Sensor Networks UCE BURLA

11/19/2015Presentation on Sensor Networks2 Technical Terms SINA – Software Information Network Architecture. Beacons. TinyOS – Tiny Micro-threading Operating System. SPIN – Sensor Protocols for Information via Navigation.

11/19/2015Presentation on Sensor Networks3Contents 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

11/19/2015Presentation on Sensor Networks4 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.

11/19/2015Presentation on Sensor Networks5 Introduction (Cont…) Earlier sensor networks… Now, sensor networks… Why distributed, wireless sensing??? – Closer placement. Depends upon: – Dense Deployment. – Co-ordination among the nodes.

11/19/2015Presentation on Sensor Networks6 Features Local Processing. Wireless Communication. Complete system on Chip. Integrated Low-power communication. Integrated Low-power transducers.

11/19/2015Presentation on Sensor Networks7 Focus Is On… Energy and computational constraints. – Energy Efficiency. – Localization algorithms. – Routing.

11/19/2015Presentation on Sensor Networks8 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.

11/19/2015Presentation on Sensor Networks9 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 )

11/19/2015Presentation on Sensor Networks10 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.

11/19/2015Presentation on Sensor Networks11 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.

11/19/2015Presentation on Sensor Networks12 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.

11/19/2015Presentation on Sensor Networks13 Figure 1:

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11/19/2015Presentation on Sensor Networks15 3. Energy Efficiency Computing Subsystem. – microprocessor. Communication subsystem. – radio. Sensing subsystem – sensors and actuators. Power Supply – con sists of a battery. Solution. – Develop methodologies which are energy aware. – Distribution of traffic. – Residual Energy Scan (eScan) – by Younggang Zaho.

11/19/2015Presentation on Sensor Networks16 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).

11/19/2015Presentation on Sensor Networks17 Trilateration/multilateration A AB AB C

11/19/2015Presentation on Sensor Networks18 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.

11/19/2015Presentation on Sensor Networks19 Suggested Alg. For Beacons Random Max Grid Heap (Selective Turning off BEacons)

11/19/2015Presentation on Sensor Networks20 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

11/19/2015Presentation on Sensor Networks21 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.

11/19/2015Presentation on Sensor Networks22 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.

11/19/2015Presentation on Sensor Networks23 7. Sensor Network Simulator NS –2 ; written in c++ and oTCL. GloMoSim (Global Mobile Information System Simulator); written in C and parsec. SensorSim;

11/19/2015Presentation on Sensor Networks24 Challenges Ad hoc deployment Unattended Operation Untethered (Limited Energy resource) Dynamic Changes Ultimate Struggle System Lifetime System robustness

11/19/2015Presentation on Sensor Networks25 Conclusion Promising applications Evolving field Scope for lots of research

11/19/2015Presentation on Sensor Networks26References

11/19/2015Presentation on Sensor Networks27 Thank You