1071  LPWAN Assessment: Fundamentals

1071.1 Introduction

This chapter tests your foundational understanding of LPWAN technologies through targeted assessment questions covering core characteristics, technology comparisons, and basic selection criteria.

NoteLearning Objectives
  • Demonstrate understanding of LPWAN core characteristics
  • Compare LoRaWAN and Sigfox capabilities for specific use cases
  • Apply technology selection criteria to real-world scenarios
  • Identify the defining trade-offs in LPWAN design

1071.2 LPWAN Core Characteristics Quiz

Test your understanding of the fundamental principles that define LPWAN technologies.

Which combination of characteristics best defines LPWAN technologies?

  1. High bandwidth, short range, low power
  2. Low bandwidth, long range, high power
  3. Low bandwidth, long range, low power
  4. High bandwidth, long range, low power
Click to reveal answer

Answer: C) Low bandwidth, long range, low power

Explanation:

LPWAN technologies are specifically designed with these three key characteristics:

Low bandwidth: - Data rates from 100 bps (Sigfox) to 50 kbps (LoRaWAN) - Small payload sizes (12-243 bytes typically) - Optimized for sensor data, not multimedia

Long range: - 2-15 km in urban environments - 15-40+ km in rural/open areas - Much longer than Wi-Fi (100m) or Bluetooth (10m)

Low power: - Battery life of 5-20 years typical - Infrequent transmissions - Simple modulation schemes - Deep sleep modes between transmissions

These characteristics are intentionally traded off: - To achieve long range with low power, bandwidth must be reduced - Sub-GHz frequencies provide better propagation than 2.4/5 GHz - Simple protocols minimize processing power requirements

Why other options are incorrect: - A: LPWAN deliberately uses low bandwidth, not high - B: LPWAN uses low power, not high (this describes cellular 4G/5G) - D: Cannot achieve both high bandwidth and long range with low power simultaneously (physics constraints)

This unique combination makes LPWAN ideal for IoT applications like smart metering, environmental monitoring, and asset tracking.

1071.3 Technology Comparison Quiz

Understanding the differences between LPWAN technologies is critical for proper solution design.

A company needs to deploy 10,000 environmental sensors across a city. Sensors report every 15 minutes (96 messages/day) with 50-byte payloads. Battery life must exceed 5 years. Should they choose LoRaWAN or Sigfox?

  1. Sigfox because it has lower power consumption
  2. LoRaWAN because Sigfox message limits are exceeded
  3. Either technology works equally well
  4. Neither technology is suitable for this application
Click to reveal answer

Answer: B) LoRaWAN because Sigfox message limits are exceeded

Explanation:

Let’s analyze the requirements against each technology’s capabilities:

Application Requirements: - 96 messages per day - 50-byte payload - 5+ year battery life - 10,000 devices

Sigfox Limitations: - Maximum 140 uplink messages per day - (96 < 140, this passes) - Maximum 12-byte payload - (need 50 bytes, FAILS) - 10-20 year battery life - acceptable - Scales to thousands of devices - acceptable

LoRaWAN Capabilities: - No daily message limit (only duty cycle restrictions) - acceptable - Up to 243-byte payload - (50 bytes well within limits) - 5-10 year battery life - acceptable (at this message frequency) - Scales to thousands of devices per gateway - acceptable

Critical failure point: Sigfox’s 12-byte payload limit is exceeded by the 50-byte requirement. Even if we could compress the data, the fundamental constraint makes Sigfox unsuitable.

Additional considerations: - 96 messages/day with 50 bytes represents ~4.8 KB/day per sensor - This is well within LoRaWAN duty cycle limits (~1% in EU) - With adaptive data rate, LoRaWAN can optimize power consumption - Battery life will depend on spreading factor selection

Why other options are incorrect: - A: While Sigfox has excellent power consumption, the payload size constraint eliminates it - C: The technologies are NOT equivalent - Sigfox physically cannot support 50-byte payloads - D: Both the message frequency (96/day) and payload size (50 bytes) are well within LoRaWAN capabilities

Recommendation: Deploy LoRaWAN with SF7-SF9 spreading factors to balance range and power consumption, achieving the required 5+ year battery life while accommodating the 50-byte payload.

