Re: [8023-10GEPON] Define TDP values
Dear Hamano-san and All,
I supprot your proposed TDP values (3av_07711_hamano_1.pdf).
Sincerely yours,
Toshiaki Mukojima
Sincerely yours,
----- Original Message -----
From: "Hiroshi Hamano" <hamano.hiroshi@JP.FUJITSU.COM>
To: <STDS-802-3-10GEPON@LISTSERV.IEEE.ORG>
Sent: Wednesday, December 19, 2007 3:04 PM
Subject: Re: [8023-10GEPON] Define TDP values
> Dear Sirs,
>
> Thank you for all of your discussions and comments for
> TDP definitions and values.
> Since there seems to be no strong arguments so far,
> I made comments on Draft1.0 yesterday to take the TDP values,
> described in the presentation 3av_0711_hamano_1.pdf,
> as a baseline proposal.
> But still I would like to hear more opinions if there will be,
> until next Portland meeting.
> Further discussions, comments, and suggestions will be highly
> appreciated.
>
> Best regards,
> Hiroshi Hamano
>
> %% Runjian Lin <rujianlin@hotmail.com>
> %% RE: [8023-10GEPON] Define TDP values
> %% Mon, 17 Dec 2007 20:03:14 +0000
>
>>
>>
>> Dear All,
>>
>> Hi, This is Rujian Lin from Shanghai Luster Teraband Photonics. I have
>> read through all the discussions taken on the web during the past two
>> weeks with interest.
>> To clarify the TDP definition and values for IEEE802.3av draft, the
>> discussions have focuses on whether to separate TDP into TP (transmitter
>> penalty) and DP( dispersion penalty) or not. In physical principle there
>> are a lot of factors in the optical transmitter, optical fiber link and
>> optical receiver degrading the eye opening at optical receiver output.
>> The degradation factors include driving waveform to laser, laser step
>> response, optical delay, laser line-width, chirp, relative intensity
>> noise, laser resonant phenomenon ( at the transmitter side), fiber
>> chromatic dispersion, PMD, optical reflection (in the fiber link),
>> thermal noise, shot noise, baseline wander, timing jitter (at the
>> receiver side) and so on. It is possible to separate TP and fiber
>> dispersion related penalty, but as to the factors causing the transmitter
>> penalty, the wavelength related properties, such as laser spectral width
>> and chirp, interacting with fiber dispersion will cause some amount of
>> eye !
> clo
>> sure at receiver output. This kind of penalty in receiver sensitivity
>> can be considered as a part of TP or a part of DP. This is an option for
>> the standard developer to take.
>> For easier measurement, I agree with Dr. Hiroshi Hamano, Dr. Frank
>> Efferberger and Dr. Pete Anslow on that it is better to take TDP as a
>> parameter and not to split it into two parameters, even for the
>> mathematic calculation on the Spreadsheet TP and DP could be dealt as two
>> parameters which are calculated separately first and then added together
>> to be TDP.
>> In measurement on TDP, it is important, but difficult to define an ideal
>> transmitter which in theoretic concept is a transmitter with perfect
>> driving waveform, perfect laser response, no optical delay, minimum
>> line-width, no chirp and minimum relative intensity noise, because
>> TDP = Receiver sensitivity in the case of test Tx with the worst fiber
>> link,
>> Receiver sensitivity in the case of ideal Tx with pure attenuation
>> (without fiber chromatic dispersion, PMD and optical reflection)
>> So I think that in the Draft we need to set up a definition on ideal Tx
>> for TDP test.
>> For the TDP values I think that the data proposed by Dr. Hiroshi Hamano-
>> 1.5dB for 1574-1580nm downstream and 3.0dB for 1260-1360nm upstream- is
>> reasonable and a good start point for further investigation.
>>
>> Best regards
>>
>> Rujian Lin
>> Shanghai Luster Teraband Photonics Co., Ltd, China
>> Tel: 86 21 56332287
>> Fax: 86 21 56332269
>> Email: rujianlin@hotmail.com
>>
>> Date: Thu, 6 Dec 2007 21:08:44 +0900
>> From: hamano.hiroshi@JP.FUJITSU.COM
>> Subject: Re: [8023-10GEPON] Define TDP values
>> To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
>>
>> Dear Sirs,
>>
>> Thank you very much again for discussing TDP parameters.
>> I would like to show briefly my opinion.
>>
>> I think this discussion goal is to define the TDP specification number
>> for the IEEE
>> 10GE-PON standard. Discussions seem to be made on the Spreadsheet
>> definitions about
>> dispersion penalties and Pass/Fail conditions accordingly. But I am not
>> sure, the
>> whole discussions, we have done so far, are going toward this TDP
>> specification goal.
