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Tytuł:
Control Mechanism for All-Optical Components
Autorzy:
Rejeb, R.
Leeson, M.
Powiązania:
https://bibliotekanauki.pl/articles/308952.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
all-optical networks
fault and performance management
securing optical networks
Opis:
In this article, we give a brief overview of security and management issues that arise in all-optical networks (AONs). Then we present an outline of the multiple attack localization and identification (MALI) algorithm that can participate in some of the tasks for fault management in AONs. Consequently, we discuss a hardware-based control unit that can be embedded in AON nodes to accelerate the performance of the MALI algorithm. We conclude the article with a discussion concerning the applicability and implementation of this device in AON management systems.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 57-62
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards broadband global optical and wireless networking
Autorzy:
Marciniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/308934.pdf
Data publikacji:
2004
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
optical networks
wireless networks
radio-over-fibre
optical packet networks
transparent networks
Opis:
This paper presents a novel, non-conventional approach to the future optical and wireless hybrid transport network, capable of supporting dominant kinds of trac, i.e., voice/real time, wireless and packet data tracffic in a single transport network. The proposed model combines different technologies as connection and connectionless networks, optical cable and wireless (microwave/millimetre wave or optical wireless), being suitable for a variety of purposes and services in order to achieve global broadband networking features. Our new networking model contains an extension to wireless world in order to achieve mobility and personalisation of connection. From the networking point of view it consists of an upgrade of real-time traffic with the microwave modulated optical wave, in order to carry out conventional mobile wireless signals via optical fibres over long distances and without significant distortion. The whole available bandwidth can be fully exploited in the hybrid network. In the IP part of the network the quality of service (QoS) can be differentiated for various classes of packets and network reliability/survivability can be categorised for the whole hybrid network. This proposal combines complete and revolutionary shift to packet traffic with smooth evolutionary upgrades. We believe the model presented here is a powerful tool to trace the future evolution of telecommunications worldwide for the next 25 years.
Źródło:
Journal of Telecommunications and Information Technology; 2004, 3; 65-70
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ant colony optimization applied to the problem of choosing the best combination among m combinations of shortest paths in transparent optical networks
Autorzy:
Brasileiro, Í
Santos, I.
Soares, A.
Rabêlo, R.
Mazullo, F.
Powiązania:
https://bibliotekanauki.pl/articles/91731.pdf
Data publikacji:
2016
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
optical networks
routing
ant colony
simulation
Opis:
This paper presents an attempt to solve the problem of choosing the best combination among the M combinations of shortest paths in optical translucent networks. Fixed routing algorithms demands a single route to each pair of nodes. The existence of multiple shortest paths to some pairs of nodes originates the problem of choose the shortest path which fits better the network requests. The algorithm proposed in this paper is an adaptation of Ant Colony Optimization (ACO) metaheuristic and attempt to define the set of routes that fits in an optimized way the network conditions, resulting in reduced number of blocked requests and better adjusted justice in route distribution. A performance evaluation is conducted in real topologies by simulations, and the proposed algorithm shows better performance between the compared algorithms.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2016, 6, 4; 231-242
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
IP over optical network: strategy of deployment
Autorzy:
Klinkowski, M.
Marciniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/308370.pdf
Data publikacji:
2001
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
optical networks
WDM
IP
MPLS
MPLambdaS
Opis:
In this paper, we present main issues of application IP technology directly over optical transport network. The capabilities of WDM transmission systems and techniques which allow the integration of IP with the physical layer are discussed. A detailed description of most solutions is reported. In particular the MPLS/MPLambdaS techniques are discussed in detail. Also problems for further development are outlined.
Źródło:
Journal of Telecommunications and Information Technology; 2001, 2; 51-56
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Threat of Optical Transmission Jamming
Autorzy:
Kowalczyk, Marcin
Marzecki, Michał
Siuzdak, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/27312945.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
clip-on coupler
optical communication jamming
optical networks vulnerability
Opis:
In this paper, we investigate how data transmissions may be affected by various types of optical interference introduced into the fiber on purpose, via a clip-on coupler. The research proved that transmissions may be jammed completely using inexpensive equipment readily available on the market, provided that the attacker has physical access to the fiber optic cable. The most dangerous attacks rely on a typical, slowly modulated communication laser with a rectangular waveform. This study urges further research aimed at counteracting such attacks.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 4; 93--101
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rearrangeability of 2×2 W-S-W Elastic Switching Fabrics with Two Connection Rate
Autorzy:
Kabaciński, W.
