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2018

The Internet of Thing (IoT) is changing EVERYTHING. There are literally billions of IoT devices around us today, with hundreds more coming online each second. By 2020, there will be roughly 50 billion connected devices. By 2028, the IoT may become so pervasive that we won’t even need to refer to devices as being part of it anymore. It will just become a given that they are connected and interoperable.

As part of that evolution, the IoT will evolve from a focus on consumer-based applications like smart appliances for the home, connected clothing, and wearable fitness gadgets, to mission-critical applications for virtually every vertical IoT market there is. Mission-critical IoT devices will be used to automate energy distribution in smart grids, to enable remote machinery and remote surgery, and in autonomous vehicles for things like automatic emergency detection and autonomous vehicle accident prevention. It’s happening already.

As these applications proliferate, what will emerge is a mission-critical ecosystem designed and hardened to withstand the rigors of the real world. It will be able to deliver new functionality and new efficiencies, and it will bring with it many new opportunities for IoT designers and manufacturing engineers alike.

Here’s 3 important tips to help you realize success in the mission-critical IoT.

1. Understand your requirements

Unlike consumer-based IoT devices, mission-critical devices must work right every time, without fail. A failure in a pacemaker after all, could result in a patient’s death. That’s why mission-critical IoT devices have specialized requirements dictated by the industry in which they will work. Most require rock-solid security, unfailing reliability—even in harsh environments and remote locations—and the ability to operate with little or no human intervention. They also must abide by any applicable industry or government regulations.

Making sure you fully understand the requirements of the product you are designing is the quickest and easiest way to avoid any costly missteps during its development. It also can help improve your confidence that the product will be utilized as intended in the real world.

2. Don’t overlook these design considerations

                                   

Designing any product is hard. Designing a mission-critical IoT product is even harder! That’s because there are just so many things you have to consider. Here are a couple of the considerations you should not overlook. 

  • Battery Life. Many mission-critical IoT devices are not connected to power and often operate using a single battery for several years without maintenance or battery replacement. To ensure a long battery life, make sure your product’s battery and power management circuit have been optimized.

 

  • Signal and Power Integrity Issues. Interference and crosstalk between each of the product module’s blocks can degrade performance. Ripple, noise and transients riding on your circuit’s low-voltage rails can do the same. Be sure to identify and eliminate these issues.

 

  • EMI/EMC. Electromagnetic interference (EMI) can be problematic in scenarios where large numbers of IoT devices operate simultaneously in close proximity to one other. Be sure to weed out such problems early in the design process when they are easier and cheaper to fix.

 

  • Wireless Connectivity. Mission-critical IoT devices have to perform in the presence of multiple users, with different wireless technologies, in the same spectrum. Verifying that your device can handle this load is critical to ensuring robust wireless connectivity.

 

  • Co-Existence and Interference. With lots of mission-critical IoT devices entering the market, the chance of interference between devices goes up and that can impede the ability of your product to peacefully co-exist with others. This can be especially problematic in hospitals where medical monitoring devices have to share the 2.4-GHz ISM band with the likes of cordless phones, wireless video cameras, and microwave ovens. Making sure your product’s operation can work as anticipated in this type of environment is crucial. 

 

3. Choose your tools wisely

While your creativity and skill are essential to a successful product, if it is not built on a solid foundation, it could all come crumbling down. To ensure your product’s foundation is solid enough to survive the real world, you have to choose the right tools for the right job, and those tools must be accurate, high performance and flexible. There is no universal Swiss Army knife when it comes to designing for the mission-critical IoT.

 

One of the tools you should consider utilizing is battery drain analysis. It can help you accurately determine your device’s current use and the duration of each of its operating modes, which is critical information when trying to optimize battery life. Signal integrity and power integrity tools can be used to evaluate high-speed serial interconnect and analyze how effectively power is converted and delivered from the source to the load within a system. An accurate EMI simulation and modeling tool will allow you to estimate emission levels before your hardware is developed. And, to ensure your product can communicate effectively, wireless connectivity and co-existence testing are essential.

 

There is no denying that the mission-critical IoT is ripe with opportunity and will continue to be so for the foreseeable future. But whether or not you succeed in this arena will depend heavily on the choices you make about your design’s requirements, regarding design considerations, and on which test and measurement tools to use. If you are looking for more information on the choices you face, please go to www.keysight.com/find/IoT. And don’t forget to keep checking the Keysight Community Page for future blogs on other related IoT topics.iotdevicetest iotwireless iotsolutions iottechnology industrialiot iiot internetofthings iot

 

 

I was recently reminded of my over-the-air (OTA) experience with 5G channel sounding.  It was like black magic at the time, and now, as it turns out, is vitally important for the success of 5G. 

