In a previous article, I wrote about 5G networks and their impacts on connectivity in agribusinesses. 5G technology is the next generation of cellular networks. It promises high speed and stability in its networks. However, predictions indicate that its installation and effective operation will still take time, especially in less populated areas, as is the case with most agricultural properties.
Connectivity in farms presents problems because many areas are not yet covered by cellular data networks. In addition, the use of equipment with high battery consumption makes it impossible to install a large number of sensors (both due to the cost and due to the need for constant recharging of energy). The high battery consumption can be compared to the need that we have to recharge our phones almost daily. In the field, devices that require almost daily recharging can derail much of the technology projects.
Thus, although the introduction of 5G networks should generate a considerable impact in relation to the digital transformation of agribusinesses, there are other technologies already underway that aim to improve the conditions for this transition — after all, the digital transformation revolution in the agricultural environment has already begun and is progressing gradually.
Among the technologies that precede or even compete with 5G networks in agricultural digital transformation, we highlight LPWAN (Low Power Wide Area Networks). These networks were created to connect thousands of things (such as sensors and devices) of lower added value to networks of better coverage, lower connection cost and lower battery consumption — thus expanding the range of Internet of Things (IoT) solutions.
The Internet of Things is a network of objects with unique identifiers and computational capacity that collect information from their local context, share it and perform actions without human interaction. In agribusiness, these objects can be sensors that collect information about farming or that are arranged in machines such as tractors, harvesters or irrigators for data collection, operation triggering or even operation tracking.
LPWANs allow these objects and sensors in farms to be connected. In addition, they answer most of the problems of agricultural connectivity, such as low coverage of long distances and excessive battery consumption in the connected equipment. Thus, it allows the development of a simpler and cheaper structure for data collection and exchange of information in farms.
Among the existing LPWAN networks, one of the technologies that has stood out commercially is the LoRa (Long Range) technology with LoRaWAN (LoRa Wide Area Network) protocol. In this article, the focus will be on LoRa technology, one of the most used alternatives when thinking about the Internet of things in general, but that, in agribusiness, has a great variety of uses due to the characteristics of low power consumption and greater range of networks.
What is the meaning of LoRa and LoRaWAN?
LoRa is a type of modulation for data transmission that is part of the physical layer of wireless communication technology. This technology was developed to be used in communications of low data transfer rate, low power consumption and long distances. The company Semtech owns this technology. Semtech supplies the LoRa radio chips, while LoRa Alliance — an association of companies that promotes the development and use of LoRa networks — takes care of the standardization of the LoRaWAN protocol.
LoRaWAN is an open specification of a large area networking protocol that utilizes LoRa technology and offers bi-directional communication between devices, end-to-end encryption support, mobility and location services. Thus, LoRa is the physical layer for information transmission and LoRaWAN is the network protocol to provide interoperability among pieces of equipment.
LoRaWAN architecture is star shaped, that is, the devices integrated into the network are connected directly to the access point, so as to optimize the power consumption in communication and, at the same time, allow the signal to reach long distances. The star topology eliminates the need to implement a complex wireless mesh routing protocol.
Figure 1: design of the LoRa/LoRaWAN architecture
The basic architecture of a LoRaWAN network comprises:
- Modules (or End nodes): sensors, alarms, equipment and monitors that record information. They are devices connected to batteries that are usually located at the edge of the system, that is, where the data is collected;
- Gateways: devices that play the role of intermediaries between modules and network servers. Usually, these are the devices connected to the network;
- Network Server: device that performs LoRaWAN protocol logic;
- Application Server: device on which the logic of the service is implemented according to the information received from the modules.
In a basic architecture, the modules (devices with sensors) send the data to the gateways. The gateways send the information received by the sensors to the network servers and the information received arrives at the application servers, which define what actions are to be taken by the modules.
A LoRa device can offer optimal rates of transmission and power, receiver sensitivity over long distances, low hardware cost and a low rate of inconsistency in the reading of the information transmitted. In IoT applications in farms, these are features that can help deploy rural connectivity. Therefore, sensors (which would normally have no network connectivity) can be placed in several remote locations (urban and rural), with an efficient, secure data transmission and the ability to offer Internet connectivity to devices through gateways.
That is, LoRa technology is quite suitable to help data reach considerable distances in extensive areas, consuming little power for transmission. However, in cases where the volume of information transmitted is critical to the application, LoRa may not be the best option.
LoRa transmission rates range from 0.3 kbps to 50 kbps— typically, these rates would only be used to send text messages. Voice, video, and other types of information would need a higher data rate. The low transmission rates, on the other hand, maximize the battery life of the end devices (avoiding the need for recharges) and overall network capacity.