Rajewski, R.
Al-Tameemi, A.
Powiązania:
https://bibliotekanauki.pl/articles/307745.pdf
Data publikacji:
2018
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
elastic optical networks
elastic optical switching nodes
interconnection networks
rearrangeable non-blocking conditions
Opis:
The rearreangeable conditions for the 2×2 three-stage switching fabric of a W-S-W architecture for elastic optical switches are considered in this paper. Analogies between the switching fabric considered and the three-stage Clos network are shown. On the other hand, differences are also shown, which presented the modifications required in the control algorithm used in rearrangeable networks. The rearrangeable conditions and the control algorithm are presented and proved. Operation of the proposed control algorithm is shown based on a few examples. The required number of frequency slot units in interstage links of rearrangeable switching fabrics is much lower than in the strict-sense non-blocking switching fabrics characterized by the same parameters.
Źródło:
Journal of Telecommunications and Information Technology; 2018, 1; 11-17
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Search for Ultimate Throughput in Ultra-Broadband Photonic Internet
Autorzy:
Romaniuk, R. S.
Powiązania:
https://bibliotekanauki.pl/articles/227176.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical networks
Internet
global network
photonic Internet
Future Internet
optoelectronic networks
Opis:
A review of our today’s understanding of the ultimately broadband photonic Internet is presented. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM. The Polish perspective closes the review.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 4; 523-538
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
100/1000 Gbit/s Ethernet and beyond
Autorzy:
Marciniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/308819.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
converged networks
dense wavelength division multiplexing
high-speed Ethernet
optical networking
transparent optical networks
Opis:
100 Gbit/s Ethernet is foreseen in metro and access by 2014, while 1 Tbit/s Ethernet is forecasted for trunk links before 1020. This paper reviews the advantages and constraints of the optical networking and discusses how they meet the 100 Gbit/s Ethernet needs.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 14-19
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault Tolerant Dense Wavelength Division Multiplexing Optical Transport Networks
Autorzy:
Ren, W.
Naderi, M.
Leeson, M.
Hines, E.
Powiązania:
https://bibliotekanauki.pl/articles/308964.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
dedicated path protection architecture
genetic algorithm
DWDM
fault-tolerant networks
optical networks
Opis:
Design of fault tolerant dense wavelength division multiplexing (DWDM) backbones is a major issue for service provision in the presence of failures. The problem is an NP-hard problem. This paper presents a genetic algorithm based approach for designing fault tolerant DWDM optical networks in the presence of a single link failure. The working and spare lightpaths are encoded into variable length chromosomes. Then the best lightpaths are found by use of a fitness function and these are assigned the minimum number of wavelengths according to the problem constraints using first-fit (FF) algorithm. The proposed approach has been evaluated for dedicated path protection architecture. The results, obtained from the ARPA2 test bench network, show that the method is well suited to tackling this complex and multi-constraint problem.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 63-67
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Network Topology Effect on QoS Delivering in Survivable DWDM Optical Networks
Autorzy:
Kavian, Y.
Rashvand, H.
Leeson, M.
Ren, W.
Hines, E.
Naderi, M.
Powiązania:
https://bibliotekanauki.pl/articles/308960.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
dedicated path protection
DWDM
network topology
optical networks
QoS
survivability
Opis:
The quality of service (QoS) is an important and considerable issue in designing survivable dense wavelength division multiplexing (DWDM) backbones for IP networks. This paper investigates the effect of network topology on QoS delivering in survivable DWDM optical transport networks using bandwidth/load ratio and design flexibility metrics. The dedicated path protection architecture is employed to establish diverse working and spare lightpaths between each node pair in demand matrix for covering a single link failure model. The simulation results, obtained for the Pan-European and ARPA2 test bench networks, demonstrate that the network topology has a great influence on QoS delivering by network at optical layer for different applications. The Pan-European network, a more connected network, displays better performance than ARPA2 network for both bandwidth/load ratio and design flexibility metrics.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 68-71
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multistage optical switching networks
Autorzy:
Kaczmarek, S.
