Simulation Effort Required to Satisfy the 802.11n Comparison Criteria March 2004 doc.: IEEE 802.11-04/307r0 March 2004 Simulation Effort Required to Satisfy the 802.11n Comparison Criteria Bjorn A. Bjerke, John Ketchum, and Irina Medvedev Qualcomm, Inc. bbjerke@qualcomm.com Bjorn Bjerke et al., Qualcomm, Inc Bjorn Bjerke et al. Qualcomm, Inc.

March 2004 Simulation Effort Significant simulation effort required to satisfy the current version of the 802.11n Comparison Criteria Two types of simulations: PHY layer sims: typically implemented in C System sims: typically implemented in NS2 or similar Bjorn Bjerke et al., Qualcomm, Inc

CCs Involving Simulations March 2004 doc.: IEEE 802.11-04/307r0 March 2004 CCs Involving Simulations PHY sims: CC59 CC67 CC67.1 CC67.2 System sims: CC15 CC18 CC19 CC20 (CC24) CC27 CC28 CC58 Bjorn Bjerke et al., Qualcomm, Inc Bjorn Bjerke et al. Qualcomm, Inc.

March 2004 PHY Sims: Assumptions NxN MIMO system  N*N possible system configurations PER vs SNR evaluated for 10 SNR values 100 packet errors collected per point CPU time per point: 1 hour  CPU time per curve: 10 hours Bjorn Bjerke et al., Qualcomm, Inc

PHY Sims: CPU Time Estimate March 2004 PHY Sims: CPU Time Estimate CC59 (PER vs SNR with fixed channel): 5 representative data rates Example: N=4  16 system configurations CPU time = 16*5*10 hours = 800 hours CC67 (PER vs SNR with fading channels): 16 system configurations 3 channel models (B, D, F) Channel D w/fluorescent lights and highest rate CPU time = (16*5*3+16)*10 hours = 2560 hours Bjorn Bjerke et al., Qualcomm, Inc

PHY Sims: CPU Time Estimate March 2004 PHY Sims: CPU Time Estimate CC67.1 (Rate vs SNR with fading channels): 16 system configurations 3 channel models (B, D, F) Channel D w/fluorescent lights CPU time = 16*4*10 hours = 640 hours CC67.2 (PER for 2 SNR values with frequency offset): Example: 5 representative freq. offset values 2 SNR values (1 hour each) CPU time = 16*5*2 hours = 160 hours Bjorn Bjerke et al., Qualcomm, Inc

PHY Sims: CPU Time Estimate March 2004 PHY Sims: CPU Time Estimate Total CPU time needed for PHY sims: 800+2560+640+160 hours = 4160 hours With 8 CPUs running continuously, this will take 4160/(24*8) days = 22 days Assume 100% overhead  44 days Bjorn Bjerke et al., Qualcomm, Inc

System Sims: Assumptions March 2004 System Sims: Assumptions Simulation Scenario 1 (baseline): 40 secs. of simulated time to reach steady state; < 1 hour of CPU time to simulate Assume CPU time goes as the square of the number of STAs Bjorn Bjerke et al., Qualcomm, Inc

System Sims: CPU Time Estimate March 2004 System Sims: CPU Time Estimate CC15: SS17: 1 AP, 1 STA, 1 channel model; < 1 hour SS18: 1 AP, 1 STA, 1 channel model; < 1 hour SS19: 1 AP, 2 STA, 1 channel model; < 1 hour CCs 18, 19, 20, 24 SS1:  1 AP, 11 STA --  1 hour SS4:  1 AP, 30 STA -- 7 hours SS6:  1 AP, 52 STA  -- 20 hours SS9:  1 AP, 6 STA --  1 hour SS11: 2 AP, 12 STA -- 2 hours Bjorn Bjerke et al., Qualcomm, Inc

System Sims: CPU Time Estimate March 2004 doc.: IEEE 802.11-04/307r0 March 2004 System Sims: CPU Time Estimate CCs 27, 28, 58 Need to run SS16 for each of the two channel models, B and D. SS16: 1 AP, 1 STA, repeated for various locations of the STA    Total: 4 hours Total CPU time for system sims: < 40 hours  Add 100% overhead: < 80 hours Bjorn Bjerke et al., Qualcomm, Inc Bjorn Bjerke et al. Qualcomm, Inc.

The Simulation Effort May Be Reduced Without Compromising Quality March 2004 The Simulation Effort May Be Reduced Without Compromising Quality PHY sims represent the majority share of the effort  focus on PHY sims: Limit the number of required system configurations to a set of 5 representative, e.g., 1xN, Nx1, N1xN1, N1xN2, and N2xN2 Let proposer choose between CC67 and CC67.1, i.e., make CC67 mandatory for fixed rate systems, and make CC67.1 mandatory for rate-adaptive systems Total CPU time required drops to 1100 hours and 500 hours, respectively (or 1300 hours if all versions of CC67 are mandatory) Bjorn Bjerke et al., Qualcomm, Inc