Wireless Sensor Network
(WSN)
WSN - Basic Concept
• WSN is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, pressure, motion or sound at different locations.
• Each node in a sensor network is typically equipped with a RF transceiver, battery powered.
WSN - Characteristics
• 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
• Large scale of deployment
• Unattended operation
• Node capacity is scalable,only limited by bandwidth of gateway node.
WSN -Radio Options for the Physical Layer in Wireless Sensor Networks
• IEEE802.11x
• Bluetooth (IEEE802.15.1 and .2)
• IEEE 802.15.4
• IEEE1451.5
WSN - Network Topology
WSN - Category
• C1WSN - Tend to deal with large-scale with massive data flows.
• C2WSN - Tend to focus on short-range point-to-point, source-to-sink applications where low data rate, ultra low power and low cost are requirements.
WSN - Category
Category 2 WSNs: point-to-point, generally-singlehop systems utilizing static routing
Application - Home Control
• Sensing applications facilitate flexible management of lighting, heating, and
• Sensing applications automate control of multiple home systems to improve
• Sensing applications capture highly detailed electric, water, and gas utility usage data.
Application - Industrial Automation
• Sensing applications extend existing manufacturing and process control systems reliably.
• Sensing applications help identify inefficient operation or poorly performing equipment.
• Sensing applications help deploy monitoring networks to enhance employee and public safety.
Application - Others
• Medical Application
• Sensors and Robots
• Military Surveillance
• Habitat Monitoring
WSN - Research Challenges
• Power Consumption
o Exploit piezoelectric materials to harvest ambient strain energy
• Hardware Constraints
• Node Unit Costs
