Accelerating 5G standardization requires coping with the complexity of test scenarios

The fifth generation of mobile communication technology, which was originally planned to be officially commercialized in 2020, is expected to arrive earlier than expected. At the 75th 3GPP RAN General Assembly held in early March, the proposal for 5G acceleration was officially passed, which means that the time point for 5G standardization will be moved forward. Some leading operators have announced that they will launch pre-commercial 5G services this year. However, the development and maturity of the 5G industry chain requires not only the cooperation of chip manufacturers, equipment manufacturers and telecom operators, but also the participation and promotion of 5G research and development by testing manufacturers, which is a very important part.

5G commercialization will be pushed forward to 2019

Test synchronization follow-up

At the 75th 3GPP RAN General Assembly, 3GPP formally approved the proposal for 5G acceleration. 3GPP will accelerate the 5G New Radio (NR) standard process in the R15 version, and complete the 5G NR non-standalone networking (option 3) feature in December 2017, six months earlier than originally planned. The conference also determined that the standalone 5G New Radio standard will be completed in June 2018 and frozen in September 2018.

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The 5G standard acceleration proposal has received support from many parties in the industry chain, including operators such as AT&T, NTT DoCoMo, and SK Telecom, equipment manufacturers such as Ericsson, Huawei, and ZTE, and terminal chip manufacturers such as Qualcomm and Intel. "We strongly support the 3GPP's 5G standardization acceleration plan, which provides a very clear timetable for the entire industry and allows global operators and equipment and terminal chip manufacturers in the 5G ecosystem to work together towards the goal of commercializing 5G in 2019," said Ma Dejia, senior vice president of engineering technology at Qualcomm.

5G networks bring extreme throughput, with rates of up to several gigabits per second. Compared with 4G networks, 5G networks have increased by dozens or even hundreds of times. In addition to high throughput, 5G networks can also bring ultra-low latency and consistent experience. Even in extremely challenging environments or at the edge of a cell, 5G networks still have reliable performance and reduced latency. The latency of interactive content can be as low as 1 millisecond, while reducing buffering requirements and delays.

However, the development and maturity of the 5G industry chain requires not only chip manufacturers, equipment manufacturers and telecom operators, but also the participation and promotion of testing manufacturers in 5G research and development. Satish Dhanasekaran, global vice president and general manager of the wireless terminal and operator division of Keysight, said that global 5G testing is currently facing four major challenges. The first is the simulation and visualization of new air interfaces and MIMO technologies; the second is the calibration challenges brought by higher millimeter wave frequency bands, and OTA testing will become more and more important in the future; the third is the real-time simulation and emulation of end-to-end real scenarios; finally, in the test, it is necessary to connect from chips to operators, from research to development, and evolve according to standards to accelerate the commercial use of 5G.

Lifang Kirchgessner, Vice President of Rohde & Schwarz, pointed out that the general direction of 5G technology is to develop higher and faster data transmission rates, increase system capacity, and ultra-dense networks, which is in line with the general trend of communication technology. For 5G's widely recognized key technologies such as millimeter waves, large-scale antenna arrays, and high bandwidth, Rohde & Schwarz can already provide complete test solutions to help equipment manufacturers conduct corresponding 5G technology research.

Entering the second stage

my country tests to achieve interoperability

my country's 5G R&D tests are also accelerating. At the beginning of last year, my country fully launched 5G technology R&D tests and clarified the 5G test frequency. At present, the first phase of testing has been successfully completed and has entered the second phase. my country's 5G second phase test is organized by the IMT-2020 (5G) Promotion Group. The test group is composed of China Academy of Information and Communications Technology, China Mobile, China Unicom, China Telecom and DoCoMo Beijing Research Institute. Instrument companies participating in the docking test include Rohde & Schwarz, Keysight Technologies, Datang Lianyi, Galaxy Bright Point, etc.

