1. Fakultät Informatik – Institut für Systemarchitektur – Professur Rechnernetze MiLAN Muhammad Mirza Zeeshan Mehmood Supervisor: Dr. Waltenegus DargieDr. Waltenegus Dargie Seminar Presentation : Wireless Sensor Networks ( Winter 2006-07 ) 16.01.2007

2. Wireless Sensor Networks: Winter 2006-07 Folie 2 Contents Introduction Motivation Architecture Conclusion Critique References

3. Wireless Sensor Networks: Winter 2006-07 Folie 3 Introduction MiLAN ( Middleware Linking Applications and Networks ) is a middleware architecture: Maximizing application lifetime While Providing application QoS by controlling and optimizing network as well as sensors.

4. Wireless Sensor Networks: Winter 2006-07 Folie 4 Motivation High respiratory rate Normal Heart Rate Low blood pressure Respiratory Rate Blood O2 Blood Pressure Blood O2 Heart Rate 0.8 0.7 High Heart Rate ECG Diagram Blood Pressure Blood O2 Heart Rate 0.3 0.8 0.3 0.8 0.3 1.0 0.3 Personal Health Monitor Application The QoS of the different variables of interest at each different states of patient The state-based Variable Requirement graph

5. Wireless Sensor Networks: Winter 2006-07 Folie 5 Motivation Personal Health Monitor Application The QoS of the different variables depends on which sensors provide data to the application The Sensor QoS Graph Blood pressure Heart rate Blood pulse Blood press Blood flow Pulse oxy ECG Blood press Blood flow Pulse oxy 0.71.00.8 0.71.00.7 0.8 1.0 Virtual sensor

6. Wireless Sensor Networks: Winter 2006-07 Folie 6 Motivation The challenging characteristics of sensor network 2. Dynamic Availability Either mobility through space, addition of new sensors, or loss of existing sensors causes the set of available sensors to change over time ? Availability is the main factor 3. Resource Limitation Both network bandwidth and sensor energy are constrained. This is especially true when considering battery-powered sensors and wireless networks ? Provide less bandwidth and less reliable connectivity than wired network 1. Inherent Distribution The sensors are distributed throughout a physical space and primarily connected wirelessly ? increase unreliability of whole system

7. Wireless Sensor Networks: Winter 2006-07 Folie 7 Goal of MiLAN Provide Application QoS Maximize Application Lifetime Control the network as well as the sensors MiLAN control sensor network as well as the sensors and maximizes Application life time and Qos Application QoS Requirement Network Monitoring State Of Monitored Objects

8. Wireless Sensor Networks: Winter 2006-07 Folie 8 Relationships among different Middleware

9. Wireless Sensor Networks: Winter 2006-07 Folie 9 MiLAN Sensor Network MiLAN Network Information Data Reading Sensor power on&off Data routing path Sensor data transmission rate Application QoS Application

10. Wireless Sensor Networks: Winter 2006-07 Folie 10 MiLAN Architecture

11. Wireless Sensor Networks: Winter 2006-07 Folie 11 MiLAN Architecture App. Feasible Set Network Feasible Set Sensor Network Configuration Sensor Network Application QoS Requirement Sensed Object States Network Information Overall Set Application Logic Sensor Reading Doctor ApplicationMiddleware - MiLAN Trade-off computation

12. Wireless Sensor Networks: Winter 2006-07 Folie 12 MiLAN Components

13. Wireless Sensor Networks: Winter 2006-07 Folie 13 A High-level overview of MiLAN operation and Partial MiLAN API

14. Wireless Sensor Networks: Winter 2006-07 Folie 14 MiLAN Network Plugin Functionality Providing available sensor sets Getting bandwidth information Discovery sensors Using service discovery protocol Ex. SDP, SLP Configure sensors Data transmission rate Sensor power on&off Setting of different sleep states Specifying the role of each sensors in multihop networks

15. Wireless Sensor Networks: Winter 2006-07 Folie 15 Computing Sets Network Feasible Set Overall Set Trade off computation App. Feasible Set State Based Variable Requirements graph

