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The Shift to 6G Communications: Vision and Requirements
Muhammad Waseem Akhtar, Syed Ali Hassan, Rizwan Ghaffar, Haejoon Jung, Sahil Garg, M. Shamim Hossain
TL;DR
The paper addresses the need for B5G/6G networks that provide higher efficiency, lower latency, and massive connectivity than existing systems. It presents a vision and overview spanning architecture, air interfaces, enabling technologies, use cases, KPI requirements, challenges, and research opportunities, concluding that hardware complexity, resource allocation, power efficiency, interoperability, and security remain important challenges.
Problem
B5G/6G requires more robust networks than existing 5G systems to support massive access alongside high spectral and energy efficiency and low latency.
Method
The paper synthesizes 6G network architecture, air-interface components, enabling technologies, network dimensions, use cases, KPI requirements, and associated research directions.
Results
The paper presents 6G applications including pandemic-monitoring biosensors, autonomous robots for harsh environments, deep-sea exploration, and reliable low-latency vehicular and industrial communications.
Takeaways & Limitations
The review frames 6G as a potential platform for integrated, intelligent, and high-capacity communications across diverse applications and environments.
Takeaways & Limitations
Scalable techniques that guarantee interoperability among multiple radio access technologies while meeting 6G KPI requirements remain an open challenge, alongside security, privacy, and trust issues from large-scale IoT connectivity.
Abstract
from arXiv · showhide
The sixth-generation (6G) wireless communication network is expected to integrate the terrestrial, aerial, and maritime communications into a robust network which would be more reliable, fast, and can support a massive number of devices with ultra-low latency requirements. The researchers around the globe are proposing cutting edge technologies such as artificial intelligence (AI)/machine learning (ML), quantum communication/quantum machine learning (QML), blockchain, tera-Hertz and millimeter waves communication, tactile Internet, non-orthogonal multiple access (NOMA), small cells communication, fog/edge computing, etc., as the key technologies in the realization of beyond 5G (B5G) and 6G communications. In this article, we provide a detailed overview of the 6G network dimensions with air interface and associated potential technologies. More specifically, we highlight the use cases and applications of the proposed 6G networks in various dimensions. Furthermore, we also discuss the key performance indicators (KPI) for the B5G/6G network, challenges, and future research opportunities in this domain.
1 Introduction
The paper frames 6G as a robust next-generation network for massive connectivity, low latency, high efficiency, and advanced applications. It surveys projected architecture, technologies, dimensions, use cases, KPIs, challenges, and research directions.
- Motivation: IoT growth is driving demand for communication systems with high spectral and energy efficiency, low latency, and massive connectivity.IoT devices are projected to reach 25 billion by 2025, challenging existing multiple-access techniques.
- Motivation: 5G supports at most 50,000 IoT or NB-IoT devices per cell, motivating more robust massive-access designs for B5G and 6G.
- Paper scope: The paper surveys projected 6G architecture, including a new air interface, AI/ML, new spectrum, multiple radio access technologies, and intelligent beamforming.
- Paper scope: It organizes 6G network dimensions around cloudification, fog and edge computing, intelligence, softwarization, and slicing.
- Applications: Tactile Internet, holographic applications, space communication, space tourism, and advanced sensing are presented as prominent 6G use cases or applications.
- Challenges: The article discusses challenges including chip-size growth, mobile-user beamforming, pre-emptive scheduling, low latency, high reliability, and variable bandwidth and coverage.
2 6G System Architecture
The proposed 6G architecture combines intelligent networking, new air interfaces, expanded spectrum, and heterogeneous access technologies to support massive, diverse connectivity. It also explores AI/ML, beamforming, and higher-frequency bands while recognizing coverage and deployment challenges.
- System architecture: 6G architecture is expected to coordinate base stations, access points, satellites, UAVs, and end devices through intelligent networking and a new air interface.Devices and network nodes exchange location, capability, and QoS information, while resource management is coordinated across users.
- Artificial intelligence and machine learning: AI and ML are proposed for self-organization, self-healing, self-configuration, anomaly handling, and network decision-making.Suggested applications include channel estimation, CSI feedback, and decoding.
- Spectrum: THz and mmWave bands could provide massive bandwidth and highly directive antennas, but higher frequencies rapidly attenuate and may restrict coverage to hundreds of meters.The resulting design challenge includes secure, adequately ranged, and energy-efficient transmission infrastructure.
- Multiple access: NOMA and RSMA are proposed access schemes in which users share resources, but both rely on successive interference cancellation and require further maturation before deployment.An AI-based software-defined air interface is also identified as a potential direction.
- Beamforming: Beamforming concentrates energy toward a desired direction, while IRSs configure reflected-ray phases using low-power passive elements.IRSs may reduce antenna and RF-chain requirements and support deep-fade or NLOS environments.
