The ITU Vision and Framework for 6G: Scenarios, Capabilities and Enablers

I. INTRODUCTION

• 5G still faces industrial integration and energy-efficiency challenges, including complex operations and legacy systems, motivating research beyond 5G-Advanced.The paper presents 6G as a prospective source of more integrated features adaptable to different needs.Source: §I · p. 1
• The paper’s objective is to summarize official 6G recommendations and decisions on usage scenarios, capabilities, technology enablers, and potential spectrum.6G is expected after 2030, while research projects and standards development organizations have begun conceptual work.Source: §I · p. 1

II. ITU-R EFFORTS IN DEFINING 6G

• ITU-R WP5D develops and evaluates terrestrial IMT systems, while 3GPP develops detailed technical specifications.WP5D’s work includes a framework recommendation, technical performance requirements, evaluation criteria, and submission templates.Source: §II · p. 1
• The 6G framework recommendation was completed in June 2023 and approved in November 2023; WP5D’s evaluation decisions are expected no earlier than 2029.The recommendation’s capability values are ranges subject to further specification, with deployment scenarios and evaluation methods to be developed during the technical phase.Source: §II · pp. 1–2
• 3GPP Release 20 is expected to start 6G study and self-evaluation in mid-2025, and Release 21 is targeted as the first 6G specification release.3GPP agreed to freeze that first release no earlier than the first quarter of 2029.Source: §II · p. 2

A. Usage Scenarios

• In 6G, the three classic usage scenarios are enhanced to immersive communication, massive communication, and hyper reliable and low-latency communication (HRLLC), alongside ubiquitous connectivity, ISAC, and AI and communication.Fig. 2 depicts the six usage scenarios in the “6G wheel”.Source: A. Usage Scenarios · p. 2, Figure 2 · p. 3
• Immersive communication targets bandwidth-intensive uses such as XR and holography, HRLLC addresses stricter reliability and latency needs, and massive communication supports many devices in a small area.Examples include remote telesurgery, autonomous driving, industrial control, and dense industrial sensor networks.Source: A. Usage Scenarios · p. 2
• Ubiquitous connectivity targets uncovered or sparsely covered areas through possible interworking with other access systems, including rural and remote regions.Typical uses include Internet of Things and mobile broadband communication.Source: A. Usage Scenarios · p. 2
• ISAC can support services such as mapping, tracking, and disaster monitoring, but must balance sensing and communication for shared resources and establish a viable operator business model.The paper notes that prior generations did not provide sensing as a service or offer experience with this trade-off.Source: A. Usage Scenarios · p. 2
• AI-and-communication services could combine functions under one supplier, such as processing surveillance video for anomalies before uploading selected clips for human inspection.The paper describes this as a way to spare customers from purchasing and integrating separate services.Source: A. Usage Scenarios · pp. 2–3

B. Overarching Aspects

• 6G design should account for sustainability, security and privacy, digital inclusion, and intelligence throughout the network and across all usage scenarios.Sustainability includes lower power consumption and equipment with longer life cycles and less environmental impact; digital inclusion addresses regions still relying on old networks.Source: B. Overarching Aspects · p. 3

C. Capabilities

• 6G is expected to enhance capabilities in almost all dimensions; peak data rates are given as 200 Gbps for 6G versus 20 Gbps for 5G.The range values are estimated targets for research and investigation, rather than finalized requirements.Source: Figure 3 · p. 4, C. Capabilities · p. 4
• The capability targets remain provisional: ITU-R will refine metrics during the TPR phase, and some ranges lack consensus or are stated qualitatively.Values within a stated range are treated with equal priority, including its upper and lower bounds.Source: C. Capabilities · pp. 3–4
• Capability items are linked to usage scenarios for TPR and evaluation, but only representative items from the broad set of relevant capabilities will be tested.Table I presents a correspondence between the six scenarios and capability items.Source: C. Capabilities · p. 4, Table I · p. 4

IV. TECHNICAL ENABLERS

• Candidate technologies contribute to different aspects of 6G, with their benefits and challenges summarized in Table II.Fig. 4 depicts prospective technology enablers.Source: §IV · p. 4, Table II · p. 5, Figure 4 · p. 5

A. AI

• AI for communication can compress UE channel feedback for reconstruction at the BS and support sensing, resource allocation, scheduling, planning, and optimization.A two-sided AI model uses an AI-based UE encoder and a corresponding BS decoder to reconstruct channel state information.Source: A. AI · p. 4
• Communication for AI requires enhanced uplink capacity for model-training data and core-network changes that move computation toward the edge.A service-based architecture and accurate QoS control are proposed as examples; AI services may also benefit from RAN slicing.Source: A. AI · pp. 4–5
• AI-enabled cross-layer designs are identified as a research opportunity for pursuing global optima beyond layered system design.The passage presents this as an area deserving further research.Source: A. AI · p. 5

