AW: [EFM] PON Optics Telephone Conference, December 5th
Hi Kent,
Thanks for your input on this topic. I believe that question 1)
has already been addressed by Roy Bynum; there are others who are
in a better position to answer this than me.
Regarding testing I see two different levels/types of testing.
Firstly there is module testing where different response times
will not present a problem (the response time is probably
one of the parameters that would be determined). Beyond this there
is then system/interoperability testing. When testing with 'non-intelligent'
equipment, the guardband between bursts would be set to the Upper-Bound
values agreed upon.
By guardband I mean the time delay between the Tx_On signal and the time
when the Rx starts examining bit to determine the BER.
With an intelligent system, i.e. protocol implementation with negotiated
parameters,
interoperability is not a problem as the optimal guardband is calculated.
The above tests determine if one Tx communicates optically with the expected
BER
with another Rx. Setting the guardband equal to the upper limit determines
that the timing requirements of the combined link are met. Direct module
testing delivers the individual Rx and Tx times. Hence, I don't see a
problem
with testing depending on the option choice for the timing parameters.
Regards
Tom
-----Ursprüngliche Nachricht-----
Von: Mccammon, Kent G. [mailto:kmccammon@xxxxxxxxxxx]
Gesendet am: Donnerstag, 5. Dezember 2002 02:45
An: Murphy Thomas (COM FO D O); stds-802-3-efm@ieee.org;
Vipul_Bhatt@xxxxxxxx; wdiab@xxxxxxxxx
Betreff: RE: [EFM] PON Optics Telephone Conference, December 5th
Tom,
Since I have a conflict with the call tomorrow and I am interested in this
decision, here are some questions.
1)Do any of the options for PON timing impact the delivery of services such
as toll quality voice, a T1, or multicast video? We had this concern
previously and the answer previously was claimed to be only an efficiency
hit for loose timing. Are the modeling assumptions to compare efficiency
valid for TDM services or is that not a consideration in this debate to
date?
2)The negotiation of timing parameters rather than a tight specification
have any impact on future interoperability testing? If we ever decide to
test interoperability of EPON OLT and ONT, can a lab testing system be
reasonably built to test compliance to a specification for OLT/ONT timing
for the various options under debate?
3)Do operating temperature swings have an impact on timing options. Is their
reason to add extra margin or extra negotiation time of timing parameters
due to temperature variations? What about cold start in cold temperatures,
that was an issue for power levels, does it also impact the electronics of
the PMD?
Comment: As an advocate of PON technologies I echo my earlier comments about
striving for common PON PMD to get the volume started in today's economy. I
am optimistic a compromise can be found in January.
Thanks,
-Kent
> -----Original Message-----
> From: Thomas.Murphy@xxxxxxxxxxxx [mailto:Thomas.Murphy@xxxxxxxxxxxx]
> Sent: Wednesday, December 04, 2002 10:12 AM
> To: stds-802-3-efm@ieee.org; Vipul_Bhatt@ieee.org; wdiab@cisco.com
> Subject: [EFM] PON Optics Telephone Conference, December 5th
>
>
> Hello Again,
>
> Attacted two possible approaches to this discussion forming
> two decision trees. Glen and I worked on these I I did not
> have a chance to co-ordinate with him and refine to one
> slide. The first slide is mine and I would like to start
> here as it allows us to generate values without having to
> make decisions. When the values are agreed upon, we can work
> towards the decision and perhaps this is simpler with the
> values we have.
>
> If this does not work, we can try the seconf slide, Glen's
> approach, which is a more top-down attack.
>
> Talk to you tomorrow
>
> Tom
>
> <<PON Timing Decision Tree.ppt>>
>
> Hello All,
>
> Items to Be Covered
>
> 1) Determine the exact meaning of the terms "Fixed Value"
> and 'Upper Bound" in terms
> of their use for PMD timing parameters.
>
> 2) Try assign placeholder values for all of the options
>
> 3) Are these values fixed or bounded for the different options.
>
> 4) Other items
>
> Regards
>
> Tom
>
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