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Re: [HSSG] <HSSG-FOAH> Meeting

Hi Ali,


Thanks for the good questions. Let me present the rationale for the choices in the table.


The 10x10G (optical wavelengths) 40km 1310nm (DML or ML) alternative is white because no HSSG participant has indicated they are actively investigating it. I can’t comment on why others are not looking at this, but to us this alternative makes no sense compared to 10x10G 40km 1550nm. It incurs steep additional fiber loss, without solving a dispersion problem. At 1550nm 10G has a modest path penalty over a 40km distance, as quantified for example in the 10GE-ER standard.


The 4x25G 10km 1310nm alternative is under active investigation; see for example presentations from us and OpNext at the last HSSG meeting. That is why it’s shaded green.


I am assuming that your comment that early implementations of 100G will be based on 10x10G is referring to the electrical interface (since you then comment on mux/de-mux complexity.) I agree with your assessment; 25G electrical interface speeds are more appropriate for follow-on implementations.




From: Ali Ghiasi []
Sent: Wednesday, April 04, 2007 2:00 PM
To: Chris Cole
Subject: Re: [HSSG] <HSSG-FOAH> Meeting



Couple of items you have shaded gray (maybe) and white (preferred) the logic for them is not clear to me:
    - Why do you have 40 Km 1310 nm with 10x10 DML and ML white and you have 1550 nm 40Km gray?
    - I also don't understand your reasoning for not selecting 4x25G over 10Km of 1310 nm, this will be the
    natural implementation when 4x25 become available as you have for 40Km!

I expect early implementation of 100G will be based on 10x10.  But when the 4x25 becomes available then
both 10Km and 40Km could go 4x25G instead of using a more complex mux/de-mux.


Chris Cole wrote:

Hi Marcus,
The 100GE Technical Feasibility Alternatives table only covers the two
proposed HSSG LAN reach objectives; 10km and 40km. There is currently no
WDM network objective in the HSSG. (In fact, a straw poll at the Dallas
meeting to not have a HSSG long haul PMD reach was supported.) So to
keep the coveted green shading we would like to encourage active
investigation efforts towards the use of serial techniques for the LAN
reach objectives.
In any case, I look forward to seeing your serial PHY contributions at
the next meeting.
-----Original Message-----
From: Marcus Duelk [] 
Sent: Wednesday, April 04, 2007 12:06 PM
To: Chris Cole
Subject: Re: [HSSG] <HSSG-FOAH> Meeting
Hi Chris,
thanks for the update. I am not speaking for a component vendor
so I don't know whether my feedback here can be considered as
a solution being "under active investigation". However, from a system
vendor's perspective I think that the serial solution (the last two rows
of your table) only makes sense for a WDM network which would
be at 1550nm and at reaches of 40km and beyond. These fields are
currently white but they are, at least from our perspective, under
investigation ... I will make further contributions on the serial PHY at
the next meeting(s).
Chris Cole wrote:
During today's Fiber Optic Ad Hoc call we discussed updating the SMF
alternatives table. We simplified the table entries to three key
qualifiers that are required to enable technical feasibility. The
updated table is enclosed. Any comments on the proper assignment of
qualifiers will be appreciated.
We would also like to get input on the alternatives that are currently
under active investigation (green shading in the table) by HSSG
During the FOAC call, the 20G/25G - 1310nm alternatives, and 10G -
1550nm alternatives were confirmed as under active investigation. 
We would like to find out if the 20G/25G - 1550nm, the 50G - 1310nm
100G - 1310nm alternatives (shaded green) continue to be under active
We would also like to find out if any of the white areas are under
active investigation.
Please send an email indicating if you are investigating any of the
areas not confirmed during today's FOAC call.
The purpose is to accurately reflect which investigations are taking
place so that we can get an idea of what presentations we can expect
see during upcoming HSSG meetings. At this point we are not making any
selection between the alternatives.
Thank you