Each issue of the IEEE Journal on Selected Areas in Communications (JSAC) is devoted to a specific technical topic and thus provides to JSAC readers a collection of up-to-date papers on that topic. These issues are valuable to the research community and become valuable references. The technical topics covered by JSAC issues span the entire field of communications and networking.

JSAC publishes only papers that are submitted in response to a Call-for-Papers. These calls are published in JSAC issues and other publications of the IEEE Communications Society as appropriate to the subject area of the call. Papers submitted for review for possible publication in a JSAC issue must be submitted to one of the Guest Editors listed in the Call-for-Papers.

Special Issue on The Future of Wi-Fi and Wireless Technologies in Unlicensed Spectra
Submission Date: 2024-11-30

The landscape of wireless communication is rapidly evolving and technologies operating in unlicensed spectra play a pivotal role in shaping the future of wireless connectivity. As we navigate the digital era, the demand for faster, more reliable, and ubiquitous connectivity is on the rise. Wi-Fi is the most prominent technology operating in unlicensed spectra and some estimates indicate that around 70% of the global Internet traffic crosses a Wi-Fi network.

Recent advances in Wi-Fi technology, including Wi-Fi 6 and Wi-Fi 7, have focused on keeping up with this growing traffic demand through the introduction of new technologies such as OFDMA to cope up with device density, wider 320 MHz channels in the 6 GHz band to provide high throughputs and lower latencies, puncturing to improve spectrum efficiency and deal with coexistence with incumbents in the 6 GHz band, and multi-link operation that enables seamless access to multiple channels thereby providing aggregate peak data rates that exceed 30 Gbps and single digit millisecond latency. The industry and academia are now researching the next generation technologies that can evolve Wi-Fi with the goal to provide deterministic operation and high reliability for applications such as AR/VR, industrial IoT, gaming, ultra-high-definition wireless display, to name a few.

At the same time, other technologies are also evolving and expanding their use of unlicensed spectra. Bluetooth and other narrowband technologies are in the process of being designed to operate in the 5 GHz and/or 6 GHz band. Ultra-wideband (UWB) is being widely deployed in the 6 GHz band to provide accurate and secure raging for applications such as access control. 5G NR-U is an extension of 5G technology that enables it to operate in unlicensed spectrum.

The evolution and coexistence of these various technologies is of utmost importance to ultimately provide the experience, performance and applications that users expect and is a major focus of this Specia Issue. Academia, industry, and regulatory bodies need to work together to define the future technologies, standards and regulatory frameworks that will provide the conditions necessary for adequate spectrum sharing and efficient spectrum utilization that will enable deterministic and reliable operation demanded by applications making use of unlicensed spectra.

This Special Issue aims to provide a comprehensive presentation of the state-of-the-art findings including technology, theory, design, optimization, and applications of Wi-Fi and other technologies operating in unlicensed spectra and their impact on the future of wireless communication. Original technical contributions are solicited in future Wi-Fi and related areas including, but not limited to, the following:

 - Analysis, experimentation, and performance evaluation of the latest and upcoming Wi-Fi and Bluetooth standards
 - Next generation PHY, MAC, and network layer architectures and protocols
 - Wi-Fi sensing and joint communication and sensing
 - Latency and time-sensitive services
 - Accurate and secure location and ranging
 - Spectrum sharing and coexistence
 - AI/ML applied to technologies operating in unlicensed spectra
 - Privacy and security
 - Spectrum and regulations
 - Implementation and deployment challenges
 - Emerging applications and services

Special Issue on Recent Advances in Integrated Sensing and Communications
Submission Date: 2025-01-30

Next-generation wireless networks are poised to become essential enablers for a variety of new applications that require not just high-speed connectivity but also precise and reliable perception capabilities. Looking ahead to 5G-A and 6G developments, a key prediction is the increasing importance of sensing technology. This advancement anticipates that future cellular systems will be able to sense and interpret their environment, supporting sophisticated location- and imaging-based services. The research area focused on merging sensing and communication technologies is known as Integrated Sensing and Communications (ISAC), which aims to develop frameworks and technologies that integrate both functionalities, enhancing resource efficiency and generating mutual advantages. This approach is being applied in several new fields, including autonomous vehicles, smart factories, digital twins, and low-altitude economy. With the convergence of mmWave/THz frequencies and massive MIMO technology, the boundaries between communication and sensing systems are blurring, particularly in terms of their hardware platforms, RF front-ends, channel characteristics, and data processing techniques. Consequently, ISAC is advancing from theoretical concept to practical implementation, and even to standardization. Evidently, the International Telecommunication Union (ITU) has recently acknowledged ISAC as a critical component of the 6G vision, identifying it as one of the six core use cases anticipated for the next generation of networks.

