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Re: [8023-10GEPON] FW: Downstream wavelength-continued



This is in line with what I interpreted Jim’s argument earlier.

 

Actually I think option (3) is part of option (2), the only difference is option (3) favor one implementation using cooled TX, which significantly increase OLT TX cost and power. While option (2) is more generic, you can use either TX implementations (cooled, semi-cooled, or uncooled).

 

From practical perspective, PR(x)30 will possibly dominate 95% of the actual deployment. And I feel PR10/20 for most of us is a “whatever”.

 

In light of this, I would rather the specs to be more generic for PR10/20 to at least possibly cover uncooled TX.

So I tends toward we should switch back to option (2) which is D2.0.

 

The question still-

Can anybody elaborate how PR10/20 going to be deployed, and how it maters?

 

Frank

 


From: Marek Hajduczenia [mailto:marek_haj@xxxxxxx]
Sent: Friday, November 07, 2008 3:24 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength-continued

 

Jim,

 

so let me try to wrap it all up because I must admit I am getting lost in here myself. We have now three options on the table

 

(1) use wavelength allocation plan as per D2.1 (all 3 PMDs use 1577 +- 3 nm)

(2) use wavelength allocation plan as per D2.0 (1577 +- 3 nm for PR(X)30 and 1590 +- 10 nm for PR(X)10/20)

(3) use something in between which You propose i.e. 1577 +- 3 nm for PR(X)30 and 1590 +- 3 nm for PR(X)10/20

 

Did I get this right ? Now, in the course of discussion we acquired one new option, which has never been on the table. As much as it seems to make sense, I am wondering what is the added gain of specifying new 6 nm band for PR(X)10/20 instead of using the same band as for PR(X)30. Distance between video overlay edge and the edge of digital data channel is the only things that comes to my mind. Did I miss anything ?

 

Note also that we have a number of contradictory comments in our pool for this meeting - some calling for option (2), some calling for option (3).

 

Regarding the cost of the resulting filters and the impact of separation gap between video channel edge and digital channel edge (using relative cost values) - can we have reliable estimate of how much it would cost to have various filter options manufactured using e.g. 20 nm CWDM like type 1580 - 1600 pass band filter for D2.0 PR(X)10/20 ONU as the base cost ? I have seen a number of presentations on cost filters and usually channel separations on the order of 15 nm between the edges of adjacent bands are quoted at 110 - 130% of costs of filter with 20 nm separation between the edges of adjacent bands. Frank I believe can confirm that. A question then: are they plain old wrong and the cost hit is much greater ? Do You have a way to provide solid values for relative cost in such cases ?

 

Thank You for this interesting discussion. I must say that it has been a while since a topic generated so much traffic on the reflector.

 

regards

 

Marek

 


From: Jim Farmer [mailto:Jim.Farmer@xxxxxxxxxxxxx]
Sent: sexta-feira, 7 de Novembro de 2008 16:48
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength-continued

Thanks for the good comments on this thread.  We would like to add a bit more clarification or our position before we meet next week.

 

We believe that PR(x)30 can stay at 1577 nm.  We would like to see the ability to operate PR(X)10/20 on 1590 +/-3 nm.  We would like to say 1590 +/-10 nm, but this is not feasible.  It requires a wider filter bandwidth, which is more difficult, as has been pointed out.  This is one of the reasons why we reduced the proposed occupied bandwidth of the 1590 nm option to +/-3 nm, even though this requires a cooled laser at the OLT.

 

We have reviewed the presentations from May 2007.  While we agree in principle with the presentations, it seems that they do not take into consideration initial wavelength calibration of the filter, nor do they take into account temperature drift of the filter.  And since the filter in question is at the ONU, it must be very low in cost.  A filter designed for either 1577 nm or 1590 nm must be wider than the occupied wavelength range of the laser, in order to account for initial calibration accuracy of the filter, and the temperature drift.  When we added these effects, the transition region of a 1577 nm filter (which must attenuate the 1550 nm broadcast signal), became unacceptably small.  The transition region for a 1590 nm filter went to 14 nm, which is tight but might be possible at ONU prices.  This is what we show on the slides we sent to the reflector earlier, and which we seek permission to present in Dallas.

