On Wed, 22 Apr 2015, Rodrigo Augusto wrote:
Buy 80km sfp+ dwdm modules? c21 and c51. On this scenario a don¹t have a EDFA, only put these sfp+ and I have link on other side( 60km) but I have a -19dbm and other side I have -21dbm( ddm sfp+ output).. I think I have a better signal than this? because I use 80km sfp+ and my distance is 60km? can I have a chromatic dispersion? I think to use a EDFA, but i¹m not sure this? if I have a chromatic dispersion I have to use a DCM not a ADFA or a booster? Right?!
If you use 80km SFP+ then they should be able to handle the CD (chromatic dispersion) of your 68km fiber stretch, and if you have a power problem, then you can solve that by adding EDFA mid-span. CD causes "noise" (OSNR) to the receiver, it doesn't cause your power levels to be low. So if you want to solve your power problem, add EDFA mid-span. If you want to be able to use 40km optics (they might be cheaper), add DCM as well if the manufacturer rates them as not being able to electronically compensate for dispersion more than 40km. -- Mikael Abrahamsson email: swmike@swm.pp.se