energy efficient routing protocol

A Review of Energy Conservation

in Wireless Sensor Networks

Guided By: Presented By: Dr. Ajit Kumar Nayak Jogeswar Tripathy

Associate Professor & HOD Regd no: 1361025014

Dept. of CSIT M.Tech(2nd sem.),CSI

1Saturday 21 February 2015

Outline• What are WSNs• Applications of WSNs • Advantages of using WSNs• Design Issues of WSNs• Power consumption in WSN• Sources of energy waste• General approaches to energy saving• Conclusion


What are WSNs?

• Wireless Sensor Networks (WSNs):– Highly distributed networks of small, lightweight

wireless nodes,– Deployed in large numbers,– Monitors the environment or system by

measuring physical parameters such as temperature, pressure, humidity.

• Node:– sensing + processing + communication


Saturday 21 February 2015 4

WSN General Architecture

Fig:1(Block diagram of sensor node)4Saturday 21 February 2015

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Wireless Sensor Network

Sensor nodes scattered in a sensor field Each nodes has the capabilities to collect data and route data back to the sink (Base Station). Protocols and algorithms with self-organization capabilities.

Saturday 21 February 2015

Fig:2(Nodes scattered in a sensor field)

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http://en.wikipedia.org/wiki/File:WSN.svg

Many Applications of WSN

6Saturday 21 February 2015 Fig:3(Various Applications of WSN)

Advantages of using WSN

• Fast, easy and flexible deployment• Reduced cost-of-ownership• Scalability• Mobility of nodes• Work under harsh conditions• Ability to deal with node failures• Dynamic network topology• Heterogeneity of nodes


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Design Issues of WSNs

The main design goals of WSNs is to carry out data communication while trying to prolong the lifetime of the network and prevent connectivity degradation by employing aggressive energy management techniques

Saturday 21 February 2015Fig:4(Architecture of a typical WSNs)

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Challenges of WSNs: Constraints, as within, so without

Physical Layer

Data Link Layer

Network Layer

Transport Layer

Application Layer

WSN

9Saturday 21 February 2015 Fig:5(Challenges of WSNs)

Power consumption in WSN


The power issue in the wireless sensor network is one of the biggest challenges, because the sensor has a limited source of power which is also hard for replace or recharge.

“e.g. Sensors in the battlefield ,

Sensors in a large forest etc.”

Why limited source of power?– Inexpensive nature.– Limited size and weight.– Redundant nature.

Useful power consumption:• Transmitting or receiving data.• Processing query requests.• Forwarding queries and data to the neighbors.


Major Sources of energy waste in WSNs


Wasteful power consumption:• Idle listening to the channel “waiting for possible

traffic.• Retransmitting because of collisions “e.g. two packets

arrived at the same time at the same sensor”.• Overhearing “when a sensor received a packet

doesn’t belong to it”.• Generating and handling control packets.• Over-emitting “when a sensor received a packet

while It is not reached.”

Major Sources of energy waste in WSNs

General approaches to energy saving


We identify three main enabling techniques namely:• Duty cycling• Data-driven and• Mobility

Fig:6(Different approaches)


Duty cycling

Duty cycling can be achieved through two different and complementary approaches :

• The first is topology control which reduces the number of nodes involved in forwarding and routing packets generated by the other nodes without reducing network connectivity and coverage.

• The second method is a power management scheme which introduces MAC protocols and a wakeup scheduling scheme in which during idle state, a node sleeps in more slots and still maintains network connectivity.



Data-driven

There are two ways by which data driven approach affects energy consumption :

• First it sorts out unneeded samples which results in useless energy consumption and stops them from being transmitted to the sink.

• Secondly, it minimizes the power consumption of the sensing subsystem by keeping the accuracy of the sensor at a reasonable level.



Mobility

Mobility of sensor nodes can be achieved in different ways:

• First, a mobilizer can be attached to a sensor which helps to change its location; however this movement is limited to few nodes which are not inhibited by energy.

• Another method is to put sensors on mobile elements such as animals and cars.



Conclusion:

• Energy is one of the most critical resources for WSNs. Extensive research has been conducted to address these limitations by developing schemes that can improve resource efficiency.• In this seminar, we have summarized some research results which have been presented in the literature on energy saving methods in sensor networks.• Although many of these energy saving techniques look promising, there are still challenges that need to be solved in the sensor networks.



References: Alippi C., Anastasi G., Francesco M.D. & Roveri M. (2009) “Energy Management in Wireless Sensor Networks with Energy-hungry Sensors” IEEE Instrumentation and Measurement Magazine Vol. 12, N. 2, pp. 16-23

Anastasi G., Coti M., Frrancesco M. & Passarella A.( 2009), “Energy Conservation in Wireless Sensor Networks: A Survey”, Elsever , Ad Hoc Network.

Gandham S. R., Dawande M., Prakash R. & Venkatesan S.(2003), “Energy efficient schemes for wireless sensor networks with multiple mobile base stations”, Proc. of IEEE Globecom, vol. 1, pp. 377–381, San Francisco, CA .


Thank you for listening!



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