%% fig-alt: "Decision tree for selecting WSN architecture components based on deployment requirements including power availability, range needs, data rate, and latency constraints"
%%{init: {'theme': 'base', 'themeVariables': {'primaryColor': '#2C3E50', 'primaryTextColor': '#fff', 'primaryBorderColor': '#16A085', 'lineColor': '#16A085', 'secondaryColor': '#E67E22', 'tertiaryColor': '#7F8C8D', 'fontSize': '13px'}}}%%
graph TD
START{WSN Deployment<br/>Requirements?}
START -->|"Power Available"| MAINS[Mains-Powered Gateway]
START -->|"Battery Only"| BATT{Data Rate?}
MAINS --> STAR[Star Topology<br/>802.15.4 or BLE]
MAINS --> Wi-Fi[Wi-Fi Sensors<br/>High bandwidth]
BATT -->|"<10 kbps"| RANGE{Range Needed?}
BATT -->|">10 kbps"| MESH[Mesh Required<br/>Higher energy cost]
RANGE -->|"<100m"| SHORTRANGE[802.15.4<br/>Zigbee/Thread]
RANGE -->|">1km"| LONGRANGE[LoRaWAN<br/>NB-IoT]
SHORTRANGE --> LATENCY{Latency?}
LONGRANGE --> LPWAN[LPWAN<br/>5+ year battery]
LATENCY -->|"<100ms"| REALTIME[Wake-up Radio<br/>or S-MAC]
LATENCY -->|">1s OK"| DUTYCYCLE[Heavy Duty Cycling<br/>X-MAC]
STAR --> RESULT1[Result: 5+ year life<br/>High reliability]
Wi-Fi --> RESULT2[Result: High bandwidth<br/>Unlimited power]
MESH --> RESULT3[Result: <1 month life<br/>Complex routing]
LPWAN --> RESULT4[Result: 10+ km range<br/>Low data rate]
REALTIME --> RESULT5[Result: Fast response<br/>Moderate energy]
DUTYCYCLE --> RESULT6[Result: Maximum life<br/>Delayed response]
style START fill:#2C3E50,stroke:#16A085,color:#fff
style MAINS fill:#16A085,stroke:#2C3E50,color:#fff
style BATT fill:#E67E22,stroke:#2C3E50,color:#fff
style RANGE fill:#E67E22,stroke:#2C3E50,color:#fff
style LATENCY fill:#E67E22,stroke:#2C3E50,color:#fff
style RESULT1 fill:#16A085,stroke:#2C3E50,color:#fff
style RESULT2 fill:#16A085,stroke:#2C3E50,color:#fff
style RESULT3 fill:#7F8C8D,stroke:#2C3E50,color:#fff
style RESULT4 fill:#16A085,stroke:#2C3E50,color:#fff
style RESULT5 fill:#16A085,stroke:#2C3E50,color:#fff
style RESULT6 fill:#16A085,stroke:#2C3E50,color:#fff
385 WSN Review: Architecture and Design
385.1 Learning Objectives
By the end of this chapter, you will be able to:
- Understand WSN Architecture: Comprehend the hierarchical organization of wireless sensor networks
- Select Appropriate Topologies: Choose optimal network topologies based on deployment constraints
- Evaluate Energy Trade-offs: Analyze energy consumption patterns and optimization strategies
- Apply Architecture Decisions: Use decision trees to guide WSN deployment choices
385.2 Prerequisites
Required Chapters: - WSN Overview Fundamentals - Core WSN concepts - Wireless Sensor Networks - WSN architecture - Sensor Fundamentals - Sensor basics
Technical Background: - Sensor node architecture - Energy constraints in WSNs - Data aggregation concepts
WSN Architecture Layers:
| Layer | Function | Example |
|---|---|---|
| Application | User services | Environmental monitoring |
| Transport | Reliability | Congestion control |
| Network | Routing | RPL, AODV |
| Data Link | MAC access | CSMA/CA, TDMA |
| Physical | Radio | 802.15.4 |
Estimated Time: 15 minutes
NoteRelated Chapters
WSN Review Series: - WSN Overview Review (Index) - Series overview - WSN Review: Knowledge Checks - Quick assessment questions - WSN Review: Scenario Analysis - Detailed scenario walkthroughs - WSN Review: Comprehensive Assessment - Advanced topics and summary
WSN Overview Series: - WSN Overview Fundamentals - Core WSN concepts - Wireless Sensor Networks - Architecture and design
Advanced Topics: - WSN Coverage Fundamentals - Area and target coverage - WSN Tracking Fundamentals - Mobile target tracking
TipFor Beginners: How to Use This Review
What is this chapter? This review chapter consolidates Wireless Sensor Network (WSN) architecture concepts. It’s designed to test and reinforce your understanding of WSN design decisions.