>>
>> Separating the TDP into TP and DP in the Spreadsheet seems to m e only
>> going back to
>> ITU-T formalism, if there will be only DP discussions and no TP
>> considerations.
>> If ITU-T formalism is OK, it may be simple because the major parameters
>> have already
>> been fixed in 3av_0711_effenberger_1.pdf. But I think we should keep the
>> IEEE procedure.
>>
>> If someone intends to divide the TDP specification itself into DP and TP
>> specifications
>> in IEEE standard, I do not think it is a good idea, either. That only
>> leads confusion
>> to component and transceiver suppliers, who are accustomed to current 10G
>> transceiver
>> productions. Besides, the suppliers definitely require production margins
>> for both
>> specification numbers independently, which may destroy Power Budget.
>>
>> I quite agree with Dr. Effenberger's comment;
>> > Now: if people want to break up the TDP into "transmitter penalty" and
>> > "Dispersion penalty" (which is very close to the optical path penalty),
>> > then
>> > fine. This is, in fact, practically the ITU way of doing things. But, I
>> > thought that the IEEE method was somewhat better for low-cost reasons.
>>
>> Apparently, if the TDP specification number is big and loose,
>> Interoperability and even
>> Power Budget itself will be in danger. If the TDP specification is too
>> tight, yield
>> problem will heavily result in higher transmitter cost.
>> When we decided the Power Budget in ITU-T formalism, I believe that we
>> counted all
>> the parameters inside the numbers, such as, worst-case dispersion
>> penalties and also
>> transmitter features. Indeed, my colleague transmitter experts, who have
>> a number of
>> XFP production experience and TDP measurement results, carefully made the
>> TDP specification
>> numbers simultaneously. (My TDP number suggestions have initially
>> appeared in
>> 3av_0707_hamano_1.pdf, along with the Power Budget table in 3av_
>> 0707_takizawa_1.pdf.)
>> Maybe it is not always every inch perfect, but they think the number is
>> most likely
>> to be consistent with the Power Budget and also with their production
>> feasibility which,
>> they think, most other suppliers may also agree.
>>
>> If the Spreadsheet provides us the appropriate TDP specification number,
>> I want happily
>> to welcome the result. But if it does not, I would rather put it on
>> component and
>> transceiver suppliers' responsibility.
>>
>> Best regards,
>> Hiroshi Hamano
>>
>> %% "Hajduczenia, Marek" <marek.hajduczenia@NSN.COM>
>> %% Re: [8023-10GEPON] Define TDP values
>> %% Tue, 4 Dec 2007 16:01:22 -0000
>>
>> > Dear Hamano-san,
>> > In a nutshell, do You suggest that we should leave the TDP parameter as
>> > a standalone value and remove the optical path penalty altogether ?
>> > Your conclusions seem to indicate that ...
>> > In that case, we would still need to make sure that our path dispersion
>> > penalty estimation is smaller than some fraction of the TDP parameter
>> > and not knowing how much the TP /or DP/ component is, such comparison
>> > is pointless.
>> > Perhaps we should be looking at other test conditions for the power
>> > budget ?
>> >
>> > Marek Hajduczenia (141238)
>> > NOKIA SIEMENS Networks S.A. - COO BBA DSLAM R&D
>> > Rua Irm?ds Siemens, 1, Ed. 1, Piso 1
>> > Alfragide, 2720-093 Amadora, Portugal
>> > * marek.hajduczenia@nsn.com
>> > (+351.21.416.7472 4+351.21.424.2082
>> >
>> > -----Original Message-----
>> > From: Hiroshi Hamano [mailto:hamano.hiroshi@JP.FUJITSU.COM]
>> > Sent: tere?-feira, 4 de Dezembro de 2007 14:08
>> > To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
>> > Subject: Re: [8023-10GEPON] Define TDP values
>> >
>> > Dear Sirs,
>> >
>> > Tha nk you all for discussing and clarifying TDP definitions.
>> > I would like to explain some backgrounds of my TDP data in the material
>> > 3av_0711_hamano_1.pdf. I hope this will not make you all more confused.
>> >
>> > [Dr. Maricondo]
>> > > From the research that I have found so far, three values that have an
>> > > influence on the TDP value are the laser spectral width, RIN and link
>> > > distance. A narrower laser spectral width or lower RIN value will
>> > > trend
>> > > toward lowering the TDP value, while a longer link will increase the
>> > > TDP.
>> >
>> > 10G DML, Direct-Modulated DFB Laser is supposed to be used as a 10G
>> > upstream
>> > transmitter in 10GE-PON ONU, and I think this transmitter will be the
>> > most
>> > controversial for TDP.
