Conversation with… Keysight: Challenges and Opportunities in Testing 5G

Estimated reading time: 6 minutes

In an interview with SMT007 Magazine, Roger Nichols, 5G program manager at test and measurement provider Keysight Technologies Inc., discusses the opportunities that 5G will enable, the many challenges facing electronics manufacturers when it comes to 5G, and how they are helping the industry address these issues.

Stephen Las Marias: Please give us a brief overview of 5G. How will this differ from 4G, and what other applications do you think it will enable?

Roger Nichols: The vision for 5G includes the following elements: great service in a crowd, amazingly fast, ubiquitous things communicating, super reliable and real-time communications, and the best service for the user. This was postulated by the Mobile and Wireless Communications Enablers for the Twenty-Twenty Information Society (METIS) program in 2013, and still holds. The best way to interpret the vision is that we will have a network that is not just faster and more real-time, but also one that is highly reliable and can handle business models and applications that today’s network cannot.

The objective is not just super-fast datalink speeds, super high-reliability or low-latency connections—for video-based augmented reality, for example— or the ability to connect the quickly growing number of devices to the network; the objective is to create a network architecture that takes advantage of virtualization. This means a network that is flexible and can be “sliced” into different functionality for different users—regardless of their physical location.

Las Marias: How will 5G impact the electronics assembly industry?

Nichols: The electronics assembly industry has already met an amazing change in demands for speed and circuit density. These demands will continue to increase with miniaturization being driven by the need for portability, reduction in power-consumption, and integration of ever-more diverse functionality. The mobile communications industry adds the needs of portable devices that are water-proof and drop-proof— accommodations that complicate the assembly of these devices and will continue to do so. And fixed infrastructure needs to tolerate weather, temperature change, lightning, and even vandalism.

The electro-mechanical design of these devices means evermore complex and demanding assembly processes. Another key demand that 5G will drive is much heavier use of wireless communications in the transportation and industrial businesses. Costs, regulations, and reliability all mean demands on manufacturing technologies with the relentless pressure on cost.

One other element that 5G will bring into mainstream regards millimeter-wave frequencies, which mean very different electromechanical designs—active antenna array systems, disaggregation of the radio and the antenna (e.g., in automobiles), etc. The assembly industry will be expected to keep up with these new ideas and improve the quality of the process.

Las Marias: From your perspective as a test and measurement systems provider, what electronics manufacturing/assembly challenges do you foresee facing your customers when it comes to 5G?

Nichols: Answering this would make a pretty long list but I can call out one specific example we see often. The advent of millimeter-wave in mainstream electronics means that manufacturers, in some cases, are insisting that these radios be tested in the manufacturing process. But the state of the art is such that these measurements must be made not only within chambers that are shielded, but also anechoic, and, in some cases, temperature-controlled. All these technologies are not new to the industry, but what is new is the aspect of applying them all to a relatively high-volume manufacturing process. This adds the complexity of making an accurate measurement, quickly, over-the-air (no galvanic connections), and moving the device-under-test (DUT) in and out of the chamber in an efficient manner. This also implies a robust repetitive controlled environment with minimal down-time and the flexibility to change the DUT form-factor.

Las Marias: How are you helping your customers address these challenges?

Nichols: We are very excited about the opportunity to flex our muscles as a solutions provider. This means going beyond the electronic measurement. We are working closely with our customers, bringing in our own expertise, even from the teams who design our own manufacturing processes, and partnering with an impressive group of companies to present a comprehensive set of solutions. Sometimes, this has put us out of our comfort zone, but we have learned a lot and been able to present some truly innovative thinking to our customers. This also means empowering these solutions with our PathWave framework to help our customers plan their automated manufacturing test processes, manage the information generated, and even manage the test assets themselves within a common platform.

Las Marias: In our discussions with electronics manufacturers, they say functional testing is one of the critical issues when it comes to electronics assembly of 5G devices/systems. What are your thoughts?

Nichols: The industry must manage both parametric measurements and functional test. I do not see a future in which both are not required. But regarding this functional test need, my comments above relate to one other relentless trend in electronics and that is ever increasing integration. This means that the manufacturing process is presented with subassemblies and assemblies with incredible levels of functionality. Simple tests are no longer a sufficient proxy that the supply-chain and upstream manufacturing process have not caused any problems.

In my example of over-the-air testing in production, it is not difficult to see a scenario of an operational device with an active antenna that would change its characteristics simply by being measured. This means that functional testing becomes a must since they are testing a functional device—a mobile radio system.

Las Marias: What developments in T&M technologies are geared toward addressing the new challenges offered by 5G systems?

Nichols:We must do the obvious like implement measurement capabilities to the new standards, make sure we can test the new frequencies and bandwidths not previously used in mobile communications, and in some cases address performance improvements needed to meet these needs. We also are working on more over-the-air test technologies not just for mmWave but also for

We have always been in the test-via-emulation business in mobile communications, and 5G will be no different. We have recently demonstrated network emulation systems for mobile test that work in the new 5G NR standard and these manage that functional test domain. We also have an array of non-signaling and parametric test solutions available for the process steps that have been streamlined for those needs. We must not forget the high-speed digital domain where our time-domain solutions require more and more functionality to address high-speed data-bus and interconnect specifications. We are adding more and more functional test capability to ensure we can cover these demands as well.

Las Marias: Is there any difference between the manufacturing process/set-up for 5G-enabled devices and that of previous generations?

Nichols: 5G manufacturing is still constrained to building for trials and perhaps the very first phases of early deployment. In these cases, we have already seen some changes from 4G, but I believe that the demands will drive changes much like what 4G did to the manufacturing processes we developed for 3G. It is difficult to predict where these trends will go, but one thing is for sure and that is the mmWave technologies will drive manufacturing test and assembly process innovation move a technology previously in the domain of high-cost aerospace and defense applications. The commercial communications market is a different beast and will make amazing changes to this set of technologies.

To read the full version of this article, which appeared in the May 2018 issue of SMT007 Magazine, click here.