Doc.: IEEE 802.15-08-0158-00 Submission March 2008 Dr. Okundu OmeniSlide 1 Project: IEEE P802.15...
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doc.: IEEE 802.15-08- 0158-00 Submiss ion March 2008 Dr. Okundu Omeni Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Area Networks (WPANs) Submission Title: [Toumaz response to 802.15 TG6 Call for Applications] Date Submitted: [11 January, 2008] Source: [Dr. Okundu Omeni] Company [Toumaz Technology Ltd] Address [85F Milton Park, Abingdon, UK] Voice:[+44 1235-438-950], FAX: [+44 1235-438-970], E-Mail: [[email protected]] Re: [n/a] Abstract: [This document is Toumaz response to 802.15 TG6 Call for Applications] Purpose: [This document is a response to P802.15 TG6 Call for Application on 18 Jan, 2008] 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
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Transcript of Doc.: IEEE 802.15-08-0158-00 Submission March 2008 Dr. Okundu OmeniSlide 1 Project: IEEE P802.15...
doc.: IEEE 802.15-08-0158-00
Submission
March 2008
Dr. Okundu OmeniSlide 1
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)(WPANs)
Submission Title: [Toumaz response to 802.15 TG6 Call for Applications]Date Submitted: [11 January, 2008]Source: [Dr. Okundu Omeni] Company [Toumaz Technology Ltd]Address [85F Milton Park, Abingdon, UK]Voice:[+44 1235-438-950], FAX: [+44 1235-438-970], E-Mail:[[email protected]]
Re: [n/a]
Abstract: [This document is Toumaz response to 802.15 TG6 Call for Applications]
Purpose: [This document is a response to P802.15 TG6 Call for Application on 18 Jan, 2008]
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.
doc.: IEEE 802.15-08-0158-00
Submission
March 2008
Dr. Okundu OmeniSlide 2
Toumaz response to 802.15 TG6 Call for Applications
doc.: IEEE 802.15-08-0158-00
Submission
Toumaz response to 802.15 TG6 Call for Applications
Dr. Okundu OmeniPrincipal Design EngineerToumaz Technology Ltd
UK
doc.: IEEE 802.15-08-0158-00
Submission
Economics of Healthcare
doc.: IEEE 802.15-08-0158-00
Submission
Wireless Sensors in Personalised Healthcare
doc.: IEEE 802.15-08-0158-00
Submission
Body Area Network Attributes
• All wireless sensor nodes are attached to the body• Data being monitored is of low frequency, but signals• should be locally processed to reduce data
transmission requirements.• Network does not need to respond immediately to
changes, except in alarm conditions.• Nodes are miniature and battery powered – Sensor nodes are resource and power constrained. – Central node is less resource and power
constrained.
doc.: IEEE 802.15-08-0158-00
Submission
“Digital Patch” Required Features
doc.: IEEE 802.15-08-0158-00
Submission
SoC Architecture
doc.: IEEE 802.15-08-0158-00
Submission
Operating Frequency – Available Spectrum
Available spectrum:
433 MHz ISM
610 MHz WMTS
870/900 MHz SRD/ISM
1.4 GHz WMTS
2.4 GHz ISM
Parameter 400 MHz 2.4 GHz
Antenna Efficiency ✘ ✔
Path Loss & Body Effects ✔ ✘
Power Consumption ✔ ✘
radloss
radrad
RR
Re
42 2
20
r
Rrado
lossr
rR
22
4
d
eP
Prad
t
r
Path Loss: Friis LOS Transmission
Antenna Efficiency
Radiation Resistance Loss Resistance
Ref: C. A. Balanis, Antenna Theory: Analysis and Design, 2nd ed. John Wiley & Sons Inc., 1997
doc.: IEEE 802.15-08-0158-00
Submission
Operating Frequency
Copper AWG24 Loop Antenna, 1.5cm radius
862-870 MHz (Europe) & 902-928 MHz (North America) license-free bands represent a good compromise for body-worn wireless biomedical applications → Meet Regulatory Requirements - ERC REC 70-03, ETSI 300-220
- FCC 47 Part 15.231, 15.247, 15.249
doc.: IEEE 802.15-08-0158-00
Submission
Off-body communication
Spatial Environment: Body Area PropagationRX
TX
f
Torso cross section
On-body communication“Creeping Waves”
Variation of path loss with movement
Ref: ”Channel model for wireless communication around human body” J. Ryckaert et al, Electronic Letters 29 th April 2004.Ref: Antennas and Propagation, Hall & Hao: Artech House
Target Worst Case Path Loss @ 72 dB (10m LOS @ 928 MHz + 20dB Fade Margin)
Hardware AGC, RSSI & Switch-able PA Power
Worst Case for Medium
Sized Room = 63dB
900 MHz
2450 MHz
doc.: IEEE 802.15-08-0158-00
Submission
Link BudgetIf Transmit Power = -10 dBm
RF Losses = 10 dB (Antenna etc.) Target Path Loss = 72 dB
Then Receiver Sensitivity = -10 – 2*(10) – 72 = -102 dBm
(Bluetooth Class 2: TX power +4dBm, RXsensitivity -80dBm → 10m @ 2.4GHz)
If Signal Bandwidth = 200 kHzDemodulator SNR = 11 dB (for 1E-3 Raw BER)
Then Noise Figure = -102 – (-174 + 53) – 11 = 8 dB
Other Top Level SpecificationsTransceiver Voltage = 1 ~ 1.5 VMaximum Current = < 3 mATemperature = 0 ~ 70oCMeet Regulatory Requirements: RF, LBT etc.Meet MAC requirements, Fast turn on/off/around, Low Sleep Current
doc.: IEEE 802.15-08-0158-00
Submission
Multiplexing 3 Sensors
doc.: IEEE 802.15-08-0158-00
Submission
Sensor Interface
• Multiple sensor interfaces (bias and signal processing) on chip:– Electrocardiogram (ECG/EKG)– Temperature (internal & external)– 3 axis accelerometer– Pressure (Wheatstone bridge)– Amperometric (P and N)– Potentiometric (Ion Sensitive FET, ISFET)
• ADC can be programmed to:– Measure only one sensor interface– Switch between (up to) 3 interfaces at a configurable rate
doc.: IEEE 802.15-08-0158-00
Submission
Medium Access Control
• Designed for ultra low power operation in the target station(s)
• Star network: up to 8 addressable target stations talking to 1 base station
• TDMA (dynamic) & FDMA• Base station always initiates communications except
for Target alarm & roaming• Automatic link establishment & configuration : ~20 ms
per RF channel searched• Variable frame length• Collision avoidance and mitigation schemes plus FEC• Implemented in hardware
doc.: IEEE 802.15-08-0158-00
Submission
Network Topology
Cluster YCluster XTS
BS
TS
BS to BSCommunications
ROAMING
BS
TS
TS
TSTS
TS
TS
TS
TS
TS TSROAMING
RF Channel X
RF Channel Y
doc.: IEEE 802.15-08-0158-00
Submission
Summary
• Health care and vital signs monitoring is a growing market
• Wireless Body Area Sensor Networks need to evolve to meet these
markets
• Implantable Wireless Body Area Sensor Nodes have MICS standard,
Battery & Antenna Constraints
• Wearable Sensor Nodes need to be ultra low power to meet small form
factors and flexible thin batteries
• Power consumption can only be reduced by considering both system
partitioning and circuit design
• Dedicated Hardware helps reduce power (e. g. hardware MAC)
• A “digital patch” solution enables low cost disposable vital signs monitoring
