Visible light communication (VLC) systems have emerged as a promising solution to radio frequency (RF) spectrum scarcity, providing wide, unlicensed bandwidth and enhanced security in RF-free environments. However, VLC systems are prone to significant signal degradation caused by receiver movement or rotation, which limits their applicability in dynamic or mobile scenarios. To address this challenge, we introduce the concept of liquid-based reconfigurable lens (LiqRL), an innovative reconfigurable optical architecture that leverages the adaptability and spatial diversity of liquid materials to enhance signal reception and mitigate the impact of blockage sensitivity in VLC networks. The key contribution of this work lies in the development of a comprehensive mathematical model to evaluate the performance of mobile user equipment (UE) in VLC environments with LiqRL-based orientation adjustable receivers (OAR). By employing stochastic geometry, we derive analytical and closed-form expressions for coverage probability and propose a novel distance-based orientation selection mechanism that optimizes spatial alignment for improved data transmission efficiency. We further account for temporal interference correlation caused by UE mobility and evaluate the probability of successful communication across different time slots. Our results show that the LiqRL-based OAR architecture improves network performance by approximately 15% compared to conventional VLC systems, demonstrating the potential of reconfigurable optical architectures for dynamic and mobile VLC scenarios.

In this paper, we propose a compact, distributed, static synchronous compensator that is supported by a solid-state transformer (SST) topology used in custom power devices (CPD) and their applications. A suitable operating frequency around 20 kHz is proposed for the high-frequency distributed static compensator (HFDSC). This new design consists of a three-level dual active bridge SST configuration and a suitable transformer ferrite core that is used to enhance performance characteristics. Furthermore, the proposed HFDSC can be used in high-power transmission-line systems in order to ensure voltage stability and system reliability. A high-frequency, transformer-based distributed static synchronous compensator (D-STATCOM) was developed for the first time. The dc capacitor reference voltages are realized using a hysteresis voltage controller by adopting a proportional-integral (PI) techniques. The reference values of the PI controller are computed in such a way as to control the power flow from the instantaneous reference frame theory, even when 3-phase symmetry is lost. MATLAB simulation results demonstrate the efficacy of the proposed design.

The rapid adoption of the Internet and the ubiquitous coverage of cellular/wireless technologies, all concur to the fusion of networks' physical boundaries. At the same time, the proliferation of mobile and wireless devices changes our expectations as users, forcing providers to rethink their network and device management (NDM) approaches. Our work contributes to the convergence of NDM, with an early prototype of a resource-oriented cloud-based management service, using YANG data modeling language and JSON notation to model and encode policies. A proof-of-concept prototype implementation on a Linux-based smartphone demonstrates how policies achieve data offloading between wireless and mobile networks, for the benefit of users and operators.

This paper proposes and devises a simple and cost-effective native Ethernet-based self-healing WDM-PON access ring architecture for next-generation broadband access. Specifically, this paper proposes and devises simple, efficient, and cost-effective fully distributed fault detection and recovery schemes for the proposed WDM-PON ring architecture. The main characteristics of the proposed architecture is that it supports a fully distributed control plane among the ONUs, which enables each and every ONU to independently detect, manage, and recover most of the networking failure scenarios.

This paper addresses the important issue of how to optimize the performance of the current mobile backhaul radio access network (RAN) infrastructure to cope with the growing and dynamic nature of the emerging data-centric mobile multimedia traffic and services. Specifically, this work proposes and devises a simple and cost-effective EPON-based dynamic multiservice RAN architecture that efficiently transports and supports a wide range of existing and emerging data-centric mobile multimedia traffic and services along with the diverse quality of service (QoS) and rate requirements set by these services.

This work proposes a simple and cost effective local access WDM-PON architecture that combines the salient features of both traditional static WDM-PON (i.e., dedicated connectivity to all subscribers with bit rate and protocol transparencies, guaranteed QoS, and increased security) and dynamic WDM-PON (i.e., efficiently utilizing network resources via dynamic wavelength allocation/sharing among end-users). Specifically, this paper proposes and devises a novel ring-based local access WDM-PON architecture that efficiently supports dynamic allocation of wavelengths/timeslots and sharing traffic as well as a truly shared LAN capability among PON end-users.

This work proposes a survivable ring-based local access PON architecture that addresses some of the limitations of current tree-based PON architectures including supporting private networking capability as well as providing a fully distributed cost-effective APS scheme.

