A Long Reach Bidirectional WDM-PON Upstream and Downstream Data rate 10Gbps by using Mode Locked Laser and RSOA

This paper presents Long Reach Wavelength Division Multiplexing Passive Optical Network (WDM-PON) system capable of delivering downstream 40 Gbit/s data and upstream 40 Gbit/s data on a single wavelength. The optical source for downstream data and upstream data is mode locked laser at central office and reflective semiconductor optical amplifier (RSOA) at each optical network unit. We use four RSOAs at each optical network unit for the 40-Gb/s upstream transmission. The operating wavelengths of these RSOAs are separated by the free-spectral range of the optical demultiplexer at the central office and remote node (RN) for demultiplexing the WDM channels. We extend the maximum reach of this WDM PON to be 50 km by using Erbium-doped fiber amplifiers at the RN. Bit error rate, were measured to demonstrate the proposed scheme. In this paper Long reach and large data service aspects of a WDM-PON is presented. The results show that the error-free transmission can be achieved for all WDM channels with sufficient power margins. DOI: 10.17762/ijritcc2321-8169.150313

Comparison between OQPSK and DPSK bidirectional radio over fiber transmission systems

Radio over fiber is becoming an increasingly important technology for the wireless market since it introduces a higher data transmission rate and large bandwidth. In this paper, we have compared OQPSK and DPSK bidirectional radio over fiber ROF systems, where an offset quadrature phase shift keying (OQPSK) or differential phase shift keying (DPSK) signals are used for down-link and an on-off keying (OOK) signal re-modulated for up-link. Several measurements were performed including Bit Error Rate (BER) curves for uplink and downlink, RSOA gain curve and noise figure with the variation of input power and temperature for each system

A FULL-DUPLEX RADIO-OVER-FIBER ARCHITECTURE USING DIFFERENTIALL PHASE-SHIFT KEYING SIGNALS FOR DOWNSTREAM AND REMODULATED OOK FOR UPSTREAM

Radio-over-Fiber (ROF) is a promising technology to achieve future broadband access requirements with reliability, transparency and flexibility. We propose a novel full-duplex bi-directional radio-over-fiber (ROF) system transmitting 10 Gb/s differential phase-shift keying (DPSK) signals at the central office (CO) for downstream and ON–OFF keying (OOK) re-modulation of the downlink carrier at the base station (BS) for upstream. As the same optical carrier is used for both uplink and downlink, no additional light source is required at the BS, which significantly reduces the cost, improves the wavelength utilization efficiency and simplifies the overall system. The simulation results show that the downstream 10 Gb/s DPSK data and the upstream 1Gb/s OOK data can transmit over 50km single-mode fiber successfully without dispersion compensation. The results show that this scheme provides a practical solution to meet the data rate and cost requirement of tomorrow’s ROF access networks

Coherent ONU based on 850 µm-long cavity-RSOA for next-generation ultra-dense access network

In this Letter, an efficient bidirectional differential phase-shift keying (DPSK)-DPSK transmission for a ultradense wavelength division-multiplexed passive optical network is proposed. A single distributed feedback laser at the optical network unit (ONU) is used both as the local laser for downlink coherent detection and the optical carrier for uplink. Phase-shift keying is generated using a low-cost reflective semiconductor optical amplifier (RSOA) at the ONU. The RSOA chip has the bandwidth of 4.7 GHz at the maximum input power and bias current. For uplink transmission, the sensitivity of the RSOA chip reaches -48.2 dBm at the level of bit error rate = 10(-3) for back-to-back, and the penalty for 50 km transmission is less than 1 dB when using polarization diversity.Peer ReviewedPostprint (published version

Field-Trial of a high-budget, filterless, lambda-to-the-user, UDWDM-PON enabled by an innovative class of low-cost coherent transceivers

©2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We experimentally demonstrate an innovative ultradense wavelength division multiplexing (UDWDM) passive optical networks (PON) that implements the full ¿-to-the-user concept in a filterless distribution network. Key element of the proposed system is a novel class of coherent transceivers, purposely developed with a nonconventional technical approach. Indeed, they are designed and realized to avoid D/A-A/D converter stages and digital signal processing in favor of simple analog processing so that they match system, cost, and power consumption requirements of the access networks without sacrificing the overall performance. These coherent transceivers target different use case scenarios (residential, business, fixed, wireless) still keeping perfect compatibility and co-existence with legacy infrastructures installed to support gray, time division multiplexed PON systems. Moreover, the availability of coherent transceivers of different cost/performance ratios allows for deployments of different quality service grades. In this paper, we report the successful field trial of the proposed systems in a testbed where 14 UDWDM channels (and one legacy E-PON system) are transmitted simultaneously in a dark-fiber network deployed in the city of Pisa (Italy), delivering real-time and/or test traffic. The trial demonstrated filterless operations (each remote node selects individually its own UDWDM channel on a fine 6.25-GHz grid), real-time GbE transmissions (by using either fully analog or light digital signal processing), multirate transmission (1.25 and 10 Gb/s), high optical distribution network loss (18-40 dB) as well as a bidirectional channel monitoring system.Peer ReviewedPostprint (author's final draft

Machine Learning-based Predictive Maintenance for Optical Networks

Optical networks provide the backbone of modern telecommunications by connecting the world faster than ever before. However, such networks are susceptible to several failures (e.g., optical fiber cuts, malfunctioning optical devices), which might result in degradation in the network operation, massive data loss, and network disruption. It is challenging to accurately and quickly detect and localize such failures due to the complexity of such networks, the time required to identify the fault and pinpoint it using conventional approaches, and the lack of proactive efficient fault management mechanisms. Therefore, it is highly beneficial to perform fault management in optical communication systems in order to reduce the mean time to repair, to meet service level agreements more easily, and to enhance the network reliability. In this thesis, the aforementioned challenges and needs are tackled by investigating the use of machine learning (ML) techniques for implementing efficient proactive fault detection, diagnosis, and localization schemes for optical communication systems. In particular, the adoption of ML methods for solving the following problems is explored: - Degradation prediction of semiconductor lasers, - Lifetime (mean time to failure) prediction of semiconductor lasers, - Remaining useful life (the length of time a machine is likely to operate before it requires repair or replacement) prediction of semiconductor lasers, - Optical fiber fault detection, localization, characterization, and identification for different optical network architectures, - Anomaly detection in optical fiber monitoring. Such ML approaches outperform the conventionally employed methods for all the investigated use cases by achieving better prediction accuracy and earlier prediction or detection capability

First demonstration and field trial on multi-user UDWDM-PON full duplex PSK-PSK with single monolithic integrated dual-output-DFB-SOA based ONUs

© 2016 [2016 Optical Society of America.]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.We demonstrate a monolithically integrated dual-output DFB-SOA, and conduct the field trial on a multi-user bidirectional coherent ultradense wavelength division multiplexing-passive optical network (UDWDM-PON). To the best of our knowledge, this is the first achievement of simplified single integrated laser-based neighboring coherent optical network units (ONUs) with a 12.5 GHz channel spaced ultra-dense access network, including both downstream and upstream, taking the benefits of low footprint and low-temperature dependence.Peer ReviewedPostprint (author's final draft