Ethernet Passive Optical Network System Research Articles

The Influence of Rayleigh and Brillouin Backscattering on the Performance of a 10 Gb EPON System

In order to improve the performance of 10 Gb Ethernet passive optical network (EPON). This paper builds a single channel bi-directional 10Gb EPON simulation system on the VPI simulation platform. By changing the system parameters such as Brillouin Scattering, Rayleigh back-scattering and AmplitudeRF, observed and analyzed the waveform, spectrum, eye diagram and bit error rate of uplink optical line terminal (OLT) received signal. Experimental results show that both Rayleigh and Brillouin backscattering have an impact on the performance of the system, but the Brillouin scattering effect is more affected when the two effects are simultaneously existed. In addition, the effect of Brillouin backscattering can be reduced by phase modulation of the optical uplink carrier.

Dynamic Bandwidth Allocation Supporting Diversified Queue Status Reporting for EPON Systems

Dynamic bandwidth allocation (DBA) is an indispensable function in Ethernet passive optical networks (EPONs). The DBA function implemented in an optical line terminal utilizes REPORT messages to learn about the upstream queue statuses in optical network units (ONUs). However, the methods for describing the REPORT messages are not fully standardized, which results in a lack of interoperability. This paper proposes a diversity DBA technique that can support different types of ONUs with diverse REPORT description methods. The diversity DBA technique is comprised of an identification process to differentiate REPORT description methods and an interpretation process to convert the content of different REPORT description methods. We provide simulation results to demonstrate the validity of the proposed DBA technique.

A Novel Mechanism for Delivering IPTV Traffic in Ethernet Passive Optical Networks

<p><strong>Abstract</strong> </p><p>IPTV offers digital television services over Internet Protocol (IP) for the ubscribers at a lower cost. Despite all the attractive IPTV services, it also requires high-speed access networks with the functions of multicasting, Quality-of-Services (QoS) guarantee and so on. In the access networks, Ethernet Passive Optical Network (EPON) is regarded as one of the best technology to meet the higher bandwidth demands applications such as IPTV. There are two common mechanisms used for delivering IPTV to the users in the EPON system such as, dedicated stream and multicast stream. The dedicated stream is not scalable to a large number of clients because of the limited bandwidth and resource consumption at the server side. Conversely, although multicast could be used as a scalable solution for media streaming, but providing such services in the EPON is still challenging due to some limitations in the EPON system. In this paper, we propose a new mechanism that is a Single Copy Broadcast (SCB) with Priority Queue (PQ) mechanism that can accommodate large number of clients IPTV streams without adding extra bandwidth and resources at the Optical Line Terminal (OLT). Simulation results have shown that our proposed mechanism can improve the QoS metrics and system performance in terms of bandwidth consumption and power consumption.</p><p>Keywords— IPTV, QoS, EPON, Unicast, Multicast, Single Copy Broadcast</p>

Mitigating the IPTV Zap Time in Enhanced EPON Systems

Zap time (channel switching time) is a critical quality of experience (QoE) metric for IPTV systems where synchronization, signaling, and propagation delays are the components under consideration. An Ethernet passive optical network (EPON) is one of the main infrastructures in broadband access networks that provides high bandwidth with low propagation delay. The functionality of the EPON hardware architecture can be extended by adding programmable networking engine (PNE) and programmable sub-system (PSS) components in the optical line terminal (OLT) and optical network unit (ONU) as described in this paper to improve IPTV delivery performance for synchronization and signaling delays in terms of traffic localization. Furthermore, a new IPTV delivery mechanism is proposed to eliminate synchronization delay by buffering the current I-frames of broadcasted channels in the OLT for possible new coming requests and dropping additional streams along with the main stream. The OLTand ONUs implement a multicasting mechanism to handle part of the IPTV request as intra-domain traffic. Simulation results show that the proposed mechanism significantly improves the QoE and quality of service (QoS). IPTV bandwidth usage and system throughput have improved mean packet delays and packet loss in enhanced EPON architecture.

