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Optical communication systems form the backbone of today’s communication and information society. Approximately six billion kilometers of optical fiber are installed around the globe today, enough to wrap a string of glass as thin as a human hair around the globe about 150000 times, or 20 times from Earth to Sun and back. Over just a single such strand of optical fiber, cutting-edge optical communication systems are able to carry tens of terabits per second over trans-Pacific distances, taking a mere 50 ms to link North America with South-East Asia. Today’s globally installed base of optical communication transponders is collectively capable to transmit several ten exabits per second of information (1 Ebit = $10^{{18}}$ bits), sending signals over short links between tens of meters and a kilometer within a data center, over tens of kilometers in links connecting datacenters, in cellular wireless fronthaul and backhaul, and in fiber-to-thehome applications, over hundreds of kilometers in metropolitan and regional networks, and over thousands of kilometers in trans-continental and submarine backbones. In short, almost every bit of information we touch or consume today, whether it belongs to an Internet search, to a streamed video, or to a mobile phone call, lives some parts of its life as an infrared photon within a gigantic global fiber-optic communications infrastructure. [ABSTRACT FROM AUTHOR]

Wavelength-division multiplexing (WDM) has historically enabled the increase in the capacity of optical systems by progressively populating the existing optical bandwidth of erbium-doped fiber amplifiers (EDFAs) in the $C$ -band. Nowadays, the number of channels—needed in optical systems—is approaching the maximum capacity of standard $C$ -band EDFAs. As a result, the industry worked on novel approaches, such as the use of multicore fibers, the extension of the available spectrum of the $C$ -band EDFAs, and the development of transmission systems covering $C$ - and $L$ -bands and beyond. In the context of continuous traffic growth, ultrawideband (UWB) WDM transmission systems appear as a promising technology to leverage the bandwidth of already deployed optical fiber infrastructure and sustain the traffic demand for the years to come. Since the pioneering demonstrations of UWB transmission a few years ago, long strides have been taken toward UWB technologies. In this review article, we discuss how the most recent advances in the design and fabrication of enabling devices, such as lasers, amplifiers, optical switches, and modulators, have improved the performance of UWB systems, paving the way to turn research demonstrations into future products. In addition, we also report on the advances in UWB optical fibers, such as the recently introduced nested antiresonant nodeless fibers (NANFs), whose future implementations could potentially provide up to 300-nm-wide bandwidth at less than 0.2 dB/km loss. [ABSTRACT FROM AUTHOR]

In order to solve the difficulty of the optical fiber communication system and network as the infrastructure of the global communication network, which is faced with the requirement of large capacity and high speed, the author proposes a method to modulate the parameters of multichannel electronic communication signals based on the nonlinear phase principle. The method includes multichannel electronic communication signal search, multichannel electronic communication signal parameter modulation, and multichannel electronic communication signal automatic acquisition algorithm realization. Experimental results show that under the conditions that the sampling frequency is set to f = 8.145 MHz, the length of the C/A code period is set to 1 ms, and the 1 ms data packet contains 8145 sampling points, under the same experimental conditions, the capture probability of this experiment reaches 100% and the traditional algorithm has a capture probability of up to 70%. Modulation of multichannel electronic communication signal parameters based on nonlinear phase principle has a positive guiding role in building a high-speed optical fiber communication system and network with long distance, large capacity, high elasticity, high reliability, and low delay. [ABSTRACT FROM AUTHOR]

At present days, metropolitan and access communication networks are markedly developing utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play a key role. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention for the next generation optical metropolitan and access networked systems. Simultaneously, the utilization of common optical network resources in wavelength domains will be more important. The main purpose of this paper is presented by the evaluation of resource efficiencies for the non-symmetric dynamic wavelength allocation method applied in the WDM-PON network design with a conventional topology. This contribution introduces a novel non-symmetric Dynamic Wavelength Allocation (DWA) method for a selected network design with the utilization only passive optical splitters in remote nodes. This novel wavelength allocation method is oriented on minimizing a number of working wavelengths that will be used for compliance of customers' requests for data transmitting in the common point-to-multipoint WDM–PON network design. For evaluation of wavelength scheduling, a simulation model related to the conventional WDM-PON network design is realized in the MATLAB programming environment is presented with results. Finally, different traffic loading scenarios are determined and, subsequently, resource efficiencies of the presented non-symmetric DWA method are evaluated from a viewpoint of application in future WDM-PON network designs. [ABSTRACT FROM AUTHOR]

