Fiber to 50-pair conversion

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Hello all.  I need to replace an old building-to-building 50-pair
burried cable (for voice) and was wondering if I can use an existing
Fiber run.

If so.  What do I need on each end of the run?
copper -> fiber / fiber -> copper device?

I'll appreciate any input as I'm new at this.

Regards,

- Frank



Re: Fiber to 50-pair conversion


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Possibly.  That fiber pair is almost certainly good for 10
Mbit/s (most likely more), and 50  voice lines need 3.2 kbit/s,
but that's uncompressed and 100%usage.

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Re: Fiber to 50-pair conversion



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50 voice lines need 50 times the 64 kbit/s which makes 3.2 Mbit/s.


--
Tomi Engdahl (http://www.iki.fi/then /)
Take a look at my electronics web links and documents at
http://www.epanorama.net /


Re: Fiber to 50-pair conversion


Robert Redelmeier wrote:

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????

A standard voice channel is 64 Kb/s Perhaps you meant 3.2 Mb/s?



Re: Fiber to 50-pair conversion


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Correct.  That post "escaped" early.  Note there was no --sig.

I also intended to add that fiber->copper is normally Ma's
stuff.  RTs are full of this sorts of gear.  OP should talk
to his PBX vendor to see if they have fiber units (likely).

-- Robert

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Re: Fiber to 50-pair conversion



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Used to be.  Nowadays it seems everything has gone from circuit switched
to packet switched.  But I don't know if that means that inexpensive
used circuit switched gear is available.  It may be more economical to
replace the cable.

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Re: Fiber to 50-pair conversion


Hey guys, a couple of things here.  Voice channels are only 56 or 64K
when they are digitized.  But for the issue about replacing the 50-pair
tie cable.  You would need four strands of fiber and four channel banks
having the appropriate interfaces.

All-in-all it would be cheaper and easier to replace the 50-pair with a
new one that is at least Cat3.

Rodgers Platt



Re: Fiber to 50-pair conversion


FratorMCSE wrote:

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You asked for it.

Very carefully, split the fibre into 50 slivers.  ;-)

Actually, the answer depends on what you want to carry.  Voice?  Data?
Network?  Etc.?



Re: Fiber to 50-pair conversion


James.  I had a heck of a hard time splitting a single fiber strand
into 50 slivers but by the end of the 48th hour I was successful.  Now
it works great.  NOT.

I just want to carry voice.  What I need to know is if there is an
interface out there that will convert fiber into cat3 copper.  I also
have more than for strands available on my fiber.

Thanks.



Re: Fiber to 50-pair conversion


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Per your original message you need more than this.

 > Hello all.  I need to replace an old building-to-building 50-pair
 > buried cable (for voice) and was wondering if I can use an existing
 > Fiber run.
 >
 > If so.  What do I need on each end of the run?
 > copper -> fiber / fiber -> copper device?

50 pairs of copper = 50 possible voice signals. Bi-directional

each strand of fiber = 1 signal in one direction.

So you're looking for a 50 channel voice (POTS I'm guessing) to fiber
converter/multiplexer/demultiplexer. Not a trivial thing.


Re: Fiber to 50-pair conversion


David Ross wrote:

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It's possible to use one fibre in both directions, by using different colour
lasers.



Re: Fiber to 50-pair conversion


James Knott wrote:
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Actually, FTTx technologies that use a single fiber are using two
wavelenghts (colors) downstream (voice is being packetized and sent as
data) and one upstream for data return.  Then there is DWDM with uses
like 12 or 16 wavelengths per strand.  But I don't deal with that stuff
so I don't know too much about it.


Re: Fiber to 50-pair conversion


FratorMCSE wrote:

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If your cable carried only voice, then you need something that can give you
up to 50 voice channels.  In the telcom industry, there's the standard D4
channel bank, which gives 24 voice channels over a 1.544 Mb/s DS1
connection (some makes include two systems in one chassis).  You'll need
these at both ends, plus some means of placing the DS1 signal(s) on the
fibre.  The lowest bandwidth I've worked with on fibre, is DS3, which is 28
DS1s.   An alternative, would be some sort of voice over IP configuration.



Re: Fiber to 50-pair conversion


James Knott wrote:
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James.  I had a heck of a hard time splitting a single fiber strand
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successful.  Now
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voice.  What I need to know is if there is an
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copper.  I also
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give you
standard D4
need
the
is 28
configuration.

Thanks a lot for all of your input.  While browsing the web for
possible solutions I stumbled accross this site
http://www.tccomm.com/TC8800.htm ,  a 4-28 Channel
Telephone/Analog/Data Fiber Optic Multiplexer.
Would two of these do the job?  I would have 56 channels available by
going this route (two 28 channel units).

Thanks again for responding to my newby questions, I know you have a
choice to respond of ignore them.



Re: Fiber to 50-pair conversion


It's difficult to comment on the applicability of this solution as we
don't have all the information.  If you do a straight cost analysis it
may be cheaper to call in a company to do a directional bore between
the buildings and lay in a new 50-pair or even a 100-pair direct burial
cable than to replace the existing run with fiber.  Bells and whistles
are what makes the world go round, but it all gets down to how much are
you willing to pay for the finish on the bell or whistle?  Spending
$10,000 for a $2,000 problem doesn't endear you to the financial
people.

Rodgers Platt



Re: Fiber to 50-pair conversion


James.  I had a heck of a hard time splitting a single fiber strand
into 50 slivers but by the end of the 48th hour I was successful.  Now
it works great.  NOT.


I just want to carry voice.  What I need to know is if there is an
interface out there that will convert fiber into cat3 copper.  I also
have more than four strands available on my fiber.


Thanks



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