AW: AW: [802.3ae_Serial] Issue with 1500 Power
Hi,
ok this clarifies (and confirms) my understanding. May be that confusion was
related to the fact of too fast reading, not being native speaker.
However this keeps the issue, I tried to point to, as is.
Regards Juergen
> ----------
> Von: Mike Dudek[SMTP:mdudek@cieloinc.com]
> Gesendet: Donnerstag, 5. Juli 2001 01:43
> An: DAWE,PIERS (A-England,ex1)
> Cc: Rahn, Juergen (Juergen); stds-802-3-hssg-serialpmd@ieee.org
> Betreff: Re: AW: [802.3ae_Serial] Issue with 1500 Power
>
> I am in full agreement with Piersexcept that I believe the minus sign in
> the document is correct. The OMA minus TDP should be equal to -1.39.
> If
> the TDP is large the OMA has to increase.
>
> "DAWE,PIERS (A-England,ex1)" wrote:
>
> > Juergen,
> >
> > You are less confused than you say! I have compared my understanding
> with
> > yours: see below. There are some editorial/clarity issues and one
> > outstanding point which is: is the 802.3ae D3.1 ER/EW receive
> sensitivity
> > very demanding or expensive?
> >
> > Piers
> >
> > > -----Original Message-----
> > > From: Rahn, Juergen (Juergen) [mailto:krahn@lucent.com]
> > > Sent: 03 July 2001 09:01
> > > To: 'Mike Dudek'
> > > Cc: stds-802-3-hssg-serialpmd@ieee.org; 'Ron Miller'
> > > Subject: AW: AW: [802.3ae_Serial] Issue with 1500 Power
> > >
> > >
> > > Sorry,
> > > I am still confused.
> > > You talk about ISI penalty now but this is stated at transmitter power
> > > anyway and not quantified.
> > > In the table it reads:
> > > Launch power (min) in OMA minus TDP * -1.39 dBm
> > > with a note:
> > > * TDP is transmitter and dispersion penalty
> > > up to now I interpreted that we have to consider the
> > > penalties and than
> > > compensate the penalties by increasing the power (Whatever
> > > the penalties
> > > are) First question is this a correct understanding?
> >
> > Yes
> >
> > > If yes you will not have any advantage at the receiver when
> > > increasing the
> > > power by the amount of penalty as a penalty represents the decrease in
> > > sensitivity, so this should add up to zero.
> >
> > Yes
> >
> > > (It comes to my mind that the - in this parameter suggests
> > > that the power
> > > may be decreased by the penalties which would give trouble
> > > but this may be a
> > > short editorial discussion)
> >
> > Juergen please make a comment. Editor please note!
> >
> > > If this understanding is correct let me make the calculation:
> > > Simple case ideal transmitter no penalties :
> > > Launch power (min) in OMA minus TDP * -1.39 dBm
> > >
> > > Stressed receive sensitivity (max) in OMA ?, ? , §
> > > (-11.40)
> > > (dBm)
> > >
> > > I calculate an attenuation budget of about 10 dB out of this not 13db.
> >
> > No, you have it right below.
> >
> > > However there is a term in the receiver table .
> > > ( I interpret max sensitivity here also as a minimum
> > > requirement, I don not
> > > hope that this means the sensitivity should not be better
> > > than this value,
> > > but this may be an editorial problem)
> >
> > Maximum is more dBm, representing worst case for a receiver sensitivity,
> so
> > I think this one is the right way round. Please make a comment if any
> doubt
> > remains.
> >
> > > Vertical eye closure penalty ** (max) 3.0 dB
> > > with a note
> > > **Vertical eye closure penalty is a test condition for
> > > measuring stressed
> > > receive sensitivity. It is not a required charac-teristic
> > > of the receiver.
> > > This note is a bit misleading for me, however I interpret
> > > this note in the
> > > way that when measuring stressed sensitivity there has to be
> > > used a signal
> > > that has 3 dB penalty, what means that for a signal that does
> > > not show this
> > > penalty ( as assumed at the transmitter in this
> > > consideration) we can add
> > > this to the sensitivity. Is this the ISI penalty you mention?
> > > In this case
> > > we really at the end coming out with 13 dB budget.
> > > Calculation would look like:
> > > _________________________________________________________
> > > transmitter OMA min -1.39 dBm
> > > _________________________________________________________
> > > receiver sensitivity (OMA) -11.40 dBm
> > > + receiver test signal penalty 3.0 dB
> > > _____________________________________________
> > > Total )penalty free signal) sensitivity in OMA
> > > -14.4 dBm
> > > __________________________________________________________
> > > attenuation budget
> > > 13.01 dB
> > >
> > > So can you confirm this understanding ?
> >
> > Yes.
> >
> > > If not would it be possible to set up a similar calculation
> > > like this and
> > > clarify.