3 Network Dimensions
6G network dimensions emphasize intelligent, adaptive, and distributed infrastructure spanning cloud, fog, edge, terrestrial, aerial, and maritime domains. Softwarization, virtualization, and slicing provide configurable services, while fog and MEC support low-latency processing for many devices.
- Network intelligence: Network intelligence is intended to make 6G act dynamically according to environmental conditions, with self-optimization, self-organization, and self-reconfiguration.Cloud, fog, and edge computing are positioned to provide fast service access.
- Cloudification/Fog/Edge: Processing workloads should move from the cloud toward fog, edge, and device ends to reduce delay and improve quality of service.The motivation is the large data volume and limited processing power of many connected devices.
- Softwarization and virtualization: Softwarization and virtualization are proposed to provide self-organization, configurability, programmability, flexibility, and heterogeneous use cases without installing hardware for every function.Softwarization decouples control and user planes, while virtualized functions use shared physical resources.
- Slicing: Network slicing delivers multiple logical networks over common physical infrastructure and can allocate slices for automotive, healthcare, and utility use cases.Configuring new slices is difficult because it affects all network components.
- Integrated network: The envisioned 6G system integrates space, air, ground, and sea communications, supporting both low-rate biosensors and high-rate HD video transmission.The architecture also includes vertical handoff, integrated BSs/APs, satellites, UAVs, fog computing, and MEC.
4 Potential Technologies
The paper surveys enabling technologies for 6G, including quantum communication and quantum machine learning. It describes quantum networking and security applications, then identifies communication-network problems where QC and QML may be applied.
- Quantum technology: Quantum technology uses quantum-mechanical properties to create systems such as accurate clocks, medical-imaging devices, and quantum computers.A quantum Internet connects quantum computers, simulators, and sensors through quantum networks.
- Quantum communication: The EU Quantum Flagship and planned quantum-communication infrastructure aim to support a secure pan-European quantum Internet.The initiative was launched in 2018 as a ten-year, 1 billion Euro effort involving 5000 scientists.
- Quantum communication: Quantum key distribution provides an intrinsically secure random key for encrypted communication and supports information sharing, digital signatures, authentication, and clock synchronization.The paper identifies it as the first service expected to run on the infrastructure.
- Quantum communication and QML: QC and QML are proposed for 6G channel capacity, channel estimation, coding, localization, load balancing, routing, and multiuser transmission.They are also described as potential tools for fast path selection in ad hoc sensor networks and Cloud IoT.
4.2 Blockchain
Blockchain is presented as a mechanism for automating telecommunications operations, enabling new services, and managing resource-sharing challenges in 6G networks.
- Internal Network Operations: Blockchain-based smart contracts can automate billing, supply-chain management, roaming, accounting, auditing, and bill authentication.They can also prevent fraudulent traffic, saving bandwidth and resources while reducing post-billing audit work.
- Blockchain Services: Telecommunication operators can create revenue streams through blockchain-based games, digital assets, music, payments, and user-to-user money transfers.
- Blockchain Services: Blockchain-based digital identity verification is proposed as a replacement for existing identity-verification systems.
- Ecosystem for Efficient Cooperation: Blockchain can support next-generation digital services and advertising by handling complex transactions and using user information effectively for machine-to-machine interactions.
- Resource Management: Massive 6G connectivity makes power, spectrum, and computational-resource management challenging, while blockchain is proposed to address these domains through smart contracts.The passage also identifies unlicensed-spectrum and energy management as application areas.
4.3 Tactile Internet
The Tactile Internet extends networked communication to real-time human–machine interaction with haptic sensations, requiring very low latency, high reliability, and high security.
- Concept: The Tactile Internet adds touch transmission and haptic sensations to real-time machine-to-machine and human-to-machine communication.
- Requirements: ITU defines the Tactile Internet as a high-performance network with ultra-low latency, high reliability, and high security for real-time human–machine interaction.
- Challenges and Enabling Technologies: Generating pressure on skin without a physical object is a central Tactile Internet challenge, with focused ultrasound presented as one approach.Ultrasonic transducers can create haptic sensations through controlled ultrasonic waves.
4.4 Free Duplexing and Spectrum Sharing (FDSS)
6G is expected to use full free duplexing and advanced spectrum sharing to let users access complete resources simultaneously, while NOMA and imperfect CSI shape performance considerations.
- Free Duplexing: Full free duplexing is expected to let all users simultaneously use complete space, time, and frequency resources, improving latency and throughput.
- Spectrum Sharing: AI and blockchain are anticipated as key technologies for developing robust spectrum monitoring and management strategies.
- Spectrum Sharing: NOMA assigns the same time–frequency resource block to all users while separating users in the power domain and using successive interference cancellation.The weakest user receives maximum base-station power, while stronger users cancel weaker-user messages before decoding their own.