In actual testing, Huawei completed the 3.5GHz frequency band field performance test under 5G-NR. The system performance met the ITU-R definition indicators. It also conducted interoperability tests with many instrument and chip manufacturers in the industry. The test results met the regulatory requirements. Datang conducted the industry's first 5G base station coverage capability test. Using large-scale antenna technology, it maintained a coverage distance of more than 2km at a download rate of 100Mbps in the 3.5GHz frequency band, achieving a coverage capability similar to that of 4G base stations in the 2.6GHz frequency band.

In response to the problems encountered in 5G testing, Li Mengxi, chief engineer of Datang Lianyi, said that Massive MIMO, beamforming technology and carrier aggregation technology have become the mainstream technologies of 5G communication networks, which is also the main challenge for 5G test equipment. Massive MIMO in the 5G era may require as many as 128 antennas. Test instruments need to be developed to support simultaneous testing of multiple antennas, more RF channels and ports, and improvements need to be made in RF design and multi-port structure solutions. Datang Lianyi is investing in the research of 5G test instruments with high measurement frequency, wide measurement bandwidth, excellent RF performance and integrated transceiver.

Chen Xiangmin, CEO of Chuangyuan, also said that the company is currently focusing a lot of its efforts on large-scale antenna solutions to solve the problem of efficient testing of 64 channels and 128 channels. "We are doing research in this area, hoping to achieve a complete system and explore some testing aspects in the entire laboratory environment. In short, large-scale antenna testing is the current development focus and also the difficulty of 5G communication testing. We will use innovative testing methods to solve it." Chen Xiangmin said.

Expert opinion

Chen Xiangmin, CEO of Chuangyuan

From 4G to 5G, testing requirements are gradually evolving

In the evolution from 4G to 5G, some testing requirements are not revolutionary, but gradually evolved. For example, carrier aggregation technology has been adopted in 4G, 4.5G/LTE-A, and of course 5G will undoubtedly aggregate more carriers. At present, the company has focused a lot of its energy on large-scale antenna solutions to solve the problem of efficient testing of 64 channels and 128 channels. In fact, we have developed a set of solutions for 5G large-scale antenna testing, which can test some performance of antenna systems efficiently and accurately. The millimeter wave band will face more testing challenges, and we are also doing research in this area. In short, large-scale antenna testing is the development focus of our company and the difficulty of 5G communication testing. We may use innovative testing methods to solve it.

For testing, the biggest challenge is to build a good basic platform. This basic platform must be forward-looking, that is, we cannot only consider the present, we cannot consider the 2G platform when we are doing 2G now, and we cannot consider the 3G platform when we are doing 3G. For Chuangyuan, when we were building the platform, we planned the 4G platform when we were doing 3G, and the platform for the evolution of 4G. Now we are developing towards the 5G platform.

Li Mengxi, Chief Engineer of Datang Lianyi

Carrier aggregation and Massive MIMO are important challenges

5G terminals have increasingly higher requirements for RF indicators. First, they must support high frequency bands, up to 60GHz, ultra-large bandwidth, at least 500MHz, and support higher-order modulation, such as 256QAM, ultra-low EVM, -50dBm, excellent phase noise indicators, -120dBc, and lower adjacent channel leakage ratio and other RF indicators. Unlike the previous situation where most mobile communications were concentrated below 3GHz, the frequency bands in the 5G era, in addition to the traditional frequency bands below 6GHz, also added high frequency bands such as 28 GHz, 38G~40GHz, 57G~64GHz, 70G~75GHz, 81G~89GHz, etc.; the bandwidth is at least 500MHz, and even up to 3GHz. Test instruments need to carry out research and development of new technologies and solutions for intermediate frequency and RF in view of the support of high frequency bands.

Carrier aggregation and Massive MIMO are also important challenges. Massive MIMO in the 5G era may require as many as 128 antennas. Test instruments need to be developed to support simultaneous testing of multiple antennas and more RF channels and ports. RF design and multi-port structure solutions need to be improved.