Search Results (7)

The anticipated transition from 5G to 6G is driven not by incremental performance demands but by a widening mismatch between emerging application requirements and the capabilities of existing cellular systems. Despite rapid progress across 3GPP Releases 15–20, the current literature lacks a unified analysis that connects these standardization milestones to the concrete technical gaps that 6G must resolve. This study addresses this omission through a cross-release, application-driven review that traces how the evolution from enhanced mobile broadband to intelligent, sensing integrated networks lays the foundation for three core 6G service pillars: immersive communication (IC), everything connected (EC), and high-precision positioning. By examining use cases such as holographic telepresence, cooperative drone swarms, and large-scale Extended Reality (XR) ecosystems, this study exposes the limitations of today’s spectrum strategies, network architectures, and device capabilities and identifies the performance thresholds of Tbps-level throughput, sub-10 cm localization, sub-ms latency, and 10 M/km² device density that next-generation systems must achieve. The novelty of this review lies in its synthesis of 3GPP advancements in XR, the non-terrestrial network (NTN), RedCap, ambient Internet of Things (IoT), and consideration of sustainability into a cohesive key performance indicator (KPI) framework that links future services to the required architectural and protocol innovations, including AI-native design and sub-THz operation. Positioned against global initiatives such as Hexa-X and the Next G Alliance, this paper argues that 6G represents a fundamental redesign of wireless communication advancement in 5G, driven by intelligence, adaptability, and long-term energy efficiency to satisfy diverse uses cases and requirements. Full article

The rapid advancement of terahertz (THz) communication systems has positioned this technology as a key enabler for next-generation telecommunication networks, including 6G, secure communications, and hybrid wireless-optical systems. This review comprehensively analyzes THz communication, emphasizing its integration with free-space optical (FSO) systems to overcome conventional bandwidth limitations. While THz-FSO technology promises ultra-high data rates, it is significantly affected by atmospheric absorption, particularly absorption beyond 500 GHz, where the attenuation exceeds 100 dB/km, which severely limits its transmission range. However, the presence of a lower-loss transmission window at 680 GHz provides an opportunity for optimized THz-FSO communication. This paper explores recent developments in high-power THz sources, such as quantum cascade lasers, photonic mixers, and free-electron lasers, which facilitate the attainment of ultra-high data rates. Additionally, adaptive optics, machine learning-based beam alignment, and low-loss materials are examined as potential solutions to mitigating signal degradation due to atmospheric absorption. The integration of THz-FSO systems with optical and radio frequency (RF) technologies is assessed within the framework of software-defined networking (SDN) and multi-band adaptive communication, enhancing their reliability and range. Furthermore, this review discusses emerging applications such as self-driving systems in 6G networks, ultra-low latency communication, holographic telepresence, and inter-satellite links. Future research directions include the use of artificial intelligence for network optimization, creating energy-efficient system designs, and quantum encryption to obtain secure THz communications. Despite the severe constraints imposed by atmospheric attenuation, the technology’s power efficiency, and the materials that are used, THz-FSO technology is promising for the field of ultra-fast and secure next-generation networks. Addressing these limitations through hybrid optical-THz architectures, AI-driven adaptation, and advanced waveguides will be critical for the full realization of THz-FSO communication in modern telecommunication infrastructures. Full article

In the field of holographic-type communication (HTC), this paper presents a comprehensive exploration of existing technologies and proposes a novel, modular architecture for holographic telepresence systems (HTPSs). We substantiate our architectural framework through a practical implementation, demonstrating its modularity, interoperability, and versatility. Quantitative and qualitative assessments reveal both the promise and areas for improvement within our platform. Our findings reinforce the premise that the key to unlocking HTC’s future lies in modularity and interoperability, serving as critical pillars for efficient standardization and the development of minimal viable products. Full article

Head-mounted displays (HMDs) have the potential to greatly impact the surgical field by maintaining sterile conditions in healthcare environments. Google Glass (GG) and Microsoft HoloLens (MH) are examples of optical HMDs. In this comparative survey related to wearable augmented reality (AR) technology in the medical field, we examine the current developments in wearable AR technology, as well as the medical aspects, with a specific emphasis on smart glasses and HoloLens. The authors searched recent articles (between 2017 and 2022) in the PubMed, Web of Science, Scopus, and ScienceDirect databases and a total of 37 relevant studies were considered for this analysis. The selected studies were divided into two main groups; 15 of the studies (around 41%) focused on smart glasses (e.g., Google Glass) and 22 (59%) focused on Microsoft HoloLens. Google Glass was used in various surgical specialities and preoperative settings, namely dermatology visits and nursing skill training. Moreover, Microsoft HoloLens was used in telepresence applications and holographic navigation of shoulder and gait impairment rehabilitation, among others. However, some limitations were associated with their use, such as low battery life, limited memory size, and possible ocular pain. Promising results were obtained by different studies regarding the feasibility, usability, and acceptability of using both Google Glass and Microsoft HoloLens in patient-centric settings as well as medical education and training. Further work and development of rigorous research designs are required to evaluate the efficacy and cost-effectiveness of wearable AR devices in the future. Full article

This paper introduces a real-time 3D reconstruction of a human captured using a depth sensor and has integrated it with a holographic telepresence application. Holographic projection is widely recognized as one of the most promising 3D display technologies, and it is expected to become more widely available in the near future. This technology may also be deployed in various ways, including holographic prisms and Z-Hologram, which this research has used to demonstrate the initial results by displaying the reconstructed 3D representation of the user. The realization of a stable and inexpensive 3D data acquisition system is a problem that has yet to be solved. When we involve multiple sensors we need to compress and optimize the data so that it can be sent to a server for a telepresence. Therefore the paper presents the processes in real-time 3D reconstruction, which consists of data acquisition, background removal, point cloud extraction, and a surface generation which applies a marching cube algorithm to finally form an isosurface from the set of points in the point cloud which later texture mapping is applied on the isosurface generated. The compression results has been presented in this paper, and the results of the integration process after sending the data over the network also have been discussed. Full article

One of the most significant challenges of telepresence distance education is to bring the professor and the students closer together in a synchronistic educational experience where the professor is perceived as anatomically proportionate. Telepresence, an educational technology ecosystem using holograms, offers a way to solve this technological challenge. Our mixed exploratory research investigating this methodology had two purposes: (1) propose the key elements to teach distance courses synchronously in an educational technology ecosystem, and (2) demonstrate the technological, didactic practices that result in positive student learning outcomes in several specified courses. This methodology included applying a student questionnaire to collect their perceptions of the educational experience. The scores and written comments from the questionnaire were analyzed using Grounded Theory. On a Likert scale from 1 to 5, the students scored their educational experience, attaining a mean of 4.05. The positive perception affirmed that they valued: (a) recreating the natural dynamics of face-to-face classes, where the students perceived their professors as being physically present in the classroom; (b) professors renowned in their disciplines; (c) professor–student and campus and intercampus learning community interactions, and, finally, (d) class design and content. The main conclusions of this research were that students positively perceived the “wow” effect of the technology, feeling comfort, amazement, interest, and engagement. In addition, we found that professors and keynote speakers with excellent pedagogical skills and experts in their disciplines were well appreciated. Key elements for the success of the experience were professor-student, campus, and intercampus interactions and the quality of the technological and communication infrastructure. Full article

Over the last few years, we have witnessed an impressive growth of data traffic and a progressive Digital Transformation of Industry and Society: the deployment of the ultra-broadband and low latency network infrastructures (e.g., 5G) are leading to a global digitalization of several domains. These techno-economic trends are expected to continue and even accelerate in the next decade, at end of which, 6G and smart networks and services will be exploited. Innovation will continue to drive the global economy into the next decade. This paper draws some technology trends and applications scenarios for this horizon, where Quantum Optical Communications are likely to disrupt Information and Communications Technology (ICT) and Telecommunications. Among the enabling technologies and solutions moving in this direction, this paper briefly addresses: quantum optical switching and computing, THz-to-optical conversions and advanced metamaterials for smart radio-optical programmable environments and Artificial Intelligence. The paper concludes with the description of a future application scenario, called Quantum Optical Twin, where the above Quantum Optical Communications technologies are exploited to provide services such as: ultra-massive scale communications for connected spaces and ambient intelligence, holographic telepresence, tactile Internet, new paradigms of brain computer interactions, innovative forms of communications. Full article