>> > 10G DML suffers an output waveform distortion by its own resonant
>> > frequency,
>> > as I have shown the example w aveform in the material
>> > 3av_0705_hamano_2.pdf.
>> > Even after the receiver equalizing filter, it still remains resulting
>> > eye
>> > closure penalty, thus a large portion of TDP.
>> > The resonant frequency also causes a dynamic chirp, but the dispersion
>> > penalty
>> > may not be dominant, because of the near zero-dispersion wavelength.
>> >
>> > [Dr. Maricondo]
>> > > I also think that if the 802.3av taskforce uses ITU, Fiber
>> > > Channel, other standards, etc, then these values and standards should
>> > > be
>> > > documented within the draft. Let me be clear, I am not opposed to
>> > > using
>> > > other standards as a reference, but it would be a help to the reader
>> > > of the
>> > > 802.3av standard in the future to understand where values have come
>> > > from; I
>> > > believe that the references can be placed in the draft as informative
>> > > notes.
>> >
>> > My TDP num ber suggestion in 3av_0711_hamano_1.pdf is based on some
>> > amount of
>> > current 10G transceiver measurement results and performance, such as
>> > XFPs,
>> > adding some expectations and assumptions by optics and transceiver
>> > experts.
>> > It does not refer to any other IEEE or ITU-T standards. Because the
>> > crucial
>> > power budget of PR30 allows no big margins for transmitters, TDP number
>> > may
>> > not be discussed in such a simple manner of only referring other
>> > standards.
>> > The TDP table in my material shows some other standards, 802.3ae, but
>> > they
>> > appear there only to be contrasted with, not to be referred to. I
>> > apologize
>> > if my TDP table makes you confused.
>> >
>> > [Dr. Maricondo]
>> > > In the absence of hard TDP data, I think that this will allow the
>> > > user
>> > > to put in a transmitter penalty value, while other users who might
>> > > think
>> > > that the T P is overkill can put in a value of zero.
>> > [Dr. Anslow]
>> > > If the group wants to call out the two components of TDP separately
>> > > then we need:
>> > > ....
>> >
>> > Even though a new high-power 10G DML development is necessary for
>> > 10GE-PON,
>> > component and transceiver suppliers have some TDP production data of
>> > current
>> > 10G transceivers, measured in the manner defined in 802.3ae standard,
>> > and from
>> > that data, 10GE-PON standard assumption can be derived.
>> > I am not sure that TP and DP can be clearly separated when they have
>> > some
>> > relationship with each other.
>> > I am not sure either, that there is such TP production data alone,
>> > apart from TDP,
>> > when the TP should be after all user input number.
>> >
>> > Best regards
>> > Hiroshi Hamano
>> >
>> > %% Frank Effenberger <feffenberger@HUAWEI.COM>
> &g t; > %% Re: [8023-10GEPON] Define TDP values
>> > %% Mon, 3 Dec 2007 13:29:30 -0500
>> >
>> > >
>> > > Dear Discussing parties:
>> > >
>> > >
>> > >
>> > > I would submit that all of this is a huge confusion - and before we
>> > > change
>> > > the spreadsheet, I want to make sure that we all are in complete
>> > > agreement
>> > > on the definition of terms, and what use they are.
>> > >
>> > >
>> > >
>> > > For the spreadsheet as it is: we have presented how this spreadsheet
>> > > and the
>> > > budget calculations are supposed to work. While there are lots of
>> > > things in
>> > > that spreadsheet, the only thing that matters is this: Tx_OMA_min =
>> > > Channel_loss + Stressed_Rx_sensitivity_OMA.
>> > >
>> > > For example, if we launch at +5, and the channel loss is 15, then the
>> & gt; > stressed sensitivity is -10. This is the simplest budget
>> calculation
>> > > possible.
>> > >
>> > >
>> > >
>> > > I believe that the definitions of Tx_OMA_min and channel loss are
>> > > self-evident.
>> > >
>> > > As for the meaning of "stressed RX sensitivity", this is the
>> > > sensitivity
>> > > that I would measure with a worst case Rx, worst case Tx, and worst
>> > > case
>> > > optical path.
>> > >
>> > >
>> > >
>> > > So, to the definition of TDP. The value of TDP given here is the
>> > > difference
>> > > between the stressed sensitivity (above) and the "ideal sensitivity".
>> > >
>> > > The ideal sensitivity is already in the spreadsheet, named simply
>> > > "sensitivity".
>> > >
>> > > This "ideal sensitivity" is what I would measure with a worst case R
>> > > x, but a
>> > > best case Tx (perfect pulses) and a best case optical path (that is,
>> > > an
>> > > attenuator!).
