This journal is indexed by Scopus.

The goal of this journal is to advance and promote significant technology advances in green communications and networks including wireline, optical, and wireless communications and networks. Green communications and networking in this context means sustainable, energy-efficient, energy-aware, and environmentally aware communications and networking. The journal will promote innovations, new technologies, concepts, and principles toward a sustainable information and communications technology (ICT).

Topics of interest include but are not limited to:

    Green wireline, optical, and wireless communications and networks;
    Network and physical layer design, strategies, algorithms, protocols, and scheduling that consider environmental factors;
    Energy-efficient and energy-aware heterogeneous networks, self-organized, and low-power sensor networks;
    Energy efficiency in machine-to-machine communications, cooperative communications, and  smart grid networks;
    Energy harvesting, storage, and recycling for network cross-layer optimization;
    Environmentally-aware designs of communications and networking devices and systems; and
    Communications and networking for environmental protection monitoring. 

Co-Sponsors: IEEE Signal Processing Society and IEEE VTS

Special Issue on Green Open Radio Access Networks: Architecture, Challenges, Opportunities, and Use Cases
Submission Date: 2024-01-01

Next-generation cellular networks will need to support RAN deployments at an unprecedent scale, as well as heterogeneous and complex use cases. Managing and optimizing these new network systems require solutions that by opening the Radio Access Network (RAN) expose data and analytics and enable advanced, data- driven optimization, closed-loop control and automation. To this aim, the Open RAN paradigm has recently emerged as an enabler of (i) openness in the RAN, with standardized interfaces that allow integration of RAN controllers and multi-vendor equipment; (ii) RAN virtualization, with RAN functionalities implemented in software and running on white box hardware; and (iii) RAN programmability through closed-loop, intelligent control. Therefore, the Open RAN allows an ecosystem where multi-vendor capabilities can be practically deployed, along with interoperable software features, and autonomous services. To fully realize the ecosystem, it is important to understand the underpinnings of multi-vendor functionality, open interfaces, and the workflows enabled by this. The scope of this Special Issue is to highlight key research problems along with solid technical solutions for the development and testing of networks based on the Open RAN vision, for the adoption of open APIs, interfaces, integration of AI and ML workflows, coexistence with proprietary virtual RAN (vRAN) alternatives, developing performance measurement metrics, and dealing with vertical and horizontal flexibility in the context of Open RAN deployments. Furthermore, the Special Issue will also focus on the Open RAN standards and architecture for the evolution of 5G to 6G, and O-RAN-based intelligent techniques for service orchestration, resource allocation and management, and O-RAN use-cases. 

- AI/ML based load balancing 
- Networking Slicing, Virtualization and scaling techniques 
- Simulation and modeling of fronthaul and open interfaces 
- Distributed cloud architectures based on service management and orchestrators (ONAP, OSM), Kubernetes, and OpenStack 
- Privacy-Preserving AI/ML methods 
- Design of Performance Measurement Metrics 
- Inter-operator orchestration 
- Coexistence of Open RAN with vRAN and cRAN 
- Design of intelligent controllers 
- Scheduling techniques 
- Lightweight Encryption, Authorization, and Authentication for data handling at interfaces 
- Boosting disaggregation of functionalities through AI/ML workflows 
- Enhancing openness and opportunities for non-top vendors with Digital Twins 
- Approaches to counter Model Poisoning and Inversion attacks for Edge Devices 
- Design of testbed architectures

Special Issue on Rate-Splitting Multiple Access for Future Green Communication Networks
Submission Date: 2024-01-01

Rate-splitting multiple access (RSMA) has the potential to realize the goals of high spectral and energy efficiency, massive connectivity, ultra-reliability, and heterogeneity of quality-of-service (QoS) envisioned in 6G. By exploiting the splitting of user messages into common and private components, RSMA can softly bridge the divide between the common interference management strategies of fully decoding interference and treating interference as noise. Recent research progress has shown that RSMA generalizes and subsumes as special cases four existing MA schemes, namely, orthogonal multiple access (OMA), physical-layer multicasting, space division multiple access (SDMA) based on linear precoding (currently adopted in 5G), and non-orthogonal multiple access (NOMA) based on linearly precoded superposition coding with successive interference cancellation (SIC). It achieves the optimal spatial multiplexing gain in a number of scenarios and provides significant room for improving spectral efficiency, energy efficiency, coverage, user fairness, reliability, QoS enhancements in a wide range of network loads and user deployments, robustness against imperfect channel state information at the transmitter (CSIT), as well as feedback overhead and complexity reduction over conventional strategies used in 5G. Moreover, RSMA decreases transmit power consumption under certain QoS constraints, reduces latency and enhances robustness under user mobility, which makes it an excellent enabling and sustainable technology for 6G. It has been recognized as a promising PHY-layer transmission paradigm for non-orthogonal transmission, interference management, and multiple access in 6G. RSMA has the potential to fundamentally transform the PHY layer and lower MAC layer design of wireless communication networks, and ultimately, pave the way for the development of future green communication networks. 