Powiązania:
https://bibliotekanauki.pl/articles/309271.pdf
Data publikacji:
2002
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
optical matrix
optical switching networks
electronic switching networks equivalent
connection properties
Opis:
The backbone networks evolution to high-speed DWDM networks generates new problems for switching. This function element must be also based on optical technology. For large capacity this cannot be realized by a single matrix, but by multistage switching networks. In the paper three types of optical matrices have been described: fiber switch FX, wavelength fiber switch WSX and wavelength interchanging fiber switch WIX. Based on these matrices, four switching network constructions were considered. The connection properties of these switching networks were evaluated, determining the electronic equivalent switching network for which these properties are well known.
Źródło:
Journal of Telecommunications and Information Technology; 2002, 2; 21-25
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of dynamic routing and spectrum allocation methods in elastic optical networks
Autorzy:
Biernacka, E.
Domżał, J.
Wójcik, T.
Powiązania:
https://bibliotekanauki.pl/articles/226037.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elastic optical networks
routing and spectrum allocation
dynamic two-step RSA method
Opis:
The introduction of flexible frequency grids and advanced modulation techniques to optical transmission, namely an elastic optical network, requires new routing and spectrum allocation techniques. In this paper, we investigate dynamic two-step routing and spectrum allocation (RSA) methods for elastic optical networks. K-shortest path-based methods as well as spectrum allocation methods are analysed and discussed. Experimental verification of the investigated techniques is provided using simulation software. Simulation results present effectiveness of routing and spectrum allocation methods for analyzed networks using requested bandwidth of connections. Moreover, performance of shortest path first methods improves considerably when a number of candidate paths increases in the UBN24 topology.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 1; 85-92
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization Balancing Algorithms for Dynamic Multicast Scheduling Problem in EON
Autorzy:
Markowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/963830.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elastic optical networks
multicast
load balancing
flow assignment
dynamic scheduling
heuristic algorithms
Opis:
Dynamic data transfer demands are often being a challenge for present communication networks, as they appear in unpredictable time and must be satisfied prior to deadline. Important kind are the multi-target demands occurring in task of replication, backup, database synchronization or file transferring in pear-to-pear networks. Optimal scheduling usually depends of the nature of transport network. In the paper dynamic deadlinedriven multicast scheduling problem over elastic optical network is considered. Particularly, the method for improving link utilization by traffic balance for multicast demands is proposed. Few heuristic algorithms and results of experiments, proving the benefits of balancing concept are presented
Źródło:
International Journal of Electronics and Telecommunications; 2016, 62, 4; 363-370
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Constrained Maximum Available Frequency Slots on Path Based Online Routing and Spectrum Allocation for Dynamic Traffic in Elastic Optical Networks
Autorzy:
Khan, Akhtar Nawaz
Powiązania:
https://bibliotekanauki.pl/articles/1844474.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elastic optical networks
routing and spectrum allocation
blocking probability
continuity constraint
contiguity constraint
Opis:
Elastic optical networking is a potential candidate to support dynamic traffic with heterogeneous data rates and variable bandwidth requirements with the support of the optical orthogonal frequency division multiplexing technology (OOFDM). During the dynamic network operation, lightpath arrives and departs frequently and the network status updates accordingly. Fixed routing and alternate routing algorithms do not tune according to the current network status which are computed offline. Therefore, offline algorithms greedily use resources with an objective to compute shortest possible paths and results in high blocking probability during dynamic network operation. In this paper, adaptive routing algorithms are proposed for shortest path routing as well as alternate path routing which make routing decision based on the maximum idle frequency slots (FS) available on different paths. The proposed algorithms select an underutilized path between different choices with maximum idle FS and efficiently avoids utilizing a congested path. The proposed routing algorithms are compared with offline routing algorithms as well as an existing adaptive routing algorithm in different network scenarios. It has been shown that the proposed algorithms efficiently improve network performance in terms of FS utilization and blocking probability during dynamic network operation.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 4; 707-714
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deep data analysis in gigabit passive optical networks
Autorzy:
Horvath, T.
Krkos, R.
Dubravec, L.