>> > >
>> > > Note that a perfect Tx is expressed in terms of OMA, so the ER
>> > > penalty *is*
>> > > captured.
>> > >
>> > >
>> > >
>> > > Currently, TDP is manually entered, and the ideal sensitivity is
>> > > calculated
>> > > to fit. If people want to reverse that, and enter the ideal
>> > > sensitivity
>> > > and calculate the TDP, well, go ahead - it will make no difference at
>> > > the
>> > > end of the day.
>> > >
>> > >
>> > >
>> > > As for what TDP does for us, it is primarily a means of controlling
>> > > the
>> > > transmitter imperfections, some of which are 'stand-alone' (like
>> > > waveform
>> > > imperfections), and some of which are interactions with the optical
>> > > path.
>> > > The IEEE idea is that we throw all of it into a common bucket, and
>> > > let the
>> > > Tx builder optimize his heart out.
>> > >
>> > >
>> > >
>> > > In contrast, the ITU way keeps them separate. The ITU specifies an
>> > > optical
>> > > path penalty, and the "transmitter penalty" is folded into the ITU
>> > > concept
>> > > of Rx_sensitivity. The ITU Rx Sensitivity is measured with a worst
>> > > cast Tx
>> > > but a best case optical path (i.e., an attenuator). So, it's all
>> > > there,
>> > > just re-arranged.
>> > >
>> > >
>> > >
>> > > In summary, the following table of definitions can be stated:
>> > >
>> > > IEEE sensitivity = best-case Tx + best-case path + worst-case Rx
>> > >
>> > > ITU sensitivity = worst-case Tx + best-case path + worst-case Rx
>> > >
>> > > IEEE stress sens. = worst-case Tx + worst-case path + worst-case Rx
>> > >
>> > >
>> > >
>> > > Now: if people want to break up the TDP into "transmitter penalty"
>> > > and
>> > > "Dispersion penalty" (which is very close to the optical path
>> > > penalty), then
>> > > fine. This is, in fact, practically the ITU way of doing things. But,
>> > > I
>> > > thought that the IEEE method was somewhat better for low-cost
>> > > reasons.
>> > >
>> > >
>> > >
>> > > Sincerely,
>> > >
>> > > Frank Effenberger
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > _____
>> > >
>> > > From: Ken Maricondo [mailto:mariconk@GMAIL.COM]
>> > > Sent: Monday, December 03, 2007 10:39 AM
>> > > To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
>> > > Subject: Re: [8023-10GEPON] Define TDP values
>> &g t; >
>> > >
>> > >
>> > > Pete,
>> > >
>> > >
>> > >
>> > > I think that there is some misunderstanding. I do not disagree with
>> > > your
>> > > earlier response to the definition of
>> > > Transmitter_+_Dispersion_Penalty
>> > > (TDP), nor am I opposed to having clear definitions of each value in
>> > > the
>> > > standard and spreadsheet; but what I was suggesting was a compromise
>> > > in the
>> > > absence of hard data for the TDP. As I understand propose of the
>> > > current
>> > > spreadsheet, the spreadsheet is designed to show a worse case
>> > > scenario, not
>> > > every minute value and calculation.
>> > >
>> > > In response to your current thread, what you have pointing out is a
>> > > more
>> > > refined definition of the TDP value which is not part of the scope of
>> > > the
>> > > 802.3av task force, as I understand it. W hat I have personally done
>> > > is
>> > > modify the spreadsheet to include the values that I feel are
>> > > pertinent.
>> > >
>> > >
>> > >
>> > > Best regards,
>> > >
>> > >
>> > >
>> > > Ken
>> > >
>> > >
>> > >
>> > > On Dec 3, 2007 4:11 AM, Pete Anslow <pja@nortel.com> wrote:
>> > >
>> > > Ken,
>> > >
>> > >
>> > >
>> > > The equation you propose for row 53 still does not make sense. TDP
>> > > and
>> > > ITU_Optical_Path_Penalty are not equivalent measures since TDP
>> > > includes the
>> > > non-ideality of the transmitter waveform and ITU_Optical_Path_Penalty
>> > > does
>> > > not.
>> > >
>> > >
>> > >
>> > > If the group wants to call out the two components of TDP separately
>> > > then we
>> > > nee d:
>> > >
>> > >
>> > >
>> > > A user input cell for Maximum Transmitter Penalty TP (penalty due to
>> > > non-ideal eye shape at the transmitter)
>> > >
>> > > A user input cell for Maximum Dispersion Penalty DP (further penalty
>> > > caused
>> > > by the link dispersion)
>> > >
>> > > A calculated cell for Maximum TDP (TDP = TP + DP)
>> > >
>> > > A cell which calculates the actual dispersion penalty (which is
>> > > already
>> > > there)
>> > >
>> > >
>> > >
>> > > I think that it would probably be a good idea to remove the reference
>> > > to
>> > > ITU_Optical_Path_Penalty from the DP row as it seems to cause
>> > > confusion
>> > > rather than help.
