Introduction to WSN

8/2/2019 Introduction to WSN

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Introduction to Wireless

Sensor NetworksPresented by

Sushanth Sivaram Vallath


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The most profound technologies are those thatdisappear. They weave themselves into the

fabric of everyday life until they areindistinguishable from it.

- The late Mark Weiser, Father of Ubiquitous Computing and Chief

Technologist of Xerox PARC


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Wireless Sensors

Smallmicrocontroller

8 kB code

512 B dataSimple, low-powerradio

10 kbps ASK

EEPROM (32 KB)

Simple sensors

WeC 99Smart Rock

Mica 1/02

NEST open exp. Platform128 kB code, 4 kB data40kbps OOK/ASK radio512 kB Flash

Rene 11/00

Designed forexperimentation

-sensor boards

-power boards

Dot 9/01

Demonstratescale

Spec 6/03Mote on

a chip

Telos 4/04

RobustLow Power250kbpsEasy to use

Mica2 12/0238.4kbps radioFSK

Tiny sensing devices capable of wireless communication


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What are sensor

networksspatially distributed sensors to monitor

conditions at different locations, such as

temperature, sound, vibration, pressure,motion or pollutants.


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Platforms

Berkeley Motes

Tiny OS

nesC

Ns-2 TOSSIM


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Applications of WSN

Temperature

Humidity

Vehicular movement Pressure

Noise levels

Mechanical stress levels on attached objects

Speed, direction

Etc


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Factors Influencing Sensor

Network Design Fault tolerance

Scalability

Operating environment

Sensor network topology

Transmission media Power consumption


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Sensors Representation

Communication Graph

Sensors are nodes

Link between the sensors are the edges


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Routing Protocols

LEACH

Directed Diffusion

PEGASIS

TEEN

APTEEN Etc


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Sensor Issues

Energy Constraint

High Communication cost

& Lot of other issues


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Management Issues

Conversion of data to Information

Data access control


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SQL

Underlying routing protocol transparentto user

Some routing protocols are consideredto be aggregation protocols (implicitaggregation)


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Sensor Database

SQL type interface

SELECT avg(temperature), room,FROM sensors

WHERE building = Nedderman Hall

ORDER BY temperature

GROUP BY room

SAMPLING PERIOD 10 min


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SQL type interfaces

Cougar

TinyDB

Approximations

Query Propagation

Data Centric StorageAging Data


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Query scenario

Sink

Selecttempfrom


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Efficiency achieved

throughIn-network aggregation


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Different types of queries

Fully aggregated queries

Un-aggregated queries

Partially aggregated queries


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Fully aggregated queries

Theorem: Finding maximum lifetimerouting tree for fully aggregated queries

with reception costs is NP-complete.

Similar to Minimum Degree Spanning

Tree(MDST) which is known to be NP-complete


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Un-aggregated queries

Theorem: Finding maximum lifetimerouting tree for unaggregated queries is

NP-complete.

Reduced from decision problem for SET-

COVER.


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Partially aggregated

queriesCan be reduced to unaggregated queries

Approximation algorithms used to solvethe unaggregated routing tree problemcan be adapted.


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Active areas in WSN

Routing Topology control Data management, aggregation and query MAC protocols Target tracking, resource discovery Monitoring and maintenance

Sensor validation Power issues Coverage and Connectivity


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Companies in Research

Crossbow

Intel

IBM Microsoft

PARC

Fujitsu Lot more


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References

[1] Cedric Florens and Robert McEliece, Packet Distribution Algorithms for Sensor Networks, IEEE INFOCOM 2003.[2] Samuel Madden, Robert Szewczyk, Michael J. Franklin and David Culler, Supporting Aggregate Queries Over Ad-Hoc Wireless

Sensor Networks,[3] Sartaj Sahni and Xiaochun Xu, Algorithms for Wireless Sensor Networks.[4] Jamal N. Al-Karaki Ahmed E. Kamal, Routing Techniques in Wireless Sensor Networks: A Survey.[5] Bhaskar Krishnamachari, D Estrin, Stephen Wicker, Modeling Data-Centric Routing in Wireless Sensor Networks.[6] S.S Iyengar, Richard R. Brooks, Distributed Sensor Networks, Chapman & Hall/CRC.[7] Wendi Rabiner Heinzelman, Anantha Chandrakasan, and Hari Balakrishnan, Energy-efficient communication protocol for wireless

microsensors networks, in 33rd Annual Hawaii International conference on System Sciences.[8] David Braginsky and Deborah Estrin, Rumor routing algorithm for sensor networks, in First ACM International Workshop on

Wireless Sensor Networks and Application.[9] Y.Xu, J. Heidemann, and D. Estrin, Geography-informed energy conservation for ad hoc routing, in Proceedings of the Seventh

Annual ACM/IEEE International Conference on Mobile Computing and Networking, 2001.[10] B. Chen, K. Jamieson, H. Balakrishnan, and R. Morris, SPAN: An energy-efficient coordination algorithm for topology maintenance

in ad-hoc wireless networks, ACM Wireless Networks Journal, September 2002.[11] Feng Zhao and Leonidas Guibas, Wireless Sensor Networks, an Information Processing Approach.[12] Yong Yao, J. E. Gehrke. The Cougar Approach to In-Network Query Processing in Sensor Networks. Sigmod Record, Volume 31,

Number 3. September 2002.[13] Yong Yao, J. E. Gehrke. Query Processing in Sensor Networks. In Proceedings of the First Biennial Conference on Innovative Data

Systems Research (CIDR 2003). Asilomar, California, January 2003.[14] Xiuli Ma, Dongqing Yang, Shiwei Tang, Qiong Luo, Dehui Zhang, and Shuangfeng Li. Online Mining in Sensor Networks. NPC

2004: 544-550[15] Chiranjeeb Buragohain, Divyakant Agrawal, and Subhash Suri, Power Aware Routing for Sensor Databases.


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Thank You

Documents

Introduction to WSN