Ubiquitous Healthcare Using MAC Protocols in Wireless Body Area

Sensor Networks (WBASNs)

Group Members

• Muhammad Sarim Hayat FA08-BET-131

• Nadir Ali Khan FA08-BET-089

• Umair Rafiq FA08-BET-132

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

Abstract(1/2)

• Wireless Body Area Sensor Networks (WBASNs)• Ubiquitous Healthcare (UHC)

o Survey of different architectures of WBANso Functionality of devices used in architectures

• Survey of different MAC protocols used in WBASNso Advantages and disadvantages is discussedo Trade-offso Mechanisms used by different protocolso Analyses of different MAC protocols with respect to

different architectures used in UHC

Abstract(2/2)

• Path loss in WBANo In-body Communication

With respect to MAC ProtocolsWith respect to WBAN models

o On-body CommunicationWith respect to MAC ProtocolsWith respect to distance, amplitude and RMS delay

o Off-body communicationWith respect to MAC Protocols

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

Introduction (1/3)

• WBASNso Emerging domain of wireless communicationo A lot of advancement in this domaino Consists of tiny sensors

• UHCo Provided to patients all around the globe, especially to

elderly peopleso Different architectures are discussed o Each architecture has its own applications depending upon

the communication scenarios

Introduction (2/3)

• Energy Efficiency of the systemo One of the basic requirement for WBASNs because of

limited power of batterieso Life time of a node depends upon:

Energy consumption during communicationEnergy wastage during communication

Packet collision Overhearing Idle listening Over emitting Control overhead

Introduction (3/3)

• Path losso Data is transferred through wireless medium so path

loss is probable to occuro Path loss is different for different scenarios and it

depends upon: Frequency of operationsDistance between transmitter and receiver nodes (d)

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)

Wearable Sensors used for Ubiquitous HealthCare

• Wrist watch (eWatch)• Oximeter• Chest belt• Wearable shirt type (smart shirt/life shirt)

General WBAN Architecture

General WBAN Architecture

General WBAN Architecture

General WBAN Architecture

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

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:

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

Energy minimization techniques in MAC Protocols for WBANs (2/2)

o Scheduled ContentionCombination of the scheduling and contention based mechanisms In Contention based protocols, contending nodes try to access the

channel for data transmissionScheduling 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 driftThe scheme is power efficient because a node gets time slot for

transmission of data and remains in sleep mode for rest of the time

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Advantages and disadvantages of MAC Protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Energy minimization mechanism in MAC protocols

Performance Trade-offs made by MAC Protocols

Observations

o For Static Topology in WBANsTa-MAC is best suited for Traffic System Architecture of

WBASNs used for UHCIt uses different mechanisms for on demand,

emergency and normal trafficso For Dynamic Topology in WBANs

B-MAC is best suited for all other architectures of WBASNs

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

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)

MAC Frame structure(2/2)

Comparison Between IEEE 802.15.4 MAC and Original

Data Traffic Control

Data Traffic Control

Data Traffic Control

Data Traffic ControlData Traffic Control

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

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.

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:

Scenarios of Path loss• Three scenarios of Path loss:

In-Body Communication On-Body Communication Off-Body Communication

IN BODY ON BODY

OFF BODY

Nodes to Calculate Path Loss in WBAN

• Implant node

• Body Surface node

• External node

Effect of WBASN Antennas

• Electrical antennas, such as dipole

• Magnetic antennas, such as loop

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

Pathloss models for In-Body Communication

• In-Body Communicationo Deep Implant to On-Bodyo Near Surface Implant to On-bodyo Deep Implant to Implanto Near Surface Implant to Implant

Implant to Implant

Implant to Body Surface

Path loss in different models of WBAN

Summary of In-Body Path Loss in WBAN

Summary of In-Body Path Loss in WBAN

Summary of In-Body Path Loss in WBAN

Summary of In-Body Path Loss in WBAN

Summary of In-Body Path Loss in WBAN

Amplitude Attenuation in On-Body

Path Loss VS Distance for On-Body Communication

RMS Delay at 15cm Separation

RMS Delay at 45cm Separation

Summary of On-Body Path Loss in WBAN

Summary of On-Body Path Loss in WBAN

Summary of On-Body Path Loss in WBAN

Summary of On-Body Path Loss in WBAN

OUTLINE

• Abstract• Introduction• Summary of Architectures of WBANs• Energy Efficient MAC Protocols• MAC Frame structure• Path Loss in WBAN• Conclusion

Conclusion(1/3)• Wireless Body Area Sensor Networks

(WBASNs)o Emerging domain in Wireless CommunicationoMost important application is Ubiquitous

Healthcare (UHC)• Survey is done on:

o General Architectures used in WBAN for UHCo Devices and their FunctionalityoMAC protocols used in WBANo Advantages and Disadvantages of MAC protocols

and their tradeoffs

Conclusion(2/3)• Path Loss in WBAN

o In-Body Communicationo On-Body Communicationo Off-Body Communication

• We conclude thato For Static Topology in WBAN

Ta-MAC is best suited for Traffic System Architecture of WBASN used for UHC

o For Dynamic Topology in WBANB-MAC is best suited for all other architectures of

WBASN

Conclusion(3/3)

• Simulation results of In-Body Communication show that

oPath loss increases with increase in Frequency and Distance between Sensor Nodes

oPath loss is greater for implantable sensors than for On-Body sensors

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.