B. ISAC

• 6G must intrinsically integrate communication and sensing into one system while meeting both functions’ requirements and minimizing overall cost, size, and power consumption.The integration may extend beyond the physical layer to higher layers and the core network, potentially requiring nodes to coordinate both functions.Source: B. ISAC · p. 5
• ISAC research challenges include near-field electromagnetic modeling, waveform design, joint beamforming, power saving, synchronization, duplexing, and balancing sensing accuracy with robust communication.The paper also identifies unified channel models and cross-domain waveform designs as beneficial research directions.Source: B. ISAC · p. 5
• Standardization must address new air interfaces and core-network changes, while integration choices affect mutual enhancement, cross-link interference, and sensing-band coordination.Sensing bands require careful selection where adjacent operators’ allocations could create inter-operator interference.Source: B. ISAC · p. 6

C. Reconfigurable Intelligent Surface (RIS)

• RIS dynamically manipulates electromagnetic waves between transmitters and receivers by changing reconfigurable-element phase shifts and amplitudes.This turns the wireless environment into a service.Source: C. Reconfigurable Intelligent Surface… · p. 6
• Compared with 5G relays and repeaters, nearly passive RIS components can reduce implementation cost and energy use, while large apertures and many reflective elements support sharp beams and better positioning and sensing resolution.RIS can also provide extra degrees of freedom in the near field.Source: C. Reconfigurable Intelligent Surface… · p. 6
• Passive RISs cannot perform channel estimation, signal regeneration, or amplification, motivating active RIS designs and advanced signal processing, compressed sensing, and AI.Short coherence times also make channel estimation challenging; direct BS control and network planning and optimization are proposed approaches.Source: C. Reconfigurable Intelligent Surface… · p. 6

D. Full Duplex Operation

• Full duplex enables simultaneous uplink and downlink on the same frequency bands and could theoretically double system capacity, but transmit self-interference can overwhelm the receive signal.The interference arises because a transceiver’s receive antennas also receive its much stronger transmitted signal.Source: D. Full Duplex Operation · p. 6
• Successive interference cancellation, high-isolation antennas, and subband full duplex are approaches to mitigating interference, with practical-environment trials supporting the methods.Subband full duplex uses full duplex only at the base station; mitigation can combine antenna isolation and digital signal processing for several interference types.Source: D. Full Duplex Operation · p. 6

E. RAN Slicing

• RAN slicing creates logically independent networks on shared physical infrastructure, with slices configured for users’ distinct requirements.Slices may differ in time and frequency resources as well as supported quality of service.Source: E. RAN Slicing · p. 6
• RAN slices can serve different industrial needs, such as factory video inspection’s uplink bandwidth and robots’ ultra-low-latency control, but require flexible design and timely configuration and management.AI is identified as a potential way to address the slice configuration and management challenge.Source: E. RAN Slicing · p. 6

F. RAN Infrastructure Sharing

• Sharing RAN infrastructure can lower operators’ costs and support new business models, but requires transparent cost and usage tracking alongside reliable, private, efficient operation.Blockchain is proposed as a decentralized, difficult-to-manipulate ledger trusted by all parties.Source: F. RAN Infrastructure Sharing · p. 6
• RAN sharing is expected to become a 6G trend that contributes to affordable connectivity for more regions and users and helps overcome the digital divide.Source: F. RAN Infrastructure Sharing · p. 7

V. SPECTRUM FOR 6G

• About 0.75 GHz for high-accuracy ISAC, 1 GHz for wide-area XR, and 1.1 GHz for holographic communications motivate 500 to 750 MHz of new spectrum alongside refarming existing bands.The passage says additional IMT spectrum should be assigned at WRC-23 and WRC-27.Source: §V · p. 7
• WRC-23 allocated 3.5 GHz across Europe, the Middle East and Africa, licensed 6.425 - 7.125 GHz globally, and assigned 10 - 10.5 GHz in the Americas with restrictions.The 10 - 10.5 GHz band is intended only for micro-cell BSs; some countries may use the allocations for 5G-Advanced because WRC-23 did not specify a generation.Source: §V · p. 7
• WRC-27 will study 4400 - 4800 MHz, 7125 - 8400 MHz, and 14.8 - 15.35 GHz for possible IMT allocation, with no other frequencies considered.The passage describes spectrum harmonization as a global, multi-stakeholder issue critical to 6G success.Source: §V · p. 7

• 6G aims to connect the whole human society and overcome the digital divide while addressing diverse demands.Source: §VI · p. 7
• Novel technology enablers and new spectrum allocations are identified as part of achieving 6G’s goal of supporting capabilities beyond previous generations.Source: §VI · p. 7
• The conclusion calls for a continuous effort by all stakeholders to develop a global 6G standard.Source: §VI · p. 7