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The paper considers a purpose and features of ontologies use in describing of subject area, both from a theoretical and an applied point of view. Criteria for identifying ontologies types are indicated. Based on cognition schematism principles, a knowledge representation ontologies system has been developed, that combines language, forms of knowledge representation and process schemes. It is shown that it is exactly such a system of ontologies makes it possible for the practical use of ontologies in computing environments.

The paper considers approaches to ontologies using in task of requirements tracing. It is stated that for successful requirements management it is necessary to reveal the image of rational activity object, not its individual properties. In this approach requirement is defined as an aspect projection of some object ontology onto considered subject area in the system purpose context. A model of the activity object ontology, as a system of functionally and logically interrelated concepts, quantities and methods, is developed. Proposed model combines an ontology of quantities and measures and an ontology of means, “technologies” of assessment. Such model makes it possible to describe processes occurring in the system in more detail, and in combination with other ontologies (ontology of an activity life cycle stages, properties ontology, certain project ontology constructed by project documentation), it allows to obtain tools for more efficient requirements revealing, understanding of causal relationship in their changing and management.

We report on the performance of channel and source coding applied for an experimentally realized hybrid fiber-wireless W-band link. Error control coding performance is presented for a wireless propagation distance of 3 m and 20 km fiber transmission. We report on peak signal-to-noise ratio performance of several encoded high-definition video sequences constrained by the channel bitrate and the packet size. We argue that light video compression and low complexity channel coding for the W-band fiber-wireless link enable low-delay multiple channel 1080p wireless HD video transmission.

The next generation of information technology demands both high capacity and mobility for applications such as high speed wireless access capable of supporting broadband services. The transport of ...

In this paper, we review our experimental and simulation work on 28- and 56-Gbaud PAM4-based 100Gbps and 400Gbps short-haul links, including 10, 40, and 80km transmission distances. We also discuss the system performances, limitations, and areas of improvement for these links and their future applications.

By using an N×M multicast switch, where N is expandable from 4 to ≥16, and M is 16, we experimentally demonstrate that in a metro optical network with OSNR ≥17dB, the sensitivity of an intradyne coherent receiver can reach < −34dBm for 28Gbaud DP-QPSK signals, thereby enabling a CDC ROADM with no drop-side EDFAs.

We propose an approach for dynamic channel allocation and multicast data delivery inside the 60 GHz unlicensed band. Channels, conveying 1.25 Gbps signals, can be allocated on demand by tuning the frequency sweep of an external cavity laser (ECL) either in the optical remote node (RN) or in the central office (CO). At the RN, we perform the replication of the original channel suitable for closely spaced multicast applications such as high definition (HD) video delivery where RN serves as a photonic radio frequency (RF) generator for both channel allocation and multicast. Experimental demonstration is presented with bit error rate (BER) performance below 10-9 for original and replicated channels after transmission through 22.8 km of standard single mode fiber (SSMF).

We experimentally demonstrate uncompressed high-definition (HD) video distribution at 84 GHz Radio over Fiber link achieving up to 3 meters of wireless transmission. We experimentally emulate Metro-Access architecture by deploying single/multimode fibers. Passive and active approaches for remote antenna unit (RAU) are experimentally investigated. The bit error rate (BER) performance of the optical and wireless channels is reported. A successful transmission of uncompressed HD video in the W-band wireless channel is demonstrated with prospects to pave the way for application-focused fiber-wireless connectivity supported by diverse optical fiber distribution infrastructure.

We experimentally investigate the 60 GHz double-sideband radio-over-fiber link. We present the bit error rate performance of the system for HD video transmission in the access architecture and the phase noise measurements for metro-access scenarios.

In this paper, we propose and experimentally demonstrate a simple, cost-effective hybrid gigabit fiber-wireless system for in-building wireless access. Simplicity and cost-effectiveness are achieved in all parts of the system by utilizing direct laser modulation, optical frequency up-conversion, combined single mode/multimode fiber transmission and envelope detection. Error-free transmission of 2-Gbps data in 60-GHz band over a composite channel including 10-km standard single-mode fiber (SSMF)/1-km multimode fiber (MMF) and 6.5-m air transmission was successfully achieved. © 2012 Elsevier Inc. All rights reserved.

[EN] The paper addresses the problem of distribution of highdefinition video over fiber-wireless networks. The physical layer architecture with the low complexity envelope detection solution is investigated. We present both experimental studies and simulation of high quality high-definition compressed video transmission over 60 GHz fiberwireless link. Using advanced video coding we satisfy low complexity and low delay constraints, meanwhile preserving the superb video quality after significantly extended wireless distance. © 2011 Optical Society of America., This work has been partly funded by the European Commission under FP7 ICT-249142 FIVER project and by the by the Spanish Ministry of Science and Innovation under the TEC2009-14250 ULTRADEF project.

The application of systems with reference model self-adjustment and control signal saturation in a task of second-order dynamic object with uncertain or varied parameters is considered in this paper. The features of system behaviour at different values of the control object and model coefficients are analyzed. The condition of a self-adjustment process stability are formulated containing the system and model parameters only. The best quality criteria of a control processes are determined. The method of a system error and time constant reduction by the increase of self-adjustment signal amplitude is offered.

We propose and experimentally demonstrate a fiber-wireless transmission system for optimized delivery of 60-GHz radio frequency (RF) signals through picocell mobile backhaul connections. We identify advantages of 60-GHz links for utilization in short-range mobile backhaul through feasibility analysis and comparison with an alternative E-band (60-90 GHz) technology. The 60-GHz fiber-wireless-fiber setup is then introduced: two spans of up to 20 km of optical fiber are deployed and bridged by up to 4 m of wireless distance. The 60-GHz radio-over-fiber technology is utilized in the first span of fiber transmission. The system is simplified and tailored for delivery of on-off keying data signals by employing a single module for lightwave generation and modulation combined with a simplified RF downconversion technique by envelope detection. Data signals of 1.25 Gb/s are transmitted, and a bit-error-rate performance below the 7% overhead forward-error-correction limit is achieved for a range of potential fiber deployment scenarios. A spurious free dynamic range of 73 dB-Hz2/3 is attained for a frequency-doubling photonic RF upconversion technique. The power budget margin that is required to extend the wireless transmission distance from 4 m to a few hundred meters has been taken into account in the setup design, and the techniques to extend the wireless distance are analyzed. © 2013 IEEE., Manuscript received July 5, 2013; revised July 29, 2013; accepted July 30, 2013. Date of current version August 20, 2013. The work of J. J. Vegas Olmos was supported in part by the Marie Curie Program through the WISCON project. M. Beltran and R. Llorente were supported by the Spain National Plan TEC2012-38558-C02-01 MODAL project. Corresponding author: A. Lebedev (e-mail: alele@fotonik.dtu.dk).

Hybrid fiber-wireless transmission of 2-Gbps signals in 60-GHz band over a composite channel (10-km SMF/1-km MMF/6.5-m wireless) is experimentally demonstrated for gigabit in-building wireless access using simple direct modulation, optical upconversion and envelope detection.

This paper presents an experimental demonstration of a millimeter-wave wireless bridge in the W-band for transparent broadband fiber access in the sub-urban areas, where full fiber connections are impracticable.

We demonstrate that, by jointly optimizing video coding and radio-over-fibre transmission, we extend the reach of 60-GHz wireless distribution of high-quality high-definition video satisfying low complexity and low delay constraints, while preserving superb video quality.