Providing high-speed, low-latency, and high-reliability services, the 5G network plays an important role in the transformation from “Made in China” to “Created in China”. The Chinese Ministry of Industry and Information Technology started 5G-related tests in 2016 with the aim to promote the commercialization of 5G. Taking advantage of this opportunity, China’s 5G industry has been advancing rapidly. Together with China Mobile, China Telecom, and China Unicom, ZTE has carried out 5G field tests in various places, providing an integrated end-to-end solution including 5G CN, base station, and test UEs. This solution is developed and verified based on system prototypes developed under the 3GPP SI framework, which promotes the finalization of the product architecture and completion of pre-commercial product specifications.
ZTE establishes its industry-leading position in 5G by creating numerous records. In June 2017, ZTE and China Mobile established the world's first pre-commercial 5G base station in Guangzhou. In the following November, China Mobile, ZTE, and Qualcomm completed the world's first end-to-end 5G NR interoperable system based on 3GPP standard at China Mobile's 5G Joint Innovation Lab. On November 8, 2017, the first 5G field call for China Telecom was successfully made in Xiong'an and Suzhou. In January 2018, ZTE was the first to complete China Mobile's 5G field test with excellent results. In March 2018, ZTE, together with China Telecom and Baidu, completed China’s first autonomous driving road test based on a 5G network environment in Xiong'an, advancing the research on 5G application scenarios.
Comparison Tests to Verify 4G/5G Co-Site and SA Feasibility
China's three major operators pay close attention to the coverage capability of 3.5 GHz NR. Whether 5G base stations can be co-located with 4G base stations determines the network architecture of 5G. Consequently, the three operators carried out comparison tests between 3.5 GHz NR and different LTE frequency bands.
3.5 GHz NR vs. 2.6 GHz TD-LTE Comparison Tests to Verify Featured Enhancement Technologies
During the field test in Guangzhou, ZTE and China Mobile jointly completed tests on complicated items within the shortest time. They obtained the ultimate performance data and verified a single 5G NR base station's performance and multi-site networking capability.
In the Lab Building of Guangdong University of Technology in 2017, comprehensive indoor and outdoor tests were carried out, covering various types of scenarios. Multiple groups of data were obtained from the best to the worst points. Generally speaking, the 5G coverage at 3.5 GHz was better than the LTE coverage at 2.6 GHz. While penetration was weak in the field, there were significantly higher gains in a mid-field or far-field position. 5G Massive-MIMO and outdoor NLOS conditions can fully verify the networking capability of 3.5 GHz NR equipment. The connection dropping point of the 64TR 3.5 GHz NR was further than that of the 2.6 GHz LTE. For an isolated site with the LOS range extended by 3 km, the downlink rate could still reach 300 Mbps and the uplink rate 0.4 Mbps. The coverage of a single 3.5 GHz cell and the remote deployment results for an isolated site were both satisfactory.
At the Nantingcun site in Guangzhou, coverage of broadcast synchronization channels were enhanced. A 5G base station was deployed on a 45-meter sightseeing tower. With an extended coverage radius of 1.2 km, it served ±30° segment of the horizon. The wide beam configuration and narrow beam configuration were used in the tests that included multiple points. The results showed that the four-beam configuration had an average gain of 3 dB, in comparison with the single-beam configuration, and was good for vertical beam configuration. The PDCCH beamforming coverage enhancement technology and the PUCCH coverage enhancement technology have been proven to be capable of overcoming the weaknesses of 4G and giving full play to the advantages of 5G Massive-MIMO.
3.5 GHz NR vs. 1.8 GHz LTE FDD Comparison Tests in Different Near-Commercial Scenarios
In the 5G field test carried out by ZTE and China Unicom in Xili, Shenzhen, a coverage capability comparison between 3.5 GHz NR and 1.8 GHz FDD could truly reflect their performance in real-world coverage environments.
