What is WSN?

• Wireless Sensor Network (WSN) is a network of sensors deployed wirelessly to monitor physical or environmental conditions, such as temperature, humidity, or pressure.
• Sensor Nodes are responsible for monitoring and collecting data. They connect to a Base Station that processes and shares the data over the internet.

WSN Architecture

• Physical Layer: Connects sensor nodes to the base station using technologies like radio waves, infrared, or Bluetooth.
• Data Link Layer: Ensures reliable communication between nodes and the base station.
• Application Layer: Facilitates data communication and defines the format for transmitting data (e.g., ZigBee).

WSN Network Topologies

• Bus Topology: Nodes connected along a single line; simple but limited.
• Star Topology: A central node connects to multiple other nodes; efficient for centralized control.
• Tree Topology: Nodes are arranged hierarchically, like a tree, for larger coverage.
• Mesh Topology: Nodes interconnect with each other to provide robust coverage and redundancy.

Types of WSN

1. Terrestrial WSN: For efficient communication on the surface; uses solar power for energy efficiency.
2. Underground WSN: Monitors underground conditions; faces high costs and limited battery life.
3. Underwater WSN: Deployed underwater; faces challenges like slow data transmission and limited power.
4. Multimedia WSN: Monitors multimedia events (audio, video); requires high power and bandwidth.
5. Mobile WSN: Composed of mobile nodes that can move and adapt to the environment.

Applications of WSN

• IoT: Interconnects devices and sensors for smart applications.
• Security & Surveillance: Monitors for threats and activities.
• Environmental Monitoring: Tracks temperature, humidity, air pressure, etc.
• Medical: Monitors patient health.
• Agriculture: Tracks soil conditions, crops, etc.
• Landslide Detection: Identifies environmental threats.

Challenges in WSN

• Energy Efficiency: Limited battery life in sensor nodes.
• Security: Vulnerable to attacks like eavesdropping or tampering.
• Network Throughput & Performance: Handling large amounts of data efficiently.
• Scalability: Managing a large number of nodes.
• Node Failure: Ensuring reliability when nodes fail.

WSN Components

1. Sensors: Capture environmental data.
2. Radio Nodes: Transmit data from sensors to the base station.
3. WLAN Access Point: Receives data wirelessly via the internet.
4. Evaluation Software: Processes data for analysis and reporting.

Advantages

• Low Cost: Affordable and easy to deploy.
• Wireless Communication: Flexible and eliminates wiring costs.
• Energy Efficiency: Operates for long periods without frequent battery changes.
• Scalability: Can add or remove sensors based on needs.
• Real-Time Monitoring: Provides immediate data for decision-making.

Disadvantages

• Limited Range: Restricted communication range.
• Limited Processing Power: Sensor nodes may struggle with complex tasks.
• Security Risks: Vulnerable to cyberattacks.
• Interference: Susceptible to interference from other wireless signals.
• Deployment Challenges: Requires careful sensor placement and network setup.