What it means for IoT-based wireless communication
Barcelona, January 2020
The rising adoption of Industrial Internet of Things (IIoT) technologies has intensified the need to better understand how IoT systems work, what options are available in the market, and what makes them different in terms of performance. When using IoT technology to monitor the risks of critical assets or infrastructures, all these elements help to ensure reliable operations. The network technology LoRa, in particular, is often referred to as the most common industrial solution to connect wireless sensors and transmit data.
In this article, Albert Zaragoza, CTO at global IoT leader Worldsensing, discusses connectivity options and provides details of how to make network systems more understandable.
Albert Zaragoza, Worldsensing’s CTO
Q: More industrial sectors are adopting IoT technologies to improve their risk management programs, optimize their operations and reduce costs. From a technical point of view, what are the current challenges for IoT?
IoT has been widely adopted by many sectors and companies, but we can’t forget that the ecosystem is still young. Many IoT technology providers are quite new to the challenges that building hardware, communications and software bring to the table.
Interoperability, that is the ability to exchange and make use of information, between all nodes and sensors from different vendors is a clear challenge. We are still far from having different platforms, data structures and interfaces exchanging data effectively in order to benefit end users.
Security is another challenge that should not only worry the IoT ecosystem, but every company worldwide. Encryption mechanisms should be adopted to guarantee data integrity, and end users should have full control over who can see and operate their data.
On top of that, IoT data travels over wireless transmission networks and a clear challenge is to assure a large number of sensor devices can transmit data without causing any data loss due to network congestion, interference or external phishing.
Most certainly, challenging but exciting times are ahead of us in the IoT space.
Worldsensing and LoRa Alliance booths during the Smart City Expo World Congress in November 2019
Q: In order to wirelessly connect battery-operated ‘things’ to the internet in regional, national or global networks, a radio communication system is needed. Is there a variety of systems or networks for that? Could you explain?
Understanding the problem we are trying to solve or the use-case requirements is key to selecting the right technology for the job. There are many wireless communication technologies out there but we can divide them in three groups:
- Short range,
- Long range.
Short range include technologies such as Bluetooth, NFC/RFID or Zigbee, amongst many others, but they are definitely not adapted to scenarios that require communications over long distances.
Cellular technologies [2G, 3G, 4G etc.] can provide larger coverage, but they also consume lots of device energy and are not ideal for use with low-power devices.
The above-mentioned features and the needs of many IoT industrial use cases have stimulated the development of a new wave of wireless communication technologies known as low-power wide-area network or LPWAN. Examples of LPWAN implementations are narrowband IoT (NB-IoT), Sigfox or LoRa, to name a few. They are ideal for industrial environments and gaining popularity due to their long-range, low-power and low-cost communication features.
Q: So, according to this, LoRa is one of the available protocols for LPWAN communications. Why has Worldsensing decided to use LoRa and not one of the other networks you mentioned?
Our clients need to monitor operations which demand wide communication coverage and excellent connection availability at the same time. In order to guarantee this, we need to consider four important factors, the first being the amount of data that can be transmitted. Data volume has a direct impact on the energy consumption of the sensor devices, which are battery powered and need to last for years. Range, meaning the distance over which the data travels, also affects battery life. Lastly, ease of deployment is paramount when working in industrial environments.
LoRa technology gives us the right balance between all these elements, in particular:
- Coverage: it guarantees a long transmission distance, with a proven range of up to 15 km or 9 miles.
- Low-power consumption: battery life is up to 10 years.
- Cost efficiency: especially in long term monitoring, LoRa technology can be more cost efficient than traditional solutions, by reducing manpower.
- Scalability: adding and/or replacing nodes to the network as the project evolves is easy and transparent to the operator, whilst maintaining data integrity.
- Reliability: it is proven to be robust and has strong protection against interference.
- Security: data protection and privacy are achieved through 128 AES encryption on multiple levels for all data being sent from the sensors to the application server and back.
