Complete Guide to LoRaWAN Coverage Calculation
Learn how to accurately calculate LoRaWAN coverage for your deployment, including factors like terrain, frequency, and antenna placement.
Accurate coverage calculation is essential for successful LoRaWAN deployments. This guide covers the key factors and formulas you need to understand.
Understanding Link Budget
The link budget is the foundation of coverage calculation. It accounts for all gains and losses between the transmitter and receiver. For LoRaWAN, a typical link budget calculation includes: Transmit Power + Antenna Gains - Path Loss - Cable Losses = Received Signal Strength.
Path Loss Models
Different environments require different path loss models. The free-space path loss model works for line-of-sight scenarios, while urban and suburban environments need models like Okumura-Hata or COST-231. For indoor deployments, the ITU-R P.1238 model is commonly used.
Frequency Considerations
LoRaWAN operates in different frequency bands depending on the region. EU868 (Europe), US915 (North America), and AS923 (Asia) are the most common. Lower frequencies generally provide better coverage and penetration, but regulatory requirements vary.
Terrain Analysis
Hills, buildings, and vegetation all affect signal propagation. Tools like Radio Mobile and CloudRF can help model terrain effects. Fresh zones (areas where the signal path is clear) should be identified to ensure reliable communication.
Practical Tips
1. Always perform a site survey before deployment 2. Use margin in your calculations (typically 10-20 dB) 3. Consider seasonal variations (foliage, weather) 4. Test coverage with actual devices, not just predictions 5. Plan for future capacity needs