CS Dept, City Univ. 1

Research Issues in Wireless Sensor Networks

Prof. Xiaohua Jia

Dept. of Computer Science

City University of Hong Kong

CS Dept, City Univ. 2

Characteristics of Sensor Networks

Low power and limited energy supply Simple CPU (low speed, small memory) Low network speed, unreliable data link, small

transmission range Large deployment and dynamic replacement No infrastructure and self & dynamic organization

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Layered Structure of Sensor Networks

Hardware / MAC layer

OS / Network

Localization

Database Queries

Applications

Time Synch Topology Cont’l Security

Data Aggregation Routing

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Localization / Time Synchronization

Localization of tagged and untagged objects Finding locations of sensors without GPS One-hop or multi-hop time synchronization

(important for scheduling of sensor nodes)

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Topology Control

Adjust transmission power of nodes or determine logical neighbors of nodes.

Achieving desirable connectivity / reducing interferences / increasing throughput

QoS topology control Dynamic, distributed (localized), and efficient.

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Placement and Coverage Issues

Placement of sensor nodes for good coverage or network connectivity.

Placement of data-sinks for efficient data collection or network throughput.

Network connectivity (or area coverage) and node density.

Scheduling of nodes sleep / active for energy saving under desirable area coverage.

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Security of Sensor Networks

Light-weight cryptographic primitives Light-weight security protocols for key distribution

/ key management / authentication Intrusion detection / intrusion tolerance Secured routing (lack of security infrastructure)

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Routing & Data Aggregation

Data centric routing (data push / pull / hybrid) Backbone computation / clustering Geographic routing (GPSR, etc) QoS routing Energy efficiency & real-time issues Broadcasting / multicasting / anycasting Data aggregation & query optimizations

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Data Query & Data Processing

Database systems for sensor networks Application data processing / signal processing /

pattern recognition Location sensitive database / spatial database

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Applications of Sensor Networks

Environment monitoring Agriculture Manufacturing industries Medicine Disaster warning / prevention / relief operations Military applications

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Concluding Remarks

Strategic Research Directions of Sensor Networks: Special-purposed hardware design (application

tailored, low cost). Security issues in sensor networks. Sensor network applications.