Wireless Sensor Networks. Atiq Ahmed

Transcription

1 Wireless Sensor Networks Atiq Ahmed

2 Outline Motes & Wireless Sensor Networks WSN Applications 9/8/2016 Introduction to WSN 2

3 Mote Radio Transceiver D/A A/D Analog I/O Ports Sensor Microcontroller External Memory Digital I/O ports Sensor A very low cost low power computer Monitors one or more sensors A Radio Link to the outside world Are the building blocks of Wireless Sensor Networks (WSN) 9/8/2016 Introduction to WSN 3

4 Wireless Sensor Network A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. - Wikipedia 9/8/2016 Introduction to WSN 4

5 Wireless Sensor Network WSNs are networks that consists of sensors which are distributed in an ad hoc manner These sensors work with each other to sense some physical phenomenon and then the information gathered is processed to get relevant results WSNs consists of protocols and algorithms with selforganizing capabilities 9/8/2016 Introduction to WSN 5

6 Wireless Sensor Networks Formed by hundreds or thousands of motes that communicate with each other and pass data along from one to another Research focuses mostly on energy aware computing and distributed computing 9/8/2016 Introduction to WSN 6

7 WSN node components Low-power processor. Limited processing. Memory. Limited storage. Radio. Low-power. Low data rate. Limited range. Sensors. Scalar sensors: temperature, light, etc. Cameras, microphones. Power. Sensors Storage Processor Radio WSN device schematics P O W E R 9/8/2016 Introduction to WSN 1-7

8 Why Now? Use of networked sensors dates back to the 1970s Primarily wired and Centralized Today, enabling technological advances in VLSI, MEMS 1, and wireless communications Ubiquitous computing and Ubiquitous communications 1 Microelectromechanical systems 9/8/2016 Introduction to WSN 8

9 Vision: Embed the World Embednumerous sensing nodes to monitor and interact with physical world Networkthese devices so that they can execute more complex task 9/8/2016 Introduction to WSN 9

10 Examples of WSN Platforms PC-104+ (off-the-shelf) UCLA TAG (Girod) UCB Mote (Pister/Culler) 9/8/2016 Introduction to WSN 10

11 Example of WSN Source: 9/8/2016 Introduction to WSN 11

12 Comparison with ad hoc networks WSNs mainly use broadcastcommunication while ad hoc networks use point-to-point communication Unlike ad hoc networks, WSNs are limited by sensors limited power, energy and computational capability Sensor nodes may not have global IDbecause of the large amount of overhead and large number of sensors The number of nodes is very large Being more prone to failure, energy drain 9/8/2016 Introduction to WSN 12

13 Characteristics of Wireless Sensor Networks WSNs mainly consists of sensors which are - low power limited memory energy constrained due to their small size Wireless networks can also be deployed in extreme environmentalconditions and may be prone to enemy attacks Although deployed in an ad hoc manner they need to be self organized andself healingand can face constant reconfiguration 9/8/2016 Introduction to WSN 13

14 Design Challenges Heterogeneity The devices deployed maybe of various types and need to collaborate with each other Distributed Processing The algorithms need to be centralized as the processing is carried out on different nodes Low Bandwidth Communication The data should be transferred efficiently between sensors 9/8/2016 Introduction to WSN 14

15 Continued.. Large Scale Coordination Sensors need to coordinate with each other to produce required results Utilization of Sensors Sensors should be utilized in a ways that produce the maximum performance and use less energy Real Time Computation Computation should be done quickly as new data is always being generated 9/8/2016 Introduction to WSN 15

16 Operational Challenges of Wireless Sensor Networks Energy Efficiency Limited storage and computation Low bandwidth and high error rates Errors are common Wireless communication Noisy measurements Node failure are expected Scalability to a large number of sensor nodes Survivability in harsh environments Experiments are time- and space-intensive 9/8/2016 Introduction to WSN 16

17 Enabling Technologies Embed numerous distributed devices to monitor and interact with physical world Embedded Control system w/ Small form factor Untethered nodes Sensing Network devices to coordinate and perform higher-level tasks Networked Exploit collaborative Sensing, action Tightly coupled to physical world Exploit spatially and temporally dense, in situ, sensing and actuation 9/8/2016 Introduction to WSN 17

18 Applications of Wireless Sensor networks Applications can be divided in three categories I. Monitoring of objects II. Monitoring of an area III. Monitoring of both area and objects 9/8/2016 Introduction to WSN 18

19 WSN Applications Environmental/Habitat monitoring Acoustic detection Seismic Detection Military surveillance Inventory tracking Medical monitoring Smart spaces Process Monitoring 9/8/2016 Introduction to WSN 19

20 Health Monitors Glucose Heart rate Cancer detection Chronic Diseases Artificial retina Cochlear implants Hospital Sensors Monitor vital signs Record anomalies Biomedical / Medical 9/8/2016 Introduction to WSN 20

21 Military Remote deployment of sensors for tactical monitoringof enemy troop movements 9/8/2016 Introduction to WSN 21

22 Industrial & Commercial Numerous industrial and commercial applications: Agricultural Crop Conditions Inventory Tracking In-Process Parts Tracking Automated Problem Reporting RFID Theft Deterrent and Customer Tracing Plant Equipment Maintenance Monitoring 9/8/2016 Introduction to WSN 22

