Re: [8023-10GEPON] Wavelength plan for PR10/20 downstream

["Hajduczenia, Marek" <marek.hajduczenia@xxxxxxx>]

Dear Dongsoo Lee,

thank You for the contribution and splendid presentation. I believe we will have some long discussions in Atlanta regarding the DS channel allocation for PR10 and PR20 systems.

I have some comments though:

note that when asked at the last meeting in Korea, the present LD vendors indicated no technical challenges related with manufacturing the 1580 - 1600 nm LDs. Are Your estimates (1-2 years after standard) based on any facts or rather it is a hearsay ? Similar arguments were brought against the 1490 nm band for 1G EPONs and yet the sources were ready when the standard was ratified. I would really like to understand what kind of limitations You foresee in terms of proliferation of 1590 nm LDs and what they are based on.

Additionally, I believe in column 2, row Remarks for L-band plan, You ought to put 2 more arguments in favour i.e. compliance with the CWDM/DWDM grid and common ONU receiver for all 10G EPON Power classes. It is not reflected in Your presentation. I do not quite grasp how You can state full compliance with 1G EPON which are deployed with RF video overlay ? It is a fact that such systems exist commercially and we do not know for sure whether RF video delivery will be discontinued once the 10G is available. I would rather bet on transitory systems, where RF video is still present to take advantage of the Return on Investment. It is the fact that 1G EPON specs do not specify formally RF overlay but we also know reality. I would therefore ask to have the coexistence with 1G EPON arguments modified accordingly to partial compliance in C band plan.

Your slide 4 indicates clearly there is no common stance on the RF video issue - the statement "Video-overlay option is initial solution, especially for 1G EPON" does not seem to be very well supported by the material You show in the presentation. Quite the contrary. Even though IP Video is the target for the system, we cannot exclude the scenario in which common channels will be still RF overlaid over PON while VoD/IPVideo will be unicast to specific users. 10G bit/s seems awfully much though when You start wondering when the capacity will be exhausted by unicast video streams. Just a thought to consider. Do not write the RF video off so quickly.

The PR10 sharing the transmission window with the PR30 was already proposed, discussed and rejected since would lead to high price OLT transmitter to maintain such channel width. That is at least what I remember. Please correct me if I am wrong.

Hope these comments are useful for something

Best wishes

Marek Hajduczenia (141238)
NOKIA SIEMENS Networks S.A. – COO BBA DSLAM R&D
Rua Irmãos Siemens, 1, Ed. 1, Piso 1
Alfragide, 2720-093 Amadora, Portugal
* marek.hajduczenia@nsn.com
(+351.21.416.7472  4+351.21.424.2082

"C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg." - Bjarne Stroustrup

 

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From: ext Lee, Dongsoo [mailto:d-soolee@etri.re.kr]
Sent: terça-feira, 6 de Novembro de 2007 12:30
To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
Subject: [8023-10GEPON] Wavelength plan for PR10/20 downstream

Dear All,

 

The attached file summarize my proposal for use of c-band wavelength for PR20-D.

Please let me know if you have comments on this proposal or you would like to be a supporter.

 

Best regards,

Dongsoo Lee

 

Senior Member of Engineering Staff / PhD.

Electronics and Telecommunications Research Institute (ETRI)

BcN Research Division, Optical Communications Research Center (OCR)

Optical Access Technology Team

1110-6 Oryong-dong Buk-gu, Gwangju, 500-480, Korea

Tel.  062-970-6525

Fax. 062-970-6989