- Performance Analysis: Imperfect SIC and imperfect CSI affect NOMA performance, motivating comparison among OMA, non-cooperative NOMA, STBC-NOMA, and CCN schemes.Figure 7 evaluates weakest-user average capacity against total users under perfect and imperfect CSI conditions.
5 6G Application
The paper surveys 6G applications spanning health, holography, space and deep-sea exploration, and automated industry. These applications combine sensing, connectivity, robotics, and intelligent computation across diverse environments.
- Application Scope: 6G application areas include medical and e-health services, transport, food, agriculture, education, and communication among intelligent machines.
- E-Health and Digital/Bio Sensing: COVID-19 motivates biosensors that are precise, accurate, sensitive, easy to use, and specific for disease-related monitoring.
- E-Health and Digital/Bio Sensing: Integrating quantum computing, machine learning, and biotechnology could support viral-disease detection from body temperature and enable optical biosensing and autonomous medical robotics.
- Holographic Communication: Holography records both light-wave intensity and phase to capture an object’s full three-dimensional image.
- Communication in Space and Deep Sea: 6G is proposed for space-related communication and research, including space tourism, space hotels, space hospitals, and commercial space flights.
- Communication in Space and Deep Sea: Autonomous intelligent robots could support communication and research in harsh environments, including deep-sea oil and mineral exploration.
- Robotics and Automated Vehicles for Beyond Industry 4.0 Era: Robots, automated vehicles, and UAV swarms are proposed for real-time diagnostics, maintenance, fire control, construction, emergency response, and agriculture.The passage links these operations with advanced hardware, ML, and QML algorithms.
6 Key Performance Indicators (KPIs)
The paper frames 6G KPIs around higher data rates, mobility, massive connectivity, traffic capacity, low latency, reliability, spectral efficiency, and energy efficiency. It also identifies infrastructure and power constraints created by dense, heterogeneous, intelligent networks.
- 6G KPI categories include peak data rate, mobility, connected devices per Km2, area traffic capacity, latency, reliability, spectral efficiency, and energy efficiency.
- 6G mobility requirements are defined as >1000Km/hr while maintaining high data rates for users in airplanes and high-speed trains.
- Massive IoT growth requires new planning and optimization approaches, cooperative device connectivity, and high-capacity backhaul for dense networks producing more than TBs of daily data.
- 1000Mbps/m2 is the minimum 6G area traffic capacity limit for reliable, low-latency communication among autonomous vehicles, industrial sensors, and other connected devices.
- The maximum allowable 6G latency is 10µ sec, while eRLLCS reliability is expected to exceed 99.9999999%.
- 6G spectral efficiency is supposed to exceed 15 times that of 3G, but intelligent robots and devices also require scalable, energy-efficient computing beyond traditional GPUs.
7 Research Challenges and Directions
The paper identifies hardware, propagation, resource-management, interoperability, and security challenges that accompany 6G’s heterogeneous devices, broad frequency range, and massive connectivity. It presents these as open research directions for meeting stringent KPI requirements.
- Variable packet sizes increase hardware complexity because mobile stations must select signal-processing and RF chains according to incoming packets.
- Covering 6G’s 3GHz to 60GHz bandwidth requires multiple antennas, filters, amplifiers, RF chains, and signal-processing chains, increasing chip size and hardware complexity.
- High-frequency propagation can cause rapid attenuation and penetration loss, while variable QoS requires dynamically assigned bandwidth, power, or both.
- Low-latency, ultra-reliable applications require powerful low-power processors, while massive-device prioritization makes latency and packet-loss guarantees difficult to maintain.
- Scalable multi-RAT techniques must support dynamic air-interface changes and interoperability with Wi-Fi, Bluetooth, ad hoc sensors, and IoT while meeting 6G KPIs.
- Large-scale IoT connectivity may increase broad-scale DDoS attacks and associated security, privacy, and trust issues, leaving these as open research challenges.
8 Conclusion
The paper surveys 6G visions, architectures, KPIs, enabling technologies, use cases, and network dimensions. It concludes by identifying commercialization challenges involving complexity, resource management, efficiency, interoperability, and trust.
- The paper provides a broad overview of B5G/6G vision, architecture, KPI requirements, enabling technologies, use cases, and network dimensions.
- It discusses how potential technologies may meet 6G KPI requirements and identifies research opportunities toward commercialization.
- The highlighted challenges include hardware complexity, variable radio-resource allocation, pre-emptive scheduling, power efficiency, multiple-RAT coexistence, and security, privacy, and trust.
9 declarations
The declarations report no applicable data or material, no competing interests, funding from a King Saud University supporting project, and author contributions across conception, analysis, organization, and oversight.
- The paper states that availability of data and material is not applicable.
- The authors declare that they have no competing interests.
- The work acknowledges funding from Researchers Supporting Project RSP-2020/32 at King Saud University, Riyadh, Saudi Arabia.
- Author contributions covered research conception, case-study findings and discussion, manuscript organization, and oversight, with final approval by all contributors.