scholarly journals COMPARISON OF PRE, POST AND SYMMETRICAL DISPERSION COMPENSATION SCHEME WITH 10 GB/S NRZ LINK FOR SCM SYSTEM

2013 ◽  
pp. 34-38
Author(s):  
RUCHI AGARWAL ◽  
VIVEKANAND MISHRA
Keyword(s):  
Dispersion Compensation ◽  
Access Network ◽  
High Capacity ◽  
Cost Effective ◽  
Test Bed ◽  
High Data ◽  
Compensation Methods ◽  
High Spectral Efficiency ◽  
Efficiency Cost ◽  
Set Up

In this paper, the implementation of subcarrier multiplexing technique is developed and investigated with pre-, post- and symmetrical-dispersion compensation methods for 10 Gb/s non-return to zero (NRZ) links using standard and dispersion compensated fibers through computer simulations to optimize high data rate optical transmission. Mathematical analysis is done to evaluate performance in term of bit error rate. Simulation is done using Optisys Software version 10.0. Motivation to this research is to compare all three compensation methods and it is found that the symmetrical compensation method is superior to pre- and post-compensation methods. On comparing pre- and post-compensation methods, it is found that the later is superior to the former. A 10-Gb/s SCM test bed has been set up in which 4 * 2.5 Gb/s data streams are combined into one wavelength that occupies a 20-GHz optical bandwidth. Thus by using these comparisions one can get a promising system to the symmetric high capacity access network with high spectral efficiency, cost effective, good flexibility.

scholarly journals Long Reach and High Capacity Hybrid Passive Optical Network

2018 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Subhashini N ◽  
Brintha Therese A
Keyword(s):  
Dispersion Compensation ◽  
Optical Network ◽  
Access Network ◽  
High Capacity ◽  
Passive Optical Network ◽  
Modulation Formats ◽  
High Data ◽  
Modulation Format ◽  
Compensation Mechanisms ◽  
Wdm Pon

<p>A number of applications are growing day by day and so the traffic. The need for bandwidth is also increasing at a rapid rate. The bandwidth and speed with which data can be transferred was very less when compared to core networks. The access network which was once a bottleneck is no longer so because of use of optic fiber (FTTH networks). A number of variants of Passive Optical Network (PON) have been proposed like the WDM PON and the Hybrid PON. Hybrid PON is a combination of TDM PON and WDM PON and is advantageous over WDMPON. This paper focuses on high capacity networks that can provide high data rate and long reach in the access part of the network. NRZ modulation format is normally used for transmission.  We consider the advantages provided by the advanced modulation formats like DPSK. This modulation format is used to here and its benefits are evaluated in Hybrid PON network to increase the capacity and the reach of the network. Parameters like the BER and the Q factors are analysed using Optisystem Software. Distortion and the phenomena of dispersion can limit the performance of such a system. Hence Dispersion compensation mechanisms like the Dispersion Compensation Fiber (DCF) are used in the system to transmit data over large distance.</p>

Increasing the Capacity of SAC-OCDMA by Using OFDM Modulation

2015 ◽  
Vol 793 ◽  
pp. 530-534
Author(s):  
A.O. Aldhaibani ◽  
S.A. Aljunid ◽  
M.S. Anuar ◽  
A.R. Arief
Keyword(s):  
Access Network ◽  
High Capacity ◽  
Cost Effective ◽  
Optical Cdma ◽  
Broadband Access ◽  
High Spectral Efficiency ◽  
Promising Solution ◽  
Improved Performance ◽  
High Level ◽  
Theoretical Results

Optical CDMA (OCDMA) systems have received more attention because CDMA allows many users share the same transmission medium asynchronously and simultaneously with a high level of transmission security. In this paper, we describe the improved performance of the spectrum amplitude coding (SAC) OCDMA system using OFDM technique compare to SCM/SAC-OCDMA system. The theoretical results of proposed system shows that, the new SAC/OCDMA system with OFDM technique provides better performance compare to SCM/OCDMA system based on Random Diagonal Code (RD), the results evaluated based on BER, number of users and weight of code. Thus this system could be one promising solution to the symmetric high capacity access network with high spectral efficiency, reducing the required power and cost effective of broadband access network

scholarly journals Latency-Aware Offloading in Integrated Satellite Terrestrial Networks

