Test and Measurement: NIST researchers develop new model for configuring shared spectrum

Researchers at the National Institute of Standards and Technology (NIST) have developed a new modeling technique that reduces by 33% the number of measurements needed for configuring shared spectrum.

“We’re introducing a new method for designing communications experiments,” said Jason Coder, co-author of a paper on the new model and leader of NIST’s Shared Spectrum Metrology Group. “This new method is adaptable, meaning that it utilizes the results of past measurements on a device to inform the next set of measurements. Using current methods, I might test a device in 100 different configurations to characterize its performance. But with this new adaptable method, I might be able to achieve the same result with fewer measurements.” 

The researchers examined coexistence between a Wi-Fi and a Bluetooth system operating in the same frequency bands, based on two arbitrarily chosen performance criteria: Bluetooth packet error rate below 3% and Wi-Fi data rate above 43 Mbps, at various Bluetooth transmission powers. “The conventional method of evaluating coexistence would be to sample virtually all possible configurations and monitor the resulting performance of both systems, an overwhelming task for all but the simplest situations,” according to NIST. But the new method, the agency explained, relies on a sequential series of experiments that select transmission configurations based on a small set of previously collected coexistence data. Then researchers used machine learning to make estimations based on a small set of measurements and assumptions about how rapidly the circumstances can change. “Researchers measured performance at many transmission powers, including those where models suggested there was only a small possibility of coexistence. As more measurements were made and models improved, the experimental design focused almost entirely on transmission configurations leading to coexistence, thereby reducing the number of measurements needed to determine success,” according to NIST.

The group simulated the experiment 50 times with actual data from previous lab experiments, NIST said, and needed an average of about eight measurements in order to identify at least 95% of the configurations that resulted in successful spectrum sharing. That’s about 33% fewer than conventional testing, which would have tested all 12 configurations, according to the agency. The new model is expected to work for up to 10 devices operating simultaneously — and researchers are also looking at other ML and AI techniques that can scale up to larger systems.

“The benefit to the larger community is that we may be able to significantly reduce the amount of time industry spends characterizing their devices, say for example, when they’re trying to navigate the regulatory approval process,” Coder said. “In some cases, we are enabling them to demonstrate compliance and performance with fewer measurements. This can save time, money, and reduce the barriers for a new product to enter the market. From the research side it should be a great new tool that enables us to characterize and understand complex systems more quickly and efficiently.” 

Read more from NIST on the research here. The paper, called “Estimating Regions of Wireless Coexistence with Gaussian Process Surrogate Models”, is being presented at IEEE’s EMC 2021 conference.

In other test news:

-Mobile phone manufacturer TCL is using Keysight Technologies‘ millimeter-wave over-the-air (OTA) test solution for 5G device validation, including verifying parameters such as transmitter output power levels and the ratio of power leaking into adjacent channels at Frequency Range 2 (mmWave).

Chih-Kai Wu, director of manufacturing solutions for Keysight’s wireless test business, said that the test company’s mmWave test solution “enables TCL to cost-effectively verify the performance of multiple devices in parallel, reducing test cycles in manufacturing.”

Keysight also said this week that that Taiwan-based mmWave start-up TMYTEK will use Keysight’s test offerings to verify the performance of its antenna-in-package (AiP) designs for 5G and satellite systems and speed up the development of Open-RAN compliant radios.

PCTel reported its results for the quarter: Revenues of $21.7 million, up more than 9% year-over-year, and a net loss of $169,000, compared to a profit of nearly $1.2 million during the same period last year.

“Our antenna business was stable and the test and measurement products continue to perform very well as we address 5G deployments and emerging public safety opportunities,” said David Neumann, PCTEL’s CEO, in a statement, going on to add, “We expect market conditions and the demand for our antenna, IoT device and scanner products to improve through the year as global economies recover.”

In addition, PCTel is expanding its global distribution channels through a new distribution agreement with Master Electronics that is focused on bolstering its antenna products for the industrial IoT market.

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