On top of that, LoRa is a physical-layer technology that modulates signals in the sub-GHz Industrial, Scientific, and Medical frequency bands. It allows us to create and deploy private networks at our customers’ locations, without restriction. This is a big plus compared to Sigfox and Narrowband Internet of Things, which are controlled by network operators.
Having the LoRa Alliance certification and compliance program, which guarantees interoperability of all LoRaWAN® products and technologies, is also great for the ecosystem. This community is becoming the largest and fastest-growing alliance in the technology sector. It is constantly working on improving LoRa technology capabilities: we were recently amazed when it broke a distance world record in data transmission.
All in all with LoRa we can ensure availability and improve data accuracy, which is very important to us in order to serve our clients and partners effectively.
Q: Are there any other elements that can significantly impact the performance and quality of data transmission?
When talking about how different components and devices communicate wirelessly within an IoT network, defining and selecting the right topology strategy is key. Topologies differ greatly in how they provide features for security, power consumption, cost, and complexity, therefore choosing the right one is essential to avoiding problems further down the line.
When architecting a wireless IoT networking solution, there are two main topologies that can be used: star and mesh. A star topology organizes devices around the central controller, also known as gateway. On the other hand, a mesh topology connects each device to another device with a point-to-point link.
Diagrams showing network topologies: star (left) and mesh (right)
We can list the following advantages and disadvantages for each topology when applied to wireless IoT networking scenarios.
- Manages high amounts of traffic. Multiple devices can transmit data simultaneously.
- A failure of one device does not cause a break in the network or transmission of data. Needs to have self-healing mechanisms in the network to be implemented.
Mesh Topology – Disadvantages:
- Very expensive to install. Especially for long-distance scenarios, the amount of required repeaters increases rapidly.
- Complicated network setup and management, due to the high number of connections.
- High power consumption. Despite low transmit power, nodes must be awake and listening to every message that needs to be relayed.
- Vulnerability to security attacks. A breach in one of the nodes puts the whole network in jeopardy.
Star Topology – Advantages:
- Installation costs and effort are controlled due to reduced complexity to set up the network. Hub is installed in a central point and the nodes are added as needed during the lifetime of the project.
- Network can be easily extended. New nodes are connected directly to the hub without having an impact on the rest of the network.
- Lower battery consumption of the nodes. It can be better controlled as it is easily calculated based on the amount of communication to the hub.
- Resilience. Malfunctioning of a single node does not affect the rest of the network.
Star Topology – Disadvantages:
- For smaller networks, the cost of the hub can represent a large investment.
- Single point of failure. Malfunctioning of the hub brings the whole network down. Choosing an expert partner with robust proven solutions and reliable monitoring mechanisms is crucial.
Q: Are there specific applications or sectors where using LoRa is more suitable or can translate into a significant benefit?
Generally, LoRa is a great fit for complex projects which present very specific monitoring challenges, like open-pit mining operations that commonly cover large areas or big construction projects.
In tunnelling and construction projects where the monitoring points are usually spread over several kilometers, operators need data to be transmitted over long distances by devices which need very little power and are not dependent on signal coverage. This is actually a requirement of the geotechnical market in general. We have to keep in mind that for tunnelling construction, in particular, the dimension of each project usually covers more than 3 km or 1.9 miles, and the distance between monitoring points can also be significant (more than 100 m or 110 yards).
Obviously, this is also valid for monitoring critical infrastructures and assets where no disruption of the service is possible because of the impact this would mean. These assets rely on data transmission to manage operations that need performance without interruption.
LoRa will be a benefit wherever a reliable real-time monitoring program is needed to ensure the integrity of any structure, like bridges, dams, buildings or other infrastructure.
Also, LoRa offers the possibility of deploying private networks, enabling the user to have control and be independent of large network operators. For projects where this is a requirement, LoRa is the most suitable option.
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