This Special Issue focuses on the signal processing advances for “Rate-Splitting Multiple Access” and its applications in future green communication networks. It aims at bringing together researchers from both academia and industry to share their original works on RSMA. Prospective authors are invited to submit original manuscripts on topics including, but not limited to: 

- Energy-efficient transceiver design for green RSMA 
- Optimization algorithms for green RSMA 
- Energy-efficient signal processing for green RSMA 
- Unfolding/unrolling, model-free and model-based learning techniques for green RSMA 
- Coding and modulation for green RSMA 
- Energy-efficient cross-layer design for green RSMA 
- RSMA-based green interference management 
- RSMA in green multi-user/multi-cell/cell-free multi-antenna networks such as MU-MIMO, massive MIMO, networked MIMO 
- Channel estimation for RSMA-enabled green wireless networks 
- Green RSMA in 6G services such as enhanced eMBB, enhanced URLLC, massive URLLC, enhanced MTC, massive MTC, human-centric services 
- Green RSMA-enabled intelligent reflecting surfaces (IRS), relaying, cooperative communications, cloudenabled platforms/radio access networks (cloud/fog/caching), cognitive radio, etc 
- Green RSMA in integrated space–air–ground networks, integrated sensing and communications, wireless powered communications, vehicle-to-everything (V2X), etc 
- Green RSMA-enabled millimetre wave/terahertz (THz)/visible light communications 
- Green RSMA-enabled semantic communications/distributed edge learning 
- Green RSMA-enabled virtual reality (VR), augmented reality (AR), extended reality (XR), and metaverse communications 
- Prototyping and experimental trails of green RSMA

Special Issue on Design of Green Near-Field Wireless Communication Networks
Submission Date: 2024-02-01

The sixth-generation (6G) wireless communication networks are expected to provide orders of magnitude improvements (higher data rates, lower latency, increased reliability, etc.) over the previous generations, enabling a wide range of applications and use cases that were previously unrealizable. The integration of various distinct technological innovations, including ultra-massive multiple-input-multiple-output (UM-MIMO), cell-free massive MIMO, reconfigurable intelligent surface (RIS), and terahertz communications, has facilitated this accomplishment. However, due to the adoption of large aperture arrays by these technological advancements, near-field (NF) communication with spherical wavefront becomes indispensable in such networks, as conventional far-field (FF) propagation with planar wavefront is no longer valid. The use of spherical waves in NF communications has several advantages over traditional far-field communications. One of the main advantages is that it allows for more efficient use of energy as they require less energy to transmit data over short distances compared to planar waves used in FF communications, which is due to the fact that the spherical waves decay rapidly with distance. Additionally, due to the spherical nature of the wavefront of the transmitted signal, the receiver can be localized more precisely based on the phase and amplitude of the received signal. This makes NF communications an attractive technology for applications that require precise localization, such as indoor navigation and tracking. In addition, the use of spherical waves allows for a more focused transmission of data over short distances. As a result, it can support high data rates, which is critical for applications such as virtual reality, augmented reality, high-definition video streaming, healthcare, automotive, and industrial automation. Thus, due to its ability to offer increased degrees of freedom and high resolution with range-dependent narrow beamwidths, the use of NF communication in advanced wireless networks offers significant potential for achieving spatial multiplexing and improving the overall performance of wireless networks. Further, despite the remarkable attributes of the technical advancement (discussed earlier) towards the 6G networks, the efficient resource allocation for achieving green communication is extremely challenging and requires the use of some promising energy efficient transmission designs and green techniques such as energy harvesting and wireless power transfer (WPT). Consequently, the transition to the radiating NF region necessitates a re-evaluation of existing wireless localization, beam focusing, communication and signal processing techniques towards developing greener wireless communications networks. In addition to this, the study of NF for 6G is still in its early stages, and there is a need for further research to fully understand its potential and challenges to support green communication. This Special Issue aims to bring together researchers from academia, industry, and government to present their latest research results and discuss the future research directions towards the green NF wireless communication networks. We invite original research contributions that address, but are not limited to, the following topics: 

- Channel measurement and channel modelling in green NF wireless communication 
- Electromagnetic information theory for green NF wireless communication 
- Channel estimation and channel tracking in green NF wireless communication 
- Low-complexity beamforming design for green NF wireless communication 
- Reconfigurable intelligent surface (RIS)-assisted green NF wireless communication 
- Simultaneous wireless information and power transfer (SWIPT)/wireless power transfer (WPT) for green NF wireless communication 
- Next generation multiple access (NGMA) schemes for green NF wireless communication 
- Positioning and sensing in green NF wireless communication 
- mm-Wave and THz systems for green NF wireless communication 
- NF-based green integrated sensing and communications (ISAC) 
- Energy efficient resource allocation and network designs in green NF wireless communication 
- Low-overhead beam training scheme for green NF wireless communication 
- Low cost and energy efficient hardware architecture design towards green NF wireless communication 
- Resource management towards green NF wireless communication 
- Secure green NF wireless communication 
- NF designs for green internet of things (IoT) 
- Energy efficient internet of vehicles (IOV)/vehicle to vehicle (V2V)/ vehicle to infrastructure (V2I)/vehicle to everything (V2X) with NF wireless communication networks 
- Green machine learning driven techniques/designs for green NF wireless communication 
- Hybrid FF and NF for green communications 
- Real testbed and validation of low power NF wireless communication