doc.: 15-07-0547-00-0ban
Jan. 2007
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.
Submission
Slide 1
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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.
Submission
Slide 2
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 3
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 4
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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?
Submission
Slide 5
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 6
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 7
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
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Submission
Slide 8
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Submission
Slide 9
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Submission
Slide 10
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Submission
Slide 11
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 12
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 13
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
How do existing 802.15 standards perform in the
measured channels?
Submission
Slide 14
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 15
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Bluetooth / IEEE 802.15.3 performs poorly
Submission
Slide 16
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 17
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
IEEE 802.15.3 model can perform well
Submission
Slide 18
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
What’s the benefit of using multiple antennas in
BAN?
Submission
Slide 19
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 20
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Both the use of spatial and polarisation diversity
result in considerable capacity increases
Submission
Slide 21
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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!)
802.15.3
TX
Lindskog
Encoder
Decoder
MIMO DFE
802.15.3
RX
Decoder
Submission
Slide 22
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Space-time coding can be used to increase
reliability and/or lower TX power
Submission
Slide 23
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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)
TX1
802.15.3 TX

interleaver
TX2
RX2
RX1
-1
deinterleaver
MIMO DFE
Submission
Slide 24
802.15.3
RX
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Performance in BAN channels
Submission
Slide 25
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 26
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
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
Submission
Slide 27
Dries Neirynck - University of Bristol - MVCE
doc.: 15-07-0547-00-0ban
Jan. 2007
Thank you!
What question do you have?
d.neirynck@tue.nl
m.a.beach@bristol.ac.uk
walter.tuttlebee@mobilevce.com
Submission
Slide 28
Dries Neirynck - University of Bristol - MVCE