CWDM over a single fiber strand for both tx and rx

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Jan 16th, 2009
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Can I use a single fiber strand for bidirectional communication? That means tx and rx will be on the same fiber strand using different wavelength. I don't need much capacity.

Thank you.


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Tom Randstrom Sat, 01/17/2009 - 07:06
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Yes, this is possible.

There is a solution available for SFPs; found in the following Cisco document:

An alternative way is to use one each 1310nm and a 1550nm GBIC/SFP and a pair of wideband WDM couplers (available from many vendors in different packages). The wideband WDM couplers split the fiber into two, one for the 1310nm signal and the other for 1550nm.

In any event, the fiber link distance will be reduced slightly by the added insertion loss of the couplers.

scottmac Sat, 01/17/2009 - 07:58
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Yes indeed you can: Verizon FIOS and AT&T's U-Verse do this.

A single fiber to the side of the house, three wavelengths (lambdas); 1310, 1490, and 1550nm.

One for voice, one for data, one for cable TV overlay (U-verse doesn't use this lambda, 1550nm, they are 100% IPTV).


Good Luck



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