Dear Mr. Li, experts,
as you wished we kindly reviewed your paper. Here are our conclusions: * it does not incorporate both the conditions used in your simulation and the scenario we proposed in APC-1993 correctly * it does not incorporate the decisions of the group at the Geneva meeting * relations to practical usage are missing To replenish this paper with all the necessary information would take to long.
We are running out of time. Therefor we completed APC-1993 with the few missing values out of your paper. An additional section with the proposed internet tests is now included. Please be so kind to supplement this section with your suggestions. We hope you can finally agree on that joint scenario document. Again, it is very important to have a complete scenario instead of
a collection of values to make our work tangible for everybody within the group.
A few points are still under discussion. Using a rate control for example does not make much sense in our case. It is not part of any standard and can be optimized to support one or the other method. To regiment the length of slices is only in favour of the UCLA proposal. Therefore we don't want to see this restriction within the test scenario.
It is still impossible to implement the UCLA proposal with the documents available. We were asking you several times concerning technical obscurities but your answer is still missing.
We are supposed to use the standard ITU-T code of H.263 for the tests. As far as we aware there is no official version including all necessary parts of H.263. That is to say only H.26L can be used for the tests. If you know a place where the appropriate software is available please provide us with the link.
Best Wishes Gero Baese
----------------------------------------------------------- Gero Bäse Siemens AG Tel.: +49 89 636 53193 Corporate Technology Fax: +49 89 636 52393 Networks and Multimediacommunication CT IC 2 -----------------------------------------------------------
<<APC-1993r2.doc>>
Mr. Baese, experts,
Thank you for your response to our simulation scenario sent on 12/21/2000. However, it is not clear from your email how you suggest to modify it.
as you wished we kindly reviewed your paper. Here are our conclusions:
- it does not incorporate both the conditions used in your simulation and the scenario we proposed in APC-1993 correctly
- it does not incorporate the decisions of the group at the Geneva
meeting
Can you be more specific on which testing conditions that we missed, or which decision of the group at Geneva that I did not incorporate? Please be a little specific so we can work to make it better.
To regiment the length of slices is only in favour of the UCLA proposal. Therefore we don't want to see this restriction within the test scenario.
I think you refer to the following paragraph of the simulation document.
"When the Annex K and/or Annex V is used, the length of the slice should be such to make packets fit in the length of segment to avoid segmentation of the IP packet (for fixed segment-loss-rate channels, see below)."
This conditions is NOT in favor of either proposal. It is a fair condition which is important to evaluate the performance of protection schemes. Let me explain:
If one want to evaluate if a protection scheme works, s/he need to show how much the performance improves between the cases "with" and "without" the proposed scheme. For a realistic measurement of the gain, the benchmark performance in the "without" case that one compared to needs to be the (near) optimal scenario. In other word, to demonstrate effectiveness of any scheme, one need to show that it can provide any gain over the *best* case the system has without it.
I think Mr. Baese agrees that use the right video slice length to avoid segmentation gives the (near) optimal performance for the case *without* any protection. That is the benchmark case that both of our proposals need to be compared to. This requirement is a fair condition and is not in favor of either proposal.
We are looking forward to hearing your comments on this and hope we can reach an agreement on the testing conditions soon.
Adam Li
---------- Adam H. Li Image Communication Lab (310) 825-5178 (Lab) University of California, Los Angeles (310) 825-7928 (Fax)
participants (2)
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Adam Li -
Baese Gero