Simon Hyun, Brett Douglas, Eldad Perahia, Dave Petsko Month 2000 doc.: IEEE 802.11-03/846r0 November 2003 Direct Path to Multipath Ratio and RMS Delay Spread Measurements in an Office and a Lab Environment Simon Hyun, Brett Douglas, Eldad Perahia, Dave Petsko Cisco Systems, Inc. Perahia et. al., Cisco Systems, Inc. John Doe, His Company

Background Information November 2003 Background Information K-factors are defined in the 802.11N Channel Models. The models for K-factors can be compared to measured data by calculating a Direct Path to Multipath Ratio (DPMPR) – The ratio of energy in the direct path (first tap) to the sum of the energy from all Multipath samples (all other taps). In 802.11N, the models have the following (DPMPR). Model B -> 9.16 dB Model C -> 1.09 dB Model D -> -6.57 dB Perahia et. al., Cisco Systems, Inc.

Direct Path to Multipath Ratio Calculation November 2003 Direct Path to Multipath Ratio Calculation Perahia et. al., Cisco Systems, Inc.

November 2003 RMS Delay Spread The 802.11N Channel Models have increasing RMS delay spread Model B: 15nsec Model C: 30nsec Model D: 50nsec Perahia et. al., Cisco Systems, Inc.

Office Data Acquisition November 2003 Office Data Acquisition 2ft y1 z1 a1 b1 c1 d1 31 ft. y2 z2 a2 b2 c2 d2 29 ft. y3 z3 a3 b3 c3 d3 27 ft. y4 z4 a4 b4 c4 d4 25 ft. 2ft Aisle way RX (Orientation: | ) Dipole antennas Aisle way Pillar Path Obstruction (5-employee cube) Aisle way Path Obstruction (5-employee cube) 25ft Perahia et. al., Cisco Systems, Inc.

Lab Data Acquisition November 2003 Obstruction 2ft y1 z1 a1 b1 c1 d1 Benchtop 2ft y1 z1 a1 b1 c1 d1 y2 z2 a2 b2 c2 d2 y3 z3 a3 b3 c3 d3 y4 z4 a4 b4 c4 d4 RX (Orientation: | ) Dipole antennas 2ft Path Obstruction (test bench / equipment) Path Obstruction (test bench / equipment) 25ft Perahia et. al., Cisco Systems, Inc.

DPMPR Distribution in an Office: LOS November 2003 DPMPR Distribution in an Office: LOS Min: -10.0 dB Mean: -1.5 dB Max: 5.7 dB Perahia et. al., Cisco Systems, Inc.

RMS Delay Spread Distribution in an Office: LOS November 2003 RMS Delay Spread Distribution in an Office: LOS Min: 19.6 nsec Mean: 33.7 nsec Max: 46.9 nsec Perahia et. al., Cisco Systems, Inc.

DPMPR Distribution in a Lab: LOS November 2003 DPMPR Distribution in a Lab: LOS Min: -7.7 dB Mean: .6 dB Max: 5.4 dB Perahia et. al., Cisco Systems, Inc.

RMS Delay Spread Distribution in a Lab: LOS November 2003 RMS Delay Spread Distribution in a Lab: LOS Min: 11.8 nsec Mean: 18.5 nsec Max: 24.2 nsec Perahia et. al., Cisco Systems, Inc.

DPMPR Distribution in an Office: NLOS November 2003 DPMPR Distribution in an Office: NLOS Min: -13.3 dB Mean: -5.1 dB Max: 3.3 dB Perahia et. al., Cisco Systems, Inc.

RMS Delay Spread Distribution in an Office: NLOS November 2003 RMS Delay Spread Distribution in an Office: NLOS Min: 28.7 nsec Mean: 37.5 nsec Max: 48.2 nsec Perahia et. al., Cisco Systems, Inc.

DPMPR Distribution in a Lab: NLOS November 2003 DPMPR Distribution in a Lab: NLOS Min: -12.7 dB Mean: -6.9 dB Max: 1.6 dB Perahia et. al., Cisco Systems, Inc.

RMS Delay Spread Distribution in a Lab: NLOS November 2003 RMS Delay Spread Distribution in a Lab: NLOS Min: 17.3 nsec Mean: 23.2 nsec Max: 31.8 nsec Perahia et. al., Cisco Systems, Inc.

November 2003 Conclusions The measurements reflect propagation conditions in a small office. This corresponds to 802.11n Channel Model C with a DPMPR of 1.09 dB and RMS delay spread of 30nsec. LOS measurements results: Mean DPMPR’s: -1.5 and -0.6 dB; close agreement with Model C. Mean RMS delay spread measurements: 33.7 and 18.5 nsec; similar to model C. NLOS measurements results: Mean DPMPR’s: -5.1 and -6.9 dB; very different than Model C. Mean RMS delay spread measurements: 37.5 and 23.2 nsec; similar to model C. We could use two Model C’s, Model CL with a K-factor of 2 or 3 dB for LOS channels. Model CN with a K-factor of (–inf) dB for NLOS channels. The NLOS mean DPMPR measurements match very closely to Model D. An alternative which results in fewer channel models would be to use Model C for LOS small office conditions and Model D for small office NLOS conditions. Though the measured RMS delay spread for NLOS conditions is higher than LOS conditions, it is still smaller than that for Model D. This would need to be resolved. Perahia et. al., Cisco Systems, Inc.