Passive Optical Network Research Articles

Next generation WDM-radio over fiber passive optical network: deep neural network based performance analysis

Next generation WDM-radio over fiber passive optical network: deep neural network based performance analysis

Performance analysis of NGPON using hybrid GPON-XGPON based robust long-haul passive optical communication network

Abstract For high data rates and extended reach capabilities, communications networks need to be enhanced by employing passive optical networks (PONs). NG-PON plays a key role in achieving the modern demands. This paper proposed novel hybrid G-PON and XG-PON based robust long-haul Passive Optical Communication Network. In this proposed network hybrid semiconductor optical amplifier (SOA) and EDFA are used to enhance the system performance for downstream (D.S.) and upstream (U.S) signals transmission. This paper analyses a hybrid G-PON and XG-PON bi-directional optical fiber link up to length of 100-km with a 128 (1:64 and 1:64) way-splitter to increase the coverage area and to enhance the quality of transmitted data. The qualitative analysis of the proposed network shows an improved performance in terms of transmission distance, quality factor and eye-diagrams.

OFDM-PON physical layer encryption scheme based on chaotic Joseph ring and fractal system

In this paper, we present a novel encryption algorithm that combines the chaotic Joseph ring and fractal system to enhance system security and resistance to chosen plain text attacks (CPAs) in orthogonal frequency division multiplexing passive optical networks (OFDM-PONs). As for this scheme, a modified chaotic Joseph ring is designed and utilized to resist CPAs, which greatly increases the randomness of the output data. The fractal function is also modified to generate a larger range and random dataset, which is used to scramble the quadrature amplitude modulation (QAM) symbols to further improve the confidentiality of the system. It is noted that, a four-dimensional conserved chaotic system is also introduced into this system to generate the initial parameters of the Joseph rings and fractal systems, thereby improving the sensitivity of the encryption scheme. With these processing techniques, multiple data encryption with a key space of ∼10358 can be created to prevent exhaustive trials. A simulated OFDM-PON system was built to confirm the feasibility of the proposed scheme. The results show that our scheme can provide excellent confidentiality of data transmission against CPAs and brute-force attack. Besides, the grayscale images are utilized to further verify that the scheme is equally resistant to statistical and cutting attacks.

Joint Resource Allocation in TWDM-PON-Enabled Cell-Free mMIMO System

Cell-free massive multiple input multiple outputs (CF-mMIMO) is considered a promising technology for sixth-generation (6G) telecommunication systems. In the CF-mMIMO system, an extensive array of distributed small base stations (BSs) is deployed across the network, which enables us to facilitate seamless collaboration among BSs. To achieve this goal, the baseband signal from these BSs needs to be transmitted to a central server via fronthaul networks. Due to the large number of BSs, the data that needs to be transmitted is usually huge, which brings severe requirements on fronthaul networks. Time and wavelength division multiplexed passive optical networks (TWDM-PON) can be a potential solution for CF-mMIMO fronthaul due to their large capacity and high flexibility. However, how to efficiently allocate both optical and wireless resources in a TWDM-PON-enabled CF-mMIMO system is still a problem to be addressed. This paper proposes a joint scheduling method of wavelength, antenna, radio unit (RU), and radio resource block (RB) resources in the TWDM-PON-enabled CF-mMIMO system. Furthermore, an integer linear programming (ILP) model for joint resource allocation is proposed to minimize the fronthaul resource occupancy, thereby increasing network scalability. Considering the complexity of the ILP model, two heuristic algorithms are also presented to solve this model. We compare the ILP with heuristic algorithms under different scenarios. Simulation results show that the proposed algorithm can reduce the fronthaul resource occupancy to improve the network scalability of the CF-mMIMO system.

Feasibility analysis of 2-dimensional permutation vector optical code division multiple access passive optical network

This paper analyzes the feasibility of a 2-dimensional (2D) permutation vector (PV) optical code division multiple access (OCDMA) passive optical network (PON) in terms of transmission capacity, network reliability, power budget, and the number of subscribers. The proposed PON is built with a novel 2D PV-OCDMA code having ideal auto- and cross-correlation properties. Furthermore, a ring-based topology at the feeder level and a tree-based topology at the distribution level are utilized to support ubiquitous computing. The proposed architecture also employs multiple remote nodes at the feeder level to facilitate adequate power budget and cardinality for high-capacity applications. Simulation results indicate that the proposed PON elevates system transmission capacity by eliminating phase-induced intensity noise and multiple access interference. Furthermore, reliability analysis using mathematical formalism demonstrates that the proposed architecture can provide a connection availability of ≈0.099993 (5 nines), which is significantly higher than the conventional tree-based topology. Power budget analysis also determines that the proposed PON can support well above 320 subscribers at adequate receiver sensitivity and optical network terminals (ONTs) per remote node.