Performance analysis of bidirectional hybrid orthogonal frequency division multiplexing-Ethernet passive optical access network

For the bottleneck problem of broadband access networks, the Ethernet passive optical network comes out as a striking and promising solution. Even though, Ethernet passive optical network nodes necessitate a cost-effective up-gradation. Accordingly, we propose and demonstrate a hybrid orthogonal frequency division multiplexing-Ethernet passive optical network employing an optical single side band modulation scheme. Case A demonstrates a contrast between a symmetric bidirectional single channel orthogonal frequency division multiplexing-Ethernet passive optical network at a data rate of 10 and 5 Gbps after a fiber link of 20 km. Case B targets the transmission of a symmetric bidirectional single channel orthogonal frequency division multiplexing-optical single side band-Ethernet passive optical network system and achieves a fiber link of 20 km with a split ratio of 8. Afterwards, eight upstream channels are transmitted simultaneously and successfully obtained at the optical linear terminal side to make a bidirectional Ethernet passive optical network system. Further, a contrast between transmission at a data rate of 10 and 5 Gbps is carried out that achieves a fiber link of 20 km with a split ratio of 8.

Trust Based Dynamic Bandwidth Allocation Scheme for Ethernet Passive Optical Networks

Recently, Ethernet Passive Optical Network (EPON) is a significant solution in the access layer of network that can provide large amount of bandwidth for different kind of traffic. In this paper, we propose a dynamic bandwidth allocation scheme based on the trust based VCG-Kelly mechanism. To enhance the EPON system performance, the proposed scheme can take into account the measure of each ONU's payoff variation succeeding at a given bandwidth allocation. By considering the current outcome, ONUs adaptively select their bid strategies and the OLT dynamically allocates bandwidth to reach a certain desired EPON outcome. In addition, we also consider the network security situation, which reflects what is happening in the EPON network including both the offense and defense behaviors. During this iterative learning approach, the EPON system can converge to a stable network state. Evidences from simulations demonstrate that the proposed scheme outperforms the existing schemes.

Distribution drop fiber in-service fault management in enhanced EPON system

Ethernet passive optical network (EPON) is considered one of the best candidates for next-generation optical access solutions. Practical and cost-effective survivability and maintenance mechanisms are therefore becoming the key issues for continued development of viable EPON solutions. In addition, 80% of faults occur within the first/last mile. Therefore, in this paper, we propose in-service integrated fault management mechanisms at the distribution drop fibers (DDFs) in EPON. The proposed mechanisms can automatically detect and identify any signal anomalies and DDF faults in the physical layer, thus decreasing the operating expense (OpEx) to be incurred in sending off technicians in the field. The mechanisms are two-fold: pre-fault and post-fault. In the pre-fault mechanism, we use optical receiver type/length/value (TLV) code as a sensor for triggering the embedded miniaturized optical-time-domain reflectometry (OTDR), placed at optical network units (ONUs). This mechanism observes and measures the abnormal condition and reports it to the optical line terminal (OLT), via restoration plan fiber link. In post-fault mechanism, we divide the ONUs into several restoration groups (RGs) to guarantee upstream transmission of the affected ONUs. Lastly, the fault dynamic bandwidth allocation for fault management, referred as FDBA, is presented. Simulation results show that the proposed mechanisms can withstand DDF faults without any significant impact on the overall quality of service (QoS) performance, in terms of mean packet delay, queue length, system throughput, and packet loss.

An autonomous recovery mechanism against optical distribution network failures in EPON

Ethernet Passive Optical Network (EPON) is chosen for servicing diverse applications with higher bandwidth and Quality-of-Service (QoS), starting from Fiber-To-The-Home (FTTH), FTTB (business/building) and FTTO (office). Typically, a single OLT can provide services to both residential and business customers on the same Optical Line Terminal (OLT) port; thus, any failures in the system will cause a great loss for both network operators and customers. Network operators are looking for low-cost and high service availability mechanisms that focus on the failures that occur within the drop fiber section because the majority of faults are in this particular section. Therefore, in this paper, we propose an autonomous recovery mechanism that provides protection and recovery against Drop Distribution Fiber (DDF) link faults or transceiver failure at the ONU(s) in EPON systems. In the proposed mechanism, the ONU can automatically detect any signal anomalies in the physical layer or transceiver failure, switching the working line to the protection line and sending the critical event alarm to OLT via its neighbor. Each ONU has a protection line, which is connected to the nearest neighbor ONU, and therefore, when failure occurs, the ONU can still transmit and receive data via the neighbor ONU. Lastly, the Fault Dynamic Bandwidth Allocation for recovery mechanism is presented. Simulation results show that our proposed autonomous recovery mechanism is able to maintain the overall QoS performance in terms of mean packet delay, system throughput, packet loss and EF jitter.

Design and Implementation of Topology Management Based on EPON Network Management System

The network bandwidth has been expanded after EPON(Ethernet Passive Optical Network ) came.So a topology management for EPON System is needed.In this paper, methods of topological data collection is analyzed, the form of topological data structure object is designed , and topological structure is displayed in the terminal by coding. With introducing in improved memory object and caching techniques, system performance was significantly improved through experiments.

RECENT DYNAMIC BANDWIDTH ALLOCATION ALGORITHM METHODS IN ETHERNET PASSIVE OPTICAL NETWORK

The “last mile” bandwidth bottleneck problem can be best solved by using Ethernet Passive Optical Network (EPON). EPON is a promising technology to implement the Fiber To The Home solution. Dynamic bandwidth allocation (DBA) is one of the critical issues in the design of the EPON system that has been studied by many researches. This paper introduces the fundamental concepts on EPONs, its protocol and its bandwidth allocation. We also compile and classify the research works in order to provide the state-of-art of the DBA algorithms. The advantages and disadvantages of each classification is provided. The classifications provide insightful presentations of the prior work on EPONs which will help the researches to choose the most suitable algorithm as according to the needs.

A study of quality of service in the universal DBA algorithm using a PIC-based EPON testbed

Ethernet Passive Optical Network (EPON) has emerged as a promising technology since it offers high bandwidth at a distance that can go up to 20 km. In the upstream EPON transmission, a dynamic bandwidth allocation (DBA) algorithm is needed to avoid collisions and to efficiently allocate the bandwidth. This paper proposes an algorithm called as a Universal DBA (UDBA) algorithm that can support the priority universally in the entire EPON system. A peripheral interface controller (PIC)-based EPON testbed is used to test the algorithm within the mulipoint control protocol environment. For the performance study, we have compared the results achieved using UDBA in terms of delay, throughput, and fairness with two other DBA algorithms. UDBA shows improvements in terms of expedited forwarding, assured forwarding and best effort delay as much as 43.9, 42.6, 20 % over User-oriented Hierarchical Bandwidth Scheduling with Single Cycle (UHSA-S) and 37.5, 20.2, 25.3 % over Modified Smallest Available Report First (MSARF), respectively. Throughput is improved as high as 17.9 % over UHSA-S and 12.8 % over MSARF. In addition, the fairness index of UDBA is higher up to 14 % as compared to UHSA-S and 2.7 % as compared to MSARF.

Enhanced Performance of Ethernet Passive Optical Networks using Dispersion Compensation

In this paper, performance evaluation of Ethernet Passive Optical Network (EPON) in the absence and presence of Dispersion Compensation Techniques (DCT) has been observed. It has been observed that Q 2 value lies in the range of 22 to 13 and 26.5 to 24 for transmission distance at 0 to 30 km in case of RZ without and with DCT. In other case, it lies in the range of 23.5 to 14.5 and 27.5 to 25 for transmission distance at 0 to 30 km in NRZ without and with DCT in EPON. Using dispersion compensation technique we can increase the transmission speed as well as transmission distance of EPON systems.

Implementing Universal Priority DBA Algorithm in PIC based EPON Testbed

Ethernet passive optical network (EPON) is becoming one of the best schemes in the broadband access network as it combines the Ethernet and passive optical network technology. In order to avoid collision in upstream EPON, Universal Dynamic Bandwidth Allocation (UDBA) algorithm is proposed in this paper where it can support a universal priority in the entire EPON system. For proof-of-concept, the UDBA algorithm is implemented inside a proposed peripheral interface controller (PIC) based EPON testbed in order to evaluate the communication protocol involved. To the best of our knowledge, this is the first time PIC is being used in EPON testbed for this purpose. To ensure that the testbed is valid, we compare the result that we achieved via testbed with the results achieved via MATLAB simulation in terms of throughput, delay and fairness. The simulated results show a good agreement with the experimental with some minor expected differences.

Application and Analysis of Long-Distance EPON in Transmission Lines Monitoring System

Ethernet Passive Optical Network (EPON) has been widely used in the Smart Grid. However, the overlay radius of EPON system is generally a 20 km, which has become the obstacle of application of EPON in Smart Grid.This paper introduces the advantages of EPON and analyzes the need for long-distance EPON of t Transmission Lines Monitoring System. And also this paper analyzes the factors affecting the long-distance transmission of EPON. Then this paper discusses the implementation of long-distance EPON and proposes a scheme of achieving communication network of Transmission Lines Monitoring System based on long-distance EPON.