Powiązania:
https://bibliotekanauki.pl/articles/174869.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
GPONXpert
gigabit passive optical networks
GPON
signalling
user plane
frame structure
payload analysis
Opis:
This paper focuses on practical aspects of gigabit passive optical networks (GPON) diagnostics during deployment, for root-cause analysis and for research purposes. While GPON signalling analysis is already quite commonly used for diagnostics, the aim of this work is a holistic approach, including both signalling and user plane (payload) analysis. User plane analysis, especially if targeted at payload Ethernet, IP and transport layers, enables detection of additional group of problems that could limit or even prevent GPON internetworking and thus degrade the user perceived service quality. Integrated signalling and payload analysis is also interesting from the research point of view, leading to the ability to study equipment idiosyncrasies that would be hard to detect otherwise and it is also one of the enablers of equipment security verification. The mentioned theories were tested during a practical diagnostic session on a real GPON network deployment and this paper presents the findings.
Źródło:
Optica Applicata; 2017, 47, 1; 157-170
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Advanced Considerations Concerning Impact of Applied Call Admission Control Mechanisms on Traffic Characteristics in Elastic Optical Network Nodes
Autorzy:
Głąbowski, Mariusz
Sobieraj, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/27312941.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
elastic optical networks
frequency slot unit
loss probability
reservation mechanism
threshold mechanism
switching networks
traffic management
Opis:
Over the past few years, a significant increase in network traffic volumes has been observed. The ever growing bandwidth demands mean that a reliable and optimum service level needs to be ensured in communication systems for specific traffic categories. Optimal allocation and use of resources may be achieved through the use of call admission control (CAC) mechanisms implemented in network systems. The resource reservation mechanism and the threshold mechanism are two of the most popular CAC methods. In the reservation mechanisms, a certain number of resources is reserved for selected (predefined) services only. In the case of threshold mechanisms, the number of resources allocated to individual traffic classes depends on the network load. This article discusses the results of simulations verifying the impact of applied CAC mechanisms on the traffic characteristics in elastic optical network (EON) nodes with a Clos structure. Loss probability results obtained with the use of the simulator are presented as well.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 4; 68--75
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Execution Simulation Design of Fiber-to-the- home (FTTH) Device Ingress Networks Using GPON with FBG Based on OptiSystem
Autorzy:
Shabaneh, Arafat Abdallah
Melhem, Masa Loai
Powiązania:
https://bibliotekanauki.pl/articles/2200708.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fiber to the home
fiber Bragg grating
power link budget
Q-factor
gigabit passive optical networks
Opis:
Consumers require high-speed data transmission for different activities, such as smartphone usage, live broadcasting of news, and video conferencing. Therefore, a reliable communication network is needed to provide this kind of service to users. Fiber to the home (FTTH) is an optical fiber architecture that uses fiber cables in the access network for direct and final connection to homes or offices of customers. Networks based on FTTH can offer high performance, speed, and quality. An optical fiber communication system based on FTTH device ingress network using gigabit passive optical networks (GPONs) with fiber Bragg grating (FBG) and optical amplifier is designed and analyzed in this study. The developed design based on the FTTH device and FBG shows a low bit error rate (BER) for downstream and upstream configurations with an optical fiber length of 20 km. Downstream and upstream configurations achieve a Q-factor of 89.5 and 181.3, respectively. Achievable sensitivity of the developed system is −28 dBm, while the received signal based on OptiSystem is −25.59 dBm. FTTH with FBG will play a major role in the future and provide effective solutions for a wide variety of applications in network communication systems and data transmission rates.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 4; 783--791
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combination of Advanced Reservation and Resource Periodic Arrangement for RMSA in EON with Deep Reinforcement Learning
Autorzy:
Silaban, R. J.
Alaydrus, Mudrik
Umaisaroh, U.
Powiązania:
https://bibliotekanauki.pl/articles/27311944.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Elastic Optical Networks (EON)
Routing Modulation and Spectrum Assignment (RMSA)
Advanced Reservation (AR)
Resource Periodic Arrangement (RPA)
Opis:
The Elastic Optical Networks (EON) provide a solution to the massive demand for connections and extremely high data traffic with the Routing Modulation and Spectrum Assignment (RMSA) as a challenge. In previous RMSA research, there was a high blocking probability because the route to be passed by the K-SP method with a deep neural network approach used the First Fit policy, and the modulation problem was solved with Modulation Format Identification (MFI) or BPSK using Deep Reinforcement Learning. The issue might be apparent in spectrum assignment because of the influence of Advanced Reservation (AR) and Resource Periodic Arrangement (RPA), which is a decision block on a connection request path with both idle and active data traffic. The study’s limitation begins with determining the modulation of m = 1 and m = 4, followed by the placement of frequencies, namely 13 with a combination of standard block frequencies 41224–24412, so that the simulation results are less than 0.0199, due to the combination of block frequency slices with spectrum allocation rule techniques.