 

At Keysight, we realized early on that making measurements at millimeter-wave (mmWave) frequencies would be difficult. What we didn’t realize was that there would be so little information in the standards regarding how to test this far along in the development of 5G. The first 5G New Radio (NR) draft specification was released in December 2017. It documents the 3GPP physical layer, but absent are the specifications for the mmWave test environment. That means the chances of getting lost in your 5G OTA measurements goes up dramatically. And that’s where I want to help.

 

Let’s review some of the things you should know about for 5G OTA measurements.

 

Are OTA tests really required?

 

Here’s a question you are probably asking yourselves right about now: is OTA testing really needed? And here’s my answer: ABSOLUTELY!

 

Current sub 6 GHz RF performance tests are mostly done using cables. That changes when you move to massive MIMO in sub 6 GHz or mmWave frequencies. At mmWave frequencies, beamforming antenna technologies are used to overcome higher path loss and signal propagation issues and to take advantage of spatial selectivity by using narrow signal beams. Phased-array antennas, such as those shown in figure 1, are typically highly integrated devices, with antenna elements bonded directly to ICs, making it difficult, if not impossible, to connect and probe. OTA enables test, but it introduces a more challenging ‘air interface’ between the component or device and the base station wherethe imperfections in the air interface need to be accounted for during test.

 

Example mmWave antenna arrays

Figure 1. Example mmWave antenna arrays

 

You Have To Test OTA, But Now What?

 

Okay, so you need to test OTA, but what kind of tests?   The types of measurements for 5G products vary throughout the development lifecycle and are different for an UE versus a base station.  During design and development, RF parametric tests such as transmitted power, transmit signal quality, and spurious emissions are done for radiated transmitter tests.  Base stations add tests such as occupied bandwidth and adjacent channel leakage ratio (ACLR), to name a few.  Beam-pattern measurements in 2D and 3D and beamsteering or null-steering performance tests are also done during R&D.  Conformance testing is also done to ensure the device meets 3GPP minimum requirements. These can be grouped into RF, demodulation, radio resource management (RRM), and signaling tests. This white paper provides an explanation of these tests: OTA Test for Millimeter-Wave 5G NR Devices and Systems.

 

OTA tests are typically conducted in the radiated near-field or radiated far-field region of the antenna system under test. Measurements in the far-field are conceptually the simplest type of OTA measurement and an approved method identified by 3GPP.  A typical far-field anechoic chamber is shown in figure 2.  With the appropriate probing and test equipment, 2D and 3D beam patterns and RF parametric tests can be performed. The challenge is selecting a reasonable chamber that won’t take up your entire lab space. The length of a far-field chamber is roughly determined by 2D2/λ, where D is the diameter of the device being tested.  With this in mind, a 15-cm device at 28 GHz would therefore require a 4.2-m chamber as shown in figure 3. These chambers will be large and quite expensive.

 

Far-field measurement                                                         Figure 2.  Far-field measurement

 

D (cm)

Frequency (GHz)

Near/far boundary (m)

5

28

0.5

10

28

1.9

15

28

4.2

20

28

7.5

25

28

11.7

30

28

16.8

Figure 3. How far is far-field?

 

An alternative for 5G RF tests that is being used by market leaders and is now being considered by 3GPP is the compact antenna test range (CATR). In Figure 4, a CATR uses a reflector so that it looks like the waveform is coming from a long way away. This seems to be a very promising direction for 5G OTA testing, and 5G market leaders are seeing this as a comprehensive and accurate test method.  However, that’s not the case for RRM test where there is no clear solution because of the many open issues due to the dynamic, multi-signal 3D environment with signal tracking and handovers. 

 

    Figure 4. Compact antenna test range (CATR)

 

If We Could Only Tell the Future

 

Yes, I know life would be a whole lot easier if we knew what to expect, but unfortunately the jury is still out on this one. What I can tell you about OTA is that progress is being made. 

 

There are many really smart PhDs working on solutions, but it’s going to take time to get these testing methods into the standards. In the meantime, I solutions coming from market leaders working directly with test vendors to enable OTA tests of the first 5G devices and basestations. These OTA test solutions are the ones to watch, as they will pave the way for the standards.

 

If you are looking for more information on 5G OTA testing, then I highly recommend watching Malcolm Robertson’s video: Testing 5G: OTA and the Connectorless World or reading the : OTA Test for millimeter-Wave 5G NR Devices and Systems white paper. Looking forward, I’ll keep you posted on important 5G topics and developments in future blogs.