IoT Testing: Key Aspects Engineers Need to Know
What you'll learn:
- IoT test challenges.
- What’s the difference between development and production testing?
- What features, functions, or performance should developers look for in IoT test equipment?
- How do setup time and the ability to handle multiple IoT devices at once impact testing?
The cloud and IoT involve multiple communication technologies, including cellular (LTE, 5G) and short-range wireless (WLAN, Bluetooth), as well as other technologies like satellite non-terrestrial networks (NTNs) and LoRaWAN. Naturally, IoT devices must support these communication protocols to provide a range of services.
A significant challenge in IoT testing is to test various aspects of each communication technology. In addition, there’s the challenge of testing across multiple communications protocol layers in IoT devices.
IoT Test Challenges
Where testing the physical layer ensures trouble-free connectivity, application-layer testing is important for identifying issues related to user experience or the correct functionality of services offered by an IoT device. Security has also become a priority, with concerns surrounding Cyber Resilience Act (CRA) legislation in Europe and post-quantum cryptography.
Developers may think IoT technologies are already mature enough and designed for trouble-free connectivity and communication. Despite this being true for individual components, each IoT device features a unique design of components that naturally interact with, and may also interfere with, one another. Unless an IoT device is properly tested, you never know how the design of its components works, regardless of the technology's maturity.
Another misconception among developers is that testing will be complicated, complex, and expensive. This isn’t true, as a number of test and measurement systems provide easy, effective, and cost-balanced solutions. Ultimately, these solutions save a significant cost in the IoT device design process.
A good IoT test strategy entails implementing concrete testing and measurements in each phase of the IoT device design and development cycle. Developing an IoT device without conducting any testing and measurements during the development cycle may result in costly consequences. This could involve a device that doesn’t work as expected or one that provides partial or no services to the end-user.
What’s the Difference Between Development and Production Testing?
The key difference between the two is in the speed of measurements. Testing during the development phase typically requires full simulation of the network and involves a protocol stack for signaling. This needs time to establish a communication link for measurement.
Conversely, production-line testing requires fast and accurate measurement. It doesn’t entail protocol stack and signaling to establish an active communication link between the IoT device and the test instrument. The production-line test operates purely in non-signaling mode. Here, the device either transmits a specific waveform signal and the test instrument measures it, or the test instrument transmits a particular waveform signal, and the IoT device measures the received signal.
IoT test equipment can be categorized as cellular test equipment supporting cellular technologies, such as 5G, 4G, 3G, and 2G, and short-range wireless equipment supporting technologies like Wi-Fi and Bluetooth. Such equipment typically serves as a network or device simulator to get the IoT device under test to the correct measurement state using protocol stack signaling. Measurements can then be carried out on the device. This naturally requires the setting of various parameters, thus adding complexity to the measurement.
On the other hand, measurements are carried out under real-life conditions, ensuring that the IoT device will also work correctly in commercial deployment and use. Another type of test equipment focuses on non-signaling testing, where only the physical layer is tested without engaging the higher protocol or application layers. Such measurements require less complex parametrization and are fast.
However, they only measure a limited part of the entire IoT device. Consequently, this can result in a negative surprise regarding performance and operation once the IoT device is commercially deployed and in use.
What Features, Functions, or Performance Should Developers Look for in IoT Test Equipment?
IoT test equipment should offer multiple measurement types, including RF and/or application-specific measurements. Test equipment should also provide high accuracy and quality in signal generation and analysis to accurately measure IoT device performance. Easy parametrization and intuitive operation are important factors in test equipment, too.
IoT test equipment, with its comprehensive simulation and measurement capabilities, provides developers with complete control over the test environment. This ensures the verification and measurement of expected behavior and performance throughout the whole development cycle. As a result, delays aren’t caused by redesigning or fixing design faults.
Pre-compliance testing, done in-house before proceeding to full certification testing, saves time and money, allowing for faster deployment and commercial launch of the IoT device to market.
How Do Setup Time and the Ability to Handle Multiple IoT Devices at Once Impact Testing?
Setup time is important in production-line testing, where the speed of measurement is crucial. Capacity is also essential due to the high volume of devices to be manufactured. Allowing for parallel testing of multiple devices simultaneously will naturally increase the capacity and, therefore, boost the overall volume of the production line.
For example, Anritsu offers a multi-technology, high-volume production-line test system that enables parallel testing of multiple devices with high accuracy. The company also offers other test and measurement systems for cellular and short-range wireless IoT devices, used in prototyping, design, and development, with functions that enable easy and fast setup, as well as precise and complex measurements.
Technology itself, whether cellular or short-range wireless, brings a certain level of complexity in parametrization and measurement environment setup. Therefore, having test equipment that enables a smooth, easy, intuitive, and stable measurement setup to bridge the complexity of technology with understandable and clear results is of utmost importance.