Optical transceiver question

Thu Sep 8 18:36:08 UTC 2016

On Wed, 7 Sep 2016, Frank Bulk wrote:

> Is it an industry practice to market distance based on the hot optics, 
> not on the worst case, which is minimum TX power?

No. If this is 1310nm optics with 0.4dB/km budget, the budget figure 
should be end-of-life figure, ie worst case according to the specs.

I don't like the "kilometer" figures, that can be marketed with very 
optimistic figures. However, if the transceiver says 0 to -5 transmit, if 
it doesn't transmit 0 to -5 then it's out of spec.

I treat the kilometer figure as "marketing", and look only at the optical 
specifications. So using your figures, if the device doesn't have 0 to -5 
out, and can receive error free at -20, then it's out of spec and it 
should be replaced free of charge.

However, if they market 1310nm with 15dB link budget at 60km reach, then 
I'd consder that false marketing.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se