1. ECN B4 : Dao Thanh Chung (bull@ht) Tutor : Takatoshi Kanazawa (takatosi@ht) fNode : Reducing Network Packet Transmission Overhead in Indoor Heterogeneous Wireless Sensor Networks Graduation Thesis Final Presentation Tokuda Lab

2. B ACKGROUND Traditional WSN deployment Because of cost and complexity of node deployment, network deployment using a single sensor node hardware platform Narrow monitoring Sensing ability: either temperature, humidity or fire Heterogeneous wireless sensor network Consist of sensor nodes with different capabilities Radio frequency, Sensing range, Hardware platform Wide monitoring Temperature, humidity, fire, sound, etc.

3. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor

4. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor

5. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2

6. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3

7. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4

8. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4 5

9. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4 5 6

10. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4 5 6 １

11. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4 5 6 １ 2

12. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4 5 6 １ 23

13. P ROBLEM D EFINITION Heterogeneous sensor nodes are required to be deployed under the same environment Sensor nodes with different hardware platforms cannot communicate with each other → Redundant Packet Transmission Overhead WC Hall Room conference room conference room WC Plant Sink Center １ Redundancy Data  Black node in the hall needs many hops (6 hops) Fire sensor Temperature sensor 2 3 4 5 6 １ 23 4

14. PACKET TRANSMISSION OVERHEAD Experiments with 8 sensor nodes in classroom environment Send packets from the first node to 8 th node Increase power consumption and delay time when the number of hops rise Consumed PowerDelay time Number of hops

15. P ROPOSED S OLUTION Propose fNode Act as an intermediate node for packet forwarding Replace redundant forwarding nodes Convert and forward packet’s format compatible with various platforms Propose fMap Algorithm Minimize the network packet transmission overhead Require an ideal deployment scenario of fNode fMap algorithm estimates fNode’s positions

16. WC Hall Room conference room conference room WC Plant Sink Center １ ２ ３ ４ ５ ６ Redundancy Data

17.  Black node’s packets in the hall are transmitted by a shorter path via fNode (3 hops) F N ODE D EPLOYMENT S CENARIO WC Hall Room conference room conference room WC Plant Sink Center fNode １ 2 3

18. D ESIGN OF F N ODE Receive packets Convert the packet’s format Transmit converted packets Micro Controller A Radio Module A Radio Module B Radio Module B Radio Module Incoming packets Outgoing packets A packet s B packet s A packet s B packet s

19. F M AP A LGORITHM Original Topology Forwarding node Fire sensor Temperature sensor

20. F M AP A LGORITHM Remove all forwarding nodes

21. F M AP A LGORITHM Topology after one fNode added (Find fNode position by reviewing all deployable positions)

22. F M AP A LGORITHM Topology after 2 nd fNode added All nodes are connected → stop loop

23. I MPLEMENTATION In order to evaluate packet transmission overhead Design fNode testbed fNode testbed A laptop Sensor nodes are connected We provide a GUI to implement fMap Java language Sun Spot node Iris node Converting packets fMap GUI

24. E VALUATION E NVIRONMENT Classroom environment (20m x 30m with minor radio blocking obstacles such as desks and chairs) 2 Macbook Pro as fNode testbeds SunSpot and Iris nodes as sensor devices 7 SunSpot nodes 6 Iris motes Deploy sensor nodes with two topologies: linear and hybrid SunSpot node Iris moteClassroom

25. T ESTBED T OPOLOGY Linear topology Non-overlapping sensing regions Hybrid topology Overlapping sensing regions Experimental assumption Same MTU Cover range: 5m Minor radio blocking obstacles No wave noise

26. E VALUATION M ETHOD Deploy the sensor nodes and a sink node with the linear and hybrid topologies 7 SunSpot and 6 Iris nodes Deploy at arbitrary positions Measure the sum of hops, the power usage and the packet transmission latency of each node that is necessary to transmit its packets to the sink node Average of 20 times measurement Use fMap to calculate positions of fNodes and deploy fNodes with existing sensor nodes, and perform the same measurement as above

27. E XPERIMENTAL R ESULTS Total number of transmitted packets Reduced by approximately 30%  Linear Topology 24 hops (Original) vs. 18 hops (Using fNode): 6 hops decreased  Hybrid Topology 30 hops (Original) vs. 20 hops (Using fNode): 10 hops decreased

28. P OWER CONSUMPTION R ESULT Transmission Power – reduced 33-39%  Linear Topology 688 mA (Original) vs. 448 mA (Using fNode): decreased by 33%  Hybrid Topology 875 mA (Original) vs. 531 mA (Using fNode): decreased by 39% fNode’s Power comsumption = (SunSpot + Iris)/2

29. L ATENCY R ESULT Delay time – reduced 35-50%  Linear Topology 381 ms (Original) vs. 167 ms (Using fNode): decreased by 50%  Hybrid Topology 386 ms (Original) vs. 251 mA (Using fNode): decreased by 35%  Linear (50%) vs. Hybrid (35%) Delay time SunSpot : 23ms Iris mote: 4ms Linear relays via Iris mote more than Hybrid does

30. R ELATED W ORK A Framework for Flexible Packet Processing in Heterogeneous Sensor Networks (M. Leogrande, C. Pastrone… at FGCN 07) Base on XML language Flexible packet processing Increase in flexibility, adaptability and extensibility However, it only focuses on processing messages Packet transmission overhead is still unsolved Adaptive Online Energy Saving for Heterogeneous sensor networks (Qiu, J. Hu, E. Sha,at 19th IASTED ) Base on time interval Obtain the best mode assignment for each node Adjust online However, availability of WSN is decreased

31. C ONCLUSION A ND F UTURE W ORK Propose fNode Forward packets of different communication architecture Packet transmission overhead, power usage and latency Reduced approximately 30% Application areas Building management system Greenhouse management system Evaluate the benefit of fNode is only the first step Our future work Implement a realistic fNode Deploy under a larger scale WSN