1071.4 Basic Cost Analysis Quiz

Understanding cost factors is essential for LPWAN deployment planning.

A water utility wants to deploy 50,000 smart water meters across a region. Each meter sends one reading per day (24 bytes). Compare the 5-year total cost of ownership between private LoRaWAN and NB-IoT. Assume: LoRaWAN gateway 1,500 EUR, sensor 15 EUR, coverage needs 30 gateways, network server 300 EUR/month. NB-IoT sensor 20 EUR, data plan 1.50 EUR/device/month.

What is the approximate 5-year TCO difference?

  1. NB-IoT costs 4,400,000 EUR more
  2. LoRaWAN costs 2,000,000 EUR more
  3. Both cost approximately the same
  4. NB-IoT costs 800,000 EUR more
Click to reveal answer

Answer: A) NB-IoT costs 4,400,000 EUR more

Explanation:

Let’s calculate the detailed 5-year Total Cost of Ownership (TCO) for each option:

Private LoRaWAN:

Initial costs (Year 1): - Gateways: 30 x 1,500 EUR = 45,000 EUR - Sensors: 50,000 x 15 EUR = 750,000 EUR - Installation labor: ~100,000 EUR (estimate) - Total initial: 895,000 EUR

Recurring costs (Years 1-5): - Network server: 300 EUR/month x 12 months x 5 years = 18,000 EUR - Maintenance: ~5,000 EUR/year x 5 years = 25,000 EUR - Total recurring: 43,000 EUR

LoRaWAN 5-year TCO: 938,000 EUR

NB-IoT (Cellular):

Initial costs (Year 1): - Sensors: 50,000 x 20 EUR = 1,000,000 EUR - Installation labor: ~100,000 EUR - Total initial: 1,100,000 EUR

Recurring costs (Years 1-5): - Data plan: 50,000 devices x 1.50 EUR/month x 12 months x 5 years = 4,500,000 EUR - Total recurring: 4,500,000 EUR

NB-IoT 5-year TCO: 5,600,000 EUR

Cost Difference: 5,600,000 EUR - 938,000 EUR = 4,662,000 EUR (approximately 4,400,000 EUR)

Key Insights:

  1. Year 1 costs: NB-IoT (1,190,000 EUR) vs LoRaWAN (913,000 EUR)

    • Similar initial investment

  2. Year 2-5 costs: NB-IoT (900,000 EUR/year) vs LoRaWAN (8,600 EUR/year)

    • Massive recurring cost difference

  3. Break-even point: LoRaWAN infrastructure pays for itself in ~2 months of operation

  4. 10-year TCO difference: Would exceed 8 million EUR in favor of LoRaWAN

Factors favoring LoRaWAN for this application: - Large scale deployment (50,000 devices) - Low data frequency (once per day) - Long-term operation (5+ years) - Fixed locations (no mobility requirements) - Small payload size (24 bytes)

When NB-IoT might be preferred despite cost: - Need guaranteed QoS - Cannot deploy/maintain gateways - Require nationwide coverage - Need higher bandwidth occasionally - Mobile devices requiring handoff

Conclusion: For large-scale, long-term, low-data-rate sensor deployments, private LPWAN networks offer dramatic cost savings compared to cellular IoT solutions. The initial infrastructure investment is recovered quickly through elimination of per-device subscription fees.

1071.5 Quick Knowledge Check

TipSelf-Assessment

Before proceeding to advanced assessment topics, ensure you can answer:

  1. What are the three defining characteristics of LPWAN?
  2. What is Sigfox’s maximum payload size limitation?
  3. Why do recurring costs dominate cellular IoT TCO?
  4. When would you choose LoRaWAN over Sigfox?

1071.6 Summary

This fundamentals assessment covered:

  • LPWAN Core Characteristics: The low bandwidth, long range, low power trade-off that defines LPWAN technologies
  • Technology Comparison: Key differences between LoRaWAN and Sigfox, including payload limits and message quotas
  • Basic Cost Analysis: Understanding TCO components and the significant impact of recurring subscription costs

Key Takeaways: - LPWAN deliberately sacrifices bandwidth for range and power efficiency - Payload size constraints can eliminate technology options regardless of other factors - At scale, private network infrastructure costs are quickly recovered versus subscription fees

1071.7 What’s Next

Continue your LPWAN assessment with: