YOU ARE AT:Test and MeasurementTest and Measurement: SRG finds 'stellar' uplink performance in Tokyo's mmWave

Test and Measurement: SRG finds ‘stellar’ uplink performance in Tokyo’s mmWave

Japanese operators have deployed a significant amount of 5G millimeter wave coverage in Toyko with unobtrusive sites and are using carrier aggregation (2 x 100 megahertz) in the uplink to achieve speeds in the hundreds of megabits per second, according to a new Signals Research Group report. (Available here.)

The report, commissioned by Qualcomm, is SRG’s second examination of mmWave networks abroad. SRG noted that it has tested mmWave 5G in the uplink multiple times since 2020, and found it “good” but not particularly impressive, especially in comparison to the multi-gigabit speeds that mmWave supports in the downlink. In Tokyo, however, SRG described the uplink performance as “stellar.”

“It wasn’t uncommon to observe 5G mmWave uplink throughput … reach 300 Mbps while we documented a peak uplink throughput of 326 Mbps – jumping to 370 Mbps with the LTE anchor cell providing additional uplink throughput thanks to the use of PDCP combining,” the research firm wrote, adding that they were 115 meters from the serving cell site in that instance. In another test, they saw 5G uplink speeds just above 300 Mbps with a downlink speed of roughly 2 Gbps, using 400 megahertz of spectrum, at a distance of 160 meters from the site—and concluded that achieving uplink throughput of 100 Mbps at a distance of 200 meters is “entirely possible.”

Comparatively, SRG found that uplink speeds with mmWave 5G disabled (using only midband spectrum, Band n78/3.5 GHz), uplink speeds were “almost always greater than 50 Mbps and frequently near 70 Mbps, peaking at 80 Mbps,” which the firm contributed to light network loading on the uplink.

The 5G sites themselves were typically placed on top of multi-story buildings, although SRG did find one site with radios mounted on a street pole and one radio mounted just inside the entrance to the busy Tokyo Station transportation hub. “From our perspective, the placement of the radios on top of buildings provided excellent coverage although it made it very difficult to spot the sites with the naked eye,” the firm said in its report. “Without companion coverage maps from the operators which show the general locations of the radios we would have never located many of them.” The placement of radios provided “extensive coverage along the wide streets” and it sometimes extended both along the street at which the radio was pointed as well as the perpendicular street.

SRG tested 5G mmWave from NTT DoCoMo, KDDI, Softbank and Rakuten Mobile at two locations, using a combination of stationary and walk-testing. Despite overall impressive performance, the firm also identified a number of issues that could have improved it even further. In some dense areas, the firm saw “frequent/nearly continuous handovers involving the LTE anchor cell” and “some of the assigned LTE cells
were also not mapped to the adjacent 5G mmWave radio so the network had no way of knowing mmWave capabilities existed.” In addition, SRG said, “Timely handovers from mid-band 5G to 5G mmWave when entering mmWave coverage is another opportunity for improvement.” Those type of network issues aren’t a reflection of mmWave’s pure capability, but “something that an operator needs to include as part of the network optimization activities,” the report concluded.

SRG said that in its testing over the past three years, it has seen mmWave evolve: A 66% increase in the maximum sustained downlink data speeds over 5G mmWave, greater effective range and now, impressive improvements in uplink throughput. And the 5G standard continues to offer up new features to be implemented in the mmWave range that will improve performance even more. Four carrier aggregation in the uplink, for instance, “will further widen the performance gap between mmWave and mid-band 5G,” SRG said.

SRG used testing and analysis solutions from Spirent Communications and Accuver to conduct its mmWave benchmarking.

In other test news:

PCTel said that it has received multi-million dollar orders of its 5G scanning receivers from two of its largest network testing OEM customers. The orders, which include its Gflex and HBflex scanning receivers, will be delivered by the end of this year.

The company also announced this week that it is working with InfoVista to jointly develop 5G network test cases for use by network operators and government regulators, using a combination of its 5G scanning receivers and InfoVista’s TEMS software for network testing and optimization. The two companies said that the first set of use cases include C-Band interference monitoring, as well as autonomous testing, automatic site location detection, automated interference detection and configuration validation for beamforming.

PCTel’s Gflex scanner supports multiple sub-8 GHz and mmWave bands in a single unit, and the company says it is the first purpose-built walk-and-drive-test scanner that measures the full bandwidth of a 100-megahertz 5G channel and the first to support every 5G spectrum band that has been defined by 3GPP as of Release 17.

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Keysight Technologies is taking its Open RAN infrastructure test solutions to the cloud, announcing this week that its Keysight Open Radio Access Network Architect (KORA) is moving to a cloud-based deployment model and that its LoadCore 5G Core testing software (a component of KORA) is now available as a metered, pay-as-you-go offering in AWS Marketplace. Loadcore 5GC can perform capacity tests and measure device data throughput as well as modeling end-user behavior and mobility scenarios.

In related company news, Keysight said that Chinese company MICAS relied on its test solutions, including KORA, to achieve O-RAN Alliance certification for MICAS’ 5G Open RAN Radio Unit (RU).

Also this week, Keysight announced that Chinese company AI-LINK is using its 5G test tools for end-to-end performance validation of cloud-native 5G RAN equipment in a digital twin laboratory environment, focusing on 5G private network deployments for large-scale smart warehouse applications. More details here.

T-Mobile US continues to hold a dominant position in network performance over AT&T and Verizon on nearly every metric, according to Ookla’s latest analysis of mobile networks. For the second quarter of 2022, T-Mo landed the best numbers in download speed, upload speed, latency, performance consistency, overall video performance, 5G availability and 5G performance. Read more details here.

-Spanish operator Telefónica and Ericsson say they have demonstrated end-to-end, automated network slicing in 5G Standalone in a proof-of-concept lab test at 5TONIC, a Madrid-based open research and innovation laboratory. Telefónica said that the demo proved that the onboarding of a network slice, from core to radio, could be configured and deployed in less than 35 minutes through the use of automation. Full story here.

ABOUT AUTHOR

Kelly Hill
Kelly Hill
Kelly reports on network test and measurement, as well as the use of big data and analytics. She first covered the wireless industry for RCR Wireless News in 2005, focusing on carriers and mobile virtual network operators, then took a few years’ hiatus and returned to RCR Wireless News to write about heterogeneous networks and network infrastructure. Kelly is an Ohio native with a masters degree in journalism from the University of California, Berkeley, where she focused on science writing and multimedia. She has written for the San Francisco Chronicle, The Oregonian and The Canton Repository. Follow her on Twitter: @khillrcr

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