Is 5G-Advanced headed for trouble in the US?

According to the GSMA, the 6GHz spectrum band will be used for 5G-Advanced services in the second half of this decade. But that band won't be available to big US wireless network operators, which is stirring up concerns among lobbying groups and others in the 5G industry.

In 2020 the FCC allocated the entire 6GHz band to unlicensed operations like Wi-Fi, precluding wireless operators from using it. But operators outside the US have access to the band.

"The 6GHz band – which has been allocated for unlicensed access in the United States across the full 1,200 megahertz – is now earmarked to be the harmonized home for licensed mobile in the top half of the band for a majority of the world," wrote Umair Javed, SVP of spectrum for CTIA, the main US lobbying association for 5G network operators, on the association's website. Before joining CTIA last year, Javed was chief counsel for the FCC, the primary regulatory agency for spectrum in the US.

Javed warned that new international regulations will give operators in other countries a leg up on those in the US. The 6GHz band "is not available in the United States [to 5G operators], again underscoring the need for the US to identify a viable path for itself and the countries following our lead on replacement spectrum for future wireless use," he wrote.

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Others agree on the importance of 6GHz to 5G operators. The financial analysts at New Street Research described the band as "potentially transformative."

"We believe the allocation of the upper-6GHz band [to 5G] has significant implications for the evolution of mobile networks over the mid-term (i.e. 2030+)," the analysts explained in a recent note to investors, adding that allocation to cellular networks would give operators more options for capacity expansion.

"This spectrum could be ideal for providing urban capacity close to macro cell sites, allowing existing bands to be used in the outer edges of the cell, thereby materially increasing overall network capacity with limited incremental capex," the analysts wrote.

An international debate

In April 2020, former FCC Chairman Ajit Pai, who was appointed by President Trump, explained the reasons to set aside the full 6GHz band for unlicensed operations: "By doing this, we would effectively increase the amount of spectrum available for Wi-Fi almost by a factor of five. This would be a huge benefit to consumers and innovators across the nation. It would be another step toward increasing the capacity of our country's networks. And it would help advance even further our leadership in next generation wireless technologies, including 5G."

But that proposal ran counter to the position of the 5G industry in the US, which urged the FCC to allocate all or a portion of the band to licensed operations like 5G.

US regulators hoped that other countries would follow its lead and allocate the 6GHz band for Wi-Fi. But in 2023 China's regulators instead set aside a large chunk of the 6GHz spectrum band for 5G network operations, sparking concern among 5G players in the US. "We risk having Chinese networks that are materially better at enabling the industries of the future," wrote Doug Brake, a CTIA policy official, at the time.

The debate eventually moved to the World Radiocommunication Conference (WRC-23), which wrapped up late last year in Dubai, United Arab Emirates (UAE). The quadrennial event is intended to harmonize spectrum usage across the world so that operators, equipment vendors and others can avoid international fragmentation and leverage global economies of scale.

WRC-23 officials agreed to support both licensed and unlicensed operations in the 6GHz band, depending on what local regulators decide.

"This therefore still leaves the door open for regional and national regulators to licence the band to mobile or Wi-Fi, or potentially a 'hybrid sharing' arrangement between the two technologies," explained the New Street analysts.

In Europe, regulators have agreed to study how mobile and Wi-Fi could coexist within the 6GHz band, though no final decisions are expected until 2026.

"For the European operators, this avoids the negative scenario that the band is exclusively allocated to Wi-Fi – as has been the case in the US, Canada, South Korea and Brazil," the New Street analysts wrote.

Looking ahead

The 6GHz band is "a 5G expansion band that will be used for 5G-Advanced in the second half of this decade, so getting that ecosystem push from the regulatory result was really important," Ross Bateson, spectrum director at GSMA, told TelecomTV. The GSMA, an international trade association for the 5G industry, has been campaigning for 5G in the 6GHz band. The group cheered the new 6GHz rules approved at the WRC-23.

As Light Reading previously reported, "5G-Advanced" is the brand name selected by the 3GPP for its Release 18 standards. The 3GPP is the primary standards group developing 5G technologies. It issues packages, or releases, of specifications for new wireless networking technologies roughly once a year. 5G first showed up in the group's Release 15 in 2017. Release 18 is currently scheduled for full availability in early 2024.

Not surprisingly, 5G equipment vendors are eager to sell new 5G-Advanced equipment.

"With AI/ML as a key component, in addition to other technologies, 5G-Advanced systems will enable support for cutting-edge technologies such as extended reality (XR) and reduced capability (RedCap) devices, while enhancing network energy efficiency," boasts Ericsson on its website.

And Qualcomm early last year outlined a wide range of technologies it hopes will be available through 5G-Advanced, including improved MIMO and lowered energy consumption.

Using other bands

It's likely that many of the technologies promised in 5G-Advanced can be implemented inside operators' existing spectrum holdings and will not necessarily need new spectrum like the 6GHz band. But wireless network operators have shown plenty of interest in debuting new technologies inside fresh, unused spectrum bands. For example, Verizon in the US is deploying its speedy 5G network via its new C-band spectrum holdings.

But such spectrum bands must also support the right usage characteristics for 5G. For example, 5G network operators in the US have generally shied away from the 3.5GHz CBRS spectrum band because of its lower power limits. "It needs to be at full power so we get full propagation and benefit with our infrastructure," explained AT&T's Chris Sambar at a recent industry event, according to FierceWireless.

The analysts from Signals Research Group agreed, writing in their analysis of Verizon's early CBRS deployments that "CBRS is impractical for macro network coverage due to its low power limitations."

Sambar explained that AT&T isn't a heavy user of the CBRS band because it would need to build more transmission sites in order to fully cover large cites. AT&T and other companies have proposed raising the power levels for CBRS transmissions, but so far the FCC hasn't acted on that topic.

Meanwhile, the Wi-Fi industry is gearing up to put the 6GHz band into use in the US and elsewhere. According to IEEE Spectrum, a new version of the Wi-Fi standard – Wi-Fi 7, due later in 2024 – will support multi-link operations (MLO) technology, which transmits data across multiple channels in a single frequency band leading to better reliability. And 6GHz is expected to boost the performance of Wi-Fi gadgets working in the band.