TGn Simulation Methodology Validation Proposal Month 2004 doc.: IEEE 802.11-03/0185r0 TGn Simulation Methodology Validation Proposal Jeff Gilbert Atheros Communications J.Gilbert, Atheros Communications J.Gilbert, Atheros Communications

Month 2004 doc.: IEEE 802.11-03/0185r0 Overview The simulations methodology ad hoc is investigating methods to accurately, yet efficiently, model the behavior of proposals’ PHYs in MAC/system simulations. Various proposals trade off accuracy of modeling of the PHY itself with accuracy of modeling of the PHY/MAC interface. I.e. some proposals use link-level detailed PHY but use abstractions to capture its performance (e.g. 11-04/0172 by Atheros/Mitsubishi) Some proposals use approximation of PHY but are able to incorporate it more exactly in the MAC / System Simulations (e.g. 11-03/0863 by Intel) J.Gilbert, Atheros Communications J.Gilbert, Atheros Communications

Month 2004 doc.: IEEE 802.11-03/0185r0 Necessity to Validate If approximations of the PHY are made, it is critical that we have a methodology to validate the approximations. Since proposals could have arbitrary PHYs, the proposer must show how they have accurately incorporated their PHY into the methodology. Otherwise the validity of results will be immediately challenged during the proposal comparison process. J.Gilbert, Atheros Communications J.Gilbert, Atheros Communications

Month 2004 doc.: IEEE 802.11-03/0185r0 A Validation Option One method to validate the PHY / MAC abstraction is to have proposers plot unidirectional, point-to-point MAC SAP throughput vs. SNR or Range for both: Simulation using link-level PHY (w/MAC) simulation – incorporating true rate adaptation etc. Simulation using proposed methodology with any approximations By only running full link-level simulation for point-to-point scenario, computation is limited. Latency and jitter curves could be included too. J.Gilbert, Atheros Communications J.Gilbert, Atheros Communications

Benefits of Validation Curves Month 2004 doc.: IEEE 802.11-03/0185r0 Benefits of Validation Curves Validate PHY abstraction The closeness of the two curves validates both the methodology but also the application of the methodology. This will be one primary source of debate when discussing results Accurate comparison of PHY / MAC properties E.g. tradeoffs between ABL and fixed-rate systems, as well as other PHY and MAC properties can be accurately assessed in terms of PHY improvements, MAC overheads, and Doppler mitigation Point-to-point would simplify vs. full usage model J.Gilbert, Atheros Communications J.Gilbert, Atheros Communications

Month 2004 doc.: IEEE 802.11-03/0185r0 Relationship to CC67 Comparison Criteria 67 currently looks at PHY-only performance in “real” channels. However being PHY-only makes it more difficult to accurately include rate adaptation effects. These validation curves could replace CC67 and thus keep the total required work from proposers similar. J.Gilbert, Atheros Communications J.Gilbert, Atheros Communications