote:

> On 3/11/11 7:16 AM, Jeff Wheeler wrote:
>> On Fri, Mar 11, 2011 at 9:25 AM, ML <ml at kenweb.org> wrote:
>>> Would it be too crazy to buy a spool of fiber and splice the end of one pair
>>> to the next pair and so on?  Won't be able to simulate 2200 miles of fiber
>>> but it'll be a long span.
>> 
>> This is by no means crazy.  If you visit a laboratory where gear is
>> tested, you'll find exactly that -- spools of fiber which can be
>> connected together (through whatever splicing or patching method is
>> desired for the simulation) to give the desired span length.  These
>> usually look nicer than big spools of cable, and are even available in
>> rack-mount enclosures with vendor logos. :)
> 
> one does not however do 2200 miles of terrestrial fiber simulation
> without simulating regeneration as well.
> 
> 
You can, but, it requires electronic retiming of the fiber signal
(fiber->ring buffer->configurable delay->fiber).

I guess technically that simulates one iteration of regeneration
to some extent, but, it certainly wouldn't represent a test of
2200 miles worth of analog regeneration of a digital signal.

Owen