There is an emerging wide interest to transition from legacy WAN transport technologies to Ethernet-based technology. The current round of carrier Ethernet standards will successfully equip service providers (SPs) with the required tools to provide carrier-grade scalability and to provision and engineer connection-oriented point-to-point (P2P) packet trunks across a native Ethernet infrastructure. Building on these standards, this paper demonstrates how to support and implement full traffic engineering in a global-scale, two-tiered native Ethernet-over-WDM optical networking architecture. To achieve these objectives, several networking innovations are presented and developed including: 1) a GMPLS-based unified control plane that offers a tighter integration between layer-1 (optical transport layer) and layer-2 (Ethernet layer), 2) a fully distributed integrated routing and signaling framework for dynamically provisioning Ethernet switched paths (ESPs) at any bandwidth granularity including both full wavelength and finer granularity (sub-lambda) ESPs in an integrated Ethernet-optical networking environment, and 3) a novel notion of an integrated link-state advertisements strategy that is consistent with a fully integrated routing and signaling protocol

This paper devises and examines via computer simulation an innovative fully distributed global information- based integrated signaling framework for dynamically provisioning EVCs at any bandwidth granularity including both full wavelength and finer granularity (sub-lambda) EVCs at the optical layer.

The problem of protecting purely multicast connections in WDM mesh network has recently started to receive some attention in the literature. In fact, WDM traffic is heterogeneous in nature and only part of the traffic is multicast and the rest is unicast, therefore we expect the presence of both unicast and multicast traffic in future optical networks. This paper studies the problem of dynamic provisioning of survivable heterogeneous unicast and multicast traffic in WDM networks. Specifically, we propose new protection schemes to provision and protect unicast and multicast connection requests against singlelink failures in WDM-mesh networks. The simulation results of the proposed protection schemes are compared with each others and with those found in the literature. The results showed that our proposed scheme TP-OSPT outperforms all other schemes for moderate and large multicast group size. On the other hand, our proposed scheme OCR performs the best for small multicast group size.

This paper presents a signaling framework for supporting and implementing traffic engineering in an all Ethernet global multi-service infrastructure.

The problem of traffic grooming is a crucial constituent in designing WDM networks and has been extensively studied in the literature. Although it is expected that a part of the future traffic of WDM networks will be multicast, most studies of traffic grooming have assumed only unicast traffic. The paper investigates the problem of grooming multicast traffic in WDM networks. More specifically, different sequential single-hop and multi-hop grooming approaches are studied and compared to traditional non-grooming approaches. We also propose a hybrid approach that utilizes the combined resources at the logical and optical layers.

This work proposes a novel fully distributed Ethernet over star coupler-based PON architecture. The architecture uses a collision-free DBA scheme in which the OLT is excluded from the implementation of the time slot assignment. To implement a distributed control plane, direct connectivity (communicability) between the ONUs should be in place without imposing any constraint on the PON topology. In addition to the added flexibility and reliability associated with a distributed architecture, the performance of the proposed decentralized Ethernet PON scheme and the associated bandwidth allocation algorithms are shown to be as efficient as their centralized counterparts.

We investigate the problem of grooming dynamic multicast traffic in WDM mesh networks. This problem is equivalent to designing a light-tree based logical topology for multicast streams. It consists of four subproblems, namely routing, wavelength assignment, design of a light-tree based logical topology, and traffic-grooming. We develop different routing schemes to efficiently groom low-speed connections on the light-tree based logical topology. Numerical results demonstrate that the proposed approaches use the network resources more efficiently compared to the nongrooming approach and the approach of serving the multicast requests as separate unicast requests. Moreover, amongst the proposed techniques, the logical-first multihop grooming scheme MC-MHl outperforms all other schemes in terms of blocking probability and performance gain.

The paper proposes a novel IP-over-optical network interconnection model that takes the best features from both the overlay and peer models while avoiding their limitations. Specifically, the proposed model utilizes an optical layer-based unified control plane that manages both routers and optical switches (analogous to the peer model), while still retaining complete separation between the optical and IP layers of the overlay model. This is achieved by shifting the control plane functionalities previously associated with the IP layer to the IP/MPLS-aware, non-traffic bearing OXC controller modules located within the optical domain. In this architecture, better decisions can be made for provisioning and managing network resources, leading to their more efficient use. Based on the proposed model, an integrated dynamic routing algorithm, that takes into account the combined topology and resource usage information at both the IP and optical layers, is developed.