In a scenario where indoor coverage was provided by outdoor base stations, 17 test points were selected on two floors of a test building. RSRP showed that good, medium, and bad points were included in the 17 test points. The comparison results demonstrated that at each point the uplink rate at 3.5 GHz NR was better than that at 1.8 GHz FDD LTE, and at 16 points the uplink rates at 3.5 GHz NR had over 100 percent gains over those at 1.8 GHz FDD LTE.
In a remote base station deployment scenario, ZTE carried out common drive tests and ultimate drive tests separately. In a common drive test, at 99.7 percent of the test points, the 3.5 GHz uplink throughput was higher than the FDD 1.8 GHz uplink throughput. Most test points had over 100 percent gains. The preliminary 5G field tests showed that the uplink coverage of 3.5 GHz NR was better than that of 1.8 GHz FDD LTE. The 3.5 GHz NR sites can be planned based on the locations of the 1.8 GHz FDD LTE sites to achieve continuous coverage.
3.5 GHz NR vs. 1.8 GHz LTE FDD Comparison Tests in More Scenarios to Verify Co-Location Capabilities of 3.5 GHz NR
China Telecom and ZTE carried out tests in Suzhou and Xiong’an to compare 3.5 GHz NR and 1.8 GHz LTE in terms of uplink and downlink coverage. Test results showed that the coverage distance, the uplink and downlink performance of 5G were obviously better than those of 4G.
Coverage comparison tests completed by multiple operators in multiple areas and multiple scenarios showed that 5G outperformed 4G in both uplink and downlink rates, and its edge rates had nearly 100 percent or even higher gains, proving the feasibility of standalone 3.5 GHz NR network architecture.
Complicated Items Tested with Great Results
In addition to coverage tests, ZTE has also carried out a series of field performance verification tests. In a scenario where the downlink resource usage ratio was 70 percent, the low-frequency SU-MIMO single-UE peak throughput exceeded 2 Gbps, and the single-cell peak throughput exceeded 6 Gbps, providing strong support for future eMBB scenarios. The assessment of the real capacity in typical densely-populated urban areas showed that user experience improved 10–100 times in comparison with 4G. The assessment of bidirectional latency in real multi-site networking environments showed that the latency of 5G was 1/3–1/5 times lower than that of 4G, making it ready for new service development. ZTE took the lead in carrying out assessments of 5G network architecture and mobility, accumulating valuable experience for future large-scale tests. In labs and field environments, ZTE conducted 26 GHz high frequency tests in various scenarios, exploring future 5G high-frequency commercial environments. ZTE completed three-party OTA verification for the first time, laying a foundation for verification of specifications for automated high-performance products. ZTE was the first to verify the dynamic scalability of cloud-based CUs, accumulating experience in defining their hardware specifications and exploring their network architecture. The first MEC service commissioning and hardware power consumption tests promoted the industry to think deeply into practical field deployment issues.
Leading-Edge 5G Service Experience
The 5G experience car unveiled during the China Mobile Global Partners Conference 2017 in Guangzhou allowed users to enjoy HD VR videos and view maps, dynamically changing tracks, speeds per hour, and real-time and historical uplink/downlink data. The IoDT test based on the 3GPP 5G NR standard was broadcast live to the conference. Moreover, cloud games based on the MEC architecture, 5G autonomous submarine, and ultra-high bandwidth video transmission by 5G UVA were also showcased, allowing people to experience 5G services before entering the 5G era.
In March 2018, together with China Telecom and Baidu, ZTE completed China’s first autonomous driving road test based on a 5G network environment in Xiong’an. This event is expected to kick off 5G’s application in autonomous driving and push forward commercialization of 5G. In this test, the three parties focused on verifying the 5G air interface transmission solution for dynamic incremental data of 3D high-precision map, including dynamic incremental updates to 3D maps from vehicle to cloud (V2C) and vehicle to vehicle (V2V) transmission.
ZTE's 5G field test sites in various areas have been gradually expanded and the number of verification scenarios have also been increased. It is believed that ZTE will achieve more breakthroughs in 5G technology and provide high-quality 5G network services for operators around the world.
[Keywords] 5G Field Tests, China Mobile's 5G Joint Innovation Lab, 4G/5G cosite, 3.5 GHz NR, co-location