transcievers/amplifiers for 150 km fiber run

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1

We are looking to light a two strand fiber link of about 95 miles (or
150km). It would be worth a lot to us not to have repeaters. We are
hoping for Gigabit Ethernet. Sonet is possible but a less attractive
solution. Are there options for this sort of distance? The longest
current link we have is about 65 miles. I understand the transmission
characteristics of the fiber will effect distance of transmission.

regards,
Fletcher

2

MRV Lambda Driver CWDM claims 200km with Raman amplification cards.
Atrica, now owned by Nokia, Ethernet switches claim 120 km

3

MRV or Finisar are good places to look for your optics. 120km is no problem for 1G/2.7G. Depending on the qualities of your fiber 150km may be within the 120km budget.

Deepak

Holmes,David A wrote:

4

Thanks to all that replied. A bit more background: By regulation, the
local ILEC is required to supply us with dark fiber where available. They
have taken the regulatory stance that it is not technically possible to use
dark fiber runs of more than 60 miles (prior, their regulatory stance was
runs of more than twenty miles were not technically feasible.) Our
counter-argument has been that we have existing fiber runs of 63 miles and
59 miles that work well without special equipment. We are now arguing
about a particular fiber run in rural Maine of about 91 miles. Our
position is it is technically feasible, depending on fiber characteristics,
to light 91 miles of fiber. Their position is that runs of more than 60
miles are not feasible. I was hoping to bolster our argument by pointing
to data sheets of optical transcievers rated up to 150 km. Then, after we
get the fiber, I was hoping to buy said equipment.

regards,
Fletcher

5

These guys claim upto 180km:

http://www.bookham.com/datasheets/transceivers/IGP-28111.cfm

Tim:>

6

EDFA's can extend your power budget a few dB. Chromatic dispersion could
still be an issue, though.

Used units that had previous homes in CATV supertrunk applications should work
well, at least for GigE; up to 120mW is easily possible (I have a few 65mW
(18.1dBm) EDFA's that came as part of a donation). You hit the input of the
EDFA with your ZX (1550nm) transceiver's transmit on each end, and don't look
at the lit fiber or even a reflection of the lit fiber (IOW, wear laser
safety goggles). And don't even think about looping the EDFA output back
around without many dB of attenuation.

At this power level you will have to use angle polish connectors at the EDFA
output (the green SC/SPC or FC/APC ones) or you can burn out the pump laser
with the reflections.

You also will need to notify your carrier's tech department of the power level
with which you're lighting that fiber, as even several km down fiber from an
EDFA is in Class IIIB laser territory.

A bare Cisco ZX GBIC or SFP is rated to light 70km of ordinary singlemoder
fiber, and up to 100km of either premium (low-loss) or dispersion-shifted
(which is also low-loss) singlemode fiber. The rated output is between 0 and
+5dBm (1 and 3.2 mW) for the ZX laser. The link budget is 23dB for the
standard ZX optics. With a high-gain EDFA outputting 13 more dBm of power
(20 times the power) you can get a link budget for loss of 36dB; which could
increase your range 40km, on ordinary fiber.

So, in a nutshell, you'd take the TX from a ZX SFP or GBIC, a few feet worth
of jumper to an EDFA, and light the fiber (with APC connectors only) from the
EDFA output. You do this at both ends.

7

http://www.ipitek.com/products/broadband/ethernet.htm

used by Cox and others.

http://www.ipitek.com/products/subsystems/transceivers.htm

Certified to 120Km, you may be able to run it further.

From: Tim Durack [mailto:tdurack@gmail.com]
Sent: Friday, October 10, 2008 1:49 PM
To: Fletcher Kittredge
Cc: nanog@nanog.org
Subject: Re: transcievers/amplifiers for 150 km fiber run

These guys claim upto 180km:

http://www.bookham.com/datasheets/transceivers/IGP-28111.cfm

Tim:>

Thanks to all that replied. A bit more background: By regulation,

the

local ILEC is required to supply us with dark fiber where available.

They

have taken the regulatory stance that it is not technically possible

to use

dark fiber runs of more than 60 miles (prior, their regulatory stance

was

runs of more than twenty miles were not technically feasible.) Our
counter-argument has been that we have existing fiber runs of 63

miles

8

or you buy some boxes from BTI Photonics that specialize into taking GigE around the world...

F.