WDM PON Research Articles

Realization of 25-GHz spaced Ultra densed Spectrum-Sliced WDM PON with 3- spectrum sliced channels using 50-GHz AWGs

Realization of 25-GHz spaced Ultra densed Spectrum-Sliced WDM PON with 3- spectrum sliced channels using 50-GHz AWGs

Evaluation of resource efficiencies for the non-symmetric dynamic wavelength allocation method applied in the P2MP WDM-PON network design

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 aconventional 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 anumber 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 aviewpoint of application in future WDM-PON network designs.

Performance analysis of WDM PON systems using PIN and APD photodiodes

Performance analysis of WDM PON systems using PIN and APD photodiodes

Performance analysis of WDM PON systems using PIN and APD photodiodes

Performance analysis of WDM PON systems using PIN and APD photodiodes

Novel analysis of blocking probability along with topologies of WDM Passive Optical Network

A novel analysis of blocking probability has been studied along with topologies. It has been shown that the algorithm proposed offers the minimum probability of blocking. The performance of wavelength division multiplexing passive optical network (WDM-PON) has been studied for different values of loads. To analyze the blocking probability, conventional algorithms have been used i.e. random and first-fit wavelength assignment using different number of wavelengths. It elaborates the proposed WDM-PON network in order to serve all ONUs providing the bandwidth as required by each ONU or end user. Performance of the system has been investigated using the quality parameters like signal-to-noise ratio (SNR), bit error rate (BER) and eye diagram. The result elaborates the performance of proposed algorithm which offers the least blocking probability. At last, study introduces different challenges and aspects of future needs in formulating an effective WDM PON system.

An ultra-dense spacing-based PON by incorporating dual drive Mach–Zehnder modulator for comb generation

Abstract Wavelength division multiplexed passive optical is promising technique to achieve a high data rate and large number of user. The notable advantages of WDM PON is the combination of reliability, cheap in cost, accessible bandwidth, high security, large optical reach and it can support large number of ONU. There are multiple approaches to achieve high-speed WDN PON using different transmission techniques. In WDM, multiple lasers are required which increase the cost of the system. To reduce cost, an optical multicarrier generation system is proposed. An economical multiple carrier generation with the incorporation of sine generator and Mach–Zehndar modulator is demonstrated. Utmost work of sine generator and dual drive modulator was to attain low cost functioning of passive optical networks. Multicarrier generation was done and replacement of laser carriers with optical multicarrier generator. Carriers were generated with the frequency spacing of 20 GHz and these carriers were used in the passive optical networks with the tone-to-noise ratio of 40 dB, amplitude difference of 1.4 dB. For the transmission of downstream in the PON, differential phase shift keying was employed at 10 Gbps data speed. Transmission distance achieved was 30 km using single-mode fiber and this was a part of optical distribution network. Optical network unit was next part after ODN and signals were received with balanced receiver. Moreover, half signal was given to intensity modulator for the signal re-modulation. Bit error rate of 10–9 was achieved at all channels in the downstream. An upstream of 10 Gbps was accomplished in the passive optical network.

Performance investigation of PM-based wavelength remodulation scheme in bidirectional TWDM-PON

Abstract Signal remodulation mechanism is a promising cost-effective choice for future optical access networks. This paper investigates the scheme of the phase modulator to remodulate upstream data in the bidirectional WDM PON and TWDM PON system. The simulation results of downstream is carried out using two data formats such as RZ and NRZ at varying lengths of single mode fibers in this scheme. In addition, the upstream transmission compares different remodulators such as Phase modulator, Mach–Zehnder modulator (MZM) and Electroabsorption modulator. By analyzing the eye diagram and Q-value, the performance of upstream and downstream transmission is obtained. It is observed that the PM remodulation TWDM-PON with NRZ modulation format has better performance, which is a rational solution for NG-PON2 cost-effectiveness.

WDM PON: An Efficient Solution for Deployment of Future Transport Network

WDM PON: An Efficient Solution for Deployment of Future Transport Network

Performance of Carrier- Suppressed Return-to-Zero(CSRZ), Duo binary Return-to-Zero(DRZ) and Modified Duo binary Return-to-Zero(MDRZ) Modulation Methods in WDM-PON Systems

In this paper the different modulation techniques used in fiber optic technology are compared to check which one has the better bit error rate (BER). There are a number of different modulation techniques used in WDN-PON systems but here the comparison is made among carrier-suppressed return-to-zero (CSRZ), duobinary return-to-zero (DRZ) and modified duobinary return-to-zero (MDRZ) modulation. The comparison to determine which is better is made my performing simulations in OptiSystem version 17 software. OptiSystem 17 is the current version of the software at the time the simulations were being carried out. In the OptiSystem software an optical fiber system is simulated from transmitter all the way to receiver. In the experiment when checking the performance of the different modulation formats, the optical fiber and the receiver are left unchanged and only the transmitter part is changed according to the modulation format being simulated at that particular instance. The modulation in the transmitter is done by using proper components from the OptiSystem library which when organized in the right order will give out a signal modulated in a certain format by the time it is fed into the optical fiber. Knowing the performance of modulation can help in WDM PON where the network gets to use passive components as it goes to user. Since no active amplification or correction equipment is used in WDM-PON, therefore using the format with the best performance can help with performance of overall system.