The intended objective of this article is to provide designers with the basic knowledge to implement an Ethernet long-reach 40 Gb/s and 100 Gb/s host board. Ethernet was originated in the early 70s and has successfully displaced other popular communication standards, such as Token- Ring, becoming the default standard for local area networks in the enterprise office and datacenter equipment. Its success has roots on its basic open architecture and asynchronous protocol. During the lifetime of the Ethernet, the data rates have dramatically increased from its original 10 Mb/s to 100 Gb/s at the present time and the standard body is in the process of generating the next higher speed project most likely to be 400 Gb/s. In 2010 the IEEE802.3 body published the Ethernet 40 Gb/s and 100 Gb/s standard targeting the support of the next generation of communication equipment and components. The IEEE802.3ba???- 2010 Ethernet standard was a quantum leap to penetrate Communication Metropolitan applications, a.k.a. Wide Area Network (WAN), which were clearly dominated by the SONET/SDH protocol. This article is a continuation to the article published in the IEEE Communication Magazine in its April 2012 edition ???40 Gb/s and 100 Gb/s Ethernet Short-Reach Optical and Copper Host Board Channel Design???[1], which presented the challenges of designing 40 Gb/s and 100 Gb/s Ethernet host board electrical and optical channels targeted for Enterprise/Datacenter applications. The article reviews the long-reach for 40 Gb/s and 100 Gb/s Ethernet and the extendedreach Ethernet for 100 Gb/s host board channel electrical and optical specifications for Metropolitan/ Carrier applications. The long- and extendedreach links are intended for communication carrier equipment in inter- and intra-city infrastructures. The host board channel comprises the electrical (host board and connector) and the optical (module) sections. This article will analyze both sections and highlight the salient specifications that the designer of 40 Gb/s and 100 Gb/s Ethernet switches and ports needs to know to comply with the standard. [ABSTRACT FROM PUBLISHER]

Optical fiber communications are essential for all types of long- and short-distance transmissions. The aim of this paper is to analyze the previously presented security risks and, based on measurements, provide the risk level evaluation. The major risk is the possibility of inserting a splitter into the optical distribution network and capturing a portion of the entire spectrum, i.e., all channels in the optical fiber. Another significant security risk is crosstalk on multiplexers in networks with wavelength division multiplexing. The paper covers the macrobend attenuation evaluation of fiber and back-reflection measurements. Based on the measurements, risks were evaluated for both point-to-point and point-to-multipoint networks and, lastly, the paper covers crosstalk measurements of an optomechanical switch. Finally, all individual risks are evaluated according to the severity, and a proposal for risk minimization is provided. [ABSTRACT FROM AUTHOR]

Recently, metropolitan and access communication networks have markedly developed by utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play an important role. This contribution discusses the symmetric sharing of common optical network resources in wavelength and time domains. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention regarding the next generation of optical metropolitan and access networks. The main purpose of this contribution is presented by the analysis of possible scheduling of wavelengths for our novel hybrid network topologies considered for WDM-PON networks. This contribution briefly deploys adequate Dynamic Wavelength Allocation (DWA) algorithms for selected WDM-PON network designs with the provision of traffic protection when only passive optical components in remote nodes are utilized. The main part of this study is focused on the use of wavelength scheduling methods for selected WDM-PON network designs. For evaluation of offline and online wavelength scheduling for novel hybrid network topologies, a simulation model realized in the Matlab programming environment allows to analyze interactions between various metropolitan and access parts in the Optical Distribution Network (ODN) related to advanced WDM-PON network designs. Finally, wavelength scheduling methods are compared from a viewpoint of utilization in advanced WDM-PON networks designs. [ABSTRACT FROM AUTHOR]

The article discusses measures undertaken to modernize and develop modern telecommunication network in the Republic of Uzbekistan under the Program of Accelerated Infrastructure Development, Transport and Communication. It discusses the construction of fiber-optic communication lines and the income generated from cell communication. It also includes coverage of digital network and computer programming in Uzbekistan.