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ADVANCED WIRELESS SENSOR NETWORKS....AWSN
- 1. ADVANCED WIRELESS Sensor Networks IVyear 1sem Course code: 18EC7150 By Dr. Vijayalakshmi. Atla Associate Professor Dept of ECE Amrita Sai Institute of Science and Technology
- 2. Syllabus: OVERVIEW OF WIRELESSSENSOTR NETWORKS Key definitions of sensor networks Advantages of sensor Networks Unique Constraints and challenges Applications of sensor networks Enabling Technologies for wireless sensor networks architectures Single-Node Architecture-Hardware components Energy consumption of sensor nodes Operating systems and execution Environments Network Architecture-Sensor network scenarios Optimization Goals and Figure of Merit Gateway Concepts TEXT BOOKS: • C. Siva Ram Murthy and B. S. Manoj, “Ad-hoc Wireless Networks”, Pearson Education, 2008. • Carlos De Morais Cordeiro and Dharma Prakash Agrawal, “Ad-hoc and Sensor Networks: Theory and Applications”, World Scientific Publishing Company, 2006. UNIT-I OVERVIEW OF WIRELESS SENSOTR NETWORKS & architectures
- 3. Key definitions ofsensor networks • wireless sensor network : A wireless sensor network (WSN) can be defined as a network of low-size and low-complex devices denoted as nodes that can sense the environment and communicate the information gathered from the monitored field through wireless links. • Sensor: A transducer that converts a physical phenomenon such as heat, light, sound, or motion into electrical or other signals that may be further operated by other apparatus. • Routing: The process of determining a network path from a packet source node to its destination. • Geographic routing: Routing of data based on geographical features such as locations or regions. This is an example of data centric networking.
- 4. • Detection: Theprocess of discovering the existence of a physical phenomenon. A threshold- based detector may flag a detection whenever the signature of a physical phenomenon is determined to be significant enough compared with the threshold. • Classification: The assignment of class labels to a set of physical phenomena being observed. • Evaluation metric: A measurable quantity that describes how well the system is performing on some absolute scale. Examples include packet loss (system), network dwell time (system), track loss (application), false alarm rate (application), probability of correct association (application), location error (application), or processing latency (application/system).
- 5. Advantages of sensorNetworks Energy Advantage Detection Advantage It accommodate new devices at any time It avoids lot of wirings These Networks are applicable on large scale
- 6. Unique Constraints andchallenges The challenges we face in designing sensor network systems are: Limited hardware: Each node has limited processing, storage, and communication capabilities, and limited energy supply and bandwidth. Limited support for networking: The networks are peer-to-peer Network: Connected Each Other via Internet and files directly shared without need of central source. Unreliable Communication: It does not depend on trust Dynamically Change: In this constant change in motion occurs. Limited support for software development: The tasks are typically real- time and massively distributed, involve dynamic teamwork among nodes, and must handle multiple competing events. Global properties can be specified only via local instructions. Because of the coupling between applications and system layers, the software architecture must be code signed with the information processing architecture.
- 7. Applications of sensornetworks • The following are applications of wireless sensor Networks: Military applications Battlefield surveillance monitoring Guiding intelligent missiles Attack detection Environment applications Medical applications Preventing wrong diagnosis Monitoring patient movements Identifying allergies
- 8. Environment applications Forest fire detection Flood detection Air pollution detection Water quality detection Industrial applications Controlling at industrial plants Dealing with data center issues Home Intelligence Smart home Remote management Agricultural applications Monitoring water tank levels Water pump controlling Irrigation automation
- 9. Enabling Technologies forwireless sensor networks wireless sensor networks have fundamental advances in enabling technologies, They are: Cost Reduction Wireless communication Simple Microcontrollers System on-chip Sensing Batteries Miniaturization Reduced Chip size Improved energy efficiency Energy Scavenging The process of recharging of batteries with energy gathered from environment
- 10. Single Node Architecture-Hardwarecomponents Controller Power Supply Sensor/Actuator Communication Devices Memory Fig. Sensor Node – Hardware components
- 11. Controller Itis Central processing unit of a Node Collects data from sensor nodes, process and decides when and where to send. Receives data from the other sensor nodes and decide based on actuators behavior. Ex: General purpose processor, DSP’s, Microcontrollers etc.. Memory RAM – For Sensor Readings ROM – For Storing the program code Flash Memory – For storing the data if RAM gets affected Communication device For sending and receiving of information over a wireless Wireless communication uses the radio frequency
- 12. Transceiver: Itis a device used for both Transmitting and Receiving operations. We have two parts of Transceiver Front end part- Analog signal processing Base band part – Digital signal processing Intermediate frequency and base band processi Antenna Interface LN A P A RF Front end Low noise amplifier Power amplifier
- 13. Power Amplifier Takes signal from IF and amplifies them for Transmitter and antenna. Low noise amplifier Amplifiers incoming signals without reducing the signal to noise ratio Sensors It is a interface to the physical world and these can observe or control physical parameters of the environment. Passive narrow-beam sensors Passive omnidirectional sensors Active sensors Actuators These are for wireless sensor networks that converts electrical signal into the physical phenomenon Power Supply For the power supply batteries are used either rechargeable or non- rechargeable.