With the rollout of 5G well underway, attention is shifting to how to provide the licensed spectrum necessary for future generations of wireless networks.

A new white paper report from 5G Americas maps out a strategic roadmap for meeting 5G-Advanced and 6G spectrum needs. 5G Americas is an industry trade organization focussed on helping to grow and advocate 5G technology. The report titled, “The Evolution of 5G Spectrum” emphasizes that developing a comprehensive licensed spectrum pipeline is crucial for deploying advanced capabilities.

While 5G is still being built out, stakeholders are already looking down the road at 6G requirements. 6G may come online around 2030 and is expected to support new use cases like multi-sensory extended reality, holographic communications and joint communication and sensing. These types of immersive and intelligent connectivity applications will require even more bandwidth and low latency.

Enterprise use cases will also help fuel the need for additional licensed spectrum. As industries digitize operations and connect daily workflows, reliable wireless connectivity is crucial.

“Releasing more licensed spectrum for the wireless industry is critical for U.S. leadership in technology, mobile communications and the economy,” said 5G Americas President Chris Pearson.

5G has already revolutionized mobile Broadband speeds and latency.

However, the report notes that the next wave of 5G evolution will move beyond mobile phones to support new services across vertical industries. Potential future use cases could include extended reality, connected cars, fixed wireless access (Fixed-Wireless Access) and Enterprise applications. To make these next-generation experiences possible, the industry will need access to additional spectrum capacity.

An estimated fourfold increase in cellular traffic is expected by 2028. In response, the International Telecommunications Union recently identified frequencies up to 15.5 GHz for future wireless use. The paper endorses making more spectrum available to support the demands of both existing and future applications.

The report specifically identifies the so-called “mid-band spectrum,” which operates between 7.125-15.35 GHz as potentially helping to meet future 5G needs with a  balance of capacity and coverage capabilities. In the U.S, T-Mobile has been particularly active over the last two years building out mid-band spectrum capacity.

5G Americas recommends exploring relocations and sharing strategies to open up bands in this range, especially below 10 GHz, for licensed 5G operations. Networks can leverage existing infrastructure in these frequencies.

To support new 5G and future 6G applications, the briefing paper recommends focusing on these mid-band ranges:

• 3.1-3.3 GHz: Being considered in the U.S. and can leverage existing infrastructure.
• 4.4-4.8 GHz: Identified globally for study towards IMT usage.
• 7.125-8.5 GHz: Enables desired coverage and capacity needs.
• 12.7-13.25 GHz: Challenging for coverage but high capacity potential.
• 14.75-15.35 GHz: Also being explored for global IMT identification.

With current licensed allocations, the U.S. trails global leaders in mid-band spectrum availability. Leading markets like China and Japan have over 1 GHz allocated in mid-band spectrum crucial for widespread 5G deployments. 5G Americas claims that more spectrum is needed domestically across low, mid and high bands to maintain 5G leadership.

While capacity is more limited, the report notes that millimeter-wave (mmWave) bands allow very high bandwidth that suits dense zones and specialized use cases.

The use of mmWave to help support 5G and future 6G networks has been a topic of discussion since at least June 2023, when the Federal Communications Commission announced it was looking at that slice of spectrum.

Deployments in urban cores, transportation hubs, entertainment venues and for FWA are well-matched applications for mmWave, according to 5G Americas. The paper observes that mmWave will continue to be important for 6G systems.

Still higher frequencies in the sub-THz (sub terahertz) range offer massive bandwidth for future 6G applications. Sub-THz spectrum enables new capabilities by supporting extremely high data rates and capacities.In early 2023, NTT and Nokia both detailed research efforts to use sub-THz for future 6G use cases.