The application of Internet of Things (IoT) sensors on a farm, with devices that measure soil moisture, can save on irrigation and bring a significant efficiency gain for agribusiness. But the implementation is not free of challenges, such as ensuring connectivity in the area so that data reaches the producer. One of the alternatives for rural connectivity, LoRa networks can be used in applications that require little data traffic. Although it does not benefit all cases, LoRa technology is inexpensive and meets the demand for IoT sensors that are spread over a large area - the network coverage reaches more than a radius of 18 km - and which require energy efficiency. Because it uses a deep sleep concept, which triggers hibernation when the device is not used, its batteries can last up to 10 years in the field. However, the used bandwidth is low, allowing small data packets traffic only. “As the farm is an area that does not have a high demographic volume, telco operators are not very interested in bringing connectivity. Then, some technologies began to emerge whose main focus is low cost and low energy consumption. There comes the LoRa network, which is a very low-cost and low energy consumption alternative. It only has to make the information arrive at the headquarters or at a central point, from then on there are a series of technologies that are put in place by the telecommunications operators”, explains the CEO and President of Go2neXt, Paulo Pichini. LoRa technology also has the advantage of working integrated with other technologies. “The future is heading for several networks working together. This joint use of various connectivity technologies is the path to the internet of things. You need several networks working together so that one can complement the other and serve a bit of backup”, comments the Executive Manager of Venturus, Marcelo Abreu. One of LoRa's applications is monitoring animals on farms. According to Pichini, connected sensors using this technology can be used to assist in the management of livestock and swine. “The sensor placed on the cattle has some characteristics, it stores the geographical position with a deviation of up to 5 meters, it also informs the animal’s temperature, and determines if the cattle are standing or walking. With that information, the dashboard at the headquarters allows the farmer to know if the cattle have been idle for a long time if their temperature is high. Considering that a sick ox can contaminate all the others, it is possible to act and remove the sick animal from the place”, explains Pichini. The safety of the animals themselves can be reinforced with the use of tags connected via LoRa, as indicated by Abreu: “imagine a farm with thousands of cattle. When connecting the herd, it is possible to know where the oxen are at all times. There are still a lot of cattle theft problems and the LoRa network can help with that part of security”. For pigs, it is also possible to predict diseases with the help of sensors. According to Pichini, tags allow the identification of diseases based on the pigs' grunt up to 5 days before what would be possible without this technology. Thus, the animal is removed from the site preventing others from being contaminated and having to be slaughtered. “The efficiency gain depends on the application, the farm’s profile, and how much technology is being implemented. In the case of pigs, it is estimated a 40% to 50% reduction in pig loss because the animals are divided into plots with 50 to 100 individuals. If a sick pig is removed, we can avoid contamination that would make it impossible to use almost 100% of the land. These sensors catch more than 50% of the cases 4 days before, which prevents contamination of all animals”, analyzes Pichini, who adds that, in the case of monitoring livestock, efficiency gains of 70% and 60% are estimated. In addition to using in the herd, soil and climate analysis can also be performed using LoRa connected sensors. “In Brazil, we see solutions for climatic seasons gaining strength. We have a tropical climate and the incidence of rainfall has to be very well controlled. We watch this movement of climatic or meteorological stations with great strength”, says Gustavo Zarife, director of technology of the Brazilian Association of Internet of Things (ABINC). This use of LoRa networks allows everything from sending information about the rainfall index of a field to controlling pH and soil humidity. The data is important to assist in farmer's choices and also to allow for corrections during production, in order to avoid crop losses. From the moment the data is transmitted using LoRa technology, it is possible to automate some functions in the field, such as determining that irrigation should be activated whenever the soil humidity is low. “It is possible to place moisture meters on the soil and leave the readers scattered around the field. So it is interesting that the LoRa network is low cost and does not consume a lot of battery. The sensors connected using this technology can be programmed to send data over a certain period of time so that the farm manager can make better decisions. The possibility of collecting data in real-time helps a lot in precision agriculture ”, says the Head of Agribusiness at Venturus, Roberto Okumura. Aerial image of pivot irrigation Grain silos solutions can also be connected via LoRa. Zarife points out that there are sensors capable of measuring the production of toxic gases and the capacity of the silo. “Often, farmworkers have to climb to the top of the silo to observe an element. At the moment the grains are stored there, there may be a risk of toxic gas accumulation, which can cause the employee to faint and result in a work accident”, he explains. Large manufacturers of agricultural machines, such as tractors and harvesters, are already shipping sensors inside their equipment. The problem remains on the connection so that the data can be properly sent to headquarters. This issue can also be resolved with the use of LoRa networks. Through these sensors, it is possible not only to analyze the position of the machines but also to diagnose the need for maintenance. “Many farms are so big that the tractor will do its job in a distant area and will not be back for months. So, it is important to be able to download the information generated by these machines’ sensors at some point. In an ideal world, this tractor