LoRaWAN Gas Leak Detection System Architecture

Introduction : Methane leaks in gas pipelines, whether overhead or underground, pose serious safety, environmental, and economic risks. Undetected leaks can lead to fire hazards, explosions, greenhouse gas emissions, and significant financial losses for utility operators. Conventional detection systems often rely on manual inspections or wired monitoring networks, which are costly, labor intensive and not always effective across vast or remote pipeline networks.

Why LoRaWAN?

It uses LoRa Modulation Technique based on Chirp Spread Spectrum. It works in unlicensed bands such as 868 MHz, 915 MHz etc. as per regional allocations. LoRa supports long range, low power consumption and low data rates (between 0.3 kbps to 27 kbps) ideal for IoT wireless applications.

• LoRaWAN range considerations are as follows.
  • Indoor : ~ 500 meters
  • Outdoor : On top of a house roof or pole (~2 Km)
  • Outdoor : On top of a high altitude building (>10 Km)
• LoRaWAN device classes : There are three classes supported by LoRaWAN including class A (Least power), class B (lower latency but high power consumption than class-A) and class C (Extremely low latency but high power usage).
• Network Joining Mechanisms : LoRaWAN supports two methods for device activation viz. OTAA (Over The Air Activation) and ABP (Activation By Personalization). OTAA is flexible and dynamic where as ABP is static.
• LoRaWAN supports two layer security viz. 128 bit NwkSKey and 128 bit AppSKey. NwkSKey is used by network server to ensure message integrity. AppSKey is used for end to end payload encryption between device and application server.

Key Gas Leak Detection System Requirements

1. Gas Detection : Sensors to detect gases like methane, propane, or hydrogen. Common sensors are MQ-series (MQ-2, MQ-4, MQ-6), infrared gas sensors or ultrasonic leak detectors.
2. Leak Positioning (Localization) : There are various methods for determining location which include triangulation (based on multiple sensor), Signal strength/concentration gradient, ultrasonic sensing, time of flight (acoustic/vibration) etc.
3. Embedded System : Consists of Microcontroller (Arduino, ESP32, STM32, etc.) for real time monitoring. Collects data from sensors and preprocesses it.
4. Communication : Wired (CAN, RS-485) or Wireless (LoRa, ZigBee, NB-IoT, 4G/5G) to send alerts. Cloud/SCADA integration for real time monitoring.
5. Power : Battery with low power mode, or solar assisted for remote areas.
6. Safety Features : Alarm (buzzer, LED, SMS/Email alert). Automatic valve shut-off mechanism (optional, can be used as per requirement).

LoRaWAN Gas Leakage Detection System Architecture

The LoRaWAN (Long Range Wide Area Network) methane leak detection system offers a modern, wireless alternative by combining sensitive gas sensors with long range, low power communication technology. Using LoRaWAN, methane sensors installed along pipelines can continuously monitor gas concentrations and transmit data over several kilometers without the need for extensive cabling or high power consumption. This enables real time monitoring, rapid leak detection, and efficient data collection for both overhead and buried pipeline infrastructure.

Case Study 1 : Overhead Gas Pipeline

Following are the components used in LoRaWAN based overhead gas pipeline monitoring system for gas leakage. The figure-1 depicts architecture of the entire system for overhead gas transmission line. Let us understand functions of each of these components.

1. LoRaWAN Wireless Sensor Nodes : These wireless sensor nodes work at LoRa frequency. It houses microcontroller with LoRaWAN module. It contains Gas sensor as well as temperature & pressure sensors. It can be deployed at intervals along the pipeline as per requirements.

2. LoRAWAN Gateway : Collects data from wireless sensor nodes. Performs leak localization using multiple sensor reports. It transmits collected data to cloud server or central monitoring station in case of SCADA. One LoRaWAN gateway can handle multiple wireless end nodes (ENs) as per its range.

3. Control Center : Displays pipeline map and leak position. Alerts operators for immediate response. Mobile app and Web app are used as per requirements for monitoring the multiple sensors and determining exact location of the leak as per localization techniques.

Case Study 2 : Under Ground Gas Pipeline

The figure-1 depicts hybrid architecture of the entire system for under ground gas transmission pipeline. It is called hybrid as it uses both wired and wireless sensor nodes. Following are the components in this application. Wired sensors (WSs) are added in addition to wireless sensor end nodes (ENs).

1. Wired Sensor Nodes : These wired sensor nodes are installed across the pipeline and are arranged such that they can relay sensed data to the wireless sensor nodes in their vicinity. There are different types of wired gas sensors which include catalytic bead, infrared NDIR, laser, electrochemical, semiconductor MOS, ultrasonic etc. These modules provide inputs such as analog (4–20 mA, 0–10 V), digital and serial (RS232/RS485) to connect existing wired sensors.

2. LoRaWAN Wireless Sensor Nodes : The wired sensor nodes and wireless sensor nodes are connected using various interface types as per output of wired sensor nodes. The data received from wired sensor node are converted to compatible LoRaWAN format using suitable converters before transmission at Lora frequency towards gateway.

3. LoRAWAN Gateway : It supports multiple wireless sensor nodes. The data collected are transmitted to cloud server or scada. Cloud dashboards include ThingsBoard, AWS IoT, Grafana etc. LoRaWAN gateways forward encrypted sensor telemetry to the Network Server, which routes decoded data to application servers. These servers can integrate directly with SCADA platforms.

4. Cloud Server or SCADA : These systems play pivotal role by aggregating real time data from remote sensor nodes, providing operational visibility, analytics and control. The additional cloud & IoT platform include ThingsBoard, Thinger.io, ThingSpeak, AWS IoT Core, Azure IoT Hub, Google Cloud IoT Core, IBM watson, Ubidots etc.

5. Web App or Mobile App or M&C GUI panel : Web App or Mobile App serves as the vital digital interface for operators to visualize, manage and respond to safety critical data. Connected to the cloud or SCADA backend, the application delivers real time alerting (e.g., pressure drops or gas level anomalies), rich dashboards showing sensor locations and statuses and streamlined control tools for incident response. Web interfaces typically integrate data via protocols like MQTT or HTTPS and offer dashboards that include interactive maps, alarm workflows and historical trends.

Advantages

Following are some of the benefits of LoRaWAN Gas Detection System.

1. Long Range : LoRaWAN enables data transmission over kilometers, with a single gateway potentially covering up to 15 km in rural areas and several kilometers in industrial or urban environments.
2. Low power : Sensors powered by LoRaWAN consume very little energy; often operating for years on a single battery.
3. Cost Effective : Deploying LoRaWAN avoids the high costs associated with cellular or satellite infrastructure.
4. Scalable : Additional nodes can be installed at later stage as per change in requirements or increase in length of pipeline. This is done with minimal investment.
5. Real time alert : Due to cloud connectivity or SCADA integration, LoRaWAN relays real time information to control centers or smart wearables or on applications running on desktop or mobile phones.This helps in taking immediate action to mitigate risks and enhance safety of the pipeline.
6. Security : LoRaWAN supports end to end encryption for secure data transmission via MQTT or HTTPS protocols.
7. Smooth integration : LoRaWAN can seamlessly be integrated with SCADA, IoT platforms, dashboards and existing systems.

Key Manufacturers

Conclusion: With its scalability, low cost and ability to operate in challenging environments, LoRaWAN based methane monitoring provides gas pipeline operators with an effective tool to improve safety, reduce maintenance costs and meet environmental compliance standards.