Wireless Test: Too Many Protocols

Testing wireless communications is getting far more difficult as more markets begin adding wireless communications and standards groups push to improve the speed, power and security of existing protocols.

There is already a long list of protocols, and it’s growing further as new communications technologies are added into the mix. With the addition of 5G, the new 802.11ax standard, and other short-range communications updates, just keeping track of all the standards is a chore. But for test and measurement companies, which already offer a comprehensive portfolio of instruments and software for testing the protocols used in autonomous vehicles, cellular communications, the Internet of Things, and other application areas, it also is putting pressure on them to limit their focus.

Anritsu, Astronics Test Systems, Keysight Technologies, LitePoint (a Teradyne company), National Instruments, Rohde & Schwarz, and Tektronix are among the top vendors vying for a piece of the ever-expanding wireless testing market.

NI last month introduced the WLAN Test Toolkit 17.0 with support for Draft 1.1 of the IEEE 802.11ax standard, which promises to provide stronger Wi-Fi signals, especially for users in crowded public environments such as airports. The WLAN Test Toolkit 17.0 is paired with NI’s second-generation Vector Signal Transceiver for 802.11ax waveform generation and analysis for characterization, validation, and production test of radio-frequency front-end components, wireless modules, and user devices, according to the company.

“As the standardization and evolution of 802.11ax continues, engineers require a software-centric test approach that can keep pace with the latest standard features and challenging new test cases,” said Charles Schroeder, NI’s vice president of RF marketing, adding, “Taking advantage of NI’s modular platform and second-generation VST can help users lower their cost of test and reduce time to market.”

National Instruments has developed a guide to 802.11ax technology.

Evolution of 802.11 wireless standards. Source: NI

“We see a lot of work and effort and engineering energy going into two different types of protocols,” said Alejandro Buritica, senior product marketing manager for wireless solutions at NI. “The first one is, of course, cellular, and the push for new releases of the 3GPP standard, and so on. The second is on the connectivity front, with the 802.11ax new version of the 802.11 standard. There is a lot of work going with different chipset vendors and companies trying to get ready for the new test challenges of 802.11ax.”

The new protocol introduces a new set of challenges. “It won’t be just a case of firmware to test your 11ax device with the same type of instrument you were using for 11ac, because now 11ax is employing new technologies,” Buritica said. “And it’s starting to look more like an LTE-type protocol in the ability to accommodate more users in the same amount of bandwidth. All these new multi-user technologies are pushing the envelope for test equipment in terms of testing 11ax devices.”

Bluetooth technology is undergoing some changes, he noted. “Of course, we’ve had Bluetooth Classic for a while, and we’ve had many profiles with Bluetooth Classic. Also, Bluetooth Low Energy is becoming more and more popular. There’s a new version of the standard, Bluetooth 5, which includes Bluetooth Low Energy and Bluetooth-extended packets to be able to send more data per transmission, while maintaining low power consumption. A Bluetooth device could have much longer battery life, greater than two or three years. So they’re trying to do a lot of work with Low Energy, especially for devices like beacons, and trying to take advantage of location, to offer new services.”

Slicing up markets
Then there are the low-power IoT protocols, such as the IEEE 802.15.4 physical layer, powering ZigBee, LoWPAN, and others.

Cellular connectivity is pushing forward into 4.5G LTE in addition to 5G. “Industry and academia see the 5G standard moving along three vectors,” Buritica said. There is the effort to boost data transmissions to 1 gigabit per second or faster, he noted. There is work on ultra-reliable, low-latency connections, which would be incorporated in V2X technology. And then there is enhanced machine-to-machine communication, for the IoT and other applications, providing “bursty signals” for use in smart metering and other applications.

NI has been working with commercial and academic partners on development of massive multiple-input, multiple-output (MIMO) technology for beam steering and beam forming. The company is employing software-defined radio and millimeter-wave technology for greater bandwidth. Meanwhile, for 5G, the company is allowing for flexibility for the international standard as it is developed in the next few years. “We do a lot of work on our software platform, not just firmware,” Buritica noted. And for advanced advanced automotive electronics, NI is testing radar sensors, with real-time processing on the instrument. “We can test cameras and more in our platform,” he said.