Development of a cost-effective optical network based on free space optical (FSO) and optical fiber links for enabling smart city infrastructure: A hybrid approach

Due to the gigantic rise in the use of high data rate-based applications and the ongoing transformation of Indian cities into smart cities, there is a need for a high-speed communication framework to handle the enormous data traffic. The radio frequency (RF) and microwave links seem to be incapable of offering sufficient bandwidth required by the data-hungry applications and consequently, the need for a more effective solution for tackling the issue of scarcity of bandwidth resources has become the necessity of current network infrastructure in India. In this study, a hybrid optical fiber-free space optical (OF-FSO) system for offering high-speed data services has been proposed to assist the implementation of smart city infrastructure in India. This study aims to inspect the system performance of the proposed model under the climatic conditions of mountainous, desert, flatland, and seaside regions of India. The proposed hybrid OF-FSO system comprises a fixed single-mode fiber (SMF) of 20 km and an FSO link (having a varied transmission range between 0–2 km). The proposed hybrid model can support an FSO link of 1.72 km for a fixed SMF of 20 km, corresponding to a bit error rate of the order of 10−4 for atmospheric conditions of the seaside location of Chennai and the range of FSO link varies from 1.32 km to 1.57 km for other locations of India, for the same length of SMF and bit error rate. Furthermore, the proposed hybrid OF-FSO has demonstrated a reduction of 30.8% in Capital Expenditure (CAPEX) cost in contrast to the conventional passive optical network (PON) system.

Wheel‐based 5G fronthaul/backhaul hybrid MDM‐NGPON/FSO system under Gamma‐Gamma turbulence and weather effects

SummaryThis work presents the bidirectional and symmetric 40 Gbps wheel architecture comprising 16 channels‐based bidirectional hybrid next generation passive optical network with free space optics (NGPON/FSO) system using mode division multiplexing (MDM) scheme. The system incorporates a low‐cost high bandwidth and integrated time and wavelength division multiplexing with orthogonal frequency division multiplexing (TWDM‐OFDM) for data transmission over mixed fiber‐FSO links to various end users at donut modes 0 and 1. This system enhances the fifth generation (5G)‐based networks reliability, survivability, and flexibility, especially in rural places where the core fiber link may be damaged/destroyed under diverse turbulent and weather conditions. The obtained results depict the faithful multimode fiber range of 100 km with fixed FSO range of 100 m at −17 dBm receiver sensitivity and low power penalty of 0.2 dB at 10−9 bit error rate. Maximum FSO range of 2800 m under weak‐to‐strong Gamma‐Gamma turbulence and the effect of fog, rain, snow, and snow with rain can be obtained successfully with fixed 50 km fiber length. Also, the proposed wheel architecture provides superior performance over hybrid ring‐mesh architecture with high split ratio of 1:64. Moreover, the system can sustain up to 70 remote nodes at symmetric 10 Gbps throughput providing high gain, high optical signal‐to‐noise ratio, and low noise figure. The comparative literature work also reveals that the proposed architecture offers high bandwidth, security, long‐reach, and cost‐effectiveness in 5G fronthaul/backhaul networks.