Data erasure in Fabry–Perot Diode Lasers: effects of facet reflectivity

ABSTRACTIn this study, the effects of facet reflectivity on the data erasure ability of injection-locked Fabry Perot Laser Diode (FPLD), based on a remodulation method in wavelength division multiplexed passive optical network (WDM PON), were investigated. For this purpose, the feasible front facet reflectivity of FPLD was determined as between 0.2% and 7%, depending on the specified injected power interval. Firstly, the system carried out analysis without applying data at the user end to comprehensively demonstrate how much downstream data was completely erased in FPLD. Then, 2.5 Gb/s of non-return-to-zero (NRZ) data was applied and the results compared with the erased downstream signal without data. The results show that upstream transmission improved with an increase in facet reflectivity between 0.2% and 7%.

Transmission Performance and Cost Analysis of Multi-Carrier-based Wavelength Division Multiplexed Passive Optical Access Network

AbstractMulti-tone-based wavelength division multiplexed passive optical networks are considered to provide cost-effective access network solution. We analysed and revealed the transmission performance, power budget concern and the cost investigation of the multi-tone-based WDM PON. A differential phase shift keying and re-modulated return to zero on/off keying signals for downlink and uplink, respectively, are transmitted via a single-mode fibre. The transmission performance of the proposed architecture is analysed using key parameters of bit error rate and optical signal to noise ratio using different data rates and channel spacing. The simulation results are in agreement with the theoretical analysis. The power budget is calculated for both upstream and downstream data signals showing excellent system margins for any unseen losses. The proposed setup is also analysed in terms of cost to prove it the cost-effective solution for the next-generation optical access networks.

Data erasure analysis of FPLD based on remodulation bidirectional PON system

ABSTRACTThe data-erasing mechanism is a promising cost-efficient option for future broadband access networks. This paper analyzes the data erasure efficiency of the Fabry Perot Laser Diode(FPLD) at a speed of 5 Gb/s based on bidirectional wavelength division multiplexed passive optical networks (WDM PONs) using the carrier remodulation technique. The effects of many parameters such as the biasing current, extinction ratio, confinement factor, and injection power demonstrate the data erasure efficiency of the FPLD in the upstream bidirectional remodulation PON system are discussed. The novelty of this study is the very high front facet reflectance results are demonstrated. A range of injection power from −25 dBm to 0 dBm and an FPLD bias current of 20-100 mA were applied to the system. The injection power below 0 dBm and bias current above 30 mA provide successful transmission of upstream data. The FPLD can suppress the residual downstream extinction ratio <0.5 dB.

Optical Power Budgeting in Colorless WDM PON

Optical Power Budgeting in Colorless WDM PON

Wideband Steady-State and Pulse Propagation Modeling of a Reflective Quantum-Dot Semiconductor Optical Amplifier

A new time-domain wideband numerical model for simulation of quantum dot-reflective semiconductor optical amplifier (QD-RSOA) steady-state and dynamic behavior, is described. The model is used to investigate 1 ps full-width at half-maximum input Gaussian pulse amplification and also modulation cancellation. A large modulation-cancellation dynamic range of about 35 dB, is predicted for high input powers, which is not attainable in bulk and QW RSOAs. The model can be applied to traveling-wave and reflective QD-SOAs. The combination of the unique features of quantum dots and a reflective structure can be used to realize a colorless modulator for wavelength-division multiplexed passive optical networks (WDM PONs).

Optical- and Electrical-Domain Compensation Techniques for Next-Generation Passive Optical Networks

High-capacity TDM-PONs, TWDM PONs, and WDM PONs have great potential to be used as next-generation PONs in emerging broadband services for various applications. As PONs typically use direct detection techniques and low-cost components, transmission impairments become one of the main limiting factors. Various transmission impairment compensation techniques, including both optical and digital signal processing (DSP) based techniques, are proposed and demonstrated for high-speed TDM-, TWDM-, and WDM-PONs. In this article, we describe the next-generation PON schemes and principles of different compensation techniques. We propose filter type optical compensation and Volterra type electrical compensation techniques to compensate nonlinear inter-symbol interference caused by vestigial sideband, limited modulation bandwidth, in-phase and quadrature imbalance, dispersion, and square-law detection. In addition, analyses and comparison of the equilibrium performances, features, characteristics, and applicability of the various optical- and electrical-domain compensation schemes are presented.