>> > >
>> > >
>> > >
>> > > The test in row 53 would then become Is Calculated_dispersion_penalt
>> > > y <= DP?
>> > >
>> > >
>> > >
>> > > We have no way of calculating an estimate of TP, so there is no way
>> > > to make
>> > > this test involve TDP rather than DP alone.
>> > >
>> > >
>> > >
>> > > As discussed earlier, if an additional cell for achievable receiver
>> > > sensitivity was to be introduced then a second test for the overall
>> > > power
>> > > budget could be added.
>> > >
>> > >
>> > >
>> > > Is Min_Tx_Pow - TDP - Max_channel_loss > Rx_Sens?
>> > >
>> > >
>> > >
>> > > The Min_Tx_Pow and Rx_Sens would be in OMA and Rx_Sens would have to
>> > > be
>> > > referred to the sensitivity you would get with an ideal transmitter
>> > > for this
>> > > to work.
>> > >
>> > >
>> > >
>> > > Regards,
>> > >
>> > > Pete Anslow
>> > >
>> > >
>> > >
>> > > Nortel Networks UK Limited, London Rd, Harlow, Essex CM17 9NA, UK
>> > >
>> > > External +44 1279 402540 ESN 742 2540
>> > >
>> > > Fax +44 1279 402543
>> > >
>> > >
>> > >
>> > > _____
>> > >
>> > > From: Ken Maricondo [mailto: kmaricondo@IEEE.ORG]
>> > > Sent: 30 November 2007 04:17
>> > >
>> > >
>> > > To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
>> > > Subject: Re: [8023-10GEPON] Define TDP values
>> > >
>> > >
>> > >
>> > > Dear All,
>> > >
>> > >
>> > >
>> > > Thank you all for the feedback and clarification. In reviewing all of
>> > > the
>> > > recent threads, I think that we all can agree that a penalty is a pen
>> > > alty.
>> > > Therefore, I suggest that the spreadsheet be change to reflect the
>> > > following:
>> > >
>> > > 1. Change the TDP cell (A39) to only be TP
>> > >
>> > > 2. Change the Transmitter Dispersion Penalty cell (D39) to
>> > > Transmitter Penalty
>> > >
>> > > 3. Change Dispersion_Penalty <= ITU_Optical_Path_Penalty cell (A53)
>> > > to Transmitter_+_Dispersion_Penalty <= ITU_Optical_Path_Penalty or
>> > > TDP <=
>> > > ITU_Optical_Path_Penalty
>> > >
>> > > 4. Change cell (D53) formula to =IF((B38+B39)<=B30,"PASSED","FAILED")
>> > >
>> > >
>> > >
>> > >
>> > > In the absence of hard TDP data, I think that this will allow the
>> > > user to
>> > > put in a transmitter penalty value, while other users who might think
>> > > that
>> > > the TP is overkill can p ut in a value of zero. At a later date and
>> > > when TDP
>> > > data is available, I think that we can readdress this issue. What do
>> > > you
>> > > think?
>> > >
>> > >
>> > >
>> > > Best regards,
>> > >
>> > >
>> > >
>> > > Ken Maricondo
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > On Nov 29, 2007 3:10 PM, Frank Chang <ychang@vitesse.com> wrote:
>> > >
>> > > Hi Pete;
>> > >
>> > >
>> > >
>> > > I am very happy you chime in to clarify the confusion which exists
>> > > for a
>> > > while in the email thread and also associated mtg discussions so far.
>> > > I also
>> > > feel the term "TDP" or even "stress RX sens" was misinterpreted in
>> > > link
>> > > budget formalism, which is quite inconsistent with what is defined in
>> > > IE EE
>> > > 802.3 for the TP2 and TP3 methodology.
>> > >
>> > >
>> > >
>> > > FYI- In line with what you said, actually I provided a tutorial to
>> > > elaborate
>> > > this during July mtg as follows:
>> > >
>> > > http://www.ieee802.org/3/av/public/2007_07/3av_0707_chang_1.pdf
>> > >
>> > >
>> > >
>> > > Best Regards
>> > >
>> > > Frank C.