Auction-based hybrid DBA algorithm in EPON-WiMAX converge network for 5G and beyond (5 GB) communications

Managing large data volumes requires high-capacity networks due to increasing internet users and bandwidth-intensive applications. Optical fiber, particularly Ethernet passive optical network (EPON), is vital for cost-efficient last-mile connectivity. EPON handles data traffic, while WiMAX demands extensive bandwidth due to rising mobile users. Both the networks experience bursty user-generated traffic with fluctuating bandwidth needs. That’s why, the bandwidth requirements of each subscriber fluctuates dynamically. Moreover, access networks must provide distinct service quality to support a large number of users and ensure the requirement of 5G and beyond (5 GB) communication standards. To address these difficulties, in this paper, we propose a prediction-based hybrid dynamic bandwidth allocation (PHDBA) algorithm for EPON-WiMAX converge network. Due to the increasing value of trustworthy network service access, we have implemented a statistical modeling technique. Our technique predicts the heavily loaded ONUs from a randomly generated dataset and provides an approximation of the amount of data that can be strongly loaded. To make this prediction, we have proposed a statistical modeling technique and updated the auction-based semi dynamic bandwidth allocation (SDBA) algorithm. To validate our proposed algorithm, computer simulation is used to evaluate different performance parameters in terms of end-to-end delay, jitter, throughput, and fairness. From the comparative analyses, it is proved that our proposed scheme surpasses the competition over the existing SDBA algorithm.

Cyclic transmission window-based bandwidth allocation scheme for asynchronous time-sensitive industrial applications in TDM-PON

The industrial Internet has become an important application scenario for time-division multiplexing passive optical networks (TDM-PONs). Time-sensitive (TS) industrial applications, such as control-to-control communications, require a TDM-PON to have deterministic transmission capability. Traditional bandwidth allocation schemes are unable to fulfill this capability; thus we proposed a time-aware deterministic bandwidth allocation (TA-DetBA) scheme to guarantee deterministic delay and jitter in our previous work. TA-DetBA allocates appropriate transmission windows (TWs) to each TS industrial flow in a supercycle based on the flow’s arrival time, cycle, delay, and jitter requirements. However, “awaring” the arrival time of flow relies on precise time synchronization between the TDM-PON and industrial devices, which makes TA-DetBA unsuitable for those TS industrial applications that are asynchronous to the TDM-PON. In addition, the diversity of flow cycles may make the size of the supercycle and the number of allocated TWs large, thus increasing the complexity of the TW scheduling algorithm. To this end, we propose a cyclic TW-based deterministic bandwidth allocation (CTW-DetBA) scheme for asynchronous industrial applications. First, we design cyclic TWs with appropriate cycle and size for TS industrial flows, which not only improves the schedulability of TWs (i.e., the ratio of the number of successfully scheduled TWs to the total number of TWs) but also reduces the complexity of the algorithm. Then, we construct a TW scheduling model based on the satisfiability model theory to schedule the TWs in the PON upstream frame. Simulation results show that the CTW-DetBA guarantees the deterministic transmission of TS industrial flows that are asynchronous to the TDM-PON system. Compared with the fixed bandwidth allocation scheme, the average schedulability of the CTW-DetBA can be increased by up to 62.03%, and the average resource utilization efficiency can be increased by up to 20.4%.

Key Technologies for a Beyond-100G Next-Generation Passive Optical Network

The explosive development of emerging telecommunication services has stimulated a huge growth in bandwidth demand as people seek universal access to telecommunication networks. In addition, the kinds of services of an existing optical access network are becoming more flexible. In order to provide higher capacity and meet higher transmission performance requirements, it is necessary to further explore the application of the beyond-100G passive optical network (PON). This paper offers a comprehensive review and outline of the prospects of technologies for bringing a beyond-100G PON to practical applications in the future. We review the current existing technologies, mainly in terms of the physical layer and higher media access control layer. These key technologies for the beyond-100G PON, which plays an increasingly significant role, include the advanced multiplexing technology, physical layer digital signal processing technology, infrastructure-sharing technology, security protection technology, and intelligent control management key technologies. Finally, open issues and new challenges for the next-generation PON are focused upon.

Flat ball topology basics multi‐transceivers 100 km/2.5 Tbps gigabit‐ethernet PON architecture for energy efficiency in data centers

