LoRa-Based Wireless Communication
Testbed for Long-Range IoT Devices
Location:
Centre of Excellence in Marine & Shipbuilding, Visakhapatnam
Timeline:
2025
Overview & Objectives
The primary objective of this project was to design and evaluate long-range, low-power wireless communication and communication reliability for IoT devices. The testbed was intended to analyse and validate performance in terms of:
• Communication range • Packet delivery reliability • RSSI & SNR behaviour under real-world conditions
• Performance in indoor vs. outdoor environments • Impact of LoRa PHY parameters (SF/BW/CR)
The project helps determine the suitability of LoRa technology for various verticals such as Environmental Monitoring, Agriculture, Industrial IoT, Maritime Applications and Asset Tracking. We chose to do this at CEMS, Vishakhapatnam to explore LoRa technology with a maritime focus. The test bed is occupied with RF Noise.
Issues Encountered & Solutions Adopted
Unstable signal in NLOS / thick obstacles
- Move antenna to higher/clearer location and use an external gain antenna.
- Use lower frequency (if possible) or increase TX power within regs.
- Add relay/repeater or more gateways to shorten hop distances.
Packet loss in dense urban / obstructed environments
- Increase gateway density or install directional antennas to cover shadowed areas.
- Enable ACK + retries and raise coding rate (more FEC).
- Stagger transmit times or use channel hopping to avoid local congestion.
Reduced SNR and occasional packet collisions
- Increase coding rate, repeat critical packets, enable random backoff.
- Use ADR and adaptive power control to improve SNR margins.
- Spread transmissions in time (duty cycle/randomize) and add gateways for spatial diversity.
Interference from nearby RF sources
- Scan spectrum, identify interferers and move to cleaner channels.
- Use narrower bandwidth, higher coding rate and CRC checks.
- Add RF filtering/shielding and maintain separation from noisy electronics.
Device sleep/wake changes when increasing SF
- Keep timing deterministic: lengthen wake window to cover longer airtime.
- Use precise RTC calibration and wake-on-interrupt where possible.
- Prefer ADR so network sets SF dynamically instead of hard-coding high SF.
Outcomes
Technologies Utilized
The LoRa testbed is a major attraction for government officials and international guests visiting CEMS, Visakhapatnam. The response from over 40 such visits has been uniformly encouraging, as the guests
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