Energy Efficiency in Ethernet Passive Optical Networks (EPONs): Protocol Design and Performance Evaluation

As concerns about energy consumption grow,the power consumption of the EPON becomes a matterof increasing importance. In respect of energy efficiency,the current standard has no management protocols aimingto reduce power consumption in EPONs. In this paper,we propose an Energy Management Mechanism (EMM)for downlink EPON systems. The proposed mechanism isdesigned to enhance the standardized control scheme inEPON with the objective to increase energy efficiency whilesatisfying diverse QoS requirements. The main idea is toput an Optical Network Unit (ONU) into the sleep modeand determine a suitable wakeup time scheduler at theOptical Line Terminal (OLT). A generic EPON system isconsidered, which is composed of an OLT and several ONUsthat are EMM enabled. An energy consumption optimizationproblem aimed at saving energy is proposed and twoheuristic sleep mode scheduling policies are addressed tosolve it. The scheduling algorithms are tightly coupled withthe upstream bandwidth allocation and downstream transmissionscheduling together through an integrated approachin which awake time in ONUs is minimized. There is atrade-off decision between maximizing the power saving andguaranteeing the network performance at the same time.Simulation results show that an EMM-based EPON withwell designed scheduling disciplines is essential to achievingsignificant energy saving while meeting the delay constraint.

Local-Traffic-Redirection-Based Dynamic Bandwidth Assignment Scheme for EPON With Active Forwarding Remote Repeater Node

The Ethernet passive optical network (EPON) has been considered as one of the most suitable next-generation optical access solutions. As a time-division multiplexing PON (TDM-PON) technology, the transmission media of EPON is shared among multiple users. Therefore, medium access control (MAC) protocol plays an important role in enabling a dynamic bandwidth assignment (DBA) mechanism that provides efficient and fair utilization of the PON resources. However, the DBA mechanism implemented in products is open for vendor customization. In this paper, we propose a novel local-traffic-prediction-based dynamic bandwidth assignment (LT-DBA) mechanism applicable in a remote-repeater-based EPON system with active forwarding. The LT-DBA aims to improve the bandwidth utilization and average packet delay performance of EPON in upstream transmission in comparison to conventional bandwidth assignment techniques such as static bandwidth assignment (SBA) and the interleaved polling algorithm (IPACT), leading to a more efficient PON system.

Design and Analysis of a WDM EPON for Supporting Private Networking and Differentiated Services

Although EPONs have been proposed as a means of overcoming the bandwidth bottleneck problem in local access networks, they may not be able to meet the ever-growing bandwidth demand from users in the near future. Accordingly, this study presents what we believe to be a novel wavelength-division-multiplexing (WDM) Ethernet passive optical network (EPON) system based on an arrayed-waveguide-grating (AWG) module to meet the rapidly increasing bandwidth demand anticipated in the future. The use of the AWG enables the proposed WDM EPON architecture to achieve wavelength spatial reuse and to provide an intercommunication capability between optical network units (ONUs). As a result, the architecture not only allows upstream access to the central office, but also facilitates a truly shared LAN capability among the end users. Furthermore, the proposed WDM EPON scheme takes account of the requirement for backward compatibility with the IEEE 802.3ah multipoint control protocol and incorporates a dynamic bandwidth allocation scheme and a quality-of-service provisioning mechanism to arbitrate the access of the individual ONUs over the WDM layer. An analytical framework is developed for evaluating the mean packet delay and mean queue length of the proposed WDM EPON system. The analytical results derived using this framework are found to be in good agreement with those obtained from computer simulations.

Technology for extending transmission distance of EPON system

At present, the maximal transmission distance between the optical line terminal (OLT) and optical network unit (ONU) of an Ethernet passive optical network (EPON) system is 20 km. However, this distance should be extended to 50 km or even longer in some applications such as fiber to the village (FTTV). A method for extending the transmission distance of an EPON system is proposed in this paper, in which the optical power amplifier and the adjustment of dynamic bandwidth allocation (DBA) are the key technologies.

Resources allocation in an Intserv/Diffserv integrated EPON system

As one of the most promising next-generation access network techniques, the user-oriented Ethernet passive optical network (EPON) should pay more attention to its quality of service (QoS). However, now the EPON adopts mostly differentiated services model (Diffserv) that only provides quality control on traffic aggregation, whereas, the quality of user session cannot be guaranteed when the network is overloaded with substantial connections. This article proposes to apply integrated services model (Intserv) in Diffserv-based EPON, which uses per-flow processing to guarantee QