1. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 1 Submission Dries Neirynck - University of Bristol - MVCE Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Channel measurements and PHY development for wearable devices] Date Submitted: [Jan. 15, 2007 ] Source: [Dries Neirynck] Company: [University of Bristol – Mobile VCE] Address: [Merchant Venturers Building, Woodland Rd, Bristol, BS8 1UB, UK] Voice:[+31 6 48 06 1793], E-Mail:[d.neirynck@tue.nl, m.a.beach@bristol.ac.uk, walter.tuttlebee@mobilevce.com] Re: [ IEEE 802.15 BAN SG ] Abstract:[Channel measurements, evaluation of current standards and use of MIMO in BAN] Purpose:[To encourage discussion.] 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.

2. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 2 Submission Dries Neirynck - University of Bristol - MVCE Aim Contribute to the drafts of the PAR and 5C by presenting the results of channel measurement campaigns into personal and body area propagation and of 802.15.1 and 15.3 PHY simulations using the recorded channel data Performed at the University of Bristol as part of the Mobile VCE Core 3 Programme Fully detailed technical reports on this research are available to Industrial Members of Mobile VCE.

3. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 3 Submission Dries Neirynck - University of Bristol - MVCE Fully detailed technical reports on this research are available to Industrial Members of Mobile VCE: In cooperation with the UK’s leading comms research Universities

4. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 4 Submission Dries Neirynck - University of Bristol - MVCE BAN versus PAN In the context of this research defined as: BAN: two (or more) communicating devices are located on the user’s body PAN: only one of the communicating devices is carried by the user

5. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 5 Submission Dries Neirynck - University of Bristol - MVCE Overview  Does the user have a significant influence on BAN channel characteristics?  How do existing 802.15 standards perform in the measured channels?  What’s the benefit of using multiple antennas in BAN?

6. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 6 Submission Dries Neirynck - University of Bristol - MVCE Does the user have a significant influence on BAN channel characteristics? No indication that user effects were taken into account during design of existing 802.15 standards: Bluetooth (IEEE 802.15.1): Channel assumptions based on WLAN Attenuation and fading simply based on distance TX-RX IEEE 802.15.3 Channel model adapted from 802.11 Exponentially decaying, Rayleigh fading tapped delay line

7. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 7 Submission Dries Neirynck - University of Bristol - MVCE 2 BAN channel measurement campaigns have been carried out MIMO channel sounder (Medav Rusk BRI)  Dual Polar Patch antennas  120 MHz @ 5.2 GHz  Office and anechoic chamber Vector network analyser  UWB antennas to measure simultaneously in: 20 MHz @ 1.9 GHz 20 MHz @ 2.1 GHz 80 MHz @ 2.4 GHz 120 MHz @ 5.2 GHz  Several indoor locations, outdoor and anechoic chamber

8. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 8 Submission Dries Neirynck - University of Bristol - MVCE

9. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 9 Submission Dries Neirynck - University of Bristol - MVCE

10. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 10 Submission Dries Neirynck - University of Bristol - MVCE

11. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 11 Submission Dries Neirynck - University of Bristol - MVCE

12. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 12 Submission Dries Neirynck - University of Bristol - MVCE User has significant influence on channel characteristics  Body shadowing leads to severe signal attenuation During periods of NLOS, link becomes dependent on multipath propagation in the environment  User motion leads to huge variation in the channel During periods of motion, coherence time is reduced to tens of milliseconds

13. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 13 Submission Dries Neirynck - University of Bristol - MVCE Measured channel characteristics differ from assumptions during development 802.15.1/3 Bluetooth (IEEE 802.15.1) Channel assumptions based on WLAN measurements attenuation and fading statistics are simply related to distance between transmitter and receiver link budget: 62 dB attenuation at 10 metres (observed at much shorter distance in measurements) IEEE 802.15.3 Exponentially decaying, Rayleigh fading model from 802.11 RMS delay spread of 25 ns should be tolerated 99.9% reliability at 10 metres No indication that body shadowing is taken into account

14. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 14 Submission Dries Neirynck - University of Bristol - MVCE How do existing 802.15 standards perform in the measured channels?

15. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 15 Submission Dries Neirynck - University of Bristol - MVCE Bluetooth/IEEE 802.15.1 simulation Parameters: Baseband only, other layers ideal GFSK modulator (h = 0.28), FEC implemented Demodulation with phase differentiator Packet header info known to receiver Throughput approximated by Throughput = (1-PER) x max. rate 100 bytes packet length TX power 0 dBm Thermal noise + 20 dB RX noise figure Recorded narrowband channel attenuation 2.4 GHz band

16. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 16 Submission Dries Neirynck - University of Bristol - MVCE Bluetooth / IEEE 802.15.3 performs poorly

17. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 17 Submission Dries Neirynck - University of Bristol - MVCE IEEE 802.15.3 simulation Parameters: Baseband only, other layers assumed ideal Modulation and FEC implemented Receiver: noise-whitening matched filter + DFE(4,3), Viterbi decoder for TC-QAM, Perfect knowledge of channel and packet header info Throughput approximated as before 100 bytes packet length TX power 10 dBm Thermal noise + 12 dB RX noise figure Recorded narrowband channel attenuation 2.4 GHz band

18. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 18 Submission Dries Neirynck - University of Bristol - MVCE IEEE 802.15.3 model can perform well

19. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 19 Submission Dries Neirynck - University of Bristol - MVCE What’s the benefit of using multiple antennas in BAN?

20. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 20 Submission Dries Neirynck - University of Bristol - MVCE The measurement data from the MIMO channel sounder is used MIMO channel sounder (Medav Rusk BRI) Dual Polar Patch antennas 2 antennas per ‘terminal’ 120 MHz @ 5.2 GHz Office and anechoic chamber 30 second routine consisting of sitting, standing, turning body and touching toes

21. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 21 Submission Dries Neirynck - University of Bristol - MVCE Both the use of spatial and polarisation diversity result in considerable capacity increases

22. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 22 Submission Dries Neirynck - University of Bristol - MVCE 2-by-2 Space-time coding is evaluated based on a scheme proposed by Lindskog  2-by-2 MIMO extension of 802.15.3 based on Lindskog’s adaptation of Alamouti’s scheme for wideband channels  Parameters identical to 802.15.3 simulation Total TX power kept constant Except for measured MIMO channels (5.2 GHz!)

23. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 23 Submission Dries Neirynck - University of Bristol - MVCE Space-time coding can be used to increase reliability and/or lower TX power

24. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 24 Submission Dries Neirynck - University of Bristol - MVCE A 2-by-2 spatial multiplexing extension to 802.15.3 has been investigated  Parameters identical to 802.15.3 simulation Total TX power kept constant (10 dBm) Except for measured MIMO channels (5.2 GHz)

25. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 25 Submission Dries Neirynck - University of Bristol - MVCE Performance in BAN channels

26. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 26 Submission Dries Neirynck - University of Bristol - MVCE How can the PHY exploit the presence of multiple antennas in PAN or BAN? Increase reliability of link with space-time coding 2-by-2 extension based on Lindskog’s scheme evaluated 4-5 dB SNR reduction for similar throughput in BAN channels can be used to extend range or lower TX power Increase throughput of link with spatial multiplexing 2-by-2 extension achieves predicted doubling of the throughput

27. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 27 Submission Dries Neirynck - University of Bristol - MVCE Final Overview  Body shadowing severely attenuates the signal  User motion leads to a very variable channel  This affects the performance of current PAN standards particularly in the case of Bluetooth/802.15.1  Use of multiple antennas should be considered

28. Jan. 2007 doc.: 15-07-0547-00-0ban Slide 28 Submission Dries Neirynck - University of Bristol - MVCE Thank you! What question do you have? d.neirynck@tue.nl m.a.beach@bristol.ac.uk walter.tuttlebee@mobilevce.com