Modulation Format Recognition Using Artificial Neural Networks for the Next Generation Optical Networks

Transmission systems that use advanced complex modulation schemes have been driving the growth of optical communication networks for nearly a decade. In fact, the adoption of advanced modulation schemes and digital coherent systems has led researchers and industry communities to develop new strategies for network diagnosis and management. A prior knowledge of modulation formats and symbol rates of all received optical signals is needed. Our approach of modulation formats identification is based on artificial neural networks (ANNs) in conjunction with different features extraction approaches. Unlike the existing techniques, our ANN-based pattern recognition algorithm facilitates the modulation format classification with higher accuracies

Dielectric Resonator Nantennas for Optical Communication

Dielectric resonator antennas (DRA) are ceramic based materials that are nonmetallic in nature. They offer high permitivity values (εr: 10-100). DRAs? have made their mark in various applications specially in the microwave and millimeter wave (MMW) spectrum, and are making encouraging progress in the THz band, because of their low conduction losses and higher radiation efficiencies compared to their metallic counterparts. With the advancements in nano fabrication, metallic antennas designed in the THz band have taken an interest. These antennas are termed as optical antennas or nantennas. Optical antennas work by receiving the incident electromagnetic wave or light and focusing it on a certain point or hot spot. Since most of the antennas are metallic based with Noble metals as radiators, the conducting losses are huge. One solution that we offer in this work is to integrate the nantennas with DRs. Two different DR based designs, one triangular and other hexagonal, are presented. Both the antennas operate in the optical C-band window (1550 nm). We design, perform numerical analysis, simulate, and optimize the proposed DR nantennas. We also consider array synthesis of the proposed nantennas in evaluating how much directive the nantennas are for use in nano network applications

OAM Modes in Optical Fibers for Next Generation Space Division Multiplexing (SDM) Systems

Due to the renewed demand on data bandwidth imposed by the upcoming capacity crunch, optical communication (research and industry) community has oriented their effort to space division multiplexing (SDM) and particularly to mode division multiplexing (MDM). This is based on separate/independent and orthogonal spatial modes of optical fiber as data carriers along optical fiber. Orbital Angular Momentum (OAM) is one of the variants of MDM that showed promising features including the efficient enhancement of capacity transmission from Tbit to Pbit and substantial improvement of spectral efficiency up to hundreds (bs-1 Hz-1). In this chapter, we review the potentials of harnessing SDM as a promising solution for next generation global communications systems. We focus on different SDM approaches and we address specifically the MDM (different modes in optical fiber). Finally, we highlight the recent main works and achievements that have been conducted (in last decade) in OAM-MDM over optical fibers. We focus on main R&D activities incorporating specialty fibers that have been proposed, designed and demonstrating in order to handle appropriates OAM modes

Multiplexing, Transmission and De-Multiplexing of OAM Modes through Specialty Fibers

Space division multiplexing (SDM) over fibers has introduced a new paradigm in optical communication thanks to its capability to meet the ever-renewed demand of more transmission capacity and on large spectral efficiency. This ever-increasing demand is pushed by the nonstop increase of the number of connected users, devices, processes, and data (toward internet of everything IOE). One of the most promising variants of SDM, that has recently shown great potential, is based on harnessing orbital angular momentum (OAM) modes as data carriers. These OAMs are multiplexed, transmitted over special optical fibers (OAM-fibers) then de-multiplexed. In order to highlight the potential of SDM system incorporating OAM modes through fibers, in this chapter, we disassemble an SDM system and we examine its main key elements. The potential of OAM-SDM is discussed as a promising candidate for the next generation local/global communications networks. This chapter is intended to provide a comprehensive and deep understanding of SDM, which will push R&D community to derive future research directions in the field

Full-Time Homemakers: Workers Who Cannot “Go Home and Relax”

This paper examined how musculoskeletal disorders (MSDs) of female homemakers were studied in the literature. It also presented preliminary findings from field observations of housework and fulltime homemakers in urban settings. PubMed, Ergonomics Abstracts, Sociofile, and PsycINFO databases were used in the literature search. The review focused on comparing demands of housework and paid work. Also, exposure factors found in studies of various occupations were compared with the results of field observations of housework in 4 homes in Beirut, Lebanon. Few studies systematically examined associations between MSDs and risk factors in housework. Some well-known risk factors for MSDs were identified in the Beirut homes; however, other unique factors were noted. Housework activities expose homemakers to known risk factors for MSDs, which calls for further studies to identify appropriate intervention and prevention strategies

Full-Time Homemakers: Workers Who Cannot “Go Home and Relax”

This paper examined how musculoskeletal disorders (MSDs) of female homemakers were studied in the literature. It also presented preliminary findings from field observations of housework and fulltime homemakers in urban settings. PubMed, Ergonomics Abstracts, Sociofile, and PsycINFO databases were used in the literature search. The review focused on comparing demands of housework and paid work. Also, exposure factors found in studies of various occupations were compared with the results of field observations of housework in 4 homes in Beirut, Lebanon. Few studies systematically examined associations between MSDs and risk factors in housework. Some well-known risk factors for MSDs were identified in the Beirut homes; however, other unique factors were noted. Housework activities expose homemakers to known risk factors for MSDs, which calls for further studies to identify appropriate intervention and prevention strategies