Sensor Network Simulation

1. Sensor Network Simulation Simulators and Testbeds Jaehoon Kim Jeeyoung Kim Sungwook Moon

2. Contents • Introduction • Simulators • TOSSIM • Avrora • Viptos • Testbeds • MoteLab • Kansei • Conclusion

3. Introduction • What is a network simulator? • Why a sensor network simulator? • What is a testbed? • Simulators vs Testbeds?

4. Simulators TOSSIM Avrora Viptos

5. TOSSIM • Overview. • A TinyOS based interrupt-level discrete event simulator • Can capture network behavior at a high fidelity while scaling to thousands of nodes (up to 8192 nodes) • Helped to discover bugs in TinyOS • Provides a high degree of accuracy by using models of only a few low-level components with or without a few modification of source code

6. TOSSIM • Disadvantages • Only compatible with TinyOS • No preemption • Does not capture CPU time (cycle count) • But it would limit scalability. • Does not capture energy consumption. • It requires adding hooks to the simulator implementations of hardware abstraction components

7. Avrora • Overview • A cycle-accurate instruction level sensor network simulator which scales to networks of up to 10,000 nodes • Uses a cycle-by-cycle implementation strategy where each node and each device are advanced by one clock cycle every round • Performs as much as 20 times faster than its previous simulator(ATEMU) • Only 50% slower than TOSSIM

8. Avrora • Disadvantages • Did not model clock drift • In reality, nodes may run at slightly different clock frequencies over time due to manufacturing tolerances, temperature, and battery reason. • Validating timing results with real-world systems for all devices remains as future work • Only verified timing results for large programs with radio communication and real hardware for small, simple programs.

9. Viptos • Overview • Graphical development and simulation environment for TinyOS-based wireless sensor networks • Transforms the diagram into a nesC program • Extends the capabilities of TOSSIM to allow simulation of heterogeneous networks • Allows application developers to easily transition between high-level simulation of algorithms to low-level implementation and simulation

10. Testbeds MoteLab Kansei

11. MoteLab • Overview • Web-based sensor network testbed • Set of permanently deployed nodes • Web interface for users • Direct interaction with individual nodes

12. MoteLab • Details • Set of software tools • Four main pieces • MySQL Database Backend • Web Interface • DBLogger • Job Daemon • Use Models • Batch Use • Real-time Access

13. Kansei • Overview • Networked sensing applications at scale • Couple general set of arrays • Readily add new platforms • Addressing the scaling challenge • Enables scaling via software in a high fidelity manner

14. Kansei • Details • Set of hardware platforms • Hardware infrastructure • Stationary array • Portable array • Mobile array • Director • High fidelity sensor data generation tools • Hybrid simulation

15. Conclusion • TOSSIM has good performance but with limited usability • Avrora has slightly improved fidelity but has a 50% slower performance rate (than TOSSIM) • Viptos enables a graphical representation of the simulation on top of TOSSIM • They are different but none are superior or inferior to the other

16. Conclusion (cont’d) • MoteLab provides a web-based interface • Kansei has better scalability • Both provide networked testbeds with shared access for users

17. Any questions?