transcievers/amplifiers for 150 km fiber run
francois at menards.ca
Sun Oct 12 12:16:19 UTC 2008
or you buy some boxes from BTI Photonics that specialize into taking
GigE around the world...
François D. Ménard
francois at menards.ca
On 11-Oct-08, at 12:25 PM, Lamar Owen wrote:
> On Friday 10 October 2008 14:50:11 Fletcher Kittredge wrote:
>> 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
>> hoping for Gigabit Ethernet. Sonet is possible but a less
>> solution. Are there options for this sort of distance? The longest
>> current link we have is about 65 miles. I understand the
>> characteristics of the fiber will effect distance of transmission.
> EDFA's can extend your power budget a few dB. Chromatic dispersion
> 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
> safety goggles). And don't even think about looping the EDFA output
> 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
> fiber, and up to 100km of either premium (low-loss) or dispersion-
> (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
> standard ZX optics. With a high-gain EDFA outputting 13 more dBm of
> (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.
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