 

We have been talking to filter experts about how to make low cost filters that will meet the requirements.  One of the experts we have consulted is our parent company's Dr. Matt Pearson in Ottawa.  I quote Dr. Pearson below (with his permission, I have modified his words to try to stay within IEEE guidelines, while not changing his meaning).  Referring to Frank Effenberger's comments (added below), Dr. Pearson writes:

 

"He's correct in his comments - 6 nm is definitely easier than 20 nm (which is why we recommend it in Jim's proposal!). 

 

"He is also correct that both the filters and lasers are available to meet these specs.  (DWDM relies on that!).  Our concern is more related to the costs, where DWDM costs are outrageous, even CWDM costs are too high for FTTH.  So we need noticeably easier specs than CWDM.  In fact, I would argue that we need noticeably easier specs than today's FTTH..!  -- There are so many more expensive aspects to 10G than 1.25G (DFB, APD, 10G electronics, extra blocking filters, etc), that if they want any hope of getting optics at a reasonable cost then they have to compromise something somewhere...

 

"Thin films and DFB lasers can meet either spec.  We believe (certain) PLC technology can also meet either spec.   But some other PLC approaches ... would quite likely never meet these 10G specs..  So again, it limits the pool of available suppliers and available technologies that could otherwise help bring down costs for systems people.  

 

"Either way, we will make it work.  We're just trying to make (the cost of the ONU lower)..."

 

Thanks,

jim farmer

Alan Brown

 

 

Jim Farmer, K4BSE
Chief Network Architect,
Enablence Technology
FTTx Networks Division.
1075 Windward Ridge Parkway
Alpharetta, GA 30005 USA

678-339-1045
678-640-0860 (cell)
jim.farmer@xxxxxxxxxxxxx
www.enablence.com

 

 

From: Frank Effenberger [mailto:feffenberger@xxxxxxxxxx]
Sent: Thursday, November 06, 2008 3:01 PM
To:
STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

Victor,

I doubt that.  >90% of EPON is deployed in Japan, so you can’t neglect their OSP and the huge influence this has on part volumes.

 

Back to the Mike’s suggestion – while it is a good idea, it will work if the big concern is the transmitter specifications.

However, the latest comment from Jim Farmer regards the filters at the ONU receiver.  And defining a super-set of the bands doesn’t help there.  

 

Actually, in my opinion, neither the filters nor the lasers are that big of a deal.  I’m not sure where Jim’s filter data come from, but there are pretty standard thin-film filter designs that can achieve the sharpness, accuracy, and temperature stability that we need for 14nm of guard band.  Our task force actually got a model of this back in May of 2007.  Actually, one of the considerations in the difficulty of making these filters is the width of the pass band, and it is actually easier to make a 6nm width pass band than a 20nm pass band.  

 

Sincerely,

Frank E.


From: Marek Hajduczenia [mailto:marek_haj@xxxxxxx]
Sent: Thursday, November 06, 2008 3:24 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

Hi Victor,

That is how Mike sees it. That does not need to be necessarily how things work out in the market. It seems to me that we are trying to guess which direction the market goes and I think we all agree that is hardly predictable. Additionally, if I recall right, we are not allowed to discuss market shares so probably it is better to leave it at this ...

Regards

Marek

 


From: Victor Blake [mailto:victorblake@xxxxxxx]
Sent: quinta-feira, 6 de Novembro de 2008 13:13
To: marek_haj@xxxxxxx; STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: RE: [8023-10GEPON] FW: Downstream wavelength

To chmine in here – I’d have to say that to me it sounds like the 1577 is the exception, not the 1590.

 

-Victor

 

From: Marek Hajduczenia [mailto:marek_haj@xxxxxxx]
Sent: Thursday, November 06, 2008 12:06 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

 

Hi Mike,

thanks for sharing Your point of view with us.