16. Wireless Sensor Networks: Winter 2006-07 Folie 16 State-based Variable Requirement graph

17. Wireless Sensor Networks: Winter 2006-07 Folie 17 Application Feasible Set F A Set #Sensors 1Blood flow, Respiratory rate 2Blood flow, ECG (3 leads) 3Pulse oxymeter, Blood pressure, ECG(1 lead), Respiratory rate 4Pulse oxymeter, Blood pressure, ECG(3 leads) 5Oxygen Measurement, Blood pressure, ECG(1 lead), Respiratory rate 6Oxygen measurement, Blood pressure, ECG(3 leads) Multiple set of sensors, which can provide application QoS at a given state, can be derived from the state-based variable requirement graph and the sensor QoS graph A patient state medium stress high heart rate, normal respiratory rate, and low blood pressure

18. Wireless Sensor Networks: Winter 2006-07 Folie 18 Network Feasible Set F N Network Feasible Set Network plugin ’ s job The subsets of nodes that can be supported by the network Suppose that the sensors and processors communicate using an IEEE 802.11a network It can support overall throughput of nearly 11Mb/s However, if multiple applications are running simultaneously on the network and the personal health monitor application can only utilize 100kb/s of the throughput, the network would not be able to support the transmission of data from the ECG sensor with either 3, 5, or 12 leads

19. Wireless Sensor Networks: Winter 2006-07 Folie 19 Overall Set F F = F A ∩ F N Example of Overall set F Suppose network can ’ t support ECG 3, 5 12 leads, since other applications are running simultaneously Set #Sensors 1Blood flow, Respiratory rate 2Blood flow, ECG (3 leads) 3Pulse oxymeter, Blood pressure, ECG(1 lead), Respiratory rate 4Pulse oxymeter, Blood pressure, ECG(3 leads) 5Oxygen Measurement, Blood pressure, ECG(1 lead), Respiratory rate 6Oxygen measurement, Blood pressure, ECG(3 leads) Set #Sensors 1Blood flow, Respiratory rate 3Pulse oxymeter, Blood pressure, ECG(1 lead), Respiratory rate 5Oxygen Measurement, Blood pressure, ECG(1 lead), Respiratory rate Application Feasible Set F A Overall Set F F A ∩ F N

20. Wireless Sensor Networks: Winter 2006-07 Folie 20 Conclusion A middleware for sensor network applications Ease the application development task Enable applications to affect the network and sensors themselves Tight coupling between the needs of the application and the management of the network Separate the policy (obtained from the application) and the mechanism (performed in the middleware)

21. Wireless Sensor Networks: Winter 2006-07 Folie 21 Critique Strong Points Application QoS requirement is actively reflected in the network and sensors Middleware control sensor network directly Application QoS is specified at each different states of monitored objects Weak Points MiLAN approach is not appropriate when there are a lot of sensors MiLAN should know a lot of information about each sensors Available energy, role of each sensor, network connectivity, etc. They didn’t present enough explanation about mechanism in detail How to choose an element among overall set F

22. Wireless Sensor Networks: Winter 2006-07 Folie 22 MiLAN Development MILAN v0.9 Beta Early Spring 2003 Documentation MILAN v1.0 Early Fall 2003 Extensibility toolkit (beta version) Additional simulators, hardware platforms etc. Tutorials MILAN v1.1 Early Summer 2004 Service release Additional simulator integration as needed Full scale demonstration

23. Wireless Sensor Networks: Winter 2006-07 Folie 23 References 1.A. Murphy and W. Heinzelman, "Milan: Middleware linking applications and networks," TR-795, University of Rochester, Computer Science, November 2002. 2.WB Heinzelman, AL Murphy, HS Carvalho, and MA Perillo. Middleware to support sensor network applications. IEEE Network Mag., 18(1):6--14, 2004. 3.MiLAN: Middleware to Support Sensor Network Applications Kyungmin Cho,Network Computing Lab., KAIST

24. Wireless Sensor Networks: Winter 2006-07 Folie 24 Thank you Questions ?