In today's world of communications, Long Range (LoRa) technology has assumed a significant role by providing strong, long-distance connections. The way LoRa sends signals and its impressive range make it an ideal option for many direct and indirect network paths.
This article explores how LoRa works in two situations: when devices can see each other (line of sight or LOS) and when they can't (no line of sight or NLOS). We will look at node-to-node and node-to-gateway configurations, discussing the benefits, challenges, and real-world uses.
In LOS, where devices are in an open environment, LoRa works well. It can cover large distances with few challenges, which makes it a good solution for monitoring systems. However, despite obstacles like buildings or trees (NLOS), LoRa can still work well, managing most reflections and interruptions. This makes it useful for cities and indoor settings.
In both scenarios, there are pros and cons. LOS provides decent range and less interference, but a clear path is needed. NLOS works even when things are getting in the way, but the range will likely be shorter. It all depends on what is needed, whether it is tracking assets or controlling irrigation systems.
As technology advances, LoRa continues to be a trusted player in wireless communication.
LOS vs NLOS LoRa communication.
LOS Communication
In line-of-sight (LOS) communication, LoRa stands out. LOS refers to a direct and unobstructed path between transmitting and receiving devices. LoRa's use of Chirp Spread Spectrum (CSS) modulation allows it to maintain reliable links over extended distances.
When there is direct visibility, the signal experiences little to no disturbance, allowing LoRa devices to achieve the specified maximum range. This makes LoRa an excellent option for tasks such as remote data collection, industrial monitoring and precision agriculture.
Consider a real-life scenario where a farm uses LoRa devices to monitor the health of its cows. Each cow wears a health device that communicates essential information to the farmer's home. In this LOS configuration, when there are no barriers, LoRa signals can cover a wide communication area as there are no barriers blocking the signals. This application showcases the strength of LoRa in LOS conditions, ensuring seamless and efficient data exchange between remote locations and the farmer's home.
Advantages of LOS communication
1. LoRa devices work well when there is a clear line of sight (LOS), featuring peak range capabilities and continuous long-distance communication.
2. Obstacle-free paths reduce signal issues, making LoRa more reliable.
3. LoRa network planning and configuration becomes easier in clear visibility situations due to predictable signal propagation. These qualities strengthen signal quality and data reliability and open doors to diverse uses. From IoT connections to remote monitoring, they change industries and connection options.
Challenges of LOS communication
While direct communication (LOS) has advantages, it also deals with terrain and structural challenges. Obstacles such as hills, buildings and structures can impede direct transmission, limiting its range. Real-world limitations may also restrict its use depending on the environment.
Such challenges highlight the need for flexible plans and new ideas, such as relay stations or smart adjustments, to reduce LOS limitations and ensure stable connections. Adopting these improvements would expand LoRa's usefulness in obstructive environments, making it useful in diverse applications such as urban planning, industrial automation, and remote monitoring.
NLOS Communication
Non-line-of-sight (NLOS) communication occurs when buildings, factories, and changes in terrain block wireless signals. LoRa's endurance and power-saving qualities shine in NLOS situations.
For example, its way of sending signals can handle signal jumps (multipath fading), ensuring a stable connection even when direct vision is blocked. LoRa's ability to overcome these issues makes it a reliable option for many uses – including smart cities and environmental monitoring – where stable, long-distance communication is critical. It also improves the connection for Internet of Things (IoT) devices.
LoRa NLOS communication in a city.
The image above shows a real example of non-direct line of sight (NLOS) communication. In an urban city, data from each household's electric meters is transmitted to the nearest gateway. The challenge lies in the tall buildings that obstruct the direct paths between the smaller houses and the gates.
However, with LoRa-powered sensors, electricity meters can overcome barriers. LoRa's strength typically overcomes signal hopping, essentially allowing messages to bypass obstacles, making it a strong communications solution.
Advantages of NLOS communication
LoRa's strength against signal hopping and dropouts makes it a decent option for NLOS communication. Its adaptability improves urban and indoor use, while NLOS capability assists in flexible and cost-effective network planning – potentially reducing infrastructure costs in challenging areas.
Challenges of NLOS communication
LoRa does well at staying connected in NLOS situations, but the distance it can cover may not be as great as when there are no obstacles. Objects can weaken its signal and effectiveness. Despite its limited range, LoRa is still one of the best options for flexible and reliable communication in most environments.
LOS x NLOS
The choice between LOS and NLOS communication depends on the specific application and surrounding obstacles. For example, in agricultural environments, where crops or terrain may obstruct line of sight, NLOS LoRa communication can enable precision irrigation and monitoring. On the other hand, LOS communication may be preferred for long-range asset tracking in rural areas with open landscapes.
A practical understanding
In the next LoRa article, we will explore uses of the LoRa E5 Mini-Board for testing distances and solving real-world problems. In LOS scenarios, the LoRa end node and gateway have an impressive range of about 3 km. In NLOS conditions, this range decreases slightly to about 1.3 km, highlighting the adaptability of LoRa.
The paper explores node-to-node communication using LoRa E5. At LOS, the range covers approximately 2 km. In NLOS conditions, the range is approximately 800 meters.
These findings highlight how NLOS affects communication between devices in a detailed way.
Lora E5 mini cards
NOS from node to node.
Conclusion
LoRa communication works well in both line-of-sight and non-line-of-sight scenarios, offering decent range, resilience, and power efficiency. Although LOS communication is better for longer distances with fewer interruptions, NLOS communication can work reliably in cities and regions with obstacles.
Knowing how LoRa works in these environments can support smart planning decisions when configuring LoRa networks. As LoRa improves, its ability to work across different locations makes it an essential part of wireless communication.
