- Dynamically using 4G spectrum for 5G could be a useful interim step...
- ...Especially since the US won't auction mid-band frequencies until next year
- But it's a question of how fast Verizon can move from the lab to the field
With the Federal Communications Commission not due to auction mid-band 5G spectrum until at least the second half of 2020, Verizon is looking at dynamic spectrum sharing to augment its patchy 5G coverage with frequencies currently used by its 4G network.
The US telco has just announced a successful lab trial with Ericsson and Qualcomm, which saw it conduct a DSS 5G data call. The technology is capable of switching 5G service onto 4G spectrum within milliseconds, based on traffic demand. DSS will work on any 5G smartphone equipped with Qualcomm's Snapdragon X55 modem – its second-generation 5G modem – unveiled in February.
US players AT&T and Verizon went straight to mmWave spectrum for their 5G deployments. Great for throughput, but not for coverage, so more sites are needed. Meanwhile, most of the rest of the world has focused its 5G efforts on mid-band frequencies, allowing them to reuse existing masts and therefore making it faster and cheaper to deliver 5G coverage.
"We will continue to focus on providing 5G over millimetre wave – especially in high density areas like airports, stadiums and urban areas – in order to continue to deliver the unique experience customers associate with 5G and that are only possible on mmWave technology," said Adam Koeppe, senior vice president of network planning at Verizon. "However, with Dynamic Spectrum Sharing we will be able to supplement mmWave deployments and accelerate the deployment of 5G in low and mid band spectrum for customers as we continue to build out our Ultra Wideband network."
Behind the curve
As mentioned above, the FCC has been slow off the mark when it comes to selling off that all-important mid-band 5G spectrum. Chairman Ajit Pai announced in September that the regulator would hold a vote on inviting comment on its plan to auction 70 MHz of 3.5-GHz spectrum on 25 June next year. Last week, he announced via Twitter that next year the FCC also plans to auction 280 MHz of 3.7-4.2-GHz spectrum – the so-called C-band, currently used by satellite operators.
By comparison, for anyone still wondering whether the US is a 5G coverage laggard:
- UK regulator Ofcom auctioned 190 MHz of 2.3-GHz and 3.4-GHz spectrum in April 2018.
- South Korea sold off 3.5-GHz spectrum in June 2018.
- Italy sold 700-MHz, 3.6-3.8-GHz and 26-GHz spectrum in October 2018.
- The UAE's Telecom Regulatory Authority allocated spectrum in the 3.3-3.8 GHz range in November last year.
- China allocated 3.5-GHz, 2.6-GHz, and 4.8-GHz spectrum to telcos in December 2018.
- Switzerland auctioned the 700 MHz, 1400 MHz, and 3.5 GHz bands for 5G this February.
- Germany completed its contentious auction of 2-GHz and 3.6-GHz frequencies in June.
- France's Arcep, which has been sluggish in getting its act together, is ready to auction mid-band 5G spectrum next spring.
These examples were chosen because they are all developed economies, in different corners of the world. The kind of countries that the US is competing with when it comes to mobile technology leadership.
As OpenSignal revealed in late October, US 5G customers only spend around 1 percent of their time actually connected to a 5G network.
With all this in mind, the motivation behind Verizon's DSS push is obvious.
"Dynamic Spectrum Sharing is essential for broad 5G coverage and we're excited to collaborate with Verizon and Ericsson on this significant milestone for the US," said Joe Glynn, vice president, business development, Qualcomm Technologies. "DSS is a game changing technology that is imperative to drive a faster transition to commercial 5G global rollout."
The only issue is, DSS between 5G and 4G is still in the lab. It hasn't gone into the field yet. So the question is, can Verizon get DSS rolled out before the mid-band auctions take place?
Verizon said DSS will be commercially deployed "in the near future", but hasn't said exactly when. It will have to move fast if it is to reap the maximum benefit that comes from tapping those 4G frequencies to improve its 5G coverage.
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