Wireless Sensors Networks - Network Address Allocation Presented by: Assaf Goren Supervisor: Dr. Yehuda Ben-Shimol

- Introduction The wireless sensors network Application - Hardware - Software - The Network Address Allocation Algorithm Motivation Implementation - Summery & Conclusions

Introduction - the WSN Sensor network are collections of small, battery operated computers with:  sensors, and possibly actuators, to sense and control their environment  radios, to report data and receive instructions  typical expected lifetimes range from a few months to several years A wireless sensor network consists of a large number of sensor nodes that may be randomly and densely deployed. the sensor nodes are capable of gathering, processing, and communicating information to other nodes and to the outside world.

Introduction - the WSN Sensor nodes are small electronic components capable of sensing many types of information from the environment. A sensor network is designed to: - detect events or phenomena - collect and process data - transmit sensed information to interested users

Introduction - the WSN Basic features of sensor networks: - Self-organizing capabilities - Static Network, no mobility of the devices - Large Number and Dense deployment - Frequently changing topology due to fading and node failures - Limitations in energy, transmit power, memory, and computing power These characteristics make sensor networks different from other wireless ad hoc

Introduction - the WSN Main issues in WSN design: Power Supply The most difficult constraints in the design- the minimum energy consumption When miniaturizing the node, the energy density of the power supply is the primary issue. Currently, investigation the use of solar cells to charge capacitors Throughput The parameters describe the network’s capability to carry traffic a traditional measure of how much traffic can be delivered by the network Routing expected to implement three main functions: determining and detecting network topology changes maintaining network connectivity calculating and finding proper routes

Introduction - Applications Sensor nodes are capable of sensing many types of information from the environment, including: - temperature - light - humidity - radiation and more... Which made the WSN eligible of many applications, such as health; agriculture; geology; military and many more

Introduction - Applications General Engineering: - Fingertip accelerometer virtual keyboards - Sensing and maintenance in industrial plants - Aircraft drag reduction- by combining flow sensors and blowing/sucking - Actuators - Commercial and residential security Agriculture and Environmental Monitoring: - Planetary exploration and surveillance in inhospitable - environments - Geophysical monitoring- Seismic activity can be detected - Disaster detection, like Forest fire and floods

Introduction - Applications Military Applications: - Surveillance and battle-space monitoring - Urban warfare - deployment in buildings, movements of friend and foe Health Monitoring and Surgery: - Micro-surgery - Medical sensing- Physiological data such as body temperature, - blood pressure and pulse

Hardware Usage of Crossbow’s hardware, which contain 3 major devices: 1. The Mote Interface Board-MIB510- allow developers to interface Motes to PCs or PDAs via the serial port and to program the Mote.

Hardware 2. The processing board- the mica2 Mote- This device runs the open-source TinyOS operating system. Responsible for the communication process. The brain of the system. 3. The sensor board- MTS300- A flexible sensor board with a variety of sensing modalities that include Light, Temperature, Acoustic, and Sounder.

Software What is TinyOS? TinyOS is an operating system designed to target limited-resource sensor network nodes TinyOS and its application are implemented in nesC, a C dialect Programming language TinyOS was Developed by Berkeley especially for the Wireless sensors networks

Software TinyOS in a nutshell System runs a single application  OS services can be tailored to the application’s needs These OS services include  timers, radio, serial port, sensing, storage, multihop collection and dissemination Application and services are built as  a set of interacting components  using a strictly non-blocking execution model Implementation based on a set of OS abstractions  tasks, atomic with respect to each other; interrupt handlers  resource sharing, power management

Software nesC in a seashell C dialect Component based  all interaction via interfaces  connections (“wiring”) specified at compile-time Two basic modules  Configuration module  Implementation module Supports TinyOS’s concurrency model  must declare code that can run in interrupts  atomic statements to deal with data accessed by interrupts

The Network Address Allocation Algorithm Motivation Deployment a large number of small nodes over a large geographical area  No access or a need of human intervention  power consumption savings needs  ( A major consumer – the communication process ) How to save power and extend Mote life?

The Network Address Allocation Algorithm Some solutions- aggregation points, clusters, sleeping mode ID instead of Mac address: - Simplified the routing tables - Less space in the packet - Less space in mote memory

The Network Address Allocation Algorithm Implementation Initial assumptions: - Sensors condition unknown- sensor is on/off - Network topology unknown- ad-hoc Network- A number of nodes whom locate inside the area of transmission/reception of the other nodes No leader  Each node capable of communicate and process data Each node keeps the ID and MAX_ID variables

The Network Address Allocation Algorithm The algorithm deals with 2 different scenarios: No network was found in the local area After a very short time a network was found

The Network Address Allocation Algorithm - Waking up - Temp id= 0xfffe - Sends brdst pkt - wait X time period No packet was received  No Network was found ID=1, MAX_ID=1 Keep sending broadcast ID_REQ packets

The Network Address Allocation Algorithm - Waking up - Temp id= 0xfffe - Sends brdst pkt - wait X time period Receive a response packet  a network was found Using the MAX_ID of the network ID= MAX_ID+1, MAX_ID= MAX_ID+1 Updating the network with the new MAX_ID by broadcast pkt

Summery & Conclusions - Learning about the WSN, the structure & components, the goals and the implementations - Get familiar with the TinyOS and the nesC language - Design and implementation of the Network Address Allocation algorithm using all the purchased knowledge