AbstractExisting electronic data sources desire high‐power requisites, in order to obtain a large bandwidth, minimum power dissipation and low latency in networks. In this instance, a gigabit ethernet passive optical network (GEPON) architecture based on a dynamic Flat Ball topology incorporating multi‐transceivers to minimize network energy consumption via passive devices along with bandwidth reconfiguration potential and low latency is reported in this paper. The proposed architecture connected with 200 nodes exhibits 26 as well as 40 dB total loss in uplink as well as downlink considerably, compared to Sirius and Sandwich tree. Also, Flat ball GEPON architecture permits 9 and 10 dBm energy saving in downlink as well as uplink, respectively, than conventional GEPON architecture at 1 ms delay. The proposed architecture with 50 Erlang load allows energy ratio of 39% in downlink and 37% in uplink, at 25 × 100 Gbps traffic rate for 55 nodes. Besides this, the faithful fiber range of 100 km considering fiber no‐linearities and impairments can be obtained successfully. The architecture can be bordered with 1:64 splitting ratio with 35 ms in downlink as well as 31 ms in uplink transmission delay at bit error rate of 10−3. Additionally, on comparing the proposed topology with existing architectures depict its superiority with minimal implementation cost, low‐power dissipation, less traffic delay as well as high scalability and high flexibility.

Fifth-generation small cell backhaul capacity enhancement and large-scale parameter effect

<span lang="EN-US">The proliferation of handheld devices has continued to push the demand for higher data rates. Network providers will use small cells as an overlay to macrocell in fifth-generation (5G) for network capacity enhancement. The current cellular wireless backhauls suffer from the problem of insufficient backhaul capacity to cater to the new small cell deployment scenarios. Using the 3D digital map of Lagos Island in the Wireless InSite, small cells are deployed on a street canyon and in high-rise scenarios to simulate the backhaul links to the small cells at 28 GHz center frequency and 100 MHz bandwidth. Using a user-defined signal to interference plus noise ratio-throughput (SINR-throughput) table based on an adaptive modulation and coding scheme (MCS), the throughput values were generated based on the equation specified by 3GPP TS 38.306 V15.2.0 0, which estimates the peak data rate based on the modulation order and coding rate for each data stream calculated by the propagation model. Finding shows achieved channel capacity is comparable with gigabit passive optical networks (GPON) used in fiber to the ‘X’ (FTTX) for backhauling small cells. The effect of channel parameters such as root mean squared (RMS) delay spread and RMS angular spread on channel capacity are also investigated and explained.</span>

Experimental study of four-wave mixing based on a quantum dot semiconductor optical amplifier

The article is devoted to the study of four-wave mixing (FWM) in a semiconductor optical amplifier with quantum dots (QD-SOA). Experimental measurements of FWM signals are characterized in nonlinear media of GaAs-based QD-SOA with gain in the 1,550 nm region. Theoretical part of nonlinear effect of FWM is studied and important all-optical communication applications are listed. Experimental studies of a four-wave system are described and an analysis of FWM signals is given for various input powers of pump signals and injection currents. The devices are compared in terms of such parameters as conversion efficiency and signal-to-noise ratio. The results of the study made it possible to reveal the possibility of the effect of FWM signals on useful signals in channels with spectral division multiplexing wavelength division multiplexing (WDM) in the downstream and upstream in a semiconductor optical amplifier. Based on the experimental results, it was concluded that FWM does not affect adjacent channels of WDM signals and does not generate additional optical noise when scaling the WDM gigabit passive optical network (GPON) up to 60 km using semiconductor optical amplifiers (SOAs).

Comparative analysis of techniques in long reach passive optical networks: overview and design

Abstract Long reach PON is an attractive option for addressing the growing bandwidth needs of internet applications and also serving multiple ONUs. Due to newly augmented technologies such as 4K/8K television, video meetings/conferencing, and online gaming, end-user bandwidth demands are exponentially rising day by day. Wavelength division multiplexing–based passive optical network (WDM-PON), which can deliver high data rates over long distances, is the ultimate solution to the growing bandwidth demand. It is possible to reduce the number of active cabinets and central offices while increasing the number of optical network units (ONUs) with the use of passive optical networks (PONs). At higher bit rates, researchers faced lot of issues like increased pulse width due to increased distance, burst loss, fault detection, etc. In this paper, we have discussed few challenges faced in passive optical networks. Also, we have discussed about the methodology to overcome these issues.