>> > >
>> > > -----Original Message-----
>> > > From: Pete Anslow [mailto: pja@nortel.com <mailto:pja@nortel.com> ]
>> > > Sent: Thursday, November 29, 2007 3:13 AM
>> > > To: STDS-802-3-10GEPON@listserv.ieee.org
>> > > Subject: Re: [8023-10GEPON] Define TDP values
>> > >
>> > > Hi,
>> > >
>> > > The way the term " TDP" is being discussed in this thread seems to me
>> > > to be
>> ; > > inconsistent with the way it is defined in IEEE 802.3.
>> > >
>> > > TDP stands for Transmitter and Dispersion Penalty. It is the penalty
>> > > due
>> > > to the combination of the eye closure of the transmitter and the
>> > > further eye
>> > > closure caused by the link dispersion.
>> > >
>> > > The TDP measurement procedure for 1000Base PX10 and PX20 is defined
>> > > in
>> > > subclause 58.7.9 . The sensitivity of the reference receiver is
>> > > measured
>> > > with as near an ideal test transmitter as possible and then this is
>> > > corrected for any residual transmitter eye closure to give the
>> > > sensitivity
>> > > with an ideal transmitter S. Then the receiver sensitivity is
>> > > measured
>> > > again using the transmitter under test through the worst case
>> > > dispersion .
>> > > T he TDP value is then the difference between the second measurement
>> > > and S.
>> > >
>> > > If we label the two penalty components as EP for the transmitter Eye
>> > > Penalty
>> > > (penalty due to non-ideal eye shape at the transmitter) and DP for
>> > > the
>> > > transmi tter Dispersion Penalty (further eye closure caused by the
>> > > link
>> > > dispersion ) then we can say:
>> > >
>> > > TDP = EP + DP
>> > >
>> > > Now, for most ITU-T power budgets Path Penalty is approximately equal
>> > > to DP
>> > > (and the specified receiver sensitivity has to be met using a
>> > > transmitter
>> > > with a worst case EP ).
>> > >
>> > > Consequently, Dispersion_Penalty <= ITU_Optical_Path_Penalt y makes
>> > > reasonable sense.
>> > >
>> > > The inequality (Dispersion_Penalty+TDP) <= ITU_Optical_Path_Penalt y
>> > > makes
>> > > no sense at all as it is roughly equivalent to saying:
>> > >
>> > > DP + (EP + DP) < = DP
>> > >
>> > > I agree that Dispersion_Penalty <= ITU_Optical_Path_Penalt y is not
>> > > sufficient to establish that the power budget is feasible with
>> > > available
>> > > optics. As I understand the current spreadsheet, it calculates the
>> > > receiver
>> > > sensitivity that would be required given the various input
>> > > parameters. In
>> > > order to test for the feasibility of this sensitivity value an
>> > > additional
>> > > input cell containing the achievable receiver sensitivity with a n
>> > > ideal
>> > > transmitter would be required.
>> > >
>> > > Regards,
>> > >
>> > > Pete Anslow
>> > >
>> > > Nortel Networks UK Limited, London Rd, Harlow, Essex CM17 9NA, UK
>> > >
>> > > External +44 1279 402540 ESN 742 2540
>> > >
>> > > Fax +44 1279 402543
>> > >< BR>> > > _____________________________________________
>> > > From: Hiroshi Hamano [ <mailto:hamano.hiroshi@JP.FUJITSU.COM>
>> > > mailto:hamano.hiroshi@JP.FUJITSU.COM]
>> > > Sent: 29 November 2007 02:55
>> > > To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
>> > > Subject: Re: [8023-10GEPON] Define TDP values
>> > >
>> > > Dear Dr. Maricondo,
>> > >
>> > > Thank you very much for your explanations, and I apologize for my
>> > > late
>> > > reply.
>> > >
>> > > Now, I understand that, in your E-mail, (Dispersion_Penalty+TDP)
>> > > means the
>> > > dispersion penalty value using a realistic transmitter with worst
>> > > case TDP,
>> > > in contrast to that using an ideal or perfect transmitter with small
>> > > or no
>> > > TDP.
>> > >
>> > > I am not sure, whether (Dispersion_Penalty), in the Spreadsheet, is
>> > > figured
>> > > out based on such an ideal transmitter or not, but I agree that the
>> > > result
>> > > should indicate the worst case value in order to d ecide the
>> > > fail/pass
>> > > condition.
>> > >
>> > > But I am not sure either, how TDP should be counted into such
>> > > transmitter
>> > > parameters for calculating (Dispersion_Penalty+TDP), in the
>> > > Spreadsheet, and
>> > > how big its impact will be. If you have any suggestions, that will be
>> > > qu
>> > > ite helpful.
