[802.3_100GNGOPTX] Question on DMT draft

[Arash Farhood <arash_farhood@xxxxxxxxxxx>]

Hi Toshiki Tanaka,Tomoo Takahara,Masato Nishihara and rest of the Fujitsu folks,
  As Dan stated, the upcoming 802.3bm meeting will be busy. In the interest of saving time, I want to open this email trail to ask question reagrding the DMT drat and direct some of the discussion to the reflector. For now I am only asking one question and I may have more questions based on your answer.
  Table 96-2 seems to suggest a Low Latency BCH FEC that takes 1E-3 BERi to 1E-12 BERo. It also says 12.5% coding overhead. The draft does not define the term coding overhead but I think it means Party_size/Data_size. (100Gb/s with 66b/64b is 103.125Gb/s. With 12.5% coding overhead which is a code rate of 0.888888, you get 116.015Gb/s specified in table 96-9. I recommend that you add the details to draft). 
  Using the proposed FEC, how much operating margin do you see for DMT system? When I go over you presentation below, it looks to me you are deisgning the FEC very close to the operating point. Generally the system needs some operating margin (for the PAM8 it is > 1dB) to gaurantee robust operation.
 
http://www.ieee802.org/3/bm/public/jan13/tanaka_01_0113_optx.pdf
 
 Regards,
Arash
 

---

Date: Wed, 8 May 2013 23:31:45 -0400
From: panslow@xxxxxxxxx
Subject: [802.3_100GNGOPTX] Two SMF proposal drafts available
To: STDS-802-3-100GNGOPTX@xxxxxxxxxxxxxxxxx

Hi,

 

I have posted two Clause 96 proposed baseline drafts (for PSM4 and PAM8) in the Task Force private area http://www.ieee802.org/3/bm/private/index.html

 

The password required to access this is given out at the face-to-face meetings of the Task Force and at the 802.3 Plenary meetings.

The draft, and any other content in the private area, is posted for your review only, and neither the content nor access information should be copied or

redistributed to others in violation of document copyrights.

 

Regards,

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