2020 ◽  
Author(s):  
Wiem Abderrahim ◽  
Osama Amin ◽  
Mohamed-Slim Alouini ◽  
Basem Shihada
Keyword(s):  
Communication Networks ◽  
Rural Areas ◽  
Access Network ◽  
High Capacity ◽  
High Load ◽  
Traffic Load ◽  
Satellite Systems ◽  
High Data ◽  
Data Rates ◽  
Terrestrial Networks

Next-generation communication networks are expected to integrate newly-used technologies in a smart way to ensure continuous connectivity in rural areas and to alleviate the traffic load in dense regions. The prospective access network in 6G should hinge on satellite systems to take advantage of their wide coverage and high capacity. However, adopting satellites in 6G could be hindered because of the {additional latency introduced}, which is not tolerable by all traffic types. Therefore, we propose a traffic offloading scheme that integrates both the satellite and terrestrial networks to smartly allocate the traffic between them while satisfying different traffic requirements. Specifically, the proposed scheme offloads the Ultra-Reliable Low Latency Communication (URLLC) traffic to the terrestrial backhaul to satisfy its stringent latency requirement. However, it offloads the enhanced Mobile Broadband (eMBB) traffic to the satellite since eMBB needs high data rates but is not always sensitive to delay. Our scheme is shown to reduce the transmission delay of URLLC packets, decrease the number of dropped eMBB packets, and hence improve the network's availability. Our findings highlight that the inter-working between satellite and terrestrial networks is crucial to mitigate the expected high load on the limited terrestrial capacity.<br>

Enhancement of Performance of Multi Diagonal Code OCDMA System Using OFDM Technique

2014 ◽  
Vol 679 ◽  
pp. 30-34 ◽  
Author(s):  
A.O. Aldhaibani ◽  
S.A. Aljunid ◽  
M.S. Anuar ◽  
A.R. Arief
Keyword(s):  
Cost Effectiveness ◽  
Spectral Efficiency ◽  
High Capacity ◽  
Access Networks ◽  
Next Generation Networks ◽  
High Spectral Efficiency ◽  
Efficiency Cost ◽  
Promising Solution ◽  
Improved Performance ◽  
Theoretical Results

In this paper, we describe the improved performance of the SAC-OCDMA system using OFDM technique compared to SCM/SAC-OCDMA system. The theoretical results of proposed system shows that the new SAC/OCDMA system with OFDM technique provides better performance compared to SCM/OCDMA system based on multi diagonal code (MD), and the results have been evaluated based on BER and number of users for bit rate 1Gb/s and 10 Gb/s . Thus this system could be a promising solution to symmetric high capacity access networks with high spectral efficiency, cost effectiveness, good flexibility and enhanced security, which is candidate for next generation networks.

scholarly journals Latency-Aware Offloading in Integrated Satellite Terrestrial Networks

2020 ◽  
Author(s):  
Wiem Abderrahim ◽  
Osama Amin ◽  
Mohamed-Slim Alouini ◽  
Basem Shihada
Keyword(s):  
Communication Networks ◽  
Rural Areas ◽  
Access Network ◽  
High Capacity ◽  
High Load ◽  
Traffic Load ◽  
Satellite Systems ◽  
High Data ◽  
Data Rates ◽  
Terrestrial Networks

