Wireless technology insights: Navigate the evolution from 5G to 6G

As 5G development progresses, developments such as the Open Radio Access Network (O-RAN) ecosystem, Non-Terrestrial Network (NTN) infrastructure, and 5G Reduced Capacity (RedCap) devices continue to gain momentum. Although 5G deployment is still underway, the wireless communications industry is already preparing for next-generation 6G wireless technology.

With so much development happening at once, it’s hard to keep up. During the Keysight Wireless Tech Days virtual event, subject matter experts explained design and development principles important to today’s RF engineers.

Take your designs for release 17

Third Generation Partnership Project (3GPP) Release 17 enhancements enable new classes of 5G wireless devices. Mobile operators continue to develop NTN technology in their efforts to provide ubiquitous coverage around the world. When fully implemented, the impact of NTN infrastructure will revolutionize numerous technologies, from emergency service systems to shipping and logistics tracking.

5G NTN intends to provide satellite services to billions of mobile phone subscribers worldwide. However, there are three critical challenges 5G NTN technology must address:

• Doppler shift
• time-varying path delay
• time-varying road damping

In 5G NTN, the network adjusts the timing of the radio frames to match the user’s location and pre-compensates part of the link frequency error caused by the satellite movement. These adjustments make it easier for the user terminal to tolerate the characteristics of the satellite link. Network Broadcast System Information Blocks (SIBs), which store information about satellite locations and speeds, allow the mobile phone to estimate link conditions, the delay of the satellite link, and Doppler errors in transmission frequency.

On the first day of Wireless Tech Days, application engineer Randy Becker described how to test the compliance of 3GPP enhanced handsets with the Keysight NTN testbed. The demonstration showed how to capture delay and error measurements, as well as demodulated uplink signal constellation, spectrum, error vector magnitude (EVM), and uplink/downlink throughput. In addition, Randy tested how the NTN handset performed SMS and video streaming functions.

Also on day one, Manuel Blanco, 5G strategic planner, discussed narrow-band internet of things (NB-IoT) applications within NTN. Although originally envisioned as a technology to connect low-cost IoT devices with limited power consumption and throughput requirements, developers plan to use NB-IoT over NTN as a means to support ubiquitous coverage for mobile phones for text messaging, voice communications, and multicast firmware updates.

Manuel demonstrated how to use the UXM 5G network emulator for satellite emulation in the lab while testing an NB-IoT enabled mobile phone for off-grid scenarios. The demonstration covered geostationary orbits (GSO) and non-geostationary orbits (NGSO). Manuel reviewed how to configure an NB-IoT cell to an NTN cell with varying delay and Doppler settings. In addition to uplink/downlink throughput and block error ratio (BLER), EVM and frequency error measurements, Miguel-Angel Guijarro, 5G Product Manager, detailed conformance testing and automation on the Keysight platform.

See the latest about NTN here: keysight.com/find/ntn

Take Open RAN to the next level

The evolution of Open RAN as defined by the O-RAN Alliance continues to reshape radio access networks. Open RAN has huge implications for increasing network energy efficiency, which was the main focus of day two of Wireless Tech Days. O-RAN equipment requires three different test categories:

• O-RAN compliance
• 3GPP compliance
• energy efficiency test

O-RAN conformance testing focuses mainly on protocol, while 3GPP conformance testing primarily deals with RF performance. Energy efficiency testing requires engineers to measure energy consumption along with protocol and RF performance. To optimize communication system energy efficiency, equipment manufacturers and network operators must:

• handle different requirements effectively
• test and correlate data across different domains: RF, protocol and energy plan (E-plan)
• automate tests to keep up with the high speed of innovation

Engineers need a unified test strategy that enables them to measure their radio performance against three different standards and then cross-correlate the results. In addition to that, developers need to automate their testing strategy for optimal regression testing across firmware releases.

Jean Dassonville, RAN solution planner, demonstrated static O-RAN radio device testing using the Keysight E-plane testbed. This solution utilizes 3GPP and O-RAN solutions and expands the possibilities for the E-planet.

Included in the automated solution platform, a time synchronization analyzer acts as a distributed unit (O-DU) emulator, while a regenerative power system is used to perform the DC measurement. The RF power sensor is time-synchronized with the O-DU emulator for time-controlled measurements.