>> > >
>> > > If TDP value should be derived from the measurement results, not from
>> > > Spreadsheet calculations, some penalty value may remain only assumed
>> > > and
>> > > uncalculated, unless the relationship between the measured TDP and
>> > > Dispersion_Penalty is justified.
>> > >
>> > > Any comments or discussions will be highly appreciated.
>> > >< BR>> > > Best regards,
>> > >
>> > > Hiroshi Hamano
>> > >
>> > > %% "Ken Maricondo" <kmaricondo@ieee.org> %% Re: [8023-10GEPON] Define
>> > > TDP
>> > > values %% Fri, 23 Nov 2007 17:07:53 -0500
>> > >
>> > > >
>> > >
>> > > > Dear Hamano-san and Hajduczenia,
>> > >
>> > > >
>> > >
>> > > > I agree (from all that I have read) that the
>> > > > ITU_optical_path_penalty
>> > >
>> > > > basically includes no transmitter penalty and that receiver
>> > >
>> > > > sensitivity value in ITU formalism should share the TDP within the
>> > >
>> > > > margin. The rationale as to why I suggested adding the TDP to
>> > >
>> > > > *Dispersion_Penalty <=
>> > >
>> > > > ITU_Optical_Path_Penalty* is as follows:
>> > >
>> > > >
>> > >
>> > > > 1. Any penalty such as chirp, extinction ratio, MPN, etc., will
>> > > > require
>> > >
>> > > > that the photodiode receiver to receive an increased proportional
>> > >
>> > > > optical receive level in order to maintain the same BER verse a
>> > > > system
>> > >
>> > > > without the same penalties. The *Dispersion_Penalty <=
>> > >
>> > > > ITU_Optical_Path_Penalty* from what I can tell assumes an ideal
>> > >
>> > > > transmitter and receiver over a given optical path and that only if
>> > >
>> > > > the dispersion penalty exceeds the optical path penalty then the
>> > > > link
>> > >
>> > > > fails. If I use only dispersion penalty in a network calculation
>> > >
>> > > > without the TDP, then I am not truly taking int o account worse
>> > >
>> > > > case/end of life network performance. In my point of view, a
>> > > > network
>> > >
>> > > > designed with a TDP of 3dB for example will have a shorter
>> > > > operational
>> > >
>> > > > lifetime or be performance limited then an identical network with
>> > > > an
>> > >
>> > > > ideal transmitter with no TDP or lower value of TDP. So to
>> > > > compensate for
>> > > the TDP a more robust FEC scheme or higher quality receiver might be
>> > > in
>> > > order.
>> > >
>> > > >
>> > >
>> > > > 2. I do not discount or object to the TDP value from being
>> > > > subtracted
>> > >
>> > > > from the *IEEE_Rx_Stressed_Sensitivity_OMA* to get
>> > > > *IEEE_Rx_Sen_OMA*,
>> > >
>> > > > but I think that TDP should show up in the system margin as worse
>> > >
>> > > > case/end of life calculation within the spreadsheet. The fact that
>> > >
>> > > > the receiver sensitivity has to go lower to compensate for the TDP
>> > >
>> > > > only points out that I have to have a higher quality ideal receiver
>> > > > at
>> > > first glance.
>> > >
>> > > >
>> > >
>> > > > I am acutely aware of the fact that 10GEPON standard will allow for
>> > >
>> > > > degree of flexibility in the network design to compensate for
>> > > > network
>> > >
>> > > > design short comings. My suggestion for *(Dispersion_Penalty+TDP)
>> > > > <=
>> > >
>> > > > ITU_Optical_Path_Penalty* to be changed is to make sure that there
>> > > > is
>> > >
>> > > > no ambiguity in the standard (spreadsheet) and to point out to the
>> > >
>> > > > adopter of the 10GEPON standard that *all* penalties have been
>> > >
>> > > > accounted for, analyzed and documented. At the end of the day it is
>> > >
>> > > > up to task force as whole to adopt what they feel is appropriate
>> > > > for the
>> > > standard.
>> > >
>> > > >
>> > >
>> > > > Best regards,
>> > >
>> > > >
>> > >
>> > > > Ken Maricondo
>> > >
>> > > >
>> > >
>> > > >
>> > >
>> > > >
>> > >
>> > > >
>> > >
>> > > > On Nov 22, 2007 5:27 AM, Hiroshi Hamano
>> > >
>> > > > <hamano.hiroshi@jp.fujitsu.com>
>> > >
>> > > > wrote:
>> > >
>> > > >
>> > >
>> > > > > Dear Dr. Maricondo and Dr. Hajduczenia,
>> > >
>> > > > >
>> > >
>> > > > > Thank you for your quick response and discussion.