Key Concepts to Master:
| Concept | Why It Matters |
|---|---|
| Sensor Nodes | Basic building blocks of WSNs |
| Network Topology | How sensors connect and communicate |
| Data Aggregation | Reducing network traffic efficiently |
| Energy Efficiency | Maximizing battery life |
Recommended Path: 1. Study WSN Overview Fundamentals first 2. Review WSN Implementations 3. Return here to test your understanding
385.3 WSN System Architecture
WSN System Architecture (Hierarchical Organization)
| Layer | Component | Function | Key Features |
|---|---|---|---|
| Physical Layer | Sensor Nodes (6 nodes shown) | Sense & transmit data | MCU + Radio + Sensors, Battery powered |
| Network Layer | Cluster Heads (2 nodes) | Data aggregation & relay | Reduce traffic with statistical summaries (min/max/avg) |
| Gateway Layer | Gateway/Sink | Protocol bridge | Network coordinator, Wi-Fi/Ethernet/Cellular |
| Application Layer | Cloud Platform | Storage & analytics | ML, user interface, command distribution |
Data Flow (Upward): Sensor Nodes → (multi-hop, 802.15.4) → Cluster Heads → (aggregated data) → Gateway → (Internet) → Cloud
Control Flow (Downward): Cloud → Gateway → Cluster Heads → Sensor Nodes (commands, configuration, actuation)
385.4 WSN Application Domains
WSN Application Domains
| Domain | Applications |
|---|---|
| Environmental | Forest Fire Detection, Air Quality Monitoring, Water Quality, Weather Stations, Flood Detection |
| Industrial | Process Monitoring, Equipment Health, Factory Automation, Supply Chain Tracking, Predictive Maintenance |
| Infrastructure | Structural Health, Bridge Monitoring, Pipeline Leak Detection, Smart Grid, Traffic Monitoring |
| Agriculture | Precision Farming, Soil Moisture, Crop Health, Livestock Tracking, Greenhouse Automation |
| Healthcare | Patient Monitoring, Vital Signs, Medication Tracking, Fall Detection, Elderly Care |
| Military | Battlefield Surveillance, Target Tracking, Intrusion Detection, Chemical Detection, Perimeter Security |
| Smart City | Parking Management, Waste Management, Street Lighting, Noise Monitoring, Public Safety |
| Wildlife | Animal Tracking, Habitat Monitoring, Migration Patterns, Population Studies, Conservation |
385.5 WSN Energy Trade-offs
Understanding energy consumption patterns is critical for WSN deployment success:
385.6 WSN Topology Selection Decision Tree
Choose the right topology based on deployment constraints:
385.7 Summary
This chapter covered the foundational architecture concepts for WSN review:
- Hierarchical Architecture: Four-layer organization from physical sensors to cloud applications
- Architecture Selection: Decision tree approach based on power, data rate, range, and latency constraints
- Application Domains: Eight major deployment areas spanning environmental, industrial, and smart city applications
- Energy Trade-offs: Understanding sleep vs. idle vs. transmission power consumption
- Topology Selection: Choosing between star, mesh, and hierarchical based on constraints
385.8 What’s Next
Continue to the knowledge check questions to test your understanding of WSN architecture concepts.