Wireless Sensor Network

Question 1

What are Wireless Sensor Networks (WSNs)?

Answer 1

Wireless Sensor Networks (WSNs) are networks consisting of spatially distributed autonomous sensors that monitor physical or environmental conditions and cooperatively pass data through the network to a base station.

Question 2

List six examples of various WSNs sensors.

Answer 2

1. Current sensor
2. Distance sensor
3. Force (Pressure) sensor
4. Gas sensor
5. Temperature and humidity sensor
6. Water sensor

Question 3

Why are Wireless Sensor Networks Important?

Answer 3

WSNs are important because they prevent failures, improve food quality, increase comfort, save resources, improve productivity, enable new knowledge, enhance safety and security, and protect health.

Question 4

List seven examples of ambient conditions that WSNs can monitor.

Answer 4

1. Temperature
2. Pressure
3. Humidity
4. Vehicular movement
5. Noise levels
6. Lighting conditions
7. Vibration or presence of objects/substances

Question 5

Draw and explain the components of a wireless sensor node.

Answer 5

Components of a wireless sensor node include:
- Sensing unit (Sensor and ADC)
- Processing unit (Processor and Memory)
- Communication unit (Radio Transceiver)
- Power unit (Battery, energy management)
Optional: Location finding system, Power generator, Mobilizer

Question 6

What are the characteristics of sensor devices?

Answer 6

Sensor devices are battery-powered, simple, low-cost, and consist of microprocessors with specific environmental instrumentation (e.g., for sound, light, and temperature).

Question 7

Draw WSNs architecture.

Answer 7

WSNs architecture typically includes sensor nodes, a base station/gateway, and a user interface for data access.

Question 8

Explain the characteristics of WSNs.

Answer 8

WSNs are energy-constrained, have limited memory, support dynamic reconfiguration, and can operate in extreme conditions. They mainly consist of low-power sensors.

Question 9

Explain five WSNs application domains.

Answer 9

1. Environmental applications (e.g., forest fire detection)
2. Medical applications (e.g., patient monitoring)
3. Smart home applications
4. Military applications (e.g., surveillance)
5. Commercial applications (e.g., inventory tracking)

Question 10

Explain the design challenges of WSNs.

Answer 10

Design challenges include:
- Heterogeneity
- Distributed processing
- Low bandwidth communication
- Large-scale coordination
- Sensor utilization
- Real-time computation

Question 11

Explain the operational challenges of WSNs.

Answer 11

Operational challenges include:
- Energy efficiency
- Limited storage and computation
- Common communication errors
- Node failures
- Scalability
- Survivability in harsh environments