>> > >
>> > > > > I am not sure how TDP values have been defined in the previous
>> > >
>> > > > > specifications such as IEEE 802.3ae and 802.3ah. If they have
>> > > > > also
>> > >
>> > > > > reflected the vendor data based on the transmitter measurement
>> > >
>> > > > > results, vendor feedbacks may be quite important similarly for
>> > >
>> > > > > 10GE-PON.
>> > >
>> > > > >
>> > >
>> > > > > > but should read *(Dispersion_Penalty+TDP) <=
>> > >
>> > > > > > ITU_Optical_Path_Penalty* to insure all possible noise and
>> > >
>> > > > > > penalties
>> > >
>> > > > > are
> &g t; > >
>> > > > > > accounted for.
>> > >
>> > > > >
>> > >
>> > > > > Perhaps, I misunderstand the last sentence of Dr. Maricondo's
>> > > > > E-mail.
>> > >
>> > > > > But my understanding is that ITU_optical_path_penalty basically
>> > >
>> > > > > includes no transmitter penalty. Receiver sensitivity value in
>> > > > > ITU
>> > >
>> > > > > formalism should share the margin, instead, for possible
>> > > > > transmitter
>> > >
>> > > > > penalty compared to the ideal one.
>> > >
>> > > > > Would you please explain again your intension about the
>> > > > > sentence??
>> > >
>> > > > >
>> > >
>> > > > > Best regards,
>> > >
>> > > > > Hiroshi Hamano
>> > >
>> > > > > Fujitsu Labs. Ltd.
>> > >
>> > > > >
>> > >
>> > > > > %% "Ken Maricondo" <kmaricondo@ieee.org> %% Re: [8023-10GEPON]
>> > >
>> > > > > Define TDP values %% Wed, 21 Nov 2007 19:15:31 -0500
>> > >
>> > > > >
>> > >
>> > > > > >
>> > >
>> > > > > > Dear Hamano-san,
>> > >
>> > > > > >
>> > >
>> > > > > > Although the TDP is a controversial value to be added to the
>> > >
>> > > > > > 10GEPON standard, I have to agree with the previous committee (
>> > >
>> > > > > > 802.3ah) for assigning a TDP value; albeit not an apparent
>> > >
>> > > > > > benefit, the TDP does set
>> > >
>> > > > > a
>> > >
>> > > > > > re ference value/point for determining transmitter quality
>> > > > > > which
>> > >
>> > > > > > does
>> > >
>> > > > > impacts
>> > >
>> > > > > > system performance. I agree with your assessment that the lack
>> > > > > > of
>> > >
>> > > > > > high power reference transmitter to make a TDP measurement at
>> > > > > > this
>> > >
>> > > > > > time is a problem. In the absence of such a reference
>> > >
>> > > > > > transmitter/s, I think that
>> > >
>> > > > > the
>> > >
>> > > > > > TDP values you have chosen are a good reference point to start
>> > >
>> > > > > > with and
>> > >
>> > > > > I
>> > >
>> > > > > > support you on this issue.
>> > >
>> > > > > &g t;
>> > >
>> > > > > > I also think that the spreadsheet should reflect the impact of
>> > > > > > TDP
>> > >
>> > > > > > on
>> > >
>> > > > > the
>> > >
>> > > > > > systems' overall performance. From what I have been able to
>> > > determine,
>> > >
>> > > > > the
>> > >
>> > > > > > TDP value is subtracted from the
>> > >
>> > > > > > *IEEE_Rx_Stressed_Sensitivity_OMA* to
>> > >
>> > > > > get *
>> > >
>> > > > > > IEEE_Rx_Sen_OMA*, which does not readily translate into a
>> > > > > > system
>> > >
>> > > > > performance
>> > >
>> > > > > > impact/limitation. The system pass/fail calculation is based on
>> > >
>> > > > > > *Dispersi on_Penalty <= ITU_Optical_Path_Penalty* only, but
>> > > > > > should
>> > >
>> > > > > > read
>> > >
>> > > > > *(Dispersion_Penalty+TDP)
>> > >
>> > > > > > <= ITU_Optical_Path_Penalty* to insure all possible noise and
>> > >
>> > > > > > penalties
>> > >
>> > > > > are
>> > >
>> > > > > > accounted for.
>> > >
>> > > > > >
>> > >
>> > > > > > Best regards,
>> > >
>> > > > > >
>> > >
>> > > > > > Ken Maricondo
> ---
> -----------------------------------------
> Hiroshi Hamano
> Network Systems Labs., Fujitsu Labs. Ltd.
> Phone:+81-44-754-2641 Fax.+81-44-754-2640
> E-mail:hamano.hiroshi@jp.fujitsu.com
> -----------------------------------------