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Body Area Networks. Katherine Liu Olivia Nordquist. Agenda . Description Motivation Challenges Applications. What are they?. BAN, WBAN, BSN, BAWSN A network of sensors and actuators residing within the limits of the body Measure physiological data on the body
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Body Area Networks Katherine Liu Olivia Nordquist
Agenda • Description • Motivation • Challenges • Applications
What are they? • BAN, WBAN, BSN, BAWSN • A network of sensors and actuators residing within the limits of the body • Measure physiological data on the body • Movement, position, levels • Dispense medication, electric shocks, etc.
Motivation • The state of human health • Heart and cardiovascular disease • Diabetes • Several cancers and chronic diseases • Allow for continuous monitoring of body • General sports and fitness monitoring
Interaction with the Body • Invasive vs. non-invasive • Most research is geared towards invasive types • If invasive, nodes must be at least 60cm apart in body • Based on government-regulated Specific Absorption Rate (SAR) • Too much exposure to electromagnetic fields can harm the human body • Maximum power density of 1.6 W/kg in U.S.
http://www.imec.be/ScientificReport/SR2007/html/1384142.html High-level overview of an invasive BAN
Network • Follows IEEE 802.15 standard • 802.15 specifies wireless personal area network (WPAN) standards • New task group 802.15.6 as of December 2011 specifically for BAN • Focusing on low-power, short-range transfers in and around the body • Data transfer rates vary roughly from 10 Kbps to 10 Mbps
Data rates vs. Power http://www.cse.wustl.edu/~jain/cse574-08/ftp/ban/index.html Energy and transfer rate comparisons amongst 802.15 groups
Challenges • Energy • Noise • Embedded software
Sources of Energy • Still a huge research topic • Harvesting and storing energy • Issue with regular batteries? • Large, needs replacing • Fuel cells possible alternative? • More expensive, but only needs refueling
Comparing Energy Sources Energy Storage Energy Harvesting
Problem with Noise • The nodes send A LOT of data, much more than can be interpreted by the off-body infrastructure. The data does not take up all the broadband width so there do existmethodsfordealingwiththe data butwhen a collisionoccurs, in BAN, thecollisioncould mean lifeordeathwhereas Ethernet justmeansslower response times.
http://www.imec.be/ScientificReport/SR2007/html/1384142.html High-level overview of an invasive BAN
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) • Media Access Control • Method of arbitration
A Simple Schematic http://en.wikipedia.org/wiki/File:CSMACD-Algorithm.svg
Why was that interesting • Method used for Ethernet, radio stations • Recent BAN research as of 2012 • Life and death
Embedded Software • Energy • Robust • Utilization of data inputs • Memory footprints of interpreting device • Interpretationof biometrics • Cost: NP-Hard
Healthcare Applications http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-812.pdf
Additional Applications • Military • Athletics • Seamless inter-BAN communication • Intuitively bizarre • Research new uses http://news.discovery.com/human/life/advanced-crime-predicting-technologies-is-minority-report-here-infographic.htm
Sources • 2011 Tenth International Symposium on Autonomous Decentralized Systems (ISADS), 519-24, 2011 • 2012 International Conference on Computing, Networking and Communications (ICNC), p 89-93, 2012 • http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-812.pdf