Submission
doc.: IEEE802.11-12/0244r0March 2012
PanasonicSlide 1
Experimental results of indoor path-loss in actual European houses
Date: 2012-03-12Name Affiliations Address Phone email Ken Mori Panasonic Corp 1 Kotari-yakemachi,
Nagaokakyo, Kyoto, 617-8520 Japan
mori.ken1 @jp.panasonic.com
Yoshio Urabe Panasonic Corp. urabe.yoshio @jp.panasonic.com
Kazu Takahashi Panasonic Corp. takahashi.kazu @jp.panasonic.com
Raymond Yu Zhan
Panasonic Singapore Labs
raymond.yuz @sg.panasonic.com
Michael Sim Panasonic Singapore Labs.
michael.Simhc @sg.panasonic.com
Masahiro Umehira
Ibaraki Univ. umehira @mx.ibaraki.ac.jp
Shusaku Shimada Yokogawa Electric Co.
2-9-32 Nakacho-town, Musashinoshi-city,Tokyo, 180-8750 Japan
Mitsuru Iwaoka Yokogawa Electric Co.
2-9-32 Nakacho-town, Musashinoshi-city,Tokyo, 180-8750 Japan
mitsuru.Iwaoka @jp.yokogawa.com
Stefan Aust NEC Communication Systems, Ltd.
1753 Shimonumabe, Hakahara-ku, Kwasaki, Kanagawa 211-8665, Japan
Authors:
Submission
doc.: IEEE802.11-12/0244r0
Slide 2 Panasonic
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
Submission
doc.: IEEE802.11-12/0244r0
Slide 3 Panasonic
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.
Submission
doc.: IEEE802.11-12/0244r0
Slide 4 Panasonic
March 2012
Measurement conditions for path loss
Two-story house
Test house #1 Test house #2
Two-story house+ the basement
TX point(1st floor)
Top view of this house8.97m x 8.97m
Top view of this house8.00m x 9.00m
TX point (4th floor)
Test house #3Top view of this house
15.00m x 15.00m
Test house #4
TX point (1st floor)
Five-story apartmentTwo-story apartment
Top view of this house14.00m x 11.00m
TX point (2nd floor)
Center frequency 868.3 MHz
Output power level 10 mW
Modulation CW
TX/RX antenna type Sleeve antenna; 2.15 dBi
TX/RX antenna location 1.2 m-height in a living room
Table 1. Measurement conditions
Submission
doc.: IEEE802.11-12/0244r0
Slide 5 Panasonic
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
Submission
doc.: IEEE802.11-12/0244r0
Slide 6 Panasonic
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
Submission
doc.: IEEE802.11-12/0244r0
Slide 7 Panasonic
March 2012
Simple study of link budget for indoor HEMSData 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
Item Value
Antenna GainAP -3 dBi[2]
STA -11 dBi
Fading Margin (coverage 99.9%) 21 dB[3]
Path loss 78 dB
Link Budget AP-STA 113 dB
Submission
doc.: IEEE802.11-12/0244r0
Slide 8 Panasonic
March 2012
Simple study of reception sensitivity levelIn 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
Item Value
MCS BPSK, R=1/2, K=7,
Eb/N0 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
Submission
doc.: IEEE802.11-12/0244r0
Slide 9 Panasonic
March 2012
Item This Docpure indoor
DCN 1482r4mixed condition of indoor and outdoor
Path Loss 78dB 105dBfading margin is included in path loss
Fading Margin 99.9% 21dB ---
Antenna GainAP -3dBi -3dBi
STA -11dBi -4dBi
Link Budget 113dB 112dB
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.
Submission
doc.: IEEE802.11-12/0244r0
Slide 10 Panasonic
March 2012
TX output power considerationAP-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
Submission
doc.: IEEE802.11-12/0244r0
Slide 11 Panasonic
March 2012
ConclusionTo 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.
Submission
doc.: IEEE802.11-12/0244r0
Slide 12 Panasonic
March 2012
Straw Poll
Do you agree thatin addition to MCS0 rep2 other technique to improve link margin especially for downlink should to be devised and included in Spec Framework?