The 6 most important features of an IoT gateway
By Daniel Perciante
Although nowadays it is very common to find sensors and actuators with integrated interfaces that allow us to connect them directly to a local or wide area network, there are still many devices that lack that capability.
If someone wants or needs to use those sensors or actuators as part of an IoT system, a gateway must be used. Thus, an IoT gateway is a device that has the primary function of connecting isolated sensors or actuators to the cloud.
In the following, I describe the 6 features that I think are the most important for an IoT gateway when it comes to implementing robust solutions.
1 – Standard interfaces to connect isolated sensors or actuators
It is usual to find devices that use standard interfaces to connect them to PLCs or simple dataloggers.
Sensors with analog outputs (0 to 10V or 4mA to 20mA) or devices that use Modbus protocol over an RS485 bus are standard in industrial applications. Similarly, serial protocols like SDI-12 are also common in environmental and agricultural applications. These are just some examples.
Those devices will be in the market for a long time. Therefore, IoT gateway designers cannot ignore it and must include standard analog or digital interfaces that allow their gateways to use those sensors and substitute the PLC or datalogger.
This way, the collected data flows directly to the cloud instead of being stored locally until someone goes to the remote location and downloads the data to a hard drive.
2 – Local datalogging capability
Even if the gateway collects data from sensors through standard interfaces and data goes to the cloud, datalogging is still necessary.
There are many monitoring applications that must run continuously. In the event of a network failure, sensors should still be sampled, and the collected information must be stored locally until the network service is normalized again so that the data is uploaded automatically to the cloud.
3 – IoT standard protocols for compatibility with cloud platforms
There are many IoT platforms and tools in the market. No matter which platform is used, the IoT gateway should be able to exchange information with the selected platform with little to no personalization.
This is only possible if standard protocols and data formats are used. The use of MQTT, CoAP, REST, and other standard protocols over IPv4 or IPv6, using JSON payloads, ensures compatibility with almost every platform in the market.
4 – Edge computing
Many IoT applications require some kind of control on the monitored infrastructure that ranges from turning some device on or off, to implementing more complicated algorithms to define what to do in different situations. In any case, some amount of real-time processing of the collected data is necessary.
When the gateway is just a bridge between field sensors and the cloud, that logic must be executed on a central server. Although in a controlled environment that works perfectly, in real situations this is not a robust solution since it may fail when the network has a problem or simply the latency is too high.
To solve this kind of problem, the remote data collectors should have some kind of programing capability to allow them to implement complex solutions with sensors and actuators controlled locally, whenever it is necessary, but connected and controlled by a central system when the network works properly.
Thus, the ideal gateway must be flexible enough to allow the IoT solution designer to select the most adequate combination of centralized and decentralized processing for each problem.
5 – Over the network firmware updates
While sometimes undervalued, this feature is one of the most important ones when the gateway is to be used in a massive deployment.
Imagine you have hundreds or thousands of distributed devices that are part of your IoT system, and one day you want to add a new feature or correct a bug. Clearly, the firmware update must be automated.
6 – Security
Finally, but not least important, the security of the complete IoT system is one of the most important issues to take care of. The privacy of the collected data and information is crucial for anyone who will implement an IoT solution.
The gateway must use encrypted protocols in all the connections to the cloud. This will protect the integrity of the data uploaded as well as avoid malicious persons taking control of the remote infrastructure.
About the author: Daniel Perciante
Researcher, Engineer and Entrepreneur.
Daniel is one of the founders of Nettra. Today he is Co-CEO and Commercial Director of the company. He is an electrical engineer with a doctorate in Engineering from the University of the Republic as well as a level II researcher of the National System of Researchers.
He has a particular interest in applied research for the generation of value and works actively to generate and deepen links between academia and industry in Uruguay. From Nettra he has participated in numerous technological research and development projects related to IoT and its applications.