As a heavyweight sub-forum of the "ICT China 2018 High-level Forum" of the 2018 China International Information and Communication Exhibition, the third 5G Innovation and Development Summit Forum held on the morning of September 28 released important news about the three-phase test of 5G.

With the announcement of the third-phase test results in 2018, the 5G third-phase work plan has ushered in a new milestone. Director Wen Ku of the Information and Communication Development Department of the Ministry of Industry and Information Technology pointed out: "The third stage of the 5G technology research and development test will be a key step before 5G realizes the '18-year-old adult'", which shows the importance of the test results of the third stage. Xu Fei, head of the 5G test working group of the IMT-2020 (5G) promotion group, reported and summarized the test progress, and the working group handed in a satisfactory "answer sheet" for the third phase of the test.

Indoors first, then outdoor, the testing process is steadily advancing

Judging from the planning of the timetable, the third phase of NSA indoor testing, outdoor testing and indoor testing of SA architecture has been basically completed, and SA field testing is being actively carried out. It is reported that the test sequence is single device first, then interoperability, indoors first, then outdoor. So the completion of SA standard indoor test.

The third-stage specification system of 5G technology research and development has added the eMBB test specification of the SA standard. In terms of core network, the technical requirements of SA architecture core network equipment and the test method of SA architecture core network equipment are proposed; in terms of base station side, the performance test of base station is proposed. Methods, technical requirements of lion room sub-equipment, test method of digital room sub-equipment, performance test method of outfield independent networking (SA); in terms of interoperability, IoDT test requirements are put forward.

The working group promotes the construction of an indoor and outdoor integrated test network, and builds more than 100 base stations in the MTNet + Huairou field; builds a 5G RF conduction test system and an OTA test system to support sub-6GHz frequency band testing; builds massive MIMO OTA based on spherical probe walls, etc. Three performance test scenarios.

NSA indoor test: all manufacturers basically completed the test

Reviewing the indoor test content of the third stage, Xu Fei said that it mainly tests the basic functions of the physical layer, the basic functions of the RRC protocol, physical channels, link adaptation and scheduling, multi-antenna technology, radio frequency test, EN-DC dual connection test, CU- DU separation architecture, NSA core network test.

The completion of Phase III NSA testing is impressive. Huawei, ZTE, and China Xinke completed the NSA 3.5/4.9GHz frequency band test content; Nokia Bell and Ericsson completed most of the test content; Samsung started the test.

Specific to all aspects of the network architecture, Xu Fei introduced in detail.

The third stage NSA indoor test core network function has been well tested and verified. The EPC system equipment has two forms: based on the virtualization platform and based on the traditional equipment upgrade. Huawei equipment supports CU separation. In addition, each system has completed the EPC system test supporting the NSA architecture, and the overall test results are good: each system supports the EPC system functions of the NSA architecture, including dual connectivity, NR access restriction, UE capability processing, QoS, billing and usage reporting, Gateway selection and other functions; verified end-to-end HTTP/FTP services; continued to improve QoS parameter negotiation and other functions.

The third phase of the NSA indoor test base station function is also a bright spot. Each system equipment manufacturer has developed 3.5/4.9GHz pre-commercial/commercial 5G base stations for eMBB macro coverage scenarios; each system uses self-developed test terminals to complete third-party terminal emulators and supports NSA-based base station function tests. The overall test results are good; The base station equipment of each system supports the basic functions of the physical layer, key technologies such as multiple antennas and dual connections, and supports the NSA option3X architecture; will continue to improve the RRC protocol functions such as measurement and mobility management; reduce the weight and volume of the AAU, increase applicability, and enhance stability sex.

In the third stage of NSA indoor test base station radio frequency (conduction), the 3.5/4.9GHz base station equipment transmitter test was completed, and the test results met the requirements of the test specifications; The index value specified by the industry competent authority.

In the third stage of NSA indoor test base station radio frequency (OTA), the China Academy of Information and Communications Technology and partners jointly developed and constructed a virtual far-field radio frequency OTA test system. For the far-field RF OTA test system, 5 system manufacturers have completed the 3.5GHz base station antenna and RF assignment tests, including EIRP, Pattern, EVM (64QAM, 256QAM), EIS, etc.; Test specification requirements.

NSA field test: the peak downlink rate of a single cell exceeds 4Gbps

NSA is making rapid progress, outdoor tests have been basically completed, the results have attracted much attention, and the transmission capacity has repeatedly reached new highs.

In the third phase of the NSA field networking test, the peak throughput of a single cell broke a record. Each system adopts 64-channel 192 large-scale antennas, uses MU-MIMO technology and high-order modulation, and improves spectral efficiency through multi-streaming; the single-cell downlink peak rate of most systems exceeds 4Gbps@100MHz, and the maximum exceeds 10Gbps.