Learn more about Open Ran here: Deep Dive into O-RAN

Take component tests from 5G to 6G

On the final day of Wireless Tech Days, Nizar Messaoudi, Heather Richardson, Afsi Moaveni and Dr. Joel Dunsmore, how Keysight network analytics solutions enable breakthrough component insights while simplifying the test setup.

Nizar, VNA Product Manager, demonstrated transmit/receive (T/R) module, low noise amplifier (LNA) and power amplifier (PA) characterization for the new Keysight ENA-X network analyzer. T/R modules support modern communication system performance through three key functions:

• amplifying transmission signals to the maximum radiated power
• establishment of the system’s noise figure during receiving operations
• provides beam steering control and angular accuracy

A power amplifier occupies the last stage of the transmitter, while the LNA is the first stage of the receiver. As a result, the PA determines the overall transmitter distortion and the LNA limits the receiver sensitivity. Furthermore, the DC power consumption of the power amplifier is the largest determining factor for the overall efficiency of the T/R module. Although many component parts contribute to successful T/R module operations—phase shifters, attenuators, limiters—the amplifiers most severely limit the modules’ transmit and receive performance. So, to optimize the performance of a T/R module, shown in Figure 5, used in a phased array application, engineers must start by characterizing the receiver’s LNA and the transmitter’s PA.

Characterization of the behavior of the T/R module places high demands on the performance and flexibility of a test system. The test system must support both transmit and receive test modes while maintaining accuracy and maximizing throughput.

In the demonstrations, Nizar showed how the ENA-X network analyzer, MXG signal generator, and modulation distortion (MOD) software work together to provide precisely calibrated wideband signals necessary for precise PA, LNA, and T/R module measurements. The integrated upconverter at port 1 of the ENA-X takes the modulated signal from the MXG and raises it to a maximum frequency of 44 GHz. ENA-X’s wide dynamic range and vector error correction minimize test set EVM, ensuring a clear assessment of PA and LNA performance without any interference from the test set. For even faster characterization of the amplifiers, ENA-X enables EVM with optional demodulation using the MOD software, which decomposes linear and non-linear signal components with spectral correlation.

To simplify noise figure calibration, the ENA-X offers two integrated low-noise receivers to reduce attachment and enable the ENA-X to measure the T/R modulus in both directions. By connecting and calibrating the test set only once, engineers collect standard network analysis metrics along with the cold source noise figure.

In the next demonstration, Afsi, senior application engineer, and Dr. Joel, Keysight Researcher, Power Amplifier Characterization on Multiport PXI VNA. Additionally, with similar features to the ENA-X network analyzer, the PXI VNA offers a configurable platform ideal for manufacturing applications. During the demonstration, Dr. Joel the direct receiver access available on the PXI network analyzer. The direct receiver access allows engineers to loop booster amplifiers or directional couplers into the measurement while maintaining the quality of the incident modulated signal and the VNA calibration of the internal receivers.

Heather, application engineer, used the high performance Keysight PNA-X network analyzer broadband active load draw solution to test a power amplifier. Amplifier designers must test their device under variable load conditions for robustness and degradation testing. Drawing on the capabilities of the modulation distortion software, Heather demonstrated how to use the PNA-X VNA and the dual channel Keysight VXG signal generator to control gamma load conditions across the entire modulation bandwidth while measuring low-residual EVM.

To achieve the wireless telepresence and massive connectivity promised in 6G, greater bandwidth and spectral efficiency are paramount. To develop 6G components that maximize bandwidth utilization, engineers need a test platform that handles additional noise power. In the final demonstration of Wireless Tech Days, Sarah Laselva, 6G marketing director, and Benjamin Schoch, researcher from the University of Stuttgart, showed how the 6G Vector Component Analysis (VCA) solution characterizes H-band amplifiers under broadband modulated signal stimulus. The demo demonstrated the ability of the 6G VCA solution to shift the test reference plane to that of the device under test, enabling greater performance measurement accuracy.

Take your next step towards innovation

As ongoing advances in 5G technology, including the O-RAN ecosystem, NTN infrastructure and 5G RedCap devices, rapidly gain traction, engineers must keep up with the evolution of standards. While 5G deployment is progressing, the communications industry is already working on the next generation, 6G wireless technology.

With this rapid pace of development, it is a challenge to stay informed with the latest information. Navigate the ever-evolving wireless technology landscape with help from industry experts. Check out the Keysight Wireless Tech Day virtual event on-demand to gain crucial insights into fundamental RF design and development principles.