1. Submission doc.: IEEE802.11-12/0244r0 March 2012 Panasonic Slide 1 Experimental results of indoor path-loss in actual European houses Date: 2012-03-12 Authors:

2. Submission doc.: IEEE802.11-12/0244r0 Slide 2Panasonic March 2012 Abstract Experimental results of indoor path-loss in actual European houses. Suggestion of link budget value, especially for down link, for HEMS (Home Energy Management System), based on the measurement results. Consideration of TX output power requirement

3. Submission doc.: IEEE802.11-12/0244r0 Slide 3Panasonic March 2012 Background For HEMS, wireless module will be installed in home appliances and antenna gain is limited due to small form factor. Antenna performance may be similar to ones used for wireless remote controllers. The antenna gain of remote controllers is around -11 dBi at sub-GHz carrier wavelength. Target link budget for HEMS is not clear so far.

4. Submission doc.: IEEE802.11-12/0244r0 Slide 4Panasonic March 2012 Measurement conditions for path loss Two-story house Test house #1Test house #2 Two-story house + the basement TX point (1st floor) Top view of this house 8.97m x 8.97m Top view of this house 8.00m x 9.00m TX point (4th floor) Test house #3 Top view of this house 15.00m x 15.00m Test house #4 TX point (1st floor) Five-story apartment Two-story apartment Top view of this house 14.00m x 11.00m TX point (2nd floor) Center frequency868.3 MHz Output power level10 mW ModulationCW TX/RX antenna typeSleeve antenna; 2.15 dBi TX/RX antenna location1.2 m-height in a living room Table 1. Measurement conditions

5. Submission doc.: IEEE802.11-12/0244r0 Slide 5Panasonic March 2012 Measurement results of path loss Worst path loss (median) in this experiment was 78dB. Fading margin is not included in this value. Test House#1#2#3#4 Path Loss (Median) 56dB @ 2nd floor 60dB @basement 78dB @1st floor 65dB @1st floor Instantaneous Max Path Loss 70dB @2nd floor 72dB @basement 81dB @1st floor 82dB @1st floor

6. Submission doc.: IEEE802.11-12/0244r0 Slide 6Panasonic March 2012 Fading margin for HEMS In HEMS, wireless devices are basically fixed. Robust fading margin must be considered to avoid loss packets because channel is not frequency selective [1] and some wireless devices may be in a dead-point. More than 99.9% link availability should be guaranteed. [1]IEEE802-11-12-101/r0

7. Submission doc.: IEEE802.11-12/0244r0 Slide 7 Panasonic March 2012 Simple study of link budget for indoor HEMS Data rate: 100kbps (MCS0, K=7) with 2 repetition This table is utilized especially for down link in which diversity techniques cannot be used due to lack of space in STAs. [2] IEEE802-11-1-1482/r4; mentioned -3dBi and -4dBi. In this document, we chose better one. [3]Martin Handforth, Asrar U. Sheikh and Majid Abdi Static Characterization of the Indoor Mobile Radio Channel at 946MHz, pp.955-959, vol.2, ICPU, 1993 ItemValue Antenna Gain AP-3 dBi [2] STA-11 dBi Fading Margin (coverage 99.9%) 21 dB [3] Path loss 78 dB Link Budget AP-STA113 dB

8. Submission doc.: IEEE802.11-12/0244r0 Slide 8Panasonic March 2012 Simple study of reception sensitivity level In case of 100kbps mode (MCS0, 2 repetition) Ref. [4] Digital Communications, John G. Prokis and Masoul Salehi, McGRAW-HILL In case of BPSK, K=7 and R=1/2, BER=1x10 -5 [5]IEEE802-11-11-0552/r2 ItemValue MCS BPSK, R=1/2, K=7, E b /N 0 4.5 dB [4] Data rate 100 kbps kT -174 dBm/Hz NF 7 dB [5] Implementation Loss 3 dB [5] Receiver Sensitivity -109 dBm

9. Submission doc.: IEEE802.11-12/0244r0 Slide 9Panasonic March 2012 Item This Doc pure indoor DCN 1482r4 mixed condition of indoor and outdoor Path Loss78dB 105dB fading margin is included in path loss Fading Margin99.9%21dB--- Antenna Gain AP-3dBi STA-11dBi-4dBi Link Budget113dB112dB Comparison with DCN 1482r4 Path loss and antenna gain of STA is different each other but link budgets are almost same as each other. Target link budget for HEMS including both pure indoor case and mixed condition of indoor and outdoor case can be up to 113dB.

10. Submission doc.: IEEE802.11-12/0244r0 Slide 10Panasonic March 2012 TX output power consideration AP-to-STA; To meet the 113 dB link budget under a condition of -109 dBm reception sensitivity (for downlink), TX output power must be larger than +4 dBm. Around 6dB output backoff should be considered to get better performance of OFDM. Around 10dBm is output power limitation for devices without an external PA from the implementation point of view. No margin for PVT variation in case of +4dBm output power level (peak power is 10dBm). 0dBm [2] output power level can be a good candidate for HEMS. Note: PVT variation stands for Process-Voltage-Temperature variation

11. Submission doc.: IEEE802.11-12/0244r0 Slide 11Panasonic March 2012 Conclusion To actualize HEMS by using TGah specification, TGah should consider following link budget, under a condition of receiver sensitivity being around -109dBm (MCS0 w/ 2 repetition) 113 dB for AP-to-STA Required TX output power shall be at least +4 dBm for AP-to-STA (MCS0 w/ 2 repetition) To realize 0dBm output power level, MCS0 with 2 repetition technique alone is not enough. Combination of MCS0 rep2 and additional technique must be needed to actualize HEMS.

12. Submission doc.: IEEE802.11-12/0244r0 Slide 12Panasonic March 2012 Straw Poll Do you agree that in addition to MCS0 rep2 other technique to improve link margin especially for downlink should to be devised and included in Spec Framework?