Download Energy Efficient for Real Time Data Aggregation in

Research Issues in
Wireless Sensor Networks
Prof. Xiaohua Jia
Dept. of Computer Science
City University of Hong Kong
CS Dept, City Univ.
1
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
CS Dept, City Univ.
2
Layered Structure of Sensor Networks
Applications
Database Queries
Data Aggregation
Localization
Time Synch
Routing
Topology Cont’l
Security
OS / Network
Hardware / MAC layer
CS Dept, City Univ.
3
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)
CS Dept, City Univ.
4
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.
CS Dept, City Univ.
5
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.
CS Dept, City Univ.
6
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)
CS Dept, City Univ.
7
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
CS Dept, City Univ.
8
Data Query & Data Processing



Database systems for sensor networks
Application data processing / signal processing /
pattern recognition
Location sensitive database / spatial database
CS Dept, City Univ.
9
Applications of Sensor Networks






Environment monitoring
Agriculture
Manufacturing industries
Medicine
Disaster warning / prevention / relief operations
Military applications
CS Dept, City Univ.
10
Concluding Remarks
Strategic Research Directions of Sensor Networks:
 Special-purposed hardware design (application
tailored, low cost).
 Security issues in sensor networks.
 Sensor network applications.
CS Dept, City Univ.
11