23 Habitat Monitoring on Great Duck Island Source: Intel Research Laboratory at Berkeleyinitiated a collaboration with the College of the Atlantic in Bar Harbor and the University of California at Berkeleyto deploy wireless sensor networks on Great Duck Island, Maine (in 2002) Monitor the microclimates in and around nesting burrows used by the Leach's Storm Petrel Goal : habitat monitoring kit for researchers worldwide 9/8/2016 Introduction to WSN 23

24 FireBugby UCB Source: D. M. Doolinand N. Sitar. Wireless sensors for wild fire monitoring, Proceedings of SPIE / NDE Wildfire Instrumentation System Using Networked Sensors Allows predictive analysis of evolving fire behavior Firebugs: GPS-enabled, wireless thermal sensor motesbased on TinyOSthat self-organizeinto networks for collecting real time data in wild fire environments Software architecture: Several interacting layers (Sensors, Processing of sensor data, Command center) 9/8/2016 Introduction to WSN 24

25 Example: Precision Agriculture Precision agriculture aims at making cultural operations more efficient, while reducing environmental impact Collected information is used to evaluate optimum sowing density, estimate fertilizers and other inputs needs, and to more accurately predict crop yields 9/8/2016 Introduction to WSN Source: Aslan, et el. "A framework for use of wireless sensor networks in forest fire detection and monitoring." Computers, Environment and Urban Systems36.6 (2012):

26 Preventive Maintenance on an Oil Collaboration of Intel & British Petroleum Use of sensor networks to support preventive maintenanceon board an oil tankerin the North Sea A sensor network deployment onboard the ship System gathered data reliably and recovered from errors when they occurred The project was recognized by InfoWorld as one of the top 100 IT projects in /8/2016 Introduction to WSN 26

27 Cricket Mote Basically a location-aware mote Includes an Ultrasound transmitter and receiver Uses the combination of RF and Ultrasound technologies to establish differential time of arrival and hence linear range estimates Based on Cricket Indoor Location System developed by MIT 9/8/2016 Introduction to WSN 27

28 Clustered Architecture Organizes the sensor nodes into clusters Each cluster is governed by a cluster-head Only heads send messages to a BS Suitable for data fusion Self-organizing 9/8/2016 Introduction to WSN 28

29 Low-Energy Adaptive Clustering Hierarchy (LEACH) Self-organizing and adaptive clustering protocol Evenly distributes the energy expenditure among the sensors Performs data aggregation where cluster heads act as aggregation points Two main phases: Setup phase: organizing the clusters Steady-state phase: deals with the actual data transfers to the BS 9/8/2016 Introduction to WSN 29

30 TinyOS What is TinyOS? open-source operating system wireless embedded sensor networks component-based architecture Developed at UCB in collaboration with Intel Research Current Stable Version is TinyOS 2.0 (T2) released on 6/11 Main Ideas Low complexity Conserve power sleep as frequently as possible Written in nesc next generation C compiler 9/8/2016 Introduction to WSN 30

31 Different Targets mica mica2 mica2dot micaz telos telosb rene2 pc 9/8/2016 Introduction to WSN 31

32 Mica2 Extremely popular mote 8-bit AVR Controller FSK radio Data-logger flash 9/8/2016 Introduction to WSN 32

33 TelosbMotes Have USB programming capability An IEEE compliant, high data rate radio with integrated antenna, a low-power MCU Also equipped with extended memory and an optional sensor suite 9/8/2016 Introduction to WSN 33

34 Future of WSN Smart Home / Smart Office Sensors controlling appliances and electrical devices in the house Better lighting and heating in office buildings The Pentagon building has used sensors extensively 9/8/2016 Introduction to WSN 34

35 References 1. Akyildiz, Ian F., and MehmetCan Vuran. Wireless sensor networks. Vol. 4. John Wiley & Sons, Stankovic, John A. "Wireless Sensor Networks." IEEE Computer (2008): Yang, Kun. "Wireless sensor networks." Principles, Design and Applications (2014). 4. Ye, Wei, et al. "An energy-efficient MAC protocol for wireless sensor networks." INFOCOM IEEE. Vol. 3. IEEE, Patwari, Neal, et al. "Locating the nodes: cooperative localization in wireless sensor networks." IEEE Signal processing magazine 22.4 (2005): Al-Karaki, et al. "Routing techniques in wireless sensor networks: a survey." IEEE wireless communications 11.6 (2004): Pal, Amitangshu. "Localization algorithms in wireless sensor networks: Current approaches and future challenges." Network protocols and algorithms2.1 (2010): Ozturk, Yusuf, et al. "An intelligent home energy management system to improve demand response." IEEE Transactions on Smart Grid 4.2 (2013): Dong, Wei, et al. "DPLC: Dynamic packet length control in wireless sensor networks." INFOCOM, 2010 Proceedings IEEE. IEEE, /8/2016 Introduction to WSN 35