Test methods for 5G ensure that the technology and services are implemented according to specifications, and quality of service matches the requirements of the application or service being delivered.
Development in technology and network concepts for 5G requires test methods and processes to evolve. Test methods for 5G ensure that the technology and services are implemented according to specifications, and quality of service matches the requirements of the application or service being delivered. 5G chipsets validate the performance of 5G New Radio (NR) smartphones and Internet of Things (IoT) devices in the lab. These do not require access to expensive and complex 5G base stations.
Testing a fully data-centric 5G network with a diverse set of applications requires massive efforts in standalone testing. Analysis of the performance of such a network requires test automation, monitoring and built-in test systems. Interconnecting radio access elements with ultra-dense networks with backhaul architecture (using cloud networks) provides the ability to develop cloud-based test services. This allows testing of everything from anywhere.
Portable devices with Internet connectivity can be used by a remote user to analyse the systems and suggest changes to the field staff immediately. Handheld testing devices eliminate the need for multiple steps and create automated results.
Sometimes, results are also integrated to the server/cloud, so these can be monitored from the field remotely by user(s). In certain cases, built-in test features are inserted along with signals. For example, radio signal strengths can be analysed by taking information from social media channels.
Madhukar Tripathi, head – marcom and optical business, Anritsu India Pvt Ltd, says, “MT8821C radio communication analyser is designed for R&D of mobile devices/user equipment such as smartphones, tablets and IoT modules.”
Hari Kamalapuram, deputy general manager – communications business unit, Cyient Ltd, says, “5G/4G technologies require multiple testing areas including drive test and optimisation, KPI analysis, benchmark, broadband, protocol, and spectrum analysis for noise and electromagnetic environment.
“Earlier, equipment used for these tests comprised complex modular designs. Test results were processed in multiple steps. We have developed many tools for our internal consumption in planning and design.
“A handheld tool, i-netracker, is used for testing signal quality, call drops, throughput, career aggregation and so on for 4G/LTE networks. This test is popularly called single-cell functional test or single-cell verification test. The solution, being Android based, can be loaded into any Android-based cellphone. All measurement parameters are captured and sent to the central cloud. After completion, data can be processed remotely, and instant reports taken at any time.”
There are two methods for measuring radiation patterns. One is using a large anechoic chamber or an over-the-air (OTA) system, which is expensive. Second is making something from scratch.
Phase-array antenna, beamforming algorithm and MMIC designers all need nearly continuous access for microwave (µWave) designs. The problem with the second option is that it is hard to do it right the first time. Many aspects of the problem are overlooked, including wire tangling, open software control, repeatability, part supply and the like. Finally, neither of these solutions address real problems.
Nynne Sole Dala, founder, mmWave Test Solutions, says, “A test chamber for testing millimetre-wave (mmWave) products, including 5G unlicensed band (57GHz to 71GHz) and 5G (5G NR, 28GHz) licensed band, is what telecom infrastructure companies are investing in, for both 5G backhaul and fixed wireless access (FWA).
“FWA replaces the expensive last 100 metres of fibre from the curb to the building. 802.11ad and 802.11ay (unlicensed 5G) deliver gigabit speeds. India is looking at expanding the use of these technologies for backhaul. From a test perspective, the 77GHz ADAS/radar test market is growing rapidly. Our MilliBox system is aimed at 20GHz – 95GHz, and does not support 4G frequencies (sub-3GHz).”
James Kimery, director of wireless research at National Instruments (NI), says, “NI recently announced two series of mmWave radio heads for mmWave transceiver system.
The radio heads, which cover the spectrum from 24.5GHz to 33.4GHz and 37GHz to 43.5GHz, are targeted at wireless researchers prototyping 5G NR systems. These are compatible with the mmWave transceiver system, including base-band sub-system and software. These are also interchangeable with previously-released mmWave radio heads. This means that existing software can be reused with minimal changes.”
Challenges and areas for development
The biggest challenge for T&M in the transition from 4G to 5G is that µWave (for 4G) paradigm always look at shielding as an important feature for a chamber. Whereas, for mmWave, shielding is secondary to addressing stray reflection issues inside the chamber.
µWave engineers treat antenna as an independent entity. This does not work well in mmWave where the antenna array cannot be isolated easily, either from the IC’s power amplifiers, phase shifters and splitters, or from beamforming algorithms, as these all contribute to achieving the desired propagation performance. This means, radiation pattern measurement is no longer something that is done once when the antenna is designed and forgotten. It is a continuous process, from design to production.
Testing protocols for 5G are still in the final stages of approval from 3GPP. A challenge faced while developing this drive testing tool is extraction of layer three messages from chip sets. (Every chipset has its own protocol.)
Bringing all parameters to one handheld device is complex. It depends on memory size, processor speed and more.
Cloud services and SDN/NFV introduce many new test requirements and challenges for 5G network testing.
With faster processing speeds and improved latency, new electronic circuits and hardware development are a challenge.
Low noise floor and low power consumption are other challenges.
Vikram Khurana, general manager – sales, at Microlease, says, “5G is set to offer exponential improvements in every area compared to prior networks. These include speed, latency, bandwidth, reliability and availability. Speed and latency are especially important and what will primarily set 5G apart is enabling applications that simply could not be accomplished with prior networks.
“In terms of speed, there will be massive improvements—on the order of 10 to 100 times faster than 4G. Speeds of 10 Gigabits per second are expected. Companies like ATT and Verizon have already achieved speeds in this range.
“In terms of latency, current 4G average in the US is 61 milliseconds. As a reference point, the blink of an eye is around 350 milliseconds, so one-sixth of that time is fast but lag or delay is still noticeable.
“We have test setups ready for signal generation and analysis, pre-5G NR solutions, antenna array testing and OTA. mmWave, small cell, massive MIMO, beamforming and full duplex are the new targeted applications.”
3GPP, the 5G standards body, officially approved the first round of 5G specifications in June 2018. This standard will be followed by the specifications of new architectural options and additional capabilities. As the standards evolve, test solutions should allow future upgrades while avoiding costly hardware changes. Commercialisation of mmWave technology is accelerating. There is a global consensus that it will be critical to achieving the goals set forth by 3GPP for 5G.