> > >
> > > If this understanding is correct than we have 14.4 dBm sensitivity
> > > requirement in OMA and this for instance get it comparable to
> > > transponders
> > > you can by translates (being optimistic into average power
> > > sensitivity of :
> > > - 14.4 dBm OMA will give -17.4 dBm ideal ER sensitivity or
> > > -16 dBm (average
> > > power sensitivity) at ER of 8.2 dB as used in ITU. This is 2
> > > dB harder as
> > > ITU and represents the BOL typical value that you get for
> > > such components.
> > > For an interface spec we however require EOL worst case!
> > > For my understanding this is not realistic today and if done will be
> > > expensive.
> >
> > Is it relevant to point out that SONET receiver sensitivities are
> > standardised for a "worst" Tx eye which has the same 3 dB penalty? Not
> sure
> > if you have already taken that into account.
> >
> > > Regards Juergen Rahn
> > >
> > >
> > > > ----------
> > > > Von: Mike Dudek[SMTP:mdudek@cieloinc.com]
> > > > Gesendet: Dienstag, 3. Juli 2001 03:02
> > > > An: Rahn, Juergen (Juergen)
> > > > Cc: stds-802-3-hssg-serialpmd@ieee.org; 'Ron Miller'
> > > > Betreff: Re: AW: [802.3ae_Serial] Issue with 1500 Power
> > > >
> > > >
> > > > A further attempt to clarify this.
> > > > The 3dB difference is the ISI penalty that is imposed when
> > > performing the
> > > > stressed receiver sensitivity test which corresponds to the
> > > maximum value
> > > > of the
> > > > Transmitter and Dispersion Penalty of the Transmitter. If one has a
> > > > transmitter
> > > > that produces this amount of penalty then one has to
> > > increase the output
> > > > power
> > > > by 3dB. Hence the 13dB is attained.
> > > > Regards Mike
> > > >
> > > > "Rahn, Juergen (Juergen)" wrote:
> > > >
> > > > > Hi
> > > > > The difference between current defined sensitivity and
> > > what would be
> > > > > required (straightforward without any additional margin
> > > penalty....) is
> > > > 3
> > > > > dB, what means the attenuation budget would be 10 dB.
> > > > > Does this clarify?
> > > > > Regards Juergen
> > > > >
> > > > > > ----------
> > > > > > Von: Ron Miller[SMTP:rmiller@brocade.com]
> > > > > > Gesendet: Mittwoch, 27. Juni 2001 18:10
> > > > > > An: Rahn, Juergen (Juergen);
> > > stds-802-3-hssg-serialpmd@ieee.org
> > > > > > Betreff: RE: [802.3ae_Serial] Issue with 1500 Power
> > > > > >
> > > > > >
> > > > > > juergen
> > > > > >
> > > > > > Please check your numbers below. Thanks
> > > > > >
> > > > > > Ron Miller
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Rahn, Juergen (Juergen) [mailto:krahn@lucent.com]
> > > > > > Sent: Wednesday, June 27, 2001 3:30 AM
> > > > > > To: stds-802-3-hssg-serialpmd@ieee.org
> > > > > > Subject: AW: [802.3ae_Serial] Issue with 1500 Power
> > > > > >
> > > > > >
> > > > > >
> > > > > > Hi,
> > > > > > as discussed in the PMD call I understand there is a
> > > mismatch in the
> > > > > > values
> > > > > > defined for the 1550 case. The minimum transmitter OMA
> > > is -1.39dBm +
> > > > > > penalties. Link attenuation is set to 13 dB , so this
> > > would give a
> > > > > > sensitivity requirement of -14,39 dBm OMA ,. however
> > > the stressed
> > > > > > sensitivity (In OMA) is defined to be -11.4 dBm.
> > > > > >
> > > > > > so there are 10 dB
> > > > > > difference between those two values.
> > > > > >
> > > > > > LOOKS MORE LIKE ABUT 3 DB TO ME.
> > > > > >
> > > > > > The trade off that has been introduced
> > > > > > (that I do not like, but this is a different
> > > discussion) will shift
> > > > this
> > > > > > complete link power level. When comparing this with powers and
> > > > > > sensitivities
> > > > > > as defined in ITU the following appears: ITU defines 2
> > > dB path penalty
> > > > > > with
> > > > > > this OMA we would end at a minimum transmitter power average of
> > > > about -
> > > > > > 1
> > > > > > dBm which is in line to ITU. with 109 dB attenuation
> > > there is margin
> > > > in
> > > > > > the
> > > > > > ITU numbers, with 11 dB and ITU sensitivity (Which has
> > > been confirmed
> > > > by
> > > > > > measurements) we add up to 0. ( -14 dBm average power
> > > sensitivity and
> > > > 2 dB
> > > > > > penalty gives us the G.691 application). When simply taking this
> > > > > > transmitter
> > > > > > power and 13 dB attenuation we end up with 2 dB better
> > > sensitivity
> > > > > > requirement as currently experienced by measurements
> > > (worst case EOL).
> > > > > > This may start this conversation.
> > > > > > Regards Juergen
> > > > > >
> > > > > >
> > > >
> > >
>