In the third phase of the NSA field network test coverage, a single terminal is used to conduct a remote test along the normal direction in a single cell. The coverage scenarios of each system are different, and the distance between stations, station height, and propagation environment are quite different. The test results only correspond to The corresponding scene is about 2~3km.

In the third phase, the NSA field test multi-cell mobility capability has been improved. Two terminals are used to conduct mobility tests in two campuses, and the handover performance and average throughput are counted; the success rate of inter-cell handover of each system is 100%; the moving average downlink throughput of a single terminal is about 350Mbps, and the average uplink throughput is about 80Mbps.

SA Indoor Testing Progress: Focus on IoDT Testing

Since the SA standard was only frozen in June 2018, the progress of the SA test has attracted much attention in the test results. At present, indoor testing is mainly carried out for SA. Huawei, China Xinke, Ericsson, and ZTE completed the SA core network test; Huawei completed the SA base station function test, and China Xinke, Ericsson, and ZTE basically completed the SA base station function test.

In the third phase of SA indoor testing of core network equipment functions and performance, 5G new network architecture and core network function tests and system performance tests based on NFV platform 5G core network were carried out. Aiming at the pain points of NFV performance, verify the single-point performance and expansion performance of the NFV platform from the three dimensions of virtual machine, server and whole system.

In the third stage of SA indoor test core network function test environment and configuration, based on the 5G core network of the general server platform, the NFV platform adopts container or virtual machine technology, adopts the same manufacturer's base station and self-developed test terminal, supporting business server, NFV management system, 4G EPS system, etc.

In terms of the core network function test results of the third stage SA indoor test, firstly, it supports the basic functions and new features of the 5G core network: the basic functions include mobility management, IPv4v6 session, handover and inter-system interoperability, etc. The interface protocol meets the version requirements; New features, including service-oriented architecture, edge computing, basic functions of network slicing, CU separation, etc. The second is the problems found in the test and optimization suggestions: At present, the allocation management of IPv6 addresses, slice identifiers, and service callback interfaces is customized by each system, and needs to be uniformly defined in the future; user registration delay needs to be further optimized; 4G/5G gateways are jointly set up The unified control scheme of the CP-UP interface needs to be further clarified; the cross-manufacturer interoperability of the service interface and the CP-UP interface needs to be further verified.

In the third stage of SA indoor test base station performance, the promotion team built three test environments to simulate channel fading including Doppler effect, multipath effect and other factors, and accurately test the throughput of 5G base station. Based on the CDL-C NLOS fading channel defined by 3GPP, under 100MHz bandwidth and 3km/h speed: the base station adopts single-user 4-stream scheduling, and the measured average downlink throughput is 1.14Gbps, which exceeds 70% of the theoretical peak value.

Phase 3 Interoperability Research and Development Testing (IoDT) was a top priority and yielded promising results. The chip manufacturer's 5G terminal test platform and system conduct interoperability R&D tests, laying the foundation for the IoDT of subsequent chips; Qualcomm's 5G terminal test platform implements the NR new air interface physical layer; Intel's 5G terminal test platform supports non-independent networking and independent networking Networking mode, supports 2.5ms dual cycle (DDDSU/DDSUU); UNISOC's 5G terminal test platform supports non-independent networking mode, supports 2.5ms dual cycle (DDDSU/DDSUU); Above 1.3Gbps; Intel and Huawei complete IoDT for NSA and SA.

Finally, Xu Fei concluded that the third phase of the 5G technology R&D test is progressing in a comprehensive and orderly manner. Adopt 3GPP international standards, formulate all test specifications, coordinate and unify main physical layer parameters, and know the research and development of 5G pre-commercial/commercial products; build 5G indoor and outdoor integrated test network environment, develop and build 5G radio frequency and performance test system, and timely meet test requirements; Comprehensively organize the collaborative R&D and testing and verification of 5G systems, chips, and instruments, complete the NSA system testing, and the SA system testing process is more than halfway through, effectively promoting the gradual maturity of 5G technology and equipment. The next step will continue to accelerate the development and optimization of system equipment, chips, terminals, and instruments, and comprehensively carry out interoperability testing of systems and chip terminals.

Communication industry experts overcome difficulties and prepare for 5G

In the end, CAICT revealed for the first time the scenarios of the experts' diligent testing during the third phase of the test. They were not afraid of hardships and difficulties, and they devoted themselves to tackling key problems and actively preparing for the 5G that will be commercialized in more than 700 days.