Re: [8023-10GEPON] FW: Downstream wavelength-continued
Thank you very much for the comments. It seems that we can agree on the need to preserve the broadcast overlay, and that the 1577 nm band will likely be relatively costly. I do acknowledge that bending issues become somewhat more of a problem as the wavelength goes up. To an extent, this can be offset in new construction by the newer fibers that have good bend radius characteristics. Also, when people operate OTDRs there can be an issue.
Unfortunately there is no perfect solution. Overall, I think the best solution is to specify 1577 +/-3 nm for PR30 and 1590 nm for PR10/20. The market can decide what makes the most sense. As to specifying 1590 +/-3 nm or +/- 10 nm as the band, obviously the OLT optics will be cheaper with a +/-10 nm specification. I am worried that the ONU filter becomes more expensive, but I have not been able to get numbers. So we can accept either +/- 3 nm or +/- 10 nm for now. That will preserve the spectrum. If my worst fears regarding filter design are true, then we may have to revisit the issue when we know more about the filter designs. Several people are trying to get more information for me, but it will be too late, and we must move past this issue and onto other issues in the specification.
Thanks, and I look forward to discussing this in Dallas.
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
-----Original Message-----
From: Victor Blake [mailto:victorblake@xxxxxxx]
Sent: Sunday, November 09, 2008 6:56 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength-continued
Kenji,
Could you explain what you mean when you say "regardless of operator-specific ODN restrictions." I obviously did not participate in those past discussions. But it is my understanding that the PR30 window was specifically select to accommodate one operator specific ODN restrictions, not "regardless." I'd like to understand.
Thanks,
Victor Blake
-----Original Message-----
From: Keiji Tanaka [mailto:kj-tanaka@xxxxxxxxxxx]
Sent: Sunday, November 09, 2008 11:23 AM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] FW: Downstream wavelength-continued
Dear Jim,
I am writing this e-mail to answer your comments. Actually, we mentioned neither inititial wavelength calibration of the filter nor temperature drift in May 2007 meeting because I did not think these were serious concerns. What we attached a high value to was coexistence with curretly deployed systems and ODNs. From this perspective, we propsed 1574-80nm wavelength band for PR30. This was the only remaining bandwidth for achieving coexistence with RF-based broadcasting video systems, regardless of operator-specific ODN restrictions such as microbend loss of optical cables and OTDR filter properties. PR30 might be costly, but we put priority on coexistence with RF-based video systems in the current ODN.
The restrictions on ODN are different in different operators or countries. It might be better to leave 1580-1600nm wavelength band to lower-cost PMD classes of PR10/20 if the band in ODN is practically usable.
Best regards,
Keiji Tanaka
Jim Farmer wrote:
> 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
> <mailto: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 <file:///%5C%5Cwww.enablence.com%5C>
> <<FilterCompare.ppt>>
>