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 3; 515--522
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
RoFnet - Reconfigurable Radio over Fiber Network Architecture Overview
Autorzy:
Medeiros, M.
Avó, R.
Laurencio, P.
Correia, N.
Barradas, A.
Powiązania:
https://bibliotekanauki.pl/articles/308954.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
optical access networks
optical single sideband
radio over fiber
reflective semiconductor optical amplifiers
wavelength division multiplexing
Opis:
This paper introduces the basic operational concepts of the RoFnet - reconfigurable radio over fiber network, which is a project supported by the Portuguese Foundation forScience and Technology. This project proposes an innovative radio over fiber optical access network architecture, which combines a low cost base station (BS) design, incorporating reflective semiconductor optical amplifiers, with fiber dispersion mitigation provided by optical single sideband modulation techniques. Optical wavelength division multiplexing (WDM) techniques are used to simplify the access network architecture allowing for different BSs to be fed by a common fiber. Different wavelength channels can be allocated to different BSs depending on user requirements. Additionally, in order to improve radio coverage within a cell, it is considered a sectorized antenna interface. The combination of subcarrier multiplexing with WDM, further simplifies the network architecture, by using a specific wavelength channel to feed an individual BS and different subcarriers to drive the individual antenna sectors within the BS.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 38-43
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elastyczne sieci optyczne
Elastic optical networks
Autorzy:
Biernacka, E.
Lasoń, A.
Powiązania:
https://bibliotekanauki.pl/articles/317692.pdf
Data publikacji:
2013
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
elastyczna sieć optyczna
interfejsy optyczne PMD
problem routingu i alokacji zasobów częstotliwościowych RSA
elastic optical networks
physical media dependent
routing and spectrum allocation
Opis:
Artykuł przybliża koncepcję elastycznej sieci optycznej i charakterystyczne zagadnienia związane z jej implementacją. Przedstawiono w nim standardy styków optycznych sieci Ethernet 40 Gbit/s i 100 Gbit/s zawarte w dokumencie IEEE 802.3ba. Następnie opisano szczelinowy charakter widma elastycznej sieci optycznej, porównując ze sztywnym podziałem częstotliwości DWDM. Nakreślono problem planowania i dynamicznej alokacji zasobów w sieci.
The paper studies a novel concept of elastic optical network and selected network–level requirements of next generation optical networks. It investigates new optical IEEE 802.3ba Physical Layer Specification. Next it is compared the fixed-grid wavelength division multiplexing optical networks with flexible-grid elastic optical networks. It is important to define routing and spectrum assignment RSA algorithms, which are required for network planning and dynamic resource allocation. Mobile lab, radiocommunication services testing, radiocommunication networks measurements.
Źródło:
Telekomunikacja i Techniki Informacyjne; 2013, 1-2; 5-17
1640-1549
1899-8933
Pojawia się w:
Telekomunikacja i Techniki Informacyjne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Światłowodowe sieci dostępowe
Optical fiber access networks
Autorzy:
Borzycki, K.
Powiązania:
https://bibliotekanauki.pl/articles/317584.pdf
Data publikacji:
2008
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
dostęp szerokopasmowy
sieci światłowodowe
sieci dostępowe
włókno światłowodowe
włókno mikrostrukturalne
kabel światłowodowy
FTTH
FTTN
FTTx
DSL
regulacje
konkurencja
broadband access
optical fiber networks
access networks
optical fiber
holey fiber
photonic fiber
optical fiber cable
regulations
competition
Opis:
Wskazano, że szybki wzrost wymagań dotyczących przepływności łączy abonenckich i jakości usług zmusza do budowy nowej infrastruktury dostępowej, przeważnie z wykorzystaniem włókien światłowodowych jako medium transmisyjnego. Przedstawiono czynniki motywujące operatorów do budowy sieci światłowodowych, rozwiązania techniczne sieci, ich klasyfikację oraz problemy związane z zapewnieniem dostępu do sieci operatorom alternatywnym.
The paper highlights that rapidly growing requirements for subscriber access speed and service quality force operators to build a new access infrastructure, preferably based on optical fibers as the transmission medium. A review of factors motivating to build fiber access networks, technical solutions, terminology and problems related to provision of access for competitive operators is presented.
