Historically, research efforts in optical networks have focused on the goal of continuously increasing capacity rather than on lowering end-to-end latency. This slowly started to change in the access environment with post-Next-Generation Passive Optical Network 2 research. The emphasis on latency grew in importance with the introduction of 5G ultra-reliable and low-latency communication requirements. In this paper, we focus on the emerging Tactile Internet as one of the most interesting 5G low-latency applications enabling novel immersive experiences. After describing the Tactile Internet’s human-in-the-loop-centric design principles and haptic communications models, we elaborate on the development of decentralized cooperative dynamic bandwidth allocation algorithms for end-to-end resource coordination in fiber-wireless (FiWi) access networks. We then use machine learning in the context of FiWi enhanced heterogeneous networks to decouple haptic feedback from the impact of extensive propagation delays. This enables humans to perceive remote task environments in time at a 1-ms granularity.

In this paper, we study the cell planning problem for a two-tier cellular network containing two types of base stations (BSs)— i.e. with fiber backhaul, referred to as wired BSs (W-BSs), and BSs with wireless backhaul, referred to as unwired-BSs (U-BSs). In-band full-duplex wireless communications is used to connect U-BSs and W-BSs. We propose an algorithm to determine the minimum number of W-BSs and U-BSs to satisfy given cell and capacity coverage constraints. Furthermore, we apply our proposed non-dominated sorting genetic algorithm II (NSGA-II) to solve the joint cell and backhaul planning problem to minimize the cost of planning, while maximizing the coverage simultaneously. Additionally, the considered cell planning program is developed into an optimization by including the problem of minimizing the cost of fiber backhaul deployment. In order to analyze the performance of the proposed algorithm, we study three different deployment scenarios based on different spatial distributions of users and coverage areas. The results show the superiority of our proposed NSGA-II algorithm for joint cell and backhaul planning to other well-known optimization algorithms. The results also reveal that there is a trade-off between cell deployment costs and SINR/rate coverage, and W-BSs are placed in congested areas to consume less resources for wireless backhauls. Similarly, a trade-off between cell and fiber deployment costs and SINR/rate coverage is observed in the joint cell and fiber backhaul planning. We show that for realistic scenarios desirable solutions can be selected from the Pareto front of the introduced multi-objective problem based on given cellular operator policies.

We analyze the mean packet delay in an Ethernet passive optical network (EPON) with gated service. For an EPON with a single optical network unit (ONU), we derive (i) a closed form delay expression for reporting at the end of an upstream transmission, and (ii) a Markov chain-based approach requiring the numerical solution of a system of equations for reporting at the beginning of an upstream transmission. Reporting at the beginning, which has not been previously examined in detail, achieves significantly smaller delays than reporting at the end of an upstream transmission for a small number of ONUs. Both of these analyses are fundamentally different from existing polling system analyses in that they consider the dependent switchover times of the EPON. We extend the analysis for reporting at the beginning of an upstream transmission to approximate the mean packet delay in an EPON with multiple ONUs and verify the accuracy of the analysis with simulations. Overall, our numerical results indicate that for utilizations up to ~75%, the mean packet delay is close to its minimum of four times the one-way propagation delay.

The idea of remotely controlling machines via the Internet for the purpose of automated tele manufacturing and shared use of manufacturing facilities by users worldwide has been studied since the late 1990s. This idea is now part of the vision of the emerging Tactile Internet, which lies at the nexus of computerization, automation, and robotization. Similar to future 5G cellular networks, the Tactile Internet is anticipated to rely on the full yet flexible convergence of different fixed and mobile access technologies, given that some use cases do not require mobility all the time. While necessary, though, the design of ultrareliable and low-latency converged communication network infrastructures is not sufficient to unleash the full potential of the Tactile Internet. In this paper, we put forward the idea that the Tactile Internet may be the harbinger of human augmentation and human-machine symbiosis envisioned by contemporary and earlyday Internet pioneers. In search for synergies between humans and machines/robots, we explore the idea of treating the human as a “member”of a team of intelligent machines rather than keep viewing him as a conventional “user”while putting a particular focus on developing systems that are human-aware and help advance the human condition, e.g., economic inequality.

With the online-everything transformation accelerated by a global Covid-19 pandemic, we may finally find ourselves on the verge of the next potentially paradigm-shifting step after the mobile Internet: The Metaverse. Among others, the Metaverse will utilize head-mounted devices (HMDs) and extended reality (XR), including but not limited to virtual and augmented reality (VR/AR), as the medium to connect avatars and users in the real world. In addition, the Metaverse is supposed to provide gamified experiences around emerging Web 3.0 technologies and is anticipated to be the precursor of the so-called Multiverse, which will serve as an architecture of advanced XR experience realms. In this paper, we focus on the anticipated 6G post-smartphone era, where smart wearables such as VR/AR HMDs are increasingly replacing the functionalities of smartphones. Our contributions are threefold: ( $i$ ) we first extend Metaverse’s primary focus on VR/AR to Multiverse’s advanced XR realms of experience. Next, we gamify and implement all eight Multiverse realms of experience using Oculus Quest 2 and Microsoft HoloLens 2 as state-of-the-art VR/AR HMDs, experimentally investigating and comparing the performance of a ( $ii$ ) single-player origami game and ( $iii$ ) multi-player maze game across our proposed integrated VR/AR HMD and Amazon Mechanical Turk crowd-of-Oz (CoZ) platform.

The opening Optical Fiber Communication Conference and Exhibition 2021 plenary talk on how technologies and applications drive the evolution of networking concluded by presenting the equation Networking = Art + Science + Engineering. Due to their growing complexity, modern networks may be better viewed as techno-social systems that resemble biological superorganisms. In this paper, we expand on the aforementioned equation in the context of future 6G mobile networks, putting a focus on its first part, the Art of 6G (TAO 6G). To set the stage, we first elaborate on the 6G vision from an optical fiber fixed networks perspective, taking into account the respective viewpoints of the International Telecommunication Union-Telecommunication Standardization Sector and the FTTH Council Europe as well as the European Telecommunications Standards Institute’s recently launched fifth-generation fixed network initiative of bringing fiber to everywhere and everything, which is supposed to be the foundation of the new digital age and is a prerequisite for the digital transformation of the whole society. Towards this end, we present our ideas on what the digital society of the future will or potentially could look like. After briefly reviewing our work on tactile immersive use cases of so-called cyber-physical-social systems (CPSS), we inquire into the emerging human-centric Industry 5.0 and its mutually beneficial underlying principles of digitalization and, more interestingly, biologization. Specifically, we borrow ideas from biological superorganisms with brain-like cognitive capabilities found in natural societies for a stigmergy-enhanced Society 5.0, using tokenized digital twins for advancing collective intelligence in CPSS via indirect communication. Finally, we present our CPSS-based bottom-up token engineering framework designed for Society 5.0.