Next-generation communication networks are expected to integrate newly-used technologies in a smart way to ensure continuous connectivity in rural areas and to alleviate the traffic load in dense regions. The prospective access network in 6G should hinge on satellite systems to take advantage of their wide coverage and high capacity. However, adopting satellites in 6G could be hindered because of the {additional latency introduced}, which is not tolerable by all traffic types. Therefore, we propose a traffic offloading scheme that integrates both the satellite and terrestrial networks to smartly allocate the traffic between them while satisfying different traffic requirements. Specifically, the proposed scheme offloads the Ultra-Reliable Low Latency Communication (URLLC) traffic to the terrestrial backhaul to satisfy its stringent latency requirement. However, it offloads the enhanced Mobile Broadband (eMBB) traffic to the satellite since eMBB needs high data rates but is not always sensitive to delay. Our scheme is shown to reduce the transmission delay of URLLC packets, decrease the number of dropped eMBB packets, and hence improve the network's availability. Our findings highlight that the inter-working between satellite and terrestrial networks is crucial to mitigate the expected high load on the limited terrestrial capacity.<br>

Radio over Fiber Access Networks for Broadband Wireless Communications

2013 ◽  
pp. 235-263 ◽  
Author(s):  
Joaquín Beas ◽  
Gerardo Castañón ◽  
Ivan Aldaya ◽  
Gabriel Campuzano ◽  
Alejandro Aragón-Zavala
Keyword(s):  
Access Network ◽  
High Capacity ◽  
Cost Effective ◽  
Base Station ◽  
Radio Over Fiber ◽  
Access Networks ◽  
Wave Band ◽  
Millimeter Wave Band ◽  
Vehicle Networks ◽  
Optical Distribution

In recent years, considerable attention has been devoted to the merging of Radio over Fiber (RoF) technologies with millimeter-wave-band signal distribution. This type of system has great potential to support secure, cost-effective coverage and high-capacity vehicular/mobile/wireless access for the future provisioning of broadband, interactive, and multimedia services. In this chapter, the authors present an overview of an RoF access networks in the context of in-vehicle networks, with special attention to the figures of merit of the system and the basic enabling technologies for downlink/uplink transmission in the RoF land network, which is divided in three main subsystems: Central Station (CS), Optical Distribution Network (ODN) and Base Station (BS). The chapter first reviews the up-conversion techniques from baseband to mm-waves at the CS, and then the different BS configurations. The work finally applies these concepts to the development of an access network proposal for in-vehicle wireless application.

scholarly journals Adaptive Decision of Wireless Access Network for Higher User Satisfaction

2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Hyunsoon Kim ◽  
Mungyu Bae ◽  
Woonghee Lee ◽  
Hwangnam Kim
Keyword(s):  
Mobile Devices ◽  
User Satisfaction ◽  
High Performance ◽  
Low Cost ◽  
Access Network ◽  
Data Communication ◽  
Network Connectivity ◽  
Cost Effective ◽  
High Data ◽  
Effective Network

Today’s mobile devices mostly contain more than one wireless interface for Internet connection. Smartphones mostly have both LTE and Wi-Fi for data communication through Internet. Although the availability of Wi-Fi is incomparable to that of cellular network, its strength lies in the low cost and high data rate due to continuous PHY and MAC advancement of 802.11 protocol extensions. In this paper, we propose a device-centric system that performs cost-effective network connectivity to the mobile device by selectively activating Wi-Fi communication according to the device mobility and corresponding history of Wi-Fi usage. By analyzing the device mobility using attached sensors, the system selects appropriate Wi-Fi that has been often used in that mobility state. The system was implemented in actual mobile devices that were used to several experiments we designed to prove high performance of the system.

scholarly journals Environmental Engineering Techniques to Restore Degraded Posidonia oceanica Meadows

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 661
Author(s):  
Luigi Piazzi ◽  
Stefano Acunto ◽  
Francesca Frau ◽  
Fabrizio Atzori ◽  
Maria Francesca Cinti ◽  
...  
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Cost Benefit ◽  
Cost Effective ◽  
Posidonia Oceanica ◽  
Environmental Engineering ◽  
Bottom Surface ◽  
Sessile Invertebrates ◽  
Set Up ◽  
Short Time