Therefore, LoRa modulation combines two important demands for digital transformation in Agribusiness: low power consumption for long periods of operation with batteries and large range extension for remote sensors that do not need to transfer large volumes of data.
Advantages of LoRa networks
LoRa networks have some advantages over the use of 4G networks of mobile operators, without any adaptations:
- Long range. In open fields, LoRa’s range go from 2 Km to 50 Km;
- Low power consumption on devices powered by small batteries. This makes a big difference in the price and technology needed at the end-point of the structure. The low energy consumption is very important, since the maintenance of several devices in the field, where there is a need for recharging or changing batteries, could impair several projects;
- Easy installation. Devices are usually small and can be powered with small batteries;
- Low cost of deployment. A base station (gateway) can receive the signal from hundreds of devices, with wide coverage.
The advantages described above, in several cases (but mainly in the agricultural environment), expand the possibility of connectivity in farms. There are some disadvantages, however, such as the low data transmission rate, despite the longer distances possible with LoRa.
Uses of LoRa in Agribusiness
In terms of agricultural processes and integration with the Internet of Things, connectivity in farms is still one of the big bottlenecks for effective technological revolution in agriculture and livestock and, within this concept, LoRa is a great alternative for connectivity.
Several types of sensors that can be used in the crops, in greenhouses or to track agricultural equipment. All these sensors — such as meters for soil and air humidity, temperature, pH and solar irradiation and anemometers — do not need to send large volumes of information instantly.
Therefore, LoRa networks are a great alternative to help bring digital technology to farms, assisting in data-based decision-making processes, production loss reduction and increasing productivity.
For example, some humidity sensors could be placed in the crops, in places that would normally have no data connection. These sensors (the modules, in the architecture) use LoRa technology to send information to network gateways. These gateways communicate with the network and pass the information obtained by the sensors to the network servers. The servers route the information to the application servers, which define what will be done with the data received from the sensors.
All processing is done on the application servers. With this information, the application servers can send signals that pass through the LoRa network in reverse until they reach a module whose function is irrigation. This signal activates the module that performs irrigation according to the needs extracted from the data.
In terms of the use of LoRa in agriculture, we see that the technology allows add many uses for digitization of farms to be added. Some examples:
- Data acquisition
The data collected in the crops — such as soil and air humidity, temperature, pH, solar irradiation and GPS coordinates — allow a quantitative analysis of environmental variables and for a historical data series to be built. Thus, the processing of raw data allows identification of patterns and bottlenecks to assist in decision-making in agricultural processes.
- Machine communication
LoRa allows communication between machines in the field, for tracking and location. This way, it would be possible to monitor the performance of the operation with telemetry information, such as engine temperature values, speed, running hours and GPS coordinates at the time the information was sent.
- Worker communication
Another possibility is communication between workers within the property, without using mobile operators’ networks. For simple communication, LoRa can be a very interesting option, as it can act over long distances independently of operators. This example was explored in a study conducted by Venturus, described below.
A LoRa study
Venturus Innovation Group executed a project for learning about LoRa equipment performance. One of Venturus’ customers requested an analysis of employee communication within a LoRa network in order to verify the efficiency of this communication in a simulated field environment.
The project was successful in exchanging messages, but one of the main problems was the handling of unconfirmed messages on receipt. As the technology itself already indicates, the messages reached long distances, with the restriction that the throughput was not the highest. That is, LoRa technology is quite suitable to help data reach considerable distances in large areas, consuming little power for transmission.
While 5G networks are not available in farms, LoRa technology is a good alternative, as it has lower implementation cost for coverage of large areas, since there is no need for licensing the operating band. It is also great for operating on devices that use batteries, due to the low power consumption to transmit information. Another important factor is the low complexity of edge devices, so as to allow the development of a simpler and cheaper structure for data collection and automation in the crops.
LoRa technology allows many projects to be developed in farms, where the amount of data to be transmitted by the sensors at the edges of the structure is not very large. This means that, in cases where videos, heavy images and other information need to be transmitted to the application server, LoRa may not be a solution yet. However, in cases where more succinct information (texts and meter data, among other types of information) will be sent, LoRa networks can be implemented with great performance.
Venturus operates with digital transformation projects at its core and also has agribusiness as one of its business focuses. LoRa networks are one of the good alternatives to bring connection to farms and it is also one of the alternatives in which Venturus acts, monitors and deploys technology in its projects focused on agribusinesses. Venturus follows the evolution of 5G networks, but also follows and participates in the evolution of connection technologies already available in agribusiness.
** This article was written by four hands, with the great help of Ventureiro Igor Livio Figueiredo Moreira. Igor Livio and João Durante led the proof of concept of LoRa communication project and with the knowledge brought together in the execution of this innovation project.