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WIRELESS BODY AREA NETWORK

ANKUR HOODA1, SONIA SHARMA

2& ANIMA

3

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Lecturer, Electronics and Communication Engineering (ECE), KIIT College of Engineering, Maharshi DayanandUniversity, Rohtak (MDU), Gurgaon, India

2Assistant Professor, Electronics and Communication Engineering (ECE), KIIT College of Engineering, Maharshi

Dayanand University, Rohtak (MDU), Gurgaon, India

ABSTRACT

A Wireless Body Area Network is a special purpose network, designed to operate autonomously to connect

various medical sensors and appliances, located inside and outside of a human body. This network enables physicians to

remotely monitor vital organs of patients and provide real time feedback for medical diagnosis.

The seamless integration of low-power, miniaturized, lightweight sensors nodes leadto the development of a

proactive and unobtrusive Wireless Body Area Network (WBAN). A WBAN provides long-term health monitoring of a

patient without any constraint on his/her normal daily life activities.

This is an easy and fast way to diagnose the patients status and to consult the doctor. The WBAN may be equally

applicable to other areas like in defense and gaming application.Network lifetime and monitoring devicesare among the

most important factors in a WBAN. The effectiveness of the WBAN strongly depends on controlling the energy

consumption of sensor nodes.

To achieve energy efficiency, low duty cycle MAC protocols are used. In this paper, we discuss about the basic

idea of WBAN, its importance, working, applications, and challenges.

KEYWORDS: WBAN, MAC Protocols, Wireless Sensor Network (WSN), Network Topology, TDMA

INTRODUCTION

Recent advancement in the healthcare studies that are basedon the state-of-the-art of wireless communications and

the advanced medical sensor technologies have provided drivingforces on Wireless Personal Area Network (WPAN)

studiesThe WBAN allows wireless communications for both medical and consumer electronics applications.

Awireless body area networkfunctions in the vicinity of the human body within 3m. The WBAN is the next

generation of wireless technology for the WPAN. IEEE 802.15.6 task group started standardizationfor the WBAN

inNovember; 2007.

Wireless Body Area Network is receiving considerable attention because they can provide ubiquitous real-time

monitoring, without restricting the persons regular activities [1]. A WBAN shown in Figure 1 is a network formed by low

power and limited-energy nodes (sensors) [2] that monitor vital human signs and are located in and around the human body

[3].

WBANs can be used in several applications such as healthcare, fitness, gaming, entertainment and military, etc.

However, the most promising application is in healthcare, where the WBANs could lead to proactive monitoring and

treatment of a persons health.

International Journal of Electronics, Communication &

Instrumentation Engineering Research and

Development (IJECIERD)ISSN 2249-684X

Vol. 3, Issue 1, Mar 2013, 203-210

TJPRC Pvt. Ltd.


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204 Ankur Hooda, Sonia Sharma & Anima

Figure 1: Wireless Body Area Network

A BAN allows combination of intelligent, low power sensor nodes attached or implanted on a human body which

monitors various body vital signs. Each node has enough capacity to process and forward information for the diagnose

purpose. The main objective of this is to provide doctor with ability to remotely monitor the patient health, diagnose and

accordingly treat the patient. Any patient properly equipped with WBAN need not be physically present at the physicians

place. A WBAN can be adequate for any emergency case because it automatically sends data about patient health condition

so that physician can make early arrangement for proper treatment.

A Wireless Sensor Network (WSN) shown in Figure 2 consists of a base station (gateway) that can communicate

with a number of wireless sensor nodes via a radio link. Data are collected at the WSN nodes, processed, and directly

transmitted to the gateway. Data transfer may be single-hop or multi-hop configuration. The transmitted data is then

presented to the system by the gateway connection. Research on WBAN has been generally studied in MAC protocols for

medical sensor devices (i.e., ultra-low power consumption, low duty cycle, etc.). Therefore existing MAC protocols

(i.e.TDMA or IEEE 802.15.4 MAC) are generally used in the WBAN. TDMA-based protocols outperform CSMA-based

protocols in all areas except the protocol adaptability. On the other hand, TDMA-based protocols need a good

synchronization scheme. Such schemes are not easy to implement in a dynamic network, but since WBAN has relatively

constant network structure and fixed sensor functions, synchronization can be simplified. Hierarchy in the proposed

WBAN also removes the need of idle listening for clear channel, since WBAN network is coordinated by Master Nodes

(MNs).

Figure 2: Wireless Sensor Network Architecture

WBANs consist of three levels shown in Fig. 3, first level is low power sensors or nodes which are battery

powered and need to be operated for a long time without repair and maintenance. These nodes may be placed on the body,

around the body or implanted in the body. Second level is called master node, gateway or coordinator which controls its


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Wireless Body Area Network 205

child nodes and its power requirements. Third level is the local or metropolitan or internet network that serves for

monitoring purposes[4] .

