Continuity is about ensuring and extending the battery life of the device. Battery life is one of the most important considerations for IoT devices. Long battery life is a huge competitive advantage in consumer IoT devices. For industrial IoT devices, a battery life of five or ten years is the common expectation. For medical devices, such as pacemakers, device life can mean the difference between life and death. Battery failure is not an option.
To meet this long battery life requirement, the integrated circuit (IC) designers need to design ICs with deep sleep modes that consume very little current, reduce the clock speed and instruction sets, as well as implement low battery voltages. From a wireless communication perspective, standard groups are also defining new low power consumption operating modes such as NB-IoT, LTE-M, LoRa, Sigfox that offer limited active operation time while maintaining low power consumption. Product designers who integrate sensing, processing, control and communication components into the final product, must know how the peripherals behave and consume power, and optimize the product’s firmware and software to simplify operation and reduce power consumption. All these activities require capable measurement tools that can offer deep insights into the device current consumption behaviors.
Compliance is about making sure your IoT devices adhere to the radio standards and global regulatory requirements before gaining market entry. There are two main categories of compliance tests: radio standards conformance and carrier acceptance tests, and regulatory compliance tests such as RF, EMC, and SAR tests. Design engineers often scramble to meet the tight product introduction timeline and ensure smooth global market penetration while complying to the latest regulations. Frequent updates to the regulations also further add to the complexity. Figure 3 shows the examples of conformance and compliance testing requirements.
Figure 3: Conformance and compliance testing requirements of IoT devices.
To reduce the risk of failure during compliance testing and to keep to the product release schedule, designers can consider investing in inhouse pre-compliance test solutions so that testing can be carried out at every stage of design to fix issues early in the design phase. Choosing a pre-compliance test system that is adapted from the compliance test system from the test lab can also help to ensure measurement correlation and reduce risk of failures. Compliance testing is complex and time-consuming. It can take up to days or weeks to complete if performed manually. Choosing an automated test system can help to save test time and allow faster time-to-market.
Coexistence is about the ability of the wireless device to operate reliably in the presence of other interfering signals. With billions of devices released to the market, congestion in the radio channels is a problem that will only get worse each day. To address wireless congestion, standard bodies have developed test methodologies to evaluate device operations in the presence of other signals. For instance, in Bluetooth®, adaptive frequency hopping (AFH) lets a Bluetooth device drop channels that experience high data collisions (figure 4). There are also other collision avoidance techniques such as listen before talk (LBT) and cooperative collision avoidance (CCA) to improve transmission effectiveness. The effectiveness in a mixed signal environment is unknown. When the radio formats don’t detect each other, collisions and data lost will happen.
Figure 4: Bluetooth device bypasses the WiFi channel 6 to avoid interference with the WiFi signal.
For consumer applications, delays or pauses in wireless headsets or wearables are annoying, but acceptable. An industrial sensor that loses the control signal, or an infusion pump that stops working due to surrounding interference signal can have dire consequences. Therefore, it is crucial to perform coexistence testing to measure and assess how your device will operate in a crowded and mixed signal environment. IEEE provides some guidance in ANSI C63.27 (American National Standard for Evaluation of Wireless Coexistence) regarding key considerations for coexistence testing that includes evaluation processes, test setups and risk-based testing tiers. Device manufacturers are highly recommended to assess the potential risk to maintain the device’s functional wireless performance in the presence of unintended signals found in the same operating environment.
With increasing deployment of IoT in mission-critical applications, the need for cybersecurity protection is becoming even more important. While cyberattacks can happen at many layers – from the device level to the communication network, cloud or applications, most of the traditional security protection tools have focused on securing the network and cloud. The endpoint and over-the-air vulnerabilities are frequently overlooked. Formats like Bluetooth and WLAN are matured technologies and are commonly used in many applications. However, little has been done to address the over-the-air vulnerabilities. The complexity of these wireless protocols translates into potential unknown pitfalls in the device radio implementations that allow hackers to access or take control the device.
According to IDC, 70% of security breaches originate from endpoints. Extra care should be taken to safeguard these IoT devices. Over-the-air vulnerabilities and potential point of entries into the IoT devices should be identified. The device should be tested using a database of known over-the-air threats/attacks to monitor the device response and to detect anomalies. The database must be regularly updated to safeguard the device from the latest threats.
Building A Strong Foundation Through the 5Cs of IoT opens doors to exciting new applications and opportunities for many industries. But it also brings unprecedented challenges that require thinking in new ways to meet the mission-critical requirements. Delivering successful IoT implementation requires designers and engineers to overcome the technical challenges in the 5Cs of IoT. Having a deep understanding of these technical challenges and knowing what the key design and test considerations will build a strong foundation for implementation and deployment across the IoT ecosystem. The right design, validation, compliance testing and manufacturing tools throughout the product lifecycle will help to ensure that the IoT delivers on its promises.
The author is Sook Hua Wong, Industry Segment manager general electronics measurement solutions at Keysight Technologies, Inc.
About the author
Sook Hua is an Industry Segment Manager with Keysight Technologies residing in Penang, Malaysia. She is the strategic solution planner responsible for Keysight Internet-of-things (IoT) solution portfolio expansion and marketing program planning to drive growth in the general electronic segment of Keysight Technologies.
Prior to this role, she was the product planner responsible for strategic planning and product portfolio development for the RF/Microwave power meter and sensor.
She received her Bachelor Degree of Electrical Engineering from University of Technologies Malaysia (1999) and Masters of Science Degree in Electronic System Design Engineering from University of Science Malaysia (2003). She has spent 20 years at Keysight Technologies with the last 15 years in the General Electronics Measurement Solution (GEMS) team under various roles, including manufacturing, product development, sales support, product marketing, and a product planner.