Źródło:
Telekomunikacja i Techniki Informacyjne; 2008, 1-2; 71-99
1640-1549
1899-8933
Pojawia się w:
Telekomunikacja i Techniki Informacyjne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The present and future of nonlinear optics applications in photonic telecommunication networks
Autorzy:
Marciniak, M.
Kowalewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/308711.pdf
Data publikacji:
2000
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
optical fibre communications
photonic networks
wavelength-division multiplexing
nonlinear optical phenomena
Opis:
A state-of-the art of photonic telecommunication technology is reviewed and possible directions of future developments are outlined. In particular, the impact of nonlinear optical phenomena inherent to silica glass on the transmission performance of wavelength-division multiplexed optical signal through fibres is discussed. Also potential applications of nonlinear photonic devices for the purposes of optical signal processing that is foreseen in future all-optical networks are pointed out.
Źródło:
Journal of Telecommunications and Information Technology; 2000, 1-2; 3-5
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combinatorial Properties and Defragmentation Algorithms in WSW1 Switching Fabrics
Autorzy:
Rajewski, Remigiusz
Kabaciński, Wojciech
Al-Tameemi, Atyaf
Powiązania:
https://bibliotekanauki.pl/articles/227184.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elastic optical network
switching networks
rearrenging algorithm
defragmentation algorithm
Opis:
A spectrum defragmentation problem in elastic optical networks was considered under the assumption that all connections can be realized in switching nodes. But this assumption is true only when the switching fabric has appropriate combinatorial properties. In this paper, we consider a defragmentation problem in one architecture of wavelength-space-wavelength switching fabrics. First, we discuss the requirements for this switching fabric, below which defragmentation does not always end with success. Then, we propose defragmentation algorithms and evaluate them by simulation. The results show that proposed algorithms can increase the number of connections realized in the switching fabric and reduce the loss probability.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 1; 99-105
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indoor localization based on visible light communication and machine learning algorithms
Autorzy:
Ghonim, Alzahraa M.
Salama, Wessam M.
Khalaf, Ashraf A. M.
Shalaby, Hossam M. H.
Powiązania:
https://bibliotekanauki.pl/articles/2063908.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
free-space optical communication
visible light communication
neural networks
random forests
machine learning
Opis:
An indoor localization system is proposed based on visible light communications, received signal strength, and machine learning algorithms. To acquire an accurate localization system, first, a dataset is collected. The dataset is then used with various machine learning algorithms for training purpose. Several evaluation metrics are used to estimate the robustness of the proposed system. Specifically, authors’ evaluation parameters are based on training time, testing time, classification accuracy, area under curve, F1-score, precision, recall, logloss, and specificity. It turned out that the proposed system is featured with high accuracy. The authors are able to achieve 99.5% for area under curve, 99.4% for classification accuracy, precision, F1, and recall. The logloss and precision are 4% and 99.7%, respectively. Moreover, root mean square error is used as an additional performance evaluation averaged to 0.136 cm.
Źródło:
Opto-Electronics Review; 2022, 30, 2; art. no. e140858
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Machine learning system for automated blood smear analysis
Autorzy:
Grochowski, Michał
Wąsowicz, Michał
Mikołajczyk, Agnieszka
Ficek, Mateusz
Kulka, Marek
Wróbel, Maciej S.
Jędrzejewska-Szczerska, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/220750.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical microscopy
blood cells
biophotonics
image analysis
classification
eigenfaces
neural networks
decision support
nanodiamonds
bioimaging
Opis:
In this paper the authors propose a decision support system for automatic blood smear analysis based onmicroscopic images. The images are pre-processed in order to remove irrelevant elements and to enhancethe most important ones – the healthy blood cells (erythrocytes) and the pathologic ones (echinocytes). The separated blood cells are analysed in terms of their most important features by the eigenfaces method. The features are the basis for designing the neural network classifier, learned to distinguish between erythrocytes and echinocytes. As the result, the proposed system is able to analyse the smear blood images in a fully automatic way and to deliver information on the number and statistics of the red blood cells, both healthy and pathologic. The system was examined in two case studies, involving the canine and human blood, and then consulted with the experienced medicine specialists. The accuracy of classification of red blood cells into erythrocytes and echinocytes reaches 96%.
Źródło:
Metrology and Measurement Systems; 2019, 26, 1; 81-93
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 27

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