Qualcomm and Ericsson reached peak speeds of 2.5 Gbps in a 5G standalone carrier aggregation test in the 2.5 GHz TDD band.
To hit 2.5 Gbps, the connection aggregated 100 MHz and 60 MHz within the 2.5 GHz (n41) TDD band in a 70% downlink configuration and using 4×4 MIMO. That is the “near peak theoretical rate” for that configuration, according to Bassil Elkadi, Qualcomm’s director of communications.
Qualcomm Technologies tweeted on Monday that the test used the company’s Snapdragon X60 Modem-RF system with Ericsson infrastructure. It took place in a test environment in Ericsson labs in Beijing this July, according to Qualcomm. There was no operator partner involved.
It’s believed to be the first public example of a successful 5G standalone carrier aggregation (CA) test in TDD 2.5 GHz band.
Carrier aggregation combines spectrum channels (sometimes referred to as component carriers). It’s helped boost 4G bandwidth as an LTE-Advanced technology. 5G carrier aggregation is getting attention as a way to help improve spectral efficiency, with increases in coverage and capacity.
Verizon hit 4.2 Gbps with Samsung and Ericsson on its live 5G network in February by combining eight channels of millimeter wave spectrum. In May, Fujitsu and Qualcomm completed a multi-gigabit 5G NR call using carrier aggregation. The data connection was established in non-standalone (NSA) mode and aggregated spectrum on the 3.5 GHz and 4.9 GHz bands.
Globally, most operators have deployed 5G using high-capacity sub-6 GHz or millimeter wave TDD (Time Division Duplex) spectrum. In the U.S. only T-Mobile has activated mid-band 2.5 GHz spectrum for 5G. Operators, like Verizon, have deployed mmWave in small pockets. But for broader coverage in the U.S., T-Mobile and AT&T have relied on low-band (sub-1 GHz) FDD spectrum that performs more like 4G LTE.
Ericsson will offer a commercial release of 5G NR carrier aggregation in the fourth quarter this year, “allowing service providers the opportunity to launch 5G services that utilize and benefit from Ericsson 5G Carrier Aggregation,” a spokesperson said via email.
In a Monday blog post, Ericsson’s Lee Forland and Raquel Herranz highlighted the vendor’s 5G carrier aggregation product that combines low-band FDD (Frequency Division Duplex) and mid-band TDD for better coverage, among other benefits.
“By increasing mid-band coverage and network capacity, many more users benefit from access to the mid-band spectrum layer,” wrote Forland and Herranz. “Today, most common 5G NR deployments use the dual connectivity configuration between the mid-band and LTE low-band to establish non-standalone (NSA) 5G services. In contrast, our low/mid-band 5G carrier aggregation solution boosts mid-band coverage by up to 7dB versus traditional dual connectivity deployments – which, in simple terms, is equivalent to a 25 percent increase in population coverage.”
With more users off-loaded from low-band onto mid-band, overall capacity increases by 27%, the post said.
Competitor Nokia in May had called out dual connectivity in its own carrier aggregation tests.
As noted, operators have largely deployed 5G in NSA mode, which relies on LTE as an anchor. The shift to standalone 5G is on though, with T-Mobile as the first U.S. operator to launch 5G in SA mode earlier this month. Verizon in July expected to start moving initial traffic over to its new 5G SA core by the end of 2020, with full commercialization in 2021. AT&T plans to start deploying 5G SA toward the end of this year, with a phased approach for implementation.
Speaking on FierceWireless 5G Blitz Week panel, AT&T’s Igal Elbaz called out carrier aggregation as key to scaling 5G SA.