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Byzantine failures during the execution of the routing algorithm may degrade or disrupt the normal operation of the network. Ant Colony Optimization (ACO)-based routing algorithms are especially vulnerable to those failures. In this work, we propose the use of crankback re-routing extensions associated to the ACO algorithm in wavelength-routed optical networks to deal with byzantine failures. We investigate three different byzantine failure scenarios: misdirection of forward ants, dropping of forward ants and dropping of backward ants. Those failures affect the routing information of the network, but they are very hard to detect and cannot be fully addressed by integrity and authentication techniques. Without any need for a byzantine failure detection mechanism, simulations have demonstrated that the proposed approach is effective in mitigating the impact on the blocking probability due to network nodes exhibiting a byzantine behavior. [ABSTRACT FROM AUTHOR]

A fast-locking all-digital phase-locked loop (ADPLL) including a fast-locking unit, a multi-level bang-bang phase detector (ML-BBPD), a dynamic gain adjustment controller (DGAC), and a digitally controlled oscillator (DCO) is presented. The ML-BBPD provides multi-level outputs with different phase errors. According to the detection results of ML-BBPD, the DGAC can adjust the dynamic integral gain of digital loop filter to provide four different operation modes and keep the ADPLL always in stable operation for fast-locking procedure. The DCO with loading compensation circuit can decrease the difference of tuning range in 13 bands less than 25%. Implemented with a 0.18-\mum CMOS technology, the area of the core circuit is 0.7735 mm^2 and the total power consumption is 35 mW from a 1.8 V supply voltage at 1.25 GHz. The ADPLL can generate output frequencies from 253.9 MHz to 1.367 GHz with 12-phase output clocks. Experimental result shows that the locking time can be accomplished in 2.9184 \mus, i.e., 57 cycles with a 19.53125 MHz reference clock. The phase noise is -108.77 dBc/Hz at 1 MHz frequency offset, and measured rms jitter and peak-to-peak jitter are 8.884 ps and 32.5 ps respectively. [ABSTRACT FROM AUTHOR]

Simple, selective and precise four spectrophotometric methods were developed and validated for quantitative determination of Salicylamide (SAD) and Ascorbic acid (ASC, Vitamin C) in their binary mixture. Method A is Area under curve spectrophotometry, in which the area under curve in the wavelength ranges 225-245 nm and 265-285 nm were selected for determination of SAD and ASC. Method B is based on dual wavelength spectrophotometry, where ASC can be determined by difference in absorbance at 249.8 and 285.8 nm. On the same way; SAD is measured by difference in absorbance at 240.4 and 286.4 nm. Method C utilizes isoabsorptive point spectrophotometry where total concentration of SAD and ASC was calculated at their isoabsorptive points at 246.4 and 287 nm, while SAD concentration alone can be determined by first derivative spectrophotometry (1D) at 315.4 nm, then ASC concentration can be determined by subtraction. Method D is ratio subtraction spectrophotometry, where ASC can be determined by dividing the spectrum of the mixture by the spectrum of the SAD (as a divisor) followed by subtracting the constant absorbance value of the plateau region, then finally multiplying the obtained spectrum by the spectrum of the divisor. The developed methods have been successfully applied for determination of the studied drugs in different laboratory prepared mixtures and in their pharmaceutical formulation. Statistical comparison between the results obtained by applying the proposed methods and the reported HPLC method was done, and it was found that there was no significant difference between them regarding both accuracy and precision. [ABSTRACT FROM AUTHOR]

We investigate the problem of multicast routing and wavelength assignment under the multi-drop path model (MRWA-MP). In a multi-drop path model, multiple paths are employed to establish a multicast session and each path can drop signals at no more than a predefined number of destination nodes. Given a network topology and a multicast session, the MRWA-MP problem is to minimize the number of wavelengths used to establish the multicast session and, as an auxiliary objective, minimize the number of fibers used. We derive bounds for both objectives. The lower bound on the number of wavelengths derived is tighter and thus more accurate than that in recent papers. To gain an insight into the complexity of the MRWA-MP problem, we formulate it as a mixed integer linear programming (MILP) problem and solve it using CPLEX integer optimizer. Our experience indicates that this problem can easily overwhelm even a state-of-the-art computing facility. To solve the MRWA-MP problem efficiently, we develop a heuristic, MFBH, based on the Edmonds–Karp maximum flow algorithm. Through experiments, we show that the MFBH heuristic achieves the lower bound on the number of wavelengths in almost all instances of the real-life and randomly generated networks that we tested. Furthermore, MFBH tends to use fewer fibers when the maximum number of drops allowed on a single path decreases, the number of destination nodes in a multicast session increases, or the connectivity of the network decreases. [Copyright &y& Elsevier]

The article reports on the move of Netrality Property 325 Hudson, a brand of the Carriet Hotel and Meet Me Room in New York City, have its internet service from Zenfi Networks Inc. It mentions that Zenfi is New York's premier provider of dedicated dark fiber networks for mobile and wavelength connectivity. It adds that the provision of the said connectivity will provide 325 Hudson will allow wireless providers to gain access to a confluence point where wireless networks can easily interconnect.

The article reports that the telephone service company Windstream Holdings Inc. will provide fiber and wavelength services in Miami, Florida through its Carrier Solutions group. It states that the company has connected its fiber network to a number of data center providers. It mentions that the company is incorporating new software to its customer portal that allows business and customers to request service quote.

The article discusses the measurement of laser-induced damage threshold (LIDT) at other wavelengths. It mentions the rule of the thumb that LIDT can be measured through an inverse square-root in relation to wavelength. It cites the test parameters for LIDT, which include repetition rate, angle of incidence, beam diameter and angle rate.

The article reports on th move of the telecommunication company Virgin Mobile Australia Pty. Ltd. to offer bonus data on customers who defect to its network to its network in Australia. It states that the company is offering up to four gigabytes (4GB) of extra data to new customers as well as those existing who upgrade on select plans. It notes that the offer coincides with the launch of Samsung's Galaxy S6 and S6 Edge.

French operators SFR and Bouygues Telecom are close to finalising talks to share their mobile networks. Both respective boards are expected to vote on the agreement on 31 January. [ABSTRACT FROM AUTHOR]

Indian ministers have agreed to cap the fees telecom companies pay to use mobile frequencies at 5% of annual gross revenue. [ABSTRACT FROM AUTHOR]

Bandwidth infrastructure provider euNetworks has extended its contract with the German freight and warehousing exchange TimoCom. [ABSTRACT FROM AUTHOR]

The article discusses findings by neural physiologist Ido Perlman and colleagues as published in the July 8, 2014 issue of "Nature Communications" on Müller cells in the retina. Topics include retinal cone and rod cell color absorption, computer simulation of cells in handling long-wavelength and short-wavelength light, and Müller cells' ability to channel light wavelengths to cone cells.

The article reports on the announcement of fiber-based service data provider Lumos Networks Corp. for the extension of its high capacity wavelength connectivity. It adds that the expansion will increase the number of data centers connected to the Lumos fiber network from 12 to 18. It also offers the insights of Joseph McCourt, chief revenue officer of Lumos on the planned network expansion of his company.

A graph is presented that shows the increase in energy bandwidth in mega-base per second (Mbps) from year 2012 to 2022.