Figure 3: Network Topology for MAC Protocol (S = Sensor Node, MN = Master Node,

and MS = Monitoring Station)

The goal of the MAC protocol is to have the following characteristics.

Collision-Free Transfer-Collisions are one of the major reasons of power wastage in a network. This protocolovercomespower wastage by using the TDMA approach.

Robustness to Communication Error-The protocol has redundancy to lower the probability of losingpackets. Energy Efficiency-The protocol allows long sleep times for sensors, without the need for channel listening. This

aspect reduces thepower consumption.

Real-Time Patient Monitoring- The protocol allows all the channels to be observed inreal time or near real time,without packet loss.

IEEEBAN DRAFT SPECIFICATION

Distance 2 m standard 5 m special use Network Density 2 - 4 nets / m2 Network Size Max- 100 devices / network Power Consumption ~1 mW / Mbps Startup Time < 100 s or < 10% of Transmitted slot Latency (end to end)- 10 ms Network setup time < 1 sec Per device setup time excludes network initialization Operation in global, license-exempt band Effective sleep modes Peer to Peer, and Point to Multi-point communication Upgradeable, scalable, backwards compatible


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206 Ankur Hooda, Sonia Sharma & Anima Quality of Service & Guaranteed Bandwidth Concurrent availability of asynchronous and isochronous channels Very Low, Low, and High duty cycle modes Allows device driven degradation of services

CHALLENGES IN ARCHITECTURE

In proposed system architecture there exist some challenges like

The routing link failure may happen during data transmission because of collision, node draining of energy, nodebusy, or other accidents. But health system requires real time information and data, which means retransmission,

is not possible. This motivates to design a multipath routing for WSN [5].

The sensors are battery operated and a prolonged network lifetime is preferred. This motivates to consider energyaware routing [6].

Thesensor mobility generates channel fading during data transmission, which degrades the performance in termsof bit error rate (BER) and frame error rate (FER). This motivates to consider mobility aware routing [7].

DEGIGN ISSUES OF WBAN

Frequency Selection Channel Modeling Antenna Design PHY Protocol Design Energyefficient Hardware MAC Protocol Design Realtime Connectivity Security and Privacy Regulatory Compliance Standardization [8]

WBAN IN DEFENCE APPLICATION

The evolution of modern soldier systems in defense is based on WBAN.The soldier is, becoming more and more

the center point of the modernwarfare [9]. By sharing information among war fighting platforms, the combat power can be

improved and a high level of mutual battlefield awareness can be achieved. Technological advances make available a huge

number of sensors and peripherals that can be used to provide useful information to the higher hierarchical levels. WBAN

will add new capabilities to modern warfare.

There are three applications that could benefit from BANs

Define ways to locate soldiers in indoor/urban scenarios


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Define ways to apply audio-based sniper detection for networked soldiers Define ways to generate a 3D audio sound reconstruction which gives the soldier immediate perception of the

relative position of the speaker.

BAN technologies could be employed to implement accelerometer based positioning and fusion of positioningsensors (Ultra Wide Band and GPS) to provide a robust localization system. The concept behind audio based sniper

detection is that a soldier can be considered as a mobile sensor platform where the sensor for sniper detection is a

microphone. Thus the soldier squad may be considered as a large dynamic distributed microphone array that may be used

for precise detection of snipers and other noise sources of tactical interest. The concept behind sound reconstruction is to

overcome mono-aural sound reception normally available to soldiers. 3D sound environment could be synthesized in the

radio communication headset to ease the communication process between individual members of small groups in high

noise situations. By adding directional clues to the headset sound reproduction, a near to natural aural communication may

be achieved. The directional clues needed for the 3D sound synthesis will require relative position between the members in

the group as well as relative head direction.

WBAN IN GAMING

For very diverse applications such as character animation in game development and studying rehabilitation

protocols in biomechanical research, being able to digitally capture the motion of a human body is crucial. A method that is

extensively used in professional applications is inertial motion capture using accelerometers and gyroscopes based on

MEMS technology.

Recently a new era emerged for inertial sensing as inertial sensors incorporated in smartphones such as the

iPhone. This resulted in inertial sensing getting into the spotlight and a significant drop in price and power-consumption.

At the same time, applications are converging and new applications emerge such as serious gaming, rehabilitation

games and virtual training environments. With these developments, it can be expected that the ambulatory human motion

capture technology will become available in our everyday life in the coming years. Professional inertial motion capture

systems used to have wires to interconnect the sensors in the past, but nowadays it has become wireless BAN.[10]

CHALLENGES

HARDWARE-CENTRIC CHALLENGES

Interoperability: WBAN systems would have to ensure seamless data transfer across standards such asBluetooth, ZigBeeetc. to promote information exchange. The system should bescalable, ensure uninterrupted

connectivity.

System Devices: The sensors used in WBAN should be low incomplexity, light in weight, power efficient, easy touse and reconfigurable.

