Introduction to Wireless Sensor Networks 1 Learning Objectives

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Introduction to Wireless Sensor Networks 1

Introduction to Wireless Sensor Networks 1

Learning Objectives • Understand the basics of Wireless Sensor Networks (WSNs) – Applications –

Learning Objectives • Understand the basics of Wireless Sensor Networks (WSNs) – Applications – Constraints – Operational Challenges • Understand representative hardware • Learn how to set up the programming environment 2

Prerequisites • Basic concepts of Computer Networks • Basic concepts of Computer Hardware, including

Prerequisites • Basic concepts of Computer Networks • Basic concepts of Computer Hardware, including microcontroller, I/O, radio transceiver, memory, and ADC. 3

Wireless Sensor Networks (WSNs) • Many simple nodes with sensors deployed throughout an environment

Wireless Sensor Networks (WSNs) • Many simple nodes with sensors deployed throughout an environment Sensing + CPU +Radio = Thousands of Potential Applications Ref. [Introduction_1] p. 102 - 105 4

WSN Applications • Indoor/Outdoor Environmental Monitoring – Habitat Monitoring – Structural Monitoring – Precision

WSN Applications • Indoor/Outdoor Environmental Monitoring – Habitat Monitoring – Structural Monitoring – Precision Agriculture • Triggered Events – Detection/Notification • Military Applications – Battlefield Surveillance • Health Monitoring Ref. [Introduction_1] p. 102 - 105 5

Some Existing Applications • Create a macroscope – Deployed on Redwood Trees – Great

Some Existing Applications • Create a macroscope – Deployed on Redwood Trees – Great Duck Island – Tracking zebra – Monitor volcanic eruptions 6

 • • Operational Challenges of Wireless Sensor Networks Energy Efficiency Limited storage and

• • 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 Ref. [Introduction_1] p. 102 - 105 7

Characteristics of Wireless Sensor Networks • Limited in – – – Energy Computation Storage

Characteristics of Wireless Sensor Networks • Limited in – – – Energy Computation Storage Transmission Range Bandwidth • Characteristics – – Self-organize Random Deployment Cooperating Local Computation Ref. [Introduction_1] p. 102 - 105 8

Enabling Technologies Embed numerous distributed devices to monitor and interact with physical world Embedded

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

Hardware Constraints • Power, size, and cost constrained – Small memory – Slow clock

Hardware Constraints • Power, size, and cost constrained – Small memory – Slow clock cycles of microcontroller 10

One Example Sensor Node - Mica. Z Mote • • Developed at UC Berkeley

One Example Sensor Node - Mica. Z Mote • • Developed at UC Berkeley Fabricated by Crossbow Inc. Integrated Wireless Transceiver CPU – MPR 2400, based on Atmega 128 L – 8 MHz • Memory – 4 KB of primary memory (SRAM) – 128 KB of program space (ROM) – 512 KB Flash Memory • Transmit Data Rate – 250 kbps • Transmission Range – Outdoor: 75 m – 100 m – Indoor: 20 m - 30 m • Frequency Band – 2. 4 GHz http: //www. xbow. com/Products/pr oductdetails. aspx? sid=164 11

I/O Sub-System • The I/O subsystem interface consists of a 51 -pin expansion connector

I/O Sub-System • The I/O subsystem interface consists of a 51 -pin expansion connector eight analog lines, eight power control lines, three pulse-width-modulated lines, two analog compare lines, four external interrupt lines, an I 2 C-bus from Philips Semiconductor, an SPI bus, a serial port, a collection of lines dedicated to programming the microcontrollers. [hardware_1] Page 17 expansion connector – – – – – 12

One Example Sensor Board - MTS 310 http: //www. xbow. com/Products/pr oductdetails. aspx? sid=177

One Example Sensor Board - MTS 310 http: //www. xbow. com/Products/pr oductdetails. aspx? sid=177 13

One More Example of Sensor Board MTS 400/420 • Besides the functions of MTS

One More Example of Sensor Board MTS 400/420 • Besides the functions of MTS 300, it mainly adds GPS functionality • Example GPS Reading – http: //firebug. sourceforge. net/gps_tests. htm http: //www. xbow. com/Products/pr oductdetails. aspx? sid=177 14

Hardware Setup Overview 15

Hardware Setup Overview 15

Programming Board (MIB 520) http: //www. xbow. com/Products/pr oductdetails. aspx? sid=227 16

Programming Board (MIB 520) http: //www. xbow. com/Products/pr oductdetails. aspx? sid=227 16

Telos. B • http: //www. xbow. com/Products/productdetails. aspx? sid=252 17

Telos. B • http: //www. xbow. com/Products/productdetails. aspx? sid=252 17

Telos. B Architecture • [Energy_1]: Figure 2 18

Telos. B Architecture • [Energy_1]: Figure 2 18

Typical WSN Platforms Ref: [Tiny. OS_1]: Table 1 19

Typical WSN Platforms Ref: [Tiny. OS_1]: Table 1 19

One Proposed WSN Functional Layer Decomposition • Ref: Fig. 1. 1 of J. Polastre

One Proposed WSN Functional Layer Decomposition • Ref: Fig. 1. 1 of J. Polastre Dissertation: http: //www. polastre. com/papers/polastre-thesisfinal. pdf 20

Architecture to Build WSN Applications • Ref: Fig. 2. 1 of J. Polastre Dissertation:

Architecture to Build WSN Applications • Ref: Fig. 2. 1 of J. Polastre Dissertation: http: //www. polastre. com/papers/polastre-thesis-final. pdf 21

Lab • The purpose of this programming assignment is to familiarize yourself with Tiny.

Lab • The purpose of this programming assignment is to familiarize yourself with Tiny. OS programming based on Xubun. TOS and various concepts in developing a simple application. Please read Tiny. OS 2. x tutorial Lesson 3 “Mote-mote radio communication” http: //docs. tinyos. net/index. php/Mote-mote_radio_communication its section “Sending a Message over the Radio” and Lesson 4 “Mote-PC serial communication and Serial. Forwarder” http: //docs. tinyos. net/index. php/Mote. PC_serial_communication_and_Serial. Forwarder After you read these tutorials, please make the following applications work: 1. a Blink. To. Radio 1. b Oscilloscope (please use both GUI and text interfaces on the PC to observe the received data) 1. c Multihop. Oscilloscope (please use both GUI and text interfaces on the PC to observe the received data) Please turn in a screenshot for each of the above mentioned applications. 22

Assignment • 1. Why is energy efficiency the most important concern in designing protocols

Assignment • 1. Why is energy efficiency the most important concern in designing protocols for wireless sensor networks? • 2. What are the main differences between Telos. B motes and Mica. Z motes from the hardware point of view? • 3. What is the main architecture to build a wireless sensor network application? 23