Overview ◦ 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, flow, level, motion or pollutants, at different locations. ◦ Wireless sensor networks are now used in many industrial and civilian application areas, including industrial process monitoring and control, machine health monitoring, environment and habitat monitoring, healthcare applications, home automation, and traffic control
Sensor nodes ◦ Nodes can be imagined as small computers, extremely basic in terms of their interfaces and their components. They usually consist of a processing unit with limited computational power and limited memory, sensors (including specific conditioning circuitry), a communication device (usually radio transceivers or alternatively optical), and a power source usually in the form of a battery.
Transceiver Memory Embedded Processor Sensors Battery 128KB-1MB Limited Storage 1Kbps - 1Mbps, 3-100 Meters, Lossy Transmissions 66% of Total Cost Requires Supervision 8-bit, 10 MHz Slow Computations Limited Lifetime Energy Harvesting System Wireless sensor Node limitations
Base Station ◦ The base stations are one or more distinguished components of the WSN with much more computational, energy and communication resources. They act as a gateway between sensor nodes and the end user.
◦ Unique characteristics of a WSN include: Limited power they can harvest or store Ability to withstand harsh environmental conditions Ability to cope with node failures Mobility of nodes Dynamic network topology Communication failures Large scale of deployment
Military applications Battle-damage assessment Battlefield surveillance Communications Monitoring Environmental applications Monitoring the behavior of organisms Forest fire detection Flood detection Mapping of the environment Precision Agriculture Health Care applications Hospital staff and patients tracking and monitoring Drug administration in hospitals Other applications Smart Buildings
Monitoring the behavior of organisms Forest fire detection Flood detection Mapping of the environment Precision Agriculture
Hospital staff and patients tracking and monitoring Drug administration in hospitals
Smart Buildings: Heating, ventilation, and air conditioning systems Lightning Air quality and window control Systems switching off devices Security and safety
Industrial robots Real-time inventory management Process and equipment monitoring Environment monitoring
1:Two power supplies 2: four primary loops 3:Wireless senor nodes 4:Robot 5:Convayer 6:Antenna 7:input module General Motors Engine assembly line
The old fashioned manual inventory management system problems: 1: out-of-stocks 2: expedited shipments 3: production slowdowns 4: excess buffer inventory Inventory management for packaged gases with WSN
General Motors utilized the monitoring system which is integrated by wireless sensor network technology to monitor the manufacturing equipments vibration and temperature : 1: forecasting the machine’s failure 2: pre-emptive maintenance 3: faster repair of equipment
Wireless sensor network can be useful to: Detecting leakage Detecting radiation Detecting intrusion “Nose-on-a-chip” is a gas detector senor and it can detect more than 400 kinds of gases and send signal to a basic station
◦ Wireless Sensor Network Advantages Wireless systems allow for energy saving enabling preventative maintenance for reduced unplanned downtimes increasing productivity saving on wiring costs
TinyOS is a free and open source component-based operating system and platform targeting wireless sensor networks (WSNs). TinyOS is an embedded operating system written in the nesC programming language as a set of cooperating tasks and processes. TinyOS started as a collaboration between the University of California, Berkeley in co-operation with Intel Research and Crossbow Technology, and has since grown to be an international consortium, the TinyOS Alliance.