1. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 1 [Reflections on TGn Development and Proposals for 802.19] Notice: This document has been prepared to assist IEEE 802.19. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.19. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the TAG of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.19 TAG. If you have questions, contact the IEEE Patent Committee Administrator at.http:// ieee802.org/guides/bylaws/sb-bylaws.pdfpatcom@ieee.org Date: 2005-03-07 Authors:

2. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 2 Abstract This presentation presents our observations and reflections on TGn development process and our suggestions on 802.19 development.

3. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 3 Our Observations on TGn Development Have a well-thought procedure to follow –Adopt Usage Models for the IEEE 802.11n amendment –Adopt Channel Models corresponding to the usage models that may be used for evaluation of proposals. –Adopt Functional Requirements that must be met by all complete proposals. –Adopt Comparison Criteria that must be address by all proposals –…

4. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 4 Proposals for.19 In a CA document, require the following: –A definition of usage cases considering reasonable victim and interferer devices –A definition of metrics establishing the impact of interferer on victim –An assessment showing this impact is reasonable

5. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 5 Our Observations on TGnSync Simulation Methodology Many required behaviors are not fully defined by specs and different heuristics for them in simulation have big impacts on the end results –E.g. scheduling, retry behavior Simulation results are sensitive to simulation parameters –E.g. TCP result is sensitive to buffer sizes. Different implementations of the same protocol results in very different performances.

6. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 6 Lessons Learned – Conclusions We are fooling ourselves if we believe a system simulation gives a precise result –Two different system simulations of the same protocol may yield very different results We can afford to make considered simplifications to avoid: –Needing to create expensive system simulation models –Needing to validate heuristics of protocols we have no expertise in We need powerful analytical models –Call to arms!

7. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 7 A Proposed Plan for TGn CA Document Create coexistence usage cases and define relevant metrics Create analytical models for interference modeling –Rely.19 to provide analytical model behavior of non TGn systems Perform simulation –Extend system-level simulator for interference modeling and collaborate results with these from analytic methodology Measure testbed results for interference –Depends on the availability of prototype equipment Produce Assessment of impact

8. doc.: IEEE 802.19-05-0008-00-0000 Submission Month Year Changwen Liu et al, IntelSlide 8 Summary It is unrealistic to expect system-level simulations as a basis of CA results It will be necessary for.19 to provide (or make available) analytical models of “other” systems for use in a CA analysis