Ubiquitous Healthcare Using MAC Protocols in Wireless Body Area
Sensor Networks (WBASNs)
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Group Members Muhammad Sarim Hayat FA08-BET-131 Nadir Ali
KhanFA08-BET-089 Umair Rafiq FA08-BET-132
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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Abstract(1/2) Wireless Body Area Sensor Networks (WBASNs)
Ubiquitous Healthcare (UHC) o Survey of different architectures of
WBANs o Functionality of devices used in architectures Survey of
different MAC protocols used in WBASNs o Advantages and
disadvantages is discussed o Trade-offs o Mechanisms used by
different protocols o Analyses of different MAC protocols with
respect to different architectures used in UHC
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Abstract(2/2) Path loss in WBAN o In-body Communication With
respect to MAC Protocols With respect to WBAN models o On-body
Communication With respect to MAC Protocols With respect to
distance, amplitude and RMS delay o Off-body communication With
respect to MAC Protocols
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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Introduction (1/3) WBASNs o Emerging domain of wireless
communication o A lot of advancement in this domain o Consists of
tiny sensors UHC o Provided to patients all around the globe,
especially to elderly peoples o Different architectures are
discussed o Each architecture has its own applications depending
upon the communication scenarios
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Introduction (2/3) Energy Efficiency of the system o One of the
basic requirement for WBASNs because of limited power of batteries
o Life time of a node depends upon: Energy consumption during
communication Energy wastage during communication Packet collision
Overhearing Idle listening Over emitting Control overhead
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Introduction (3/3) Path loss o Data is transferred through
wireless medium so path loss is probable to occur o Path loss is
different for different scenarios and it depends upon: Frequency of
operations Distance between transmitter and receiver nodes (d)
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Most Frequently Used Standards for WBAN Communication IEEE
802.15.1 Bluetooth ZigBee Medical Implant Communications Service
(MICS) IEEE 802.15.6 Ultra Wide Band (UWB)
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Wearable Sensors used for Ubiquitous HealthCare Wrist watch
(eWatch) Oximeter Chest belt Wearable shirt type (smart shirt/life
shirt)
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General WBAN Architecture
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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Energy Efficient MAC Protocols MAC Layer is the most suitable
layer for discussing energy and power issues Collision avoidance
for energy efficiency, minimum latency, high throughput, and
communication reliability, are basic requirements in the design of
MAC protocol. There are several sources of energy wastage:
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Energy minimization techniques in MAC Protocols for WBANs (1/2)
There are three main approaches adopted for the energy saving
mechanisms in MAC protocols for WBANs, which are listed and
discussed below: o Low Power Listening (LPL) Node awakes for a very
short period to check activity of channel If the channel is not
idle then the node remains in active state to receive data and
other nodes go back to sleeping mode. LPL is sensitive to traffic
rates
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Energy minimization techniques in MAC Protocols for WBANs (2/2)
o Scheduled Contention Combination of the scheduling and contention
based mechanisms In Contention based protocols, contending nodes
try to access the channel for data transmission Scheduling or
Contention free means that each node has the schedule of
transmission in the form of bandwidth or time slot. o Time Division
Multiple Access (TDMA) Time slots are allocated to the sensor nodes
by a master node (MN). This scheme is highly sensitive to clock
drift The scheme is power efficient because a node gets time slot
for transmission of data and remains in sleep mode for rest of the
time
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Advantages and disadvantages of MAC Protocols
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Energy minimization mechanism in MAC protocols
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Performance Trade-offs made by MAC Protocols
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Observations o For Static Topology in WBANs Ta-MAC is best
suited for Traffic System Architecture of WBASNs used for UHC It
uses different mechanisms for on demand, emergency and normal
traffics o For Dynamic Topology in WBANs B-MAC is best suited for
all other architectures of WBASNs
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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MAC Frame structure(1/2) MAC frame structure consists of
control portion or control packet and data portion. Control portion
is responsible for the management and control messages Data portion
consist of two sub parts: o Contention Access Period (CAP) o
Contention Free Period (CFP)
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MAC Frame structure(2/2)
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Comparison Between IEEE 802.15.4 MAC and Original
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Data Traffic Control
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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Path Loss in WBAN (1/2) WBASNs is greatly influenced by the
amount of path loss that occurs due to different impairments.
Devices for WBASNs are generally placed inside or on the body
surface. Reduction in power density of an electromagnetic wave
introduces path loss.
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Path Loss in WBAN (2/2) The path loss model in dB between the
transmitting and the receiving sensor nodes as a function of the
distance d is computed by as:
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Scenarios of Path loss Three scenarios of Path loss: In-Body
Communication On-Body Communication Off-Body Communication
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Nodes to Calculate Path Loss in WBAN Implant node Body Surface
node External node
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Effect of WBASN Antennas Electrical antennas, such as dipole
Magnetic antennas, such as loop
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Characteristics of Human Body Not Ideal Medium for
Communication Human body consists of materials with different
dielectric, thickness and impedance It encounters impairments due
to different frequency of operation
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Pathloss models for In-Body Communication In-Body Communication
o Deep Implant to On-Body o Near Surface Implant to On-body o Deep
Implant to Implant o Near Surface Implant to Implant
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Implant to Implant Implant to Body Surface
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Path loss in different models of WBAN
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Summary of In-Body Path Loss in WBAN
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Amplitude Attenuation in On-Body
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Path Loss VS Distance for On-Body Communication
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RMS Delay at 15cm Separation
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RMS Delay at 45cm Separation
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Summary of On-Body Path Loss in WBAN
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OUTLINE Abstract Introduction Summary of Architectures of WBANs
Energy Efficient MAC Protocols MAC Frame structure Path Loss in
WBAN Conclusion
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Conclusion(1/3) Wireless Body Area Sensor Networks (WBASNs) o
Emerging domain in Wireless Communication o Most important
application is Ubiquitous Healthcare (UHC) Survey is done on: o
General Architectures used in WBAN for UHC o Devices and their
Functionality o MAC protocols used in WBAN o Advantages and
Disadvantages of MAC protocols and their tradeoffs
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Conclusion(2/3) Path Loss in WBAN o In-Body Communication o
On-Body Communication o Off-Body Communication We conclude that o
For Static Topology in WBAN Ta-MAC is best suited for Traffic
System Architecture of WBASN used for UHC o For Dynamic Topology in
WBAN B-MAC is best suited for all other architectures of WBASN
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Conclusion(3/3) Simulation results of In-Body Communication
show that o Path loss increases with increase in Frequency and
Distance between Sensor Nodes o Path loss is greater for
implantable sensors than for On-Body sensors
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List Of Publications Nadir Ali Khan, Jaffar Kulachi, Umair
Rafiq, Ayesha Bibi, Zahoor Ali Khan, Nadeem Javaid, Ubiquitous
Healthcare in Wireless Body Area Networks, 11th IEEE International
Conference on Ubiquitous Computing and Communications (IUCC-2012),
Liverpool, UK, 25-27 June 2012. Sarim Hayat, Abida Shareef, Anzar
Mahmood, Zahoor Ali Khan, Safdar Hussain Bouk, Nadeem Javaid,
Energy Efficient MAC Protocols in Wireless Body Area Sensor
Networks, 14th IEEE International Conference on High Performance
Computing and Communications (HPCC-2012), 25-27 June, Liverpool,
UK, 2012.