First Realization of a Three-Channel Lithium-Niobate Photonic Filter for 50G Passive Optical Networks

First Realization of a Three-Channel Lithium-Niobate Photonic Filter for 50G Passive Optical Networks

High-Capacity Free Space Optics-Based Passive Optical Network for 5G Front-Haul Deployment

With the expansion of Information and Communication Technology, it is important to develop a communication network that can provide high-capacity ubiquitous connectivity. This work proposes an energy-efficient passive optical network (PON) using orthogonal frequency division multiple access (OFDMA) and wavelength division multiplexing (WDM) to facilitate the dense deployment of radio units (RUs) in a beyond 5G (B5G) communication network. High-speed connectivity is ensured by employing a hybrid PON architecture that includes a combination of free space optics (FSO) links and optical fiber (OF) media to carry OFDM and WDM multiplexed traffic. Furthermore, an optical frequency comb generator (OFCG) is utilized at the transmitter module to generate and leverage the spectrum for transmitting information from baseband units (BBUs) to the RUs situated near the end users. The proposed system is analyzed through (i) simulation analysis using Optisystem for transmission capacity computations and (ii) mathematical analysis to determine the total savings in energy. The simulation analysis shows that the given architecture can carry data across 3 km of FSO medium using 512 subcarriers per BBU transmitting at 10 Gbps of data with QPSK-modulated bit sequence. Additionally, energy efficiency shows that the use of an OFCG cuts the total energy usage by 22% at the transmitter module without negatively impacting the system’s high cardinality and transmission capacity.

Mitigation of the parallel-path effect for reliable monitoring of a passive optical network using standard optical time domain reflectometry

Optical access networks evolve towards higher bit-rates, which is driven by a growing number of fiber-to-the-home users and by bandwidth-demanding mobile transport. Maintenance requirements of such networks call for very effective and efficient supervision of the fiber infrastructure. Moreover, since the fiber is also known for its sensing capabilities, the outside distribution plant of the access network has been recently considered for providing sensing services co-existing with telecom services. To enable reliable fiber monitoring and sensing, the detrimental impact of the parallel-path effect in point-to-multipoint access networks needs to be addressed. This paper introduces the concept of serialization of an optical time domain reflectometry trace of a point-to-multipoint passive optical network, which radically reduces the parallel-path effect impact on fiber anomaly detection and measurement. The concept is experimentally proven in a representative access network architecture.

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.

Development and verification of an on-board integrated optics scheme for a 50G/10G combo PON system

We propose an on-board integrated optics (OBO) scheme within a 50G/10G combo passive optical network (PON) system, for the first time to our best knowledge, which can achieve high port density, low cost, and low power consumption required by the 50G PON system. We provide an OBO scheme that integrates record-high power distributed feedback (DFB) lasers, low insertion loss silicon modulators, a planar lightwave circuit wavelength-division multiplexer, and avalanche photodiodes on a single board, which can solve key issues faced by the demand of coexistence and smooth evolution from 10G to 50G PON for global access network operators. In this system, the slope efficiency of the lasers has been optimized at high temperatures, allowing the output power of the lasers to achieve a record-breaking 23.5 dBm at 1577 and 1342 nm, while reducing cooling power consumption to realize low carbon emission in access networks. We developed a low-loss broadband silicon modulator to meet the large power budget and high data rate requirements of 50G PON by optimizing doping parameters and constructing electrodes that match the driver. This silicon modulator has a 6.6 dB insertion loss and an electro-optic bandwidth of more than 38 GHz, making it the ideal silicon modulator for 50G PON systems. In addition, we verify the end-to-end performance, including receiver sensitivity in the upstream direction and the dispersion penalty in the downstream direction. This suggests that the OBO scheme can satisfy the criteria of the 50G PON system according to the ITU-T G.9804 standard series.

Threshold design in fiber termination identification using local injection and OTDR

We study how to set a threshold for how to identify the end of an optical fiber by reflectance ratio between wavelengths calculated from measurements of a temporary optical coupler (TOC) and a two-wavelength Optical Time Domain Reflectometer (OTDR). The threshold is affected by the difference in propagation loss between the wavelengths from the OTDR to the end of the optical fiber. The effectiveness of the threshold is inferred from measurements of the reflectance ratio of an Optical Network Unit (ONU) used for a Passive Optical Network (PON) and the propagation loss difference between the wavelengths of the TOC. The threshold adaptation conditions are also explained. Our results show that even with the worst propagation loss of existing single-mode fiber standards, it is possible to identify fiber ends 3.8 km away. However, if large bending or connection losses occur between the OTDR and the fiber end, the propagation loss difference between the wavelengths of the TOC must be improved.