Please confirm whether I understand You right. You say that we should go with a wider window and carriers may require vendors to actually build equipment which complies to a certain part of this sub-band. In our case, we could hypothetically specify a downstream band between 1574 and 1600 nm while e.g. a narrow band option between 1574 and 1580 nm could be required by some carriers to remain compliant with their ODN. Is this what You're trying to relay in Your email ? Please confirm

Thank You

Marek

 


From: Mike Dudek [mailto:Mike.Dudek@xxxxxxxx]
Sent: quinta-feira, 6 de Novembro de 2008 10:22
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

As an outsider to 10GEPON, but member of IEEE 802.3 working group I’d like to suggest that the IEEE standard should be working to provide the best solution for the new future installs of the IEEE standard while paying attention to the existing infrastructure.     When you come to a point that you are having to drive the cost of the new standard higher in order to be compatible with existing infrastructure that may or may not exist in many applications I’d suggest that the IEEE standard should work for the long term low cost solution, while making it technically feasible for people with the existing infrastructure to add additional requirements to make it compatible with their existing infrastructure.   That way you do not burden the long term cost of new installs.     EG if the low cost solution needs a Tx window of xnm to x+30nm but for compatibility with a non-IEEE standard can only be xnm +10nm, then the IEEE spec should be xnm to x+30nm and individual vendors that are using the non-IEEE standard can impose the tighter (subset spec) of xnm to xnm +10nm.   (This obviously only applies if the PAR and objectives have not made compatibility with the non-IEEE standard a requirement.).   Please note my example is for illustration only the numbers in it are not meant to apply to this specific question.

 


From: Jim Farmer [mailto:Jim.Farmer@xxxxxxxxxxxxx]
Sent: Wednesday, November 05, 2008 8:53 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

 

My primary concern is that the 1577 nm downstream wavelength is inconsistent with use of the 1550 nm broadcast (auxiliary) wavelength.  The problem is that the two wavelengths are too close together to allow us to build economical filters at the ONU to separate the two wavelengths.  It is a little easier with the 1590 nm wavelength, though it is still difficult.  Originally I wanted to specify the wavelength band as 1580 - 1600 nm as it was originally.  But I found that when I put in real filter characteristics, I still had an extremely narrow transition region for the filter.  So I accepted that we would have to narrow the transmit window.  I chose +/-3 nm (1587 - 1593 nm) following the reasoning for PR(X)30.  We are adding cost to the laser, but at the OLT, which is not as cost sensitive as is the ONU.

 

I also had to accept that the auxiliary wavelength was limited to 1550 - 1555 nm, even though commercial practice is to use wavelengths up to almost 1560 nm.  People may complain about this restriction, but I think in the end they will live with it.

 

Unfortunately I have not been able to get quantitative information on the filter complexity - I would like to see filter vendors jump in with comparative numbers.  Some vendors I spoke with gave me more pessimistic numbers than I used in preparing the slides.

 

So the application is for anyone who wants to use the 1550 nm broadcast wavelength.  This is the only way I see to possibly make use of 1550 nm overlay practical.  And it still demands a more difficult filter than we demand currently.  But presumably advances in the state-of-the-art will made the filter practical at some point.

 

Thanks,

jim

 

 

Jim Farmer, K4BSE
Chief Network Architect,
Enablence Technology
FTTx Networks Division.
1075 Windward Ridge Parkway
Alpharetta, GA 30005 USA

678-339-1045
678-640-0860 (cell)
jim.farmer@xxxxxxxxxxxxx
www.enablence.com

 


From: Frank Chang [mailto:ychang@xxxxxxxxxxx]
Sent: Wednesday, November 05, 2008 7:06 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

I just reviewed this thread, and my interpretation to Jim’s slides is that-

 

1)       The argument is not for PR(X)30 as cooled TX is assumed because of tight power budget, so narrower 1577nm band considered feasible for PR(X)30.

  

2)       For PR10/20, possibly uncooled optical sources are assumed, so bring about the argument that larger wavelength band, such as wider 1590nm band, is only feasible.  

 

To satisfy this argument, basically call for the group to switch back to the wavelength plan originally specified in D2.0. So actually we are re-visiting the argument the group made during the baseline stage a year ago.

 

Jim- Can you confirm this is what you are looking for?

 

As it is clear the PR(X)30 will be assumed mainstream deployment which requires co-existence with installed 1G version, can anybody elaborate the scenarios on how PR10/20 going to be deployed? My question is weather PR10/20 scenarios has to use cooled or semi-cooled optical source?     

]

thanks

Frank C.

 


From: Frank Effenberger [mailto:feffenberger@xxxxxxxxxx]
Sent: Wednesday, November 05, 2008 3:22 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

 

To pile onto this thread, I have a question regarding Jim Farmer’s most recent presentation and Maurice’s support of it:

Did you notice that Jim’s presentation is asking to change the PR10/20 OLT transmitter wavelength range to 1587 to 1593nm?  

