1. Sensor Networks by K. Subrahmanya Sreshti (05IT6004)
Under the Guidance of
Prof. Shamik Sural
School of Information Technology
Indian Institute of Technology, Kharagpur.

2. Presentation on Sensor Networks
Technical Terms
SINA – Software Information Network Architecture.
Beacons.
TinyOS – Tiny Micro-threading Operating System.
SPIN – Sensor Protocols for Information via Navigation.
9/17/2018
Presentation on Sensor Networks

3. Presentation on Sensor Networks
Contents
Introduction
Overview of Architecture and Operating System
Energy Efficient methods
Localization
Routing
Applications (Some systems which make use of sensor networks)
Sensor Network simulators
Conclusion
9/17/2018
Presentation on Sensor Networks

4. Presentation on Sensor Networks
Introduction
Definition:
Sensor networks are dense wireless networks of small, low-cost sensors, which collect and disseminate environmental data.
Used for monitoring and controlling of physical environments from remote locations with better accuracy.
9/17/2018
Presentation on Sensor Networks

5. Presentation on Sensor Networks
Introduction (Cont…)
Earlier sensor networks…
Now, sensor networks…
Why distributed, wireless sensing???
Closer placement.
Depends upon:
Dense Deployment.
Co-ordination among the nodes.
9/17/2018
Presentation on Sensor Networks

6. Presentation on Sensor Networks
Features
Local Processing.
Wireless Communication.
Complete system on Chip.
Integrated Low-power communication.
Integrated Low-power transducers.
9/17/2018
Presentation on Sensor Networks

7. Presentation on Sensor Networks
Focus Is On…
Energy and computational constraints.
Energy Efficiency.
Localization algorithms.
Routing.
9/17/2018
Presentation on Sensor Networks

8. Presentation on Sensor Networks
2. Architecture
Characteristics:
Small physical size and low power consumption.
Concurrency intensive operation.
Limited physical parallelism and controller hierarchy.
Diversity in design and usage.
Robust Operation.
Sensor Information Networking Architecture – A middle ware.
Issue queries and command tasks into.
Collects replies and results from.
Monitor changes.
Hierarchical Clustering.
Attribute-based naming.
Location Awareness.
9/17/2018
Presentation on Sensor Networks

9. Presentation on Sensor Networks
2. Architecture (Cont…)
Data sheets.
Sensor Query and Tasking Language (SQTL).
Interface between sensor application and SINA middleware.
getTemperature, turnON, isNeighbor, getPosition, tell, execute, etc.
Event handling: Receive, every, expire.
Software Execution Engine ( ALL, NEIGHBORS, etc )
9/17/2018
Presentation on Sensor Networks

10. Information Gathering
Sampling Operation (Adaptive Probability Response).
Self-Orchestrated Operation.
Diffused Computation Operation.
Internetworking between a Mobile User and Stationary Network.
Tracking the mobile User.
Progressive footprint chaining.
9/17/2018
Presentation on Sensor Networks

11. Presentation on Sensor Networks
2. Architecture (Cont…)
Hardware Organization.
Processor and co-processor.
Provide interfaces to sensing devices (light, temperature, etc).
Designed to work in three different modes (idle, power down, power save).
Three leads available.
Power Characteristics.
Why an OS?
Requirement of an OS which can perform the tasks.
Effective usage of hardware.
Support concurrent-intensive operation.
Unused CPU cycles are spent in sleep mode.
Achieve robustness.
9/17/2018
Presentation on Sensor Networks

12. Presentation on Sensor Networks
2. Architecture (Cont…)
TinyOS design.
Event modeling.
A stack based threaded approach.
Two level scheduling.
Components.
Set of command handlers.
Set of event handlers.
An encapsulated fixed size frames.
Bundle of simple tasks.
9/17/2018
Presentation on Sensor Networks

13. Presentation on Sensor Networks
9/17/2018
Figure 1:
Presentation on Sensor Networks

14. Presentation on Sensor Networks
9/17/2018
Presentation on Sensor Networks

15. Presentation on Sensor Networks
3. Energy Efficiency
Computing Subsystem. – microprocessor.
Communication subsystem. – radio.
Sensing subsystem – sensors and actuators.
Power Supply – consists of a battery.
Solution.
Develop methodologies which are energy aware.
Distribution of traffic.
Residual Energy Scan (eScan) – by Younggang Zaho.
9/17/2018
Presentation on Sensor Networks

16. Presentation on Sensor Networks
4. Localization
Nodes are in general deployed into an unplanned infrastructure (no priori knowledge).
Problem of estimating the spatial co-ordinates is referred to as Localization (generally done by trilateration).
Initial high-level nodes (beacons) broadcasts their address. (Proximity based Localization).
Multilateration (iterative process).
9/17/2018
Presentation on Sensor Networks

17. Trilateration/multilaterationB A A B C
9/17/2018
Presentation on Sensor Networks

18. Presentation on Sensor Networks
4. Localization (Cont…)
Fine – grained.
Timing.
Signal Strengths.
Signal Pattern Matching.
Pre-scanning takes place. A central system assigns a unique signature to each square in the location grid.
Coarse – grained.
Proximity based Localization. Nodes should adopt themselves to avoid to available reference points.
Connectivity metric=(tot. no. of signals received)/(tot. no. of signals sent).
Node’s position is calculated by centroid of all reference points.
9/17/2018
Presentation on Sensor Networks

19. Suggested Alg. For Beacons
Random
Max
Grid
Heap (Selective Turning off BEacons)
9/17/2018
Presentation on Sensor Networks

20. Presentation on Sensor Networks
5. Routing
Implosion
Ad-hoc protocols
Proactive – static: maintains a routing table.
Reactive – dynamic: establishes when required.
Negotiation based protocols
SPIN (meta-data) : uses ADV, REQ and DATA.
SPIN – PP (point-to-point)
SPIN – EC (energy conservative)
SPIN – BC (broadcast)
SPIN – RL
9/17/2018
Presentation on Sensor Networks

21. Presentation on Sensor Networks
5. Routing (Cont…)
Directed diffusion.
Attribute-value pairs are maintained.
Sink.
Interest cache.
Fields.
Timestamp.
Gradient – data rate.
Duration – lifetime.
Energy Aware Routing.
Destination initiative reactive protocol.
Multiple good optimal paths are maintained.
9/17/2018
Presentation on Sensor Networks

22. Presentation on Sensor Networks
6. Applications
Active Badge Location System.
Pin-point 3D-iD local positioning system.
Intelligence department.
Environmental monitoring.
Military purposes.
Gathering sensing information in inhospitable locations.
9/17/2018
Presentation on Sensor Networks

23. 7. Sensor Network Simulator
NS –2 ; written in c++ and oTCL.
GloMoSim (Global Mobile Information System Simulator); written in C and parsec.
SensorSim;
9/17/2018
Presentation on Sensor Networks

24. Presentation on Sensor Networks
Challenges
Ad hoc deployment
Unattended Operation
Untethered (Limited Energy resource)
Dynamic Changes
Ultimate Struggle
System Lifetime
System robustness
9/17/2018
Presentation on Sensor Networks

25. Presentation on Sensor Networks
Conclusion
Promising applications
Evolving field
Scope for lots of research
9/17/2018
Presentation on Sensor Networks

26. Presentation on Sensor Networks
References
9/17/2018
Presentation on Sensor Networks

27. Presentation on Sensor Networks
Thank You
9/17/2018
Presentation on Sensor Networks