would be online, but a good option is to make the equipment go through the farm’s backbone, which has connectivity to download the information. This is an important application and LoRa is a strong candidate to be the carrier of information”, explains Pichini. Solutions based on the LoRaWAN protocol are also applied to monitoring forest growth, especially in the cultivation of wood for commercial purposes. This application allows you to know what is the size of a tree and if the growth is in line with what is expected. Communication within rural properties can be optimized with LoRa networks, which are very effective when sending text-based information. Pichini points out that, due to the lack of connectivity, many farm employees either do not communicate or use a satellite phone, which is very expensive. Venturus created a prototype to test the use of a LoRa network for field communication. The test aimed to connect two devices through this network in order to exchange messages. The model was successful in sending text-based information, and the messages managed to reach long distances that were not previously connected, but it did not work for routing audio, for instance. “It is possible to transmit data over long distances using little power, but you have to transmit little information. Depending on what needs connectivity, if you need to move machines and other things that do not need to send a large volume of data for a long time, LoRa is able to fill the needs”, explains Abreu. Safety LoRa networks are an option for a number of IoT applications in the field, but you need to ensure that the data sent using this technology is safe and reliable. The good news is that LoRaWAN is a technology with native encryption, so the message that travels through this network has security linked to cryptographic keys. “As long as the sensor is working correctly, there is a level of security for the sensor to send a message, go through the cloud and reach the application. Today, the security of LoRaWAN is high and it is still possible to include elements in the device to provide an additional layer of security”, says Zarife. The LoRa Alliance®, a global association of companies that support the open LoRaWAN standard for low-power long-distance networks (LPWANs), points out that the connectivity standard is designed to be very secure, with authentication and encryption as mandatory items. However, as a warning, these networks and devices could be compromised if security keys are not kept secure, or if they are not random across devices, or if cryptographic numbers used once (nonces) are reused. The association claims one should look for LoRaWAN CertifiedCM devices to ensure that the device has been tested against the standard and works as expected. According to the LoRa Alliance®, the inherent security of the LoRaWAN protocol needs to be accompanied by secure implementation and the secure establishment of devices and/or networks to maintain the protocol's native security mechanisms. It is important to use certified devices and work with trusted providers. It is also necessary to differentiate the needs of each type of network: private or national. Zarife explains that the end-user of national networks, such as ATC LoRaWAN, in Brazil, does not have to worry about monitoring the infrastructure since the contract provides for service level agreements that need to be maintained. "There are companies that take care of this operation", he points out. In a private network model, it is up to the customer who sets up the infrastructure to be concerned with issues such as the gateway installation, determining the backhaul technology, feeding the energy infrastructure, and performing the gateway’s operation and maintenance. According to Zarife, private network solutions allow the definition of parameters and alerts to monitor the gateway. “There is a challenge to create and operate a private network. For an isolated gateway in a restricted area, I have no problem with setting up a private network, but when we start thinking about very large applications, it may be interesting to choose a network operated by a third party, if the area is covered by a national network”, indicates Zarife. There are also models that allow the association of both networks and even sharing of networks between neighboring farmers. Pichini calculates that the LoRa network is responsible for only 30% of the data reliability, the rest is related to the quality of the information generated by the sensor. “The LoRa has a set of reliable mechanisms that if the sensor information is lost along the way, a signal is returned so that the information can be sent again. Thus, the data when it arrives is reliable. If it is not reliable, it could be an application problem, in the way it is capturing information”, he ponders. Monitoring the sensors is a challenge in the field, where these tags are applied over large areas. Okumura indicates the application of Artificial Intelligence at the gateway to analyze whether the information is being received at the right time. “Even without artificial intelligence, this will be read by someone who knows the field, that person can see if something is going wrong or not. From there, maintenance or diagnosis can be done to find out what causes the errors in the signal”, he explains. The network is responsible for ensuring transmission stability. According to Pichini, the network is reliable both in terms of battery and connection. In the installation of a LoRa infrastructure, stability tests are carried out and the connection should only be dropped in the event of a power failure or in very aggressive bad weather. "The chance of the connection dropping is very small, much less than Wi-Fi, for example", he compares. The security policies of LoRa networks must be applied at two points: in the security of the network, which is a guarantee that the connection is stable; and data protection. For this, the network architecture must be designed considering the place’s weather, after all, it is wireless technology. In addition, the application that will use the data must also follow security protocols, with a firewall, and be able to detect malware and hackers. “LoRa will integrate with this environment. The technology does not have a firewall but uses the firewall that already exists. LoRa does not propose to do information security but to make a secure transmission”, summarizes Pichini.