(At least, that is how I read it, but I should say that the exact numbers are not clear.)

 

Perhaps Jim can clarify exactly what he is asking for… that would be helpful.

 

Sincerely,

Frank E>

 

 


From: Marek Hajduczenia [mailto:marek_haj@xxxxxxx]
Sent: Wednesday, November 05, 2008 6:12 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

 

Hi Maurice,

Just following the arguments You used in Your email: does that mean that You see PR(X)20 OLT transmitters as uncooled devices? Are the power levels we are targeting achievable using uncooled optics? As far as I understand, cooling is necessary not only to keep the central wavelength within the predefined range but also assure higher output power level. Can You comment on this?

Regards

Marek


From: Maurice Reintjes [mailto:maurice.reintjes@xxxxxxxxxxxxx]
Sent: quarta-feira, 5 de Novembro de 2008 12:49
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength

 


Hi Victor:  I appreciate your comments, as they describe the existing conditions in the end solution space.

To that end I support your comments, and position which is also advocated by Jim Farmer.

My rational is that optical sources do not need to be so expensive and tightly temperature controlled when you can use the  1580-1600nm band,
and when you remove the tight wavelength requirement, optical , sources get cheaper, and thus increase the chances of wide
acceptance as was the case of 1GEPON, which uses low-cost optics.

Allowing a wider wavelength range also consumes less power, and can be viewed as being more "green";  something which was not
a direct component to the initial PAR, but should be a factor that all engineers take in to account when developing a new standard.

Best Regards

Maurice Reintjes
MindspeedTM
Hillsboro, Oregon,USA
Office Phone (503)-403-5370
Mobile (503)-701-0797

Victor Blake <victorblake@xxxxxxx>

11/04/2008 06:21 PM

Please respond to
Victor Blake <victorblake@xxxxxxx>

To

STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx

cc

 

Subject

Re: [8023-10GEPON] FW: Downstream wavelength

 

 

 




Jim,
 
As an early supporter of 10GigEPON (starting at the CFI) I am writing to the task force to express my support for your proposal. I believe that the 1580-1600nm wavelength would be more appropriate for use in the North American and in particular US MSO market. This market is composed of operators have existing wavelengths in use of their plant. Some already have substantial EPON deployments.
 
As you have pointed out, 1577 (1574-1580nm) could be substantial problem for MSOs. Having the second wavelength available for this market need would help to avoid a conflict between 10GigEPON and broadcast video – to which 10GigEPON would surely loose out. If the task force were to elect to keep 1590nm out of the plan, they would be spelling out certain disaster for 10GigEPON as we know specifically of the efforts to use 1590nm for current proposals for a next generation GPON solution. The result of keeping 1590nm out of 10GigEPON would be to force the MSO industry to GPON. I’ll just assume that is not the goal of the 10GigEPON Task Force, but it nevertheless would be the most likely outcome.
 
In fact it is no surprise to find that the GPON vendors are the ones most supportive of this proposed change.
 
I’ve communicated with a number of major US MSOs about this issue. The three I have directly received responses from all support 1590nm and wish to continue to see it as their first choice. Although these organizations are not directly represented in the IEEE today, they have from time to time participated in the past, and are certainly the largest EPON and 10GigEPON market in North America currently. For this reason, I urge the task force members to reach out to the MSO community and solicit their opinions if you do not already know where they stand.
 
Victor Blake
Independent Consultant

 



From: Jim Farmer [mailto:Jim.Farmer@xxxxxxxxxxxxx]
Sent:
sábado, 1 de Novembro de 2008 15:59
To:
STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject:
[8023-10GEPON] FW: Downstream wavelength

We request to make the attached presentation during the 10GEPON meeting in Dallas.  We remain concerned over the decision to drop the 1590 nm downstream band from the plan, for reasons shown in the attached.  Note that there are notes that go with most of the slides.  You can see them by going to View|Notes Page

Thanks,
Alan Brown

Jim Farmer

 

Jim Farmer, K4BSE
Chief Network Architect,

Enablence Technology

FTTx Networks Division.

1075 Windward Ridge Parkway
Alpharetta, GA 30005 USA

678-339-1045

678-640-0860 (cell)

jim.farmer@xxxxxxxxxxxxx

www.enablence.com

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