This Special Issue seeks to bring together contributions from researchers and practitioners in the area of wireless communications, signal processing, with an emphasis on the recent advances of new approaches and techniques for ISAC designs. We solicit high-quality original research papers on topics including, but not limited to:

    Fundamental information-theoretic limits for ISAC
    Waveform/sequence/coding/modulation/beamforming design for ISAC
    MIMO, massive MIMO, and extremely large-scale MIMO for ISAC
    Intelligent/holographic surface and movable/fluid antennas for ISAC
    Millimeter wave and THz technologies for ISAC
    Channel modeling and measurement for ISAC
    RF front-ends and circuits design for ISAC
    Hardware prototyping and field-tests for ISAC
    Near-field ISAC transmission
    Security and privacy issues in ISAC
    ISAC design for V2X/UAV networks
    Sensing and positioning over communication networks
    Cell-free ISAC networks
    AI for ISAC
    Integrated communications and multi-modal sensing
    Integrated optical/underwater sensing and communications
    Wi-Fi sensing for indoor positioning and target recognition
    Standardization progress of ISAC

Special Issue on Fluid Antenna System and Other Next-Generation Reconfigurable Antenna Systems for Wireless Communications
Submission Date: 2025-02-15

Next-generation reconfigurable antenna (NGRA) technology has been explored as a promising solution for enabling flexible and adaptive wireless communications. Fluid antenna system (FAS) encompasses any software-controllable fluidic, dielectric or conductive structures, including but not limited to liquid-based antennas, pixel-based antennas, and metasurfaces, that can dynamically reconfigure their shape, size, position, length, orientation, and other radiation characteristics. This technology has inspired several related research studies, such as movable antenna system, flexible-position multiple-input multiple-output (MIMO) system, reconfigurable antenna MIMO system, and flexible antenna array, which can be referred to as other NGRA systems. Compared to traditional antenna systems, the reconfigurability of FAS and other NGRA systems introduces new degrees of freedom, thereby enhancing the diversity and multiplexing performance. With their ultra-high spatial resolution, FAS and other NGRA systems offer new capabilities to exploit spatial opportunities where interference naturally experiences deep fades in multiuser communications, leading to concepts such as Fluid Antenna Multiple Access (FAMA) and Compact Ultra Massive Antenna Arrays (CUMA).

Furthermore, FAS and other NGRA systems can be integrated with other enabling technologies such as reconfigurable intelligent surfaces (RIS), non-orthogonal multiple access (NOMA), rate-splitting multiple access (RSMA), integrated sensing and communications (ISAC), non-terrestrial networks (NTN), vehicular-to-everything (V2X), and more to enhance the performance of future wireless communications. Recent findings also suggest that FAS is closely related to holographic MIMO systems, offering potential advancements for both technologies. In addition, the emergence of virtual FAS presents new opportunities to improve wireless communication systems by enhancing the dimensions of the channels using AI techniques. To fully unleash the potential of FAS and other NGRA systems in future-generation wireless networks, various research challenges must be addressed, including accurate system modeling, system optimization, artificial intelligence (AI) management, multiple access and interference mitigation technologies, channel estimation, and more. 

This Special Issue seeks for the latest research, novelties, and applications of FAS and other NGRA-enabled wireless communication technologies in 6G networks. We solicit original and high-quality papers that cover several topics of interest, including but not limited to:

    System models for FAS and other NGRA systems, compliant with the principles of physics, antenna, and/or circuit theories
    Investigation of electromagnetic- or information-theoretic performance limits for FAS and other NGRA systems
    Advanced optimization theories and algorithms for FAS and other NGRA systems
    AI-assisted algorithms, management, and protocols for FAS and other NGRA systems
    Efficient channel estimation/extrapolation/reconstruction techniques for FAS and other NGRA systems
    New coding and modulation schemes based on FAS and other NGRA systems
    FAS and other NGRA-assisted multiple access schemes for achieving extremely massive connectivity
    FAS and other NGRA-enabled interference mitigation techniques for cell-free and multicell networks 
    FAS and other NGRA systems for millimeter wave and terahertz communications
    Seamless integration of FAS and other NGRA systems with RIS
    Joint communication, sensing, and/or computing designs in FAS and other NGRA systems
    Enhancements in physical layer security and privacy through FAS and other NGRA systems
    Interrelation analysis between holographic MIMO systems and FAS and other NGRA systems
    Applications of FAS and other NGRA systems in V2X and NTN
    Energy-efficient strategies for FAS and other NGRA systems, including energy-aware scheme, energy harvesting, and wireless energy transfer
    Industrial trials, applications, and testbed results of FAS and other NGRA systems for wireless communications

Special Issue on Private and Covert Communications: Fundamentals, Methods, and Applications
Submission Date: 2025-04-15

With the proliferation of terminal devices in fifth-generation (5G) and upcoming sixth-generation (6G) wireless communications, modern society is becoming increasingly reliant on information transmission. Wireless communications offer convenience, but information privacy is increasingly critical and cannot be overlooked. Research into transmission security and privacy is advancing, particularly with the rise of the Internet-of-Things (IoT) era. Transmitted data often includes sensitive individual information, such as personal health and location data. In addition to ensuring the secrecy and integrity of transmitted information, there may be scenarios where a transmitter wishes to send messages over wireless networks without being detected. This is particularly important to protect the transmitter's privacy, especially in situations involving government and military operations where stealth is essential.

