3.5 GHz spectrum expansion: maintaining US 5G leadership

The 3.5 GHz (3.3-4.2 GHz) range has been widely used as the 5G launch band due to its robust capacity and city-wide coverage. Over 60 countries have assigned parts of the 3.5 GHz range for their 5G network deployments. The US options for maximizing the 3.5 GHz range for 5G development are outlined in a new GSMA report.

The US is among an elite group of countries pioneering 5G deployments and innovation. The country boasts high 5G coverage, speeds, and adoption rates. This development can continue, but while the US has shown early progress, it has yet to demonstrate a clear path to increasing mid-band capacity. The growth of 5G and its economic potential of the 5G ecosystem are at risk.

Extension of the 3.5 GHz band for 5G is an available tool to maintain US status as a 5G leader. It will deliver the capacity required to drive US connectivity in the era of 5G-Advanced technologies.

Economic impact of 5G in the US

In 2030, 5G is expected to generate $960 billion in GDP, with the majority of benefits (65%) driven by mid-band spectrum. North America is set to represent almost 25% of the global benefits generated by mid-bands – this spectrum range alone can generate a positive impact on national GDP of 0.36% in 2030. As well as the measurable economic impact of mid-band 5G technology and services, further benefits are expected, such as improved access to healthcare and education, increased public security and response times, safer driving conditions, and reduced pollution. However, if spectrum is constrained to today’s levels, there would be a 40% loss to the socio-economic benefits of 5G.

The mobile industry is agnostic about how that mid-band demand can be met but there are common themes in how countries are addressing this:

  • By maximising the 3.5 GHz range up to 4.2 GHz and even considering below 3.3 GHz
  • By relying on adding more spectrum using 6 GHz for mobile – another 700 MHz of capacity

However, in the US, the entirety of the 6 GHz band will not be made available for licensed 5G in the forseeable future. This makes the expansion of the 3.5 GHz range an essential option for continued capacity growth in the US market.

Current 3.5 GHz status in the US

In the US, the band 3.45-3.98 GHz is available for mobile use through several licensing mechanisms, although there are restrictions in various parts of it. A portion of the band (150 MHz) is dedicated to Citizens Broadband Radio Service (CBRS), a shared band with restrictive base station power limits. Most of the CBRS band (80 MHz) is limited to general authorized access for unlicensed use (e.g., private networks).

The 150 MHz in the lower part of the band, below 3.45 GHz is an option for 5G but remains unavailable for 5G services in the US due to its use for military radars. However, 5G coexists in the lower 3.5 GHz band in several countries alongside military and NATO radar systems. This is supported by mechanisms such as frequency separation (i.e., with radar use in 3.3-3.4 GHz and 5G operating in the adjacent band above 3.4 GHz) or geographical separation (i.e., where one geographic area uses the band for 5G, and adjacent locations are optimized for radars).

To support the need for more dedicated mid-band spectrum in the US, stakeholders must work collaboratively to investigate options for clearing, tuning, or increased coordination in the lower 3.5 GHz range. 

Policy recommendations

Without 6 GHz – at least in the foreseeable future – the US does not have the same mid-band options as other countries. Considering the lower part of the 3.5 GHz band is one of the best harmonized pieces of 5G spectrum left in the US.

To fully benefit from 3.5 GHz connectivity, the GSMA recommends that the US:

  • Analyzes optimal use of the lower 3.5 GHz band and considers the use of the band 3.3-3.45 GHz for mobile.
  • Considers measures including retuning, relocation or compression of the existing military radar bands or a variety of coexistence mechanisms which would make the band available on a predictable basis.
  • Considers the international use of the 3.5 GHz range and international best practice of coexistence from countries with radar systems and mobile in similar ranges.