Re: [8023-10GEPON] Wavelength plan proposal : current status
Marek and Frank,
Thank you for your comments and clarification.
The second filter in case-2 to extract 10G downstream signal was not a
notch filter but a pass band filter as Frank kindly explained. I will
revise the slide so as to clarify this point. Sorry for the confusion.
As for two wavelength option proposals, I will summarize pros. and
cons.by next meeting.
Regarding wavelentgh window, I understand Frank's comment; a longer
window would be better. This issue is also associated with loss budget
and LD types, namely power budget ad hoc discussion. If cooled typed LD
is indispensible for a high loss budget case, a narrow wavelength window
would be preferable in terms of ONU blocking filter. I will follow the
discussion in the power budget ad hoc and consider a solution.
Thank you again for your useful and constructive comments.
Best regards,
Keiji Tanaka
Frank Effenberger wrote:
> Marek, Tanaka-san,
> Regarding case-2, the filter does not need to have a notch... it is a pass
> band filter... I think the chart on page 4 has the filter curve drawn upside
> down. The whole point of that style of filtering is that you use a simple
> pass-band filter in front of the detector.
>
> If we have problems making passband filters, then we have big problems.
>
> Regarding the suggestion of using only 6nm of passband for the new
> transmitter, that will force cooling. Perhaps cooling is a foregone
> conclusion at this point, but still, it will make hardened OLTs nearly
> impossible. If possible, a window of 15nm would be much better.
>
> Regards,
> Frank E.
>
> p.s. I didn't receive the original Email from the exploder... was that just
> me?
>
>
> -----Original Message-----
> From: Hajduczenia, Marek [mailto:marek.hajduczenia@SIEMENS.COM]
> Sent: Tuesday, May 08, 2007 7:21 AM
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: Re: [8023-10GEPON] Wavelength plan proposal : current status
>
>
> Dear Tanaka-san,
>
> Thank You for the splendid presentation and high quality report on the
> progress of this particular ad hoc.
>
> IMHO, I would not like to see two wavelength channels standardized for
> downstream channel for a single reason: even though it is relatively easy to
> manufacture ONU modules with different wavelengths (change of complete
> optical subassembly with laser, filters and receiver), it may cause stock
> problems and accidental mix-up when a system set up to operate with 10G
> downstream in 1480-1500 nm window suddenly has an ONU which expects a
> downstream channel in the 1574-1580 nm band. The OLT would have to be also
> equipped with varying laser sources.
>
> As much as it is a practical solution, I do not know whether it is the best
> choice possible. I would rather stick with a single downstream band for the
> sake of simplicity and transparency of the system.
>
> As for the proposal of the filter structure in the presentation - I must say
> that the case-2 (see page 4 for example), will require pass band filter of
> quite super quality, which will have to be uniform for a large band
> (upstream 1310 window, downstream 1490 window, video 1550 window), then have
> a notch above 1570 nm and then again have minimum loss in the window above.
> I am concerned whether such devices can be designed in practice. At least
> what I gather from the work I did with Joao Santos, it is quite challenging
> to have a filter with a large flat top, then sharp, high isolation narrow
> band.
> This is mainly a practical concern - I do not know how such a structure will
> impact the other channels i.e. what will happen when the part of the video
> channel leaks into the 10G signal.
>
> Additionally, I did some minor editorial changes in the presentation. You
> can find it attached. In its current form, I am ready to support its
> conclusions. It would be beneficial also to add a slide on the proposed 2
> option wavelength allocation system and consider its pros and cons. The
> topic came out already so we may as well tackle it in the right ad hoc
> group.
>
> Best wishes and thank You for Your time
>
> Marek Hajduczenia (141238)
> NOKIA SIEMENS Networks S.A., Portugal - R
> Rua Irmãos Siemens, 1
> Ed. 1, Piso 1
> Alfragide
> 2720-093 Amadora
> Portugal
> * Marek.Hajduczenia@siemens.com
> http://www.marekhajduczenia.info/index.php
> (+351.21.416.7472 4+351.21.424.2082
>
>
> -----Original Message-----
> From: Keiji Tanaka [mailto:kj-tanaka@KDDILABS.JP]
> Sent: quarta-feira, 2 de Maio de 2007 5:42
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: [8023-10GEPON] Wavelength plan proposal : current status
>
> Dear Colleagues,
>
> Attached please find the intermediate report on wavelength plan proposal,
> which is based on local discussion in Japan. In addition, I received study
> results from Dr. Joao Miguel Santos of Siemens and discussed the filter
> configuration issues. I appreciate his contribution.
>
> I would like to elaborate the wavelength plan from the proposal in the
> slides, and it would be appreciated if you could give me any comments and
> technical proposals. I wish to apologize in advance for the
> inconvenience that I will be out of my office from May 2 to 8.
>
> Through the study, I recognize the difficulty of deciding the downstream
> wavelength. The situation of broadband services and its access technologies
> varies widely depending on countries and operators. Some operators may not
> care the coexistence among 1G-, 10G-EPON, and RF-video. As a solution to
> resolve the problem, is it possible to specify two wavelenth band for
> downstream? For example,
> Option-1: 1480-1500 for greenfield deployment,
> Option-2: 1574-1580 for the coexistence among 1G-, 10G-EPON and RF-video.
> I hope that the concept of creating options is acceptable.
>
> Best regards,
> Keiji Tanaka
>
>