Seagrass planting techniques have shown to be an effective tool for restoring degraded meadows and ecosystem function. In the Mediterranean Sea, most restoration efforts have been addressed to the endemic seagrass Posidonia oceanica, but cost-benefit analyses have shown unpromising results. This study aimed at evaluating the effectiveness of environmental engineering techniques generally employed in terrestrial systems to restore the P. oceanica meadows: two different restoration efforts were considered, either exploring non-degradable mats or, for the first time, degradable mats. Both of them provided encouraging results, as the loss of transplanting plots was null or very low and the survival of cuttings stabilized to about 50%. Data collected are to be considered positive as the survived cuttings are enough to allow the future spread of the patches. The utilized techniques provided a cost-effective restoration tool likely affordable for large-scale projects, as the methods allowed to set up a wide bottom surface to restore in a relatively short time without any particular expensive device. Moreover, the mats, comparing with other anchoring methods, enhanced the colonization of other organisms such as macroalgae and sessile invertebrates, contributing to generate a natural habitat.

scholarly journals K-seq, an affordable, reliable, and open Klenow NGS-based genotyping technology

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Peio Ziarsolo ◽  
Tomas Hasing ◽  
Rebeca Hilario ◽  
Victor Garcia-Carpintero ◽  
Jose Blanca ◽  
...  
Keyword(s):  
Cost Effective ◽  
Genetic Distances ◽  
Set Design ◽  
Special Equipment ◽  
Genetic Studies ◽  
Set Up ◽  
Genomic Regions ◽  
Biology Laboratory ◽  
Genotyping Technology ◽  
Genetic Results

Abstract Background K-seq, a new genotyping methodology based on the amplification of genomic regions using two steps of Klenow amplification with short oligonucleotides, followed by standard PCR and Illumina sequencing, is presented. The protocol was accompanied by software developed to aid with primer set design. Results As the first examples, K-seq in species as diverse as tomato, dog and wheat was developed. K-seq provided genetic distances similar to those based on WGS in dogs. Experiments comparing K-seq and GBS in tomato showed similar genetic results, although K-seq had the advantage of finding more SNPs for the same number of Illumina reads. The technology reproducibility was tested with two independent runs of the tomato samples, and the correlation coefficient of the SNP coverages between samples was 0.8 and the genotype match was above 94%. K-seq also proved to be useful in polyploid species. The wheat samples generated specific markers for all subgenomes, and the SNPs generated from the diploid ancestors were located in the expected subgenome with accuracies greater than 80%. Conclusion K-seq is an open, patent-unencumbered, easy-to-set-up, cost-effective and reliable technology ready to be used by any molecular biology laboratory without special equipment in many genetic studies.

scholarly journals Sustainable Ventilation Strategies for a Medium-Sized Space with Regional Effect

2021 ◽  
Vol 13 (9) ◽  
pp. 4651
Author(s):  
Ming-Lun Alan Fong
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Co2 Emission ◽  
High Efficiency ◽  
Regional Climate ◽  
Cost Effective ◽  
Regional Effect ◽  
Climate Conditions ◽  
Ventilation Strategies ◽  
Set Up

The analysis of ventilation strategies is fundamentally affected by regional climate conditions and local cost databases, in terms of energy consumption, CO2 emission and cost-effective analysis. A systematic approach is covered in this paper to estimate a local economic and environmental impact on a medium-sized space located in two regions during supply-and-installation and operation phases. Three ventilation strategies, including mixing ventilation (MV), displacement ventilation (DV) and stratum ventilation (SV) were applied to medium-sized air-conditioned space with this approach. The trend of the results for three ventilation systems in the life cycle assessment (LCA) and life cycle cost (LCC) analysis is SV < DV < MV. The result of CO2 emission and regional LCC shows that SV is the lowest one in both regional studies. In comparison with the Hong Kong Special Administrative Region (HKSAR) during 20 Service years, the case analysis demonstrates that the percentage differences in LCC analysis of MV, DV & SV in Guangdong are less than 20.5%, 19.4% and 18.82% respectively. Their CO2 emission of MV, DV and SV in Guangdong are more than HKSAR in 10.69%, 11.22% and 12.05%, respectively. The present study could provide information about regional effects in the LCA and LCC analysis of three ventilation strategies emissions, and thereby help set up models for decision-making on high efficiency and cost-effective ventilation strategy plans.

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