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

Dear Dongsoo Lee,
 
I understand Your point on the RF video and Your concerns about the potential lack of interest for such a scenario. However, from the standard definition point of view, we should not / cannot do 2 things:
 
1. provide several solutions for the same problems (as called by the chair several times already) - we have to converge to a single wavelength plan otherwise we have a no-go at the 802.3
 
2. close deployment options for some carriers who have RF video equipment, are not willing to / do not have reason to deploy higher power budget equipment (PR30) due to very short loops. This may be a situation for Europe for example where an average fibre loop if overbuilt on top of standard DSL would be less than 2 - 3 kilometers long. I do not think it would serve as a good motivator to move to EPON from BPON if one has to throw away investment in RF video equipment just because it is only compatible with more expensive PR30 equipment. I believe in the freedom of choice. We have 3 power classes, which have certain reach / split targets. They are to be used world-wide and not only in Korea, Canada, Japan or any other country interested in the particular option. 
I agree with You that whatever we decide, we must decide with care and looking at the technical aspects of it. Were there any concern voiced by any laser manufacturer present at the meeting or ones I contacted in person, I would opt more for the C band plan. However, all the companies I talked to are quite agreeable - if there is demand, they will do it. Market demand drives the development and if we do give a clear signal to the manufacturers right now that such devices are to be market ready in mid 2009 or before, they will be ready. All we need is to decide and put the numbers into the standard.
 
As for the line saving issue - sometimes decreasing the font does miracles. Feel free however to structure the table at Your will. My comments were merely suggestions.
 
Thank You for Your time and consideration
 
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

 

From: Lee, Dongsoo [mailto:d-soolee@etri.re.kr]
Sent: quarta-feira, 7 de Novembro de 2007 11:53
To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
Subject: Re: [8023-10GEPON] Wavelength plan for PR10/20 downstream

Dear Marek,
 
Very thanks for your comments.
 
My points in the presentation are 1) that we can use 1550nm EML for PR20-D if not RF overlaid, and 2) that use of widely available 1550nm source will make it easy to deploy 10G EPON at initial state.
 
As for the first point, I said about RF video overlay compared to IP video. I believe that RF overlay is an attractive solution for 1G EPON network because it provides additional bandwidth for video delivery "like CATV" and it also reuses the existing CATV infrastructure and Set-Top Box(STB). And other reasons to use RF video overlay option may be unmatured IP video technology and regulatory on IP video. However, I do not agree that RF video overlay should be essential for 10G EPON because 1G EPON has been deployed with RF video overlay by some Telcos. We have already selected 1577nm wavelength plan for coexistence with RF video overlay for the existing networks with 29dB CHIL. Furthermore 10G EPON provides enough bandwidth for video delivery based on IP transport mechanism and IP video has much comparative advantages against CATV in terms of interactive service and personalized service. In additioin, though two Telcos (to my knowledge) have deployed RF video overlay option in their PON network, I heard that many other telcos are willing to use IP video option. I do not mean that RF video overlay should be written off quickly, but I suggest that we could use 1550nm in the case that  RF video overlay is not considered. As I showed at page 8, we can treat variable schemes for 10G EPON even when we select 1550nm for PR20-D.
 
As for the second point, I have presented about the wide availability of 1550nm source. For 10G optics, c-band source is adopted to all the applications and I can purchase 10Gb/s EML which is what  I want at this moment. While, L-band EML at 10Gb/s needs to be developed. My concern is that, if we decide 1590nm wavelength for PR20/10 of 10G EPON downstream, we will have two solutions for downstream, one is 1590nm and the other is 1577nm. For Japan market, one of the biggest market for EPON deployment, 1577nm will be developed and used. Then, 1590nm may not be highlighted from the market and thus commercialization of 1590nm EML at 10Gb/s may be delayed.  This is different from 1G EPON case, which have only one solution (1490nm) and there are demands from the market for 1G EPON, thus the manufacturers focused to develop 1490nm DFB LD to make it in time. Thus I represented my concern as writing "Maybe 1~2 years after standard" at page 3 even though I agreed that the 1590nm EML at 10Gb/s can deveop within 2 year technically. I believe that the wavelength option for PR20-D should be very available at the time of standardization.
 
As for your indication at page 3, I will reflect your comments. In order to save the lines, I will delete 'DWDM/CWDM grid" from the remark of c-band plan and insert "common ONU receivers" for the remark of L-band plan.
 
At page 3, coexistence with 1G EPON for c-band plan means that c-band wavelength can coexist with 1490nm EPON downstream wavelength. I have written coexistence with RF video overlay for L-band to represent that L-band can coexist with RF video overlay, separately from 1G EPON.
 
As for the wavelength plan of PR10, I suggested the use of 1577nm for common use of OLT transmitter with PR30. But I have add a remark "Possibly 20nm bandwidth when uncooled EML is required" at page 6 due to the cost problem. 
 
I hope this to be an answer for your comments.
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

-----?? ???-----
From: "Hajduczenia, Marek" <marek.hajduczenia@nsn.com>
From Date: 2007-11-06 ?? 11:36:31
To: "Lee, Dongsoo" <d-soolee@etri.re.kr>, "STDS-802-3-10GEPON@LISTSERV.IEEE.ORG" <STDS-802-3-10GEPON@LISTSERV.IEEE.ORG>
Cc:
Subject: RE: [8023-10GEPON] Wavelength plan for PR10/20 downstream

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 Irm?os 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

 

From: ext Lee, Dongsoo [mailto:d-soolee@etri.re.kr]
Sent: ter?a-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