Last mile mobile hybrid optical wireless access network routing enhancement

This study focuses on mobile ad hoc networks (MANETs) that support Internet routing protocol imposing stringent resource consumption constraints of Quality of service (QoS). The mobile Internet causes the ongoing issue of inefficient use of the MANET resources due to its random nature of wireless environments. In this paper, the new improved architecture of the last mile mobile hybrid optical-wireless access network (adLMMHOWAN) is proposed and designed to tackle the arised issues. The proposed design is based on a unified wireless-wired network solution required the deployment of MANET-based wireless fidelity (WiFi) technology at the wireless front-end and wavelengths division multiplexing passive optical network (WDM PON) at the optical backhaul. The critical performance metrics such as network capacity and energy consumption based on modified AODVUU routing protocol using OMNeT++ software is analyzed with 2 scenarios, namely the number of nodes and mobility speed. This mode of communication results in better QoS network capacity of 47.07% improvement, with 26.85% reduction of lower energy resource consumption for mobile wireless front-end over passive optical network backhaul architecture when compared with the existing work of oRiq scheme that focus on improvement in MANETs.

Performance Enhancement in Colorless WDM–PON Using SSB-SC

Abstract In this manuscript, an attempt has been made to enhance the performance of colorless wavelength division multiplexed-passive optical network (WDM–PON) system using a combination of dual-drive Mach–Zehnder modulator and single sideband-suppressed carrier (SSB-SC) technique along with splicing. The proposed design makes use of SSB-SC technique for optical line terminal (OLT) as well as for optical network unit (ONU) that is generated by using dual-drive modulator which in turn reduces the expense for complete communication process. Suppressed RF signals with four channels at a bit rate of 10 Gbps for each channel are multiplexed before injecting into fiber span of 25 km at OLT side. Half of the downlink power is consumed for re-modulating the data signal at ONU side. The performance is further improved by using signal splicing method. Due to suppression in the carrier in this technique, there is no carrier Rayleigh scattering problem. The proposed model is compared with the existing one for error-free transmission of signal. The results revealed that the proposed model possess less value of bit error rate with the same value of received optical power as well as channel.

A Review of Self-Seeded RSOA Based on WDM PON

The colorless technology has been offered as a solution to decrease the cost in wavelength-division multiplexed passive optical network (WDM PON). The self-seeded reflective semiconductor optical amplifier (SS-RSOA) based on WDM PON has been proved to be a promising solution among colorless operations. In this paper, the principles, transmission limitations, and recent research of SS-RSOA based on the WDM-PON technology are reviewed. This paper aims to provide a broad perspective on the status of the SS-RSOA technology to researchers and application engineers who work with solutions in colorless operations. A list of more than 60 research publications on the subject has also been appended for a quick reference.

Anti-Stokes contribution to the SBS Stokes gain in remotely seeded bidirectional NG-PON systems.

We assess the importance of Stimulated Brillouin scattering (SBS) anti-Stokes wave on reflection tolerance in remotely seeded wavelength-division multiplexing passive optical networks (WDM PON). Experimental validation of the extended model for the externally seeded SBS is presented towards assessing the conditions in which the anti-Stokes contribution becomes relevant in the variant scenario of remotely carrier-seeded PON. We identify relevant operating conditions in which the latter can no longer be reliably neglected, and analyze the remote seed power budget implications of such contribution. Considering typical launch powers in PON systems we found that, even for seed launch powers below SBS threshold, non-optimized upstream (US) power spectral density may lead to a considerable anti-Stokes contribution to the SBS gain. In effect, in order to maintain a reference optical return loss (ORL) of 32 dB in such scenario, anti-Stokes wave contribution imposed rigorous remote seed power budget restrictions depending on fiber parameters.

Effects of Electrical and Optical Equalizations in 28-Gb/s RSOA-Based WDM PON

We experimentally investigate the roles of electrical and optical equalizers in the 28-Gb/s wavelength-division-multiplexed passive optical network implemented by using reflective semiconductor optical amplifiers (RSOAs) and direct-detection receivers. For the generation of 28-Gb/s signal, we directly modulate an RSOA in the polar return-to-zero (RZ) ${N}$ -ary pulse-amplitude-modulation (PAM) format. The results show that the optical equalization is capable of compensating the waveform distortions caused by both the bandwidth-limitation of RSOA and fiber’s chromatic dispersion without deteriorating the signal-to-noise ratio (SNR). On the other hand, the electrical equalization is effective for the compensation of the bandwidth-limitation of RSOA only at the cost of SNR. The results also show that the electrical equalization is helpful to compensate for the remaining waveform distortions after the optical equalization. By using both equalizers, we demonstrate the transmission of the 28-Gb/s signals in polar RZ-PAM- ${N}$ formats ( ${N} =2$ , 3, and 4) over 20 km of standard single-mode fiber.