System Security: The data generated from WBAN should be secure and access to authenticated user. Sensor Validation: It is of the utmost importance especially within a healthcare domain that all sensor readings

are validated. This helps to reduce false alarm generation and to identify possible weaknesses within the hardware

and software design. [11]

Data Consistency: Data residing on multiple mobile devices and wireless patient nodes need to be collected andanalyzed in a seamless fashion. [12]


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208 Ankur Hooda, Sonia Sharma & Anima Interference: The wireless link used for body sensors should reduce the interference. This is especially important

for large scale implementation of WBAN system. [13], [14]

HUMAN-CENTRIC CHALLENGES

Cost: Today's consumers expect low cost health monitoring solutions which provide high functionality. WBANimplementations will need to be cost optimized.

Constant Monitoring: Users may require different levels of monitoring depending on the seriousness of thepatients health. The level of monitoring influences the amount of energy requiredand the life cycle of the BAN.

Constrained Deployment: The WBAN needs to be wearable, lightweight and it should not alter the user's dailyactivities.

Consistent Performance: The performance of the WBAN should be consistent. Sensor measurements should beaccurate and calibrated. The wireless links should be robust and work under various user environments.[15]

CONCLUSIONS

Preventive care in daily life has been getting more important along with the increase in medical costs for the aging

and lifestyle -related diseases. "Personal smart health care (PSHC)" measuring user's living conditions and health status

using small sensing devices under daily life and collects data over a network can be expected as a new trend that

corresponds to preventive care.A wearable Wireless Body Area Network (WBAN) of physiological sensors integrated into

a telemedical system holds the promise to become a key infrastructure to provide a better and less expensive alternative for

rehabilitation healthcare and may provide benefit to patients.The proposed system architecture for healthcare monitoring

applications is very effective, especially for older people. It provides small, inexpensive, and flexible BAN in contrast to

existing wireless cardiac monitoring systems. The WBAN is of utmost importance in defense and gaming application. In

modern warfare system it provides efficient way to assist the soldier during an emergency where soldier can be consideredas a mobile sensor.It can be concluded that WBAN technology is still emerging and there are a lot of problems left to

solve. Setting aside ethical issues like privacy, there are still plenty of technical challenges that we must overcome before

WBAN will become an effective solution in different areas.

REFRENCES

1. H. B. Li, R. Kohno. Introduction of SG-BAN in IEEE 802.15 with related discussion.Proc. IEEE Internationalconference on Ultra Wideband, pp. 134{139, September 2007.

2. IEEE 802.15 WPAN Task Group 6 BAN: http://www.ieee802.org/15/pub/TG6.html.3. 802.15.6 Call for Applications - Response Summary, IEEE 802.15-08-0407-05-0006.4. IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 13, NO. 6,

NOVEMBER 2009 915Energy-Efficient Low Duty Cycle MAC protocol for Wireless Body Area Networks

Stevan Jovica Marinkovic, Emanuel Mihai Popovici, Senior Member, IEEE, Christian Spagnol, Associate

Member, IEEE, Stephen Faul, and William Peter Marnane, Member, IEEE.

5. M.Chen, S. Gonzalez, A.Vasilakos, H. Cao, Body Area Networks: A survey, Springer Mobile NetworkApplications, vol 16, pp 171-193, 2011.


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6. H. Wang, W. Wang, D. Peng, H. Hwa Chen, A Khoneyzhad, H. Sharif, Resource- Aware Secure ECGHealthcare Monitoring Through Body Sensor Network,IEEE, Wireless Communication 2010.

7. X. Wu, B. Auriol, J. Cho, S. Lee, Optimal Routing in Sensor Network for In home Health Monitoring withMulti-factor Considerations IEEE International conference on Pervasive Computing and Communications in

2008.

8. M. Patel and J. Wang, Applications, Challenges and Prospective in Emerging BAN Technologies, IEEEWireless Communications, to appear.

9. www.google.com10. http://bodynets.org/201211. O?Donoghue, J. Herbert, J. and Fensli, R.: Sensor Validation within a Pervasive Medical Environment, In

proceedings of IEEE Sensors, South Korea, ISBN 1-4244-0376-6, 2006.

12. O?Donoghue, J., Herbert, J. and Kennedy, R.: Data Consistency within a Pervasive Medical Environment, InProceedings of IEEE Sensors, South Korea, ISBN 1-4244-0376-6, 2006

13. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THG-5093N36-&_user=915767&_coverDate=07%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=

d&_docanchor=&view=c&_acct=C000047922&_version=1&_urlVersion=0&_userid=915767&md5=bfcb3fbcaf

1e3295f8a625a3cf5b75fc&searchtype=a

14. Garcia P., "A Methodology for the Deployment of Sensor Networks", IEEE Transactions On Knowledge AndData Engineering, vol. 11, no. 4, December 2011.

15. Lai, D. , Begg, R.K. and Palaniswami, M. eds, Healthcare Sensor Networks: Challenges towards practicalimplementation, ISBN 978-1-4398-2181-7, 2011


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