Private and covert communications aim to conceal the transmission's existence from adversarial wardens. They are also known as low probability of detection/intercept communications. By concealing the transmission within environmental or artificial noise, private and covert communications can offer a higher level of security to preserve the privacy compared to cryptography and physical layer security. Wardens are less likely to attempt decoding signals they are unaware of, thereby reducing the risk of detection and interception. Concealing wireless communication through covert methods has received significant research attention and has various applications. By leveraging inherent or man-made uncertainties such as background noise uncertainty, channel uncertainty, location uncertainty, artificial noise, and other factors, private and covert communications can degrade the detection performance of potential adversaries. 

Furthermore, research in private and covert communications has flourished across various applications, including cognitive radio, non-orthogonal multiple access, ultra-reliable and low-latency communications, IoT networks, unmanned aerial vehicle (UAV)-assisted networks, remote networks, satellite networks, and more. The evolution of wireless technologies necessitates the evolution of methodologies for private and covert communications to introduce additional uncertainty and adapt to new security requirements in emerging applications and scenarios. This is crucial to counteract the increasing computational capabilities of potential adversaries.

Based on these observations, this Special Issue will provide a comprehensive collection of the state-of-the-art theory, design, optimization, and applications of private and covert communications. We solicit high-quality original research papers on topics including, but not limited to:

    Fundamentals and methods of private and covert communications;
    Novel uncertainty techniques for private and covert communications;
    Information-theoretic limits of private and covert communications;
    Tradeoff between transmission and covertness;
    Potential attacks towards private and covert communications;
    Privacy preservation via covert communications;
    Multi-dimensional resource allocation for private and covert communications;
    Private and Covert communications with imperfect channel state information;
    Private and Covert communications towards active wardens;
    Private and Covert communications with massive MIMO;
    Private and Covert communications with multiple access;
    Private and Covert communications for mmWave and Terahertz;
    Private and Covert communications for visible optical communication;
    Private and Covert communications with reconfigurable intelligent surfaces;
    Private and Covert communications for integrated sensing and communication;
    Private and Covert communications in space-air-ground-sea integrated networks;
    Array signal processing for space-air-ground private and covert communications;
    Private and Covert communications assisted satellite networks;
    Private and Covert communications for UAV-assisted networks;
    Private and Covert communications for IoT networks;
    Artificial intelligence aided private and covert communications;
    Other related topics for private and covert communications.

Special Issue on Large AI Model for Future Wireless Communication Systems
Submission Date: 2025-05-01

The emergence of future wireless networks, e.g., 6G aims to further enhance users’ experience by offering services of superior reliability, speed, and quality compared to existing wireless technologies. Artificial Intelligence (AI) has evolved from traditional algorithms to deep learning and now to Large AI Models (LAMs), increasingly revolutionizing wireless communication systems. Renowned LAMs like SORA, GPT-4o and Gemini have demonstrated amazing performance across diverse applications, positioning them as powerful tools for tackling complex challenges in future wireless communication systems. For example, by integrating advanced cognitive modules such as comprehensive perception, world modeling, and action planning, LAMs can achieve fully autonomous and intelligent network operations, handle unforeseen communication scenarios, and provide revolutionary capabilities and experiences in various complex environments. These applications not only demonstrate the powerful learning and optimization capabilities of LAMs but also offer new directions and insights for the development of future wireless network technologies.

Despite the potential benefits of LAMs in future wireless communication systems, deploying them in the practical environment introduces several challenges, such as computational power requirements, efficient training methodologies, and model parameter scaling along with the characteristics of wireless networks. The primary goal of this Special Issue is to encourage researchers to tackle the crucial challenges that emerge when applying LAMs to future wireless communication systems. The topics of interest include (but are not limited to):

    LAMs for cognitive-level resource allocation, channel estimation, mobility management and physical layer algorithm design
    LAMs for semantic communications
    LAMs for intelligent operation and maintenance
    LAMs for telecom language understanding
    LAMs for low-latency digital twins
    LAMs for network protocol design, control and architecture development
    LAMs for intent-driven edge intelligence applications
    LAMs for future energy-efficient and green networks
    Performance analysis of LAMs in wireless networks, e.g., explainability, trust, privacy, and security-related issues
    Novel testbeds, complex simulations and experiment of LAMs in future wireless networks