NI isn’t alone in developing test solutions for individual markets. Astronics Test Systems is employing system-level test and massively parallel testing for RF devices.

“A lot of the things we might be interested in looking at it closer are the things that are trending toward the high-volume manufacturing,” said David Vondran, senior product marketing manager at Astronics. “A lot of discussions are at the idea level right now. It’s not just about creating innovative silicon. It’s also, ‘How am I going to create a supplier-chain story that leads to commercial success?’ And a lot of times that commercial success is greatly influenced by the competitive positioning of not just the performance of their product, but the price. That’s where cost of test really becomes very important. It doesn’t matter if it’s a 5G device, an IoT device, or just a wireless link in a mobile phone.”

Vondran sees RF in future devices becoming much more ubiquitous. “RF links will be much more like a commodity,” he predicts. For now, software-defined technology is taking hold. At 6 gigahertz bandwidth, “it’s important what the hardware is you’re using,” he adds. “5G components, automotive radar, and 60 GHz are not high-volume manufacturing yet.”

Still, “RF goes ahead in leaps and bounds,” Vondran said. “Moore’s Law is going to enable bigger pipes, especially for the mobile devices. You don’t see a lot of wearables with a cellular link yet. But change in the test and measurement industry is usually slow. We’re a necessary evil.”

Tektronix is another player in this arena. The company is a subsidiary of Fortive, a spinoff from Danaher Corp., which bought Tek in 2007 for $2.85 billion. Danaher also bought Keithley Instruments 2010, merging many of its operations and products with Tektronix.

Dorine Gurney, a product marketing manager in RF Test at Tek, said her company tests the physical layer on wireless communications chips. Tek addresses Bluetooth, P25 (digital radio communications), and Wi-Fi testing with its products, along with wireless and RF testing for the Internet of Things and other applications.

Fig. 2: Wireless tester from Tek.

“We also have a different kind of offering,” Gurney said. “A general-purpose offering, so you can do all sorts of spectrum analysis. After that, if needed, you can also demodulate the signal, and look at the signal quality of the signal which covers a number of different modulation types.”

Tektronix offers two kinds of packages – a general-purpose package, or a more vertical package for specific standard measurements, like Bluetooth, or P25 emergency communications.

With the proliferation of protocols, Tek must decide on a case-by-case basis which ones will represent the best investment, according to Gurney. “We’re like everyone else,” she said. “We’re limited in our resources. We want to choose the best development that will return the most for us.”

This explains why Tek has not yet invested in 5G wireless communications test, she noted. “The actual standard is still in the process of being formed,” she said. “We know there are areas in 5G that we will want to address with our products, especially in the need to share some spectral bands at some point in the U.S. This is an area where we are working with the government to help them to try to figure out ways we can monitor the network and make sure that when things happen, there is not going to be conflict.”

Tek hasn’t decided yet whether the Internet of Things is the right investment, either, for the company. “We’re still kind of on the edge of it,” Gurney said. The market is “fragmented” and lacking standards, making it difficult to commit resources to that area, she added.

The company is working with Audi on self-driving car technology, dealing with “the latency of protocols” in automotive electronics, she noted. And it is supporting “new flavors” in Bluetooth and Wi-Fi, the Bluetooth 5 standard and IEEE 802.11ax in particular, Gurney said. Tek is also interested in LoRa, Sigfox, and LoWPAN.

“All products have to go through regulatory testing,” Gurney noted.

Conclusion
There is a lot going on in wireless communications these days—perhaps too much. In many ways, the wireless market is looking like the Wild West of protocols and standards. New markets, new requirements, and pressure to utilize bandwidth more efficiently and with lower power, all are driving the development of new protocols and approaches to communications.

Now the question is which companies will play in which segments, and how quickly they will reap returns from those choices. Just making investments in some of these protocols is no guarantee of a healthy ROI because this entire segment is in flux, and likely will continue to be for the foreseeable future.

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