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Re: [802.3_100GNGOPTX] SMF Ad Hoc questions



Pete,

Thanks for the loss analysis.  Clause 52 says the connection loss allocation for 10GBASE-ER is 2 dB.

 

The maximum link distances for single-mode fiber are calculated based on an allocation of 2 dB total connection

and splice loss at 1310 nm for 10GBASE-L, and 2 dB for 30 km total connection and splice loss at

1550 nm for 10GBASE-E.

 

Using 1.5 dB would not necessarily ensure an upgradable channel.  

 

Paul


From: Anslow, Peter [mailto:panslow@xxxxxxxxx]
Sent: Wednesday, August 22, 2012 11:00 AM
To: STDS-802-3-100GNGOPTX@xxxxxxxxxxxxxxxxx
Subject: [802.3_100GNGOPTX] SMF Ad Hoc questions

 

Hi,

 

As noted in the draft minutes of yesterday’s SMF Ad Hoc meeting, there were a couple of questions related to the maximum channel loss:

 

·         What coverage of links is the 18 dB loss for 100GBASE-ER4 equivalent to?

·        What loss does the channel loss for 10GBASE-ER translate to for 40GBASE-ER4 wavelengths?

The answer to the first question is that (18-2)/40 = 0.4 dB/km at 1294.53 nm (lowest wavelength for 100GBASE-ER4) is equivalent to about 50% of installed links on Figure 10-8 of G.Sup39.

 

The maximum channel insertion loss for 10GBASE-ER from Table 52-24 is 11 dB with 1.5 dB for connectors at 1550 nm.  This is (11-1.5)/40 = 0.2375 dB/km

This covers about 50% of installed links on Figure 10-8 of G.Sup39.

0.2375 dB/km at 1550 nm is equivalent to 17.25 dB for a 40km link at 1264.5 nm.  If we add 1.5 dB for connectors (assuming that we are going to upgrade an existing 10GBASE-ER link) we get 18.75 dB which fits well with the proposed 19 dB maximum channel insertion loss for 40GBASE-ER4.

 

Regards,

Pete Anslow | Senior Standards Advisor
43-51 Worship Street | London, EC2A 2DX, UK
Direct +44 2070 125535 |