Test-equipment designers and suppliers are carrying a heavy load, trying to meet the expected test requirements of 5G wireless systems. In fact, the expected needs of next-generation wireless networks are shaping the next generation of RF/microwave test equipment.
5G is the next evolutionary step in cellular communication positioned to become the global wireless standard for a totally connected society. In addition to bolstering gigabit speeds over mobile networks, 5G promises to support the massive growth of devices and connections, virtualization, 8k HD video streaming, exponential growth in traffic, connectivity of the Internet of Things, and yet unidentified emerging technologies that meet the growing high bandwidth consumer demands for high-speed mobile broadband.
These demands are so monumental that 5G promises 1000× the mobile data and 10 to 100× the number of connected devices of 4G, while delivering 1–10 Gbit throughputs per user, 90 percent reduction in network energy usage, and just 1 millisecond or less of end-to-end round-trip latency.
While the technologies that will constitute 5G are still being worked on, the ITU-R has identified three main usage scenarios for 5G – enhanced mobile broadband with up to 20 Gbps peak data rate, massive machine-type communications, and ultra-reliable and low-latency communications. To meet the requirements for this next generation of mobile communications, researchers are looking to a wide range of enabling technologies in RF, microwave, and millimeter-wave (mmWave) frequencies – ranging from advanced waveforms and multiple access schemes to multiple antenna techniques such as massive MIMO and beam forming.
While users around the world are currently enjoying 4G/LTE and LTE-Advanced mobile broadband services, standardization efforts for 5G have begun and many operators are planning for initial 5G trials. In fact, Verizon expects some level of commercial deployment of 5G to begin by 2017, much earlier than the 2020 5G standard adoption date.
5G Testing Challenges
As the network concepts and technologies develop for 5G, so the corresponding test methods and processes will evolve to match this. Future 5G test methods will need to provide a high confidence to operators that technology and services are implemented according to specification, and that the quality of service is matching to the requirements of the application or service being delivered.
A fully data-centric 5G network with a very wide and diverse set of applications to test would require a massive effort in standalone testing. Test automation, monitoring and built-in test systems will be essential for analyzing properly the performance of such a network. In addition, the emergent solution to use Ultra Dense Networks (UDN) for interconnecting the radio access elements with the backhaul architecture using cloud networks will enable the development of cloud-based test services for testing everything from everywhere. So, although 5G will introduce many new test requirements and challenges by the use of SDN/NFV and cloud services, this same technology can also be used for creating new test solutions that address these needs.
The new wireless networks and their components will present numerous challenges for test-equipment companies, due not only to the need for achieving wide bandwidths and high performance levels in many components, but to the implementation of a number of technologies not so widely used at present– mmWave frequencies, multiple-input, multiple-output (MIMO) antennas, and phased-array antennas.
Some of these advanced technologies have been part of military radar and electronic-warfare systems for some time. But, as with the movement of mmWave signals and radar systems from purely military applications to increasing use in safety systems, the measurement community must now develop practical, cost-effective methods for measuring different types and frequencies of signals used in commercial and industrial applications.
The ways in which signals are transmitted and received in 5G systems – using phased-array techniques and MIMO antennas, which are essentially multiple antennas within a single housing – will also impact the requirements of future test equipment, boosting the need for measurement gear with multiple channels and enhanced measurement speeds to scan and process multiple signals with a number of different modulation formats.
These fundamental test requirements for 5G do not even touch upon the measurement needs for what are expected to be billions of IoT devices with different types of sensors using low-power wireless links to connect to the Internet. The common vision of 5G is to have sensors everywhere – that can be accessed via Internet, using a smartphone or other wireless device – to check on such things as whether a home or office thermostat is properly set or a garage door is open.
The benefits certainly sound wonderful. But all of those wireless devices must be tested before they are installed (and continuously tested once installed) to check for such things as interference to other devices, or their own performance degradation because of interference from other devices.
Some Recent Vendor Updates
NI has made a sizable donation to the university research team at NYU Wireless to further mmWave communications, channel measurement, and channel emulation research for 5G communications and beyond. As part of the donation, NI will equip NYU WIRELESS labs with hardware and software from its flexible software-defined radio (SDR) solutions, which researchers in both industry and academia are already using to help usher in the next generation of 5G wireless communications.
The gift brings together two powerhouses in the race to create wireless technology that can deliver broadband speeds over the air. An important aspect of this partnership is the tight pairing of NI’s hardware and software, which reduces the time to ramp up an SDR system so the NYU WIRELESS group can go beyond simulations to build and evaluate concepts. Thus, NYU WIRELESS has identified system-level bottlenecks and solved problems that are critical in achieving high-throughput wireless systems.
In the last year, the FCC, 3GPP, and other standardization bodies for 5G fixed and mobile networks have earmarked mmWave frequencies. Only in the last few years has the mmWave radio spectrum – driven by research at NYU WIRELESS – become widely accepted as holding potential for the next generation of wireless networks. The technology is developing at a rapid pace and is in the midst of many innovations. Because much of the work around mmWave is still in its infancy, many research institutions and companies lack access to the mmWave SDRs and test and measurement equipment necessary to transition this technology from concept and simulation in the lab to a real-world environment.
Rohde & Schwarz and MediaTek have announced collaboration on Test Concepts for 5G Wireless Communication Technologies. The purpose of the cooperation is to be strategic partners in driving 5G developments in several areas including mmWave for 5G radio access and over-the-air (OTA) testing concepts for massive MIMO antenna arrays.
Qualcomm Technologies, Inc. has selected an RF test system from Rohde & Schwarz to test and characterize its first-generation 5G RF transceiver (SDR051). Superior technical parameters and the demonstrated performance, stability, and reliability required in a production and manufacturing environment, convinced Qualcomm Technologies to select Rohde & Schwarz to provide 5G production test systems. The newly designed production and manufacturing R&S TS7830 RF test systems are based on the R&S SMW200A vector signal generator and the R&S FSW43 signal and spectrum analyzer, supplemented by additional equipment, components and automation software. The systems are supplied as a fully featured 5G turnkey solution.
Anritsu opened the door for LTE technology and developed cutting-edge technology for LTE-Advanced, including the world’s first signaling tester that could verify connections with a transfer speed up to 1 Gbps and conformance testers to verify that devices comply with standards. In addition to mmWave measurement technology, the vendor has developed the core competence required for measurement of wired 5G technology, including measuring instruments for 100 and 400 Gbps connections. Anritsu is also developing technology for modulation analysis and waveform analysis for 5G devices.
Keysight positioned itself as an early enabler of 5G research and development, particularly with major Asia-Pacific players. Prior to its spin off from Agilent in 2014, Keysight was inking 5G collaboration deals with China Mobile and KT in 2015.
More recently, Keysight has collaborated with ZTE on predeployment 5G plans in China, as well as participating in a demo with ZTE in which a ZTE device is said to have achieved 1Gbps IP data throughput. The company is also working with Samsung on designing and deploying 5G devices for early operator trials, noting it has been cooperating closely with Samsung since September 2016, to align their respective product portfolios around the specification and build an ecosystem of interoperable products.
The company recently conducted the first integration tests with Huawei’s 5G prototype base station and is working with the company on the second phase of 5G research testing in China, led by the IMT-2020 Promotion Group. The first phase of tests, completed in 2016, centered on verifying certain aspects of 5G technology. The second phase is considered technical program validation and started in the second half of 2016. That testing is focused on the verification and validation of wireless air interface and networking technologies used in the four major 5G scenarios – continuous broad coverage; hot spot high capacity; ultra-reliable, low-latency communications; and massive connection.
The tests have already started and are scheduled to be completed by the end of 2017. It will participate in the RF and functional test areas in seven test scenarios, including numerology, frame structure, a new waveform, and coding schemes.
Other vendors including Viavi, Narda, Fujikura, Sumitomo, Exfo, Ixia, Livingstone, and Savitri Telecom are also sparing no efforts to be aggressive participants in this evolving scenario.
As the vendors promise to take the industry from evolution to revolution to reality, the stalwarts silently wonder when they will need to be readying for 6G!