Katherine Liu Olivia Nordquist 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 Noise: depending on the communication between nodes, multipath through the entire body vs cluster of nodes collecting the same data, the statistically model varies from Weibull/poisson process to uniform—creates wider variance for noise

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 Source Min Max Batteries 0.14 mW 150 mW Fuel Cells 2.2 microW 430 microW Energy Harvesting Source Min Max Kinetic Sources 40 microW 80 microW Thermoelectric Sources 1 microW 30 microW

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 exist methods for dealing with the data but when a collision occurs, in BAN, the collision could mean life or death whereas Ethernet just means slower response times. Csma-cd wiki, re-word, auction theory

High-level overview of an invasive BAN Memory footprints, point out mucho data and the interpreting devices 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 Draw picture here of beacon, reserve spaces v collisions, combination of the two styles proposed in paper

A Simple Schematic Go back a slide and draw the picture….. 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 Ethernet refers to obsolete variants but there must exist backwards capabilities

Embedded Software Energy Robust Utilization of data inputs Memory footprints of interpreting device Interpretation of biometrics Cost: NP-Hard Kat discussed hardware energy components—software also needs to be efficient, auction theory: NP-hard, no pt m that can determine optimization

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

Questions???

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