Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Channel Characterization for SUN Date Submitted: 29 April, 2009 Source: Multiple (see inserts) Group Coordination: Clint Powell Contributions by: George Flammer,Emmanuel Monnerie, Steve Shearer, Shusaku Shimada Re: IEEE 802.15 Task Group 4g Call for Proposals (CFP) on the 22 January 2009 Abstract: Summary and conclusion from the TG4g Channel Characterization subgroup Purpose: A subgroup within TG4g has been created in an ad-hoc manner to discuss the SUN channel and to try to characterize it. A significant amount of data was exchanged and is summarized in this document. The conclusion and recommendations of the subgroup are also formulated for consideration by the TG4g proposers. Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. TG4g - Channel Characterization

2. Geographical Data Source: Emmanuel Monnerie Company Landis+Gyr Address 30000 Mill Creek Avenue, Alpharetta, GA 30022 Voice: +1 678 258 1695 , FAX: , E-Mail: Emmanuel . Monnerie [at] landisgyr.com TG4g - Channel Characterization

3. The following data shows the different types of meter densities in typical large meter deployments in the USA. • The charts are representing for each category of meter density : • The % of meters in each category (blue bars) • The area in square miles occupied by each category (green bars) • The average minimum distance between meters for each category (X-axis) TG4g - Channel Characterization

4. Utility A - 2.6 million electric meters spread over 7000 sq miles TG4g - Channel Characterization

5. Utility B - 1.4 million gas meters spread over 5000 sq miles TG4g - Channel Characterization

6. Utility C - 350k electric meters spread over 400 sq miles TG4g - Channel Characterization

7. Connectivity Data Source: George Flammer Company Silver Spring Networks Address Voice: , FAX: , E-Mail: Source: Emmanuel Monnerie Company Landis+Gyr Address 30000 Mill Creek Avenue, Alpharetta, GA 30022 Voice: +1 678 258 1695 , FAX: , E-Mail: Emmanuel . Monnerie [at] landisgyr.com TG4g - Channel Characterization

8. The following data shows some examples of connectivity distributions for normally deployed meters in urban/suburban and rural areas. TG4g - Channel Characterization

9. Suburban network TG4g - Channel Characterization

10. Rural Network TG4g - Channel Characterization

11. Link distance distribution TG4g - Channel Characterization

12. Channel Multipath Characterization Source: Emmanuel Monnerie Company Landis+Gyr Address 30000 Mill Creek Avenue, Alpharetta, GA 30022 Voice: +1 678 258 1695 , FAX: , E-Mail: Emmanuel . Monnerie [at] landisgyr.com Source: Steve Shearer Company Self Address 3655 Bernal Avenue Pleasanton CA 94566 USA Voice: +1 905 997-0576 , FAX: , E-Mail: shearer_inc [at] yahoo . com Source:Shusaku Shimada Company Yokogawa Electric Corporation Address 2-9-32 Nakacho-town Musashino-city Tokyo, 180-8750 Japan Voice: , FAX: , E-Mail: shusaku [at] ieee . org Data collected and processed in cooperation with Dr Yimin Zhang and Dr Xin Li (Villanova University) TG4g - Channel Characterization

13. Test Setup 917MHz DSSS Meter module 1 PN sequence every 52us 20 feet high Trigger * 4 antennas Oscilloscope 4 channels 2GHz sampling rate 3 feet high LNA Post-processing 1st Low pass filter Dec 2nd Low pass filter Dec Frequency offset correction DSSS Correlators Peak Detection and rearrangement 917 MHz * The oscilloscope recording is triggered by a hardware-based DSSS receiver TG4g - Channel Characterization

14. Test Location: Philadelphia, PA TG4g - Channel Characterization

15. Ideal Output (location FS1) TG4g - Channel Characterization

16. Location FS10, antenna #2 TG4g - Channel Characterization

17. Location MN9, antenna #3 TG4g - Channel Characterization

18. Location MN17, antenna #1 TG4g - Channel Characterization

19. Location MS6, antenna #1 TG4g - Channel Characterization

20. Location MS12, antenna #3 TG4g - Channel Characterization

21. Location TN19, antenna #3 TG4g - Channel Characterization

22. Location TS2, antenna #3 TG4g - Channel Characterization

23. Location TS7, antenna #1 TG4g - Channel Characterization

24. Measurement Characteristics • Many channels measured have some degree of dispersion between 1 and 2us for these relatively short distances • Rapid fading appears to be absent on all but a few measurements as expected • It seems reasonable to model a channel characterizing this urban environment by a simple two path pseudo-static model • Each path gain is chosen from different Rayleigh distributions and held constant for the time that the channel is used • This method allows average performance to be evaluated for a population of receivers in an area, or for a receiver used in a frequency hopping scenario [*] [*] Performance modeling for Smart Grid radios in Geographically Stationary and Frequency Hopping environments. Steve Shearer April 2009 TG4g - Channel Characterization

25. Example Matlab Code function [y]=TN19channel(x) % This channel is designed to mimic the channel % whose impluse response was measured by Landis&Gyr % with certain simplifying assumptions % amp1=0; % Average amplitude of 1'st path in dB amp2=0; % Average amplitude of 2'nd path in dB n_FsDelay=1; % Delay is 1 sample. (1.6us at Fs=600kHz) RV1=(randn(1,1)+1i*randn(1,1))/sqrt(2)*10^(amp1/20); RV2=(randn(1,1)+1i*randn(1,1))/sqrt(2)*10^(amp2/20); % Create the output from scaled and delayed versions % of the input y=(x*RV1 + [zeros(1,n_FsDelay) x(1:(length(x)-n_FsDelay))]*RV2); % Normalise the output according to the average amplitudes % of the two paths to ensure that long-term average=1 y=y/sqrt(10^(amp1/20) + 10^(amp2/20)); TG4g - Channel Characterization

26. Results from reference [2] “The results of multipath power delay profile measurements of 900-MHz mobile radio channels in Washington, DC, Greenbelt, MD, Oakland, CA, and San Francisco, CA, are presented. The measurements have focused on acquiring worst case profiles for typical operating locations. The data reveal that at over 98% of the measured locations, rms delay spreads are less than 12 us. Urban areas typically have rms delay spreads on the order of 2-3 us and continuous multipath power out to excess delays of 5 us. In hilly residential areas and in open areas within a city, root mean square (rms) delay spreads are slightly larger, typically having values of 5-7 us. In very rare instances, reflections from city skylines and mountains can cause rms delay spreads in excess of 20 us. The worst case profiles show resolvable diffuse multipath components at excess delays of 100 us and amplitudes 18 dB below that of the first arriving signal.” TG4g - Channel Characterization

27. Conclusion regarding the multipath analysis • Signal delay spread in urban environment can reach 1us to 2us, even in line of sight and short distance conditions (100 to 150 meters). • A 2-path Rayleigh model is applicable in many cases. • Fast time fading due to moving objects appears to have a minimal impact. • Measurements are compatible with results published in reference #2. • Considering these test results and the results publish in reference [2], it is clear that, while many links will have no multipath, another significant percentage of the links will have multipath with a delay spread between 1us and 5us. TG4g - Channel Characterization

28. References • Localization of orphan utility meters based on spatio-temporal signature information (Zhang, Y.; Li, X.; Monnerie, E.; Pritchard G.; Salazar Cardozo, R.). Sensor Array and Multichannel Signal Processing Workshop, 2008. SAM 2008. 5th IEEE • 900 MHz multipath propagation measurements for US digital cellular radiotelephone (Rappaport, T.S.; Seidel, S.Y.; Singh, R.). Global Telecommunications Conference, 1989, and Exhibition. Communications Technology for the 1990s and Beyond. GLOBECOM’89., IEEE TG4g - Channel Characterization

29. Group Conclusion and Recommendations • The data analyzed shows a broad range of deployment conditions ranging from low density areas with less than 10 meters per sq mile, to high density areas with more than 2500 meters per sq mile (and some up to 6600 meters per sq mile). • While the area covered by meters in low density zones can be significant (sometimes > 60%), the corresponding proportion of meters in this areas can be less than 10%. • The vast majority of meters are deployed in areas with more than 1000 meters per sq mile. The average minimum distance between meters ranges from 50 to 200 feet (15m to 60m). • The meters in this area are well connected with a typical neighbor count of around 30. • Regarding Multipath Mitigation, the subgroup recommends that the TG4g proposers state the following: • For proposed PHY in widespread deployment, state how SUN multipath has been mitigated, • Otherwise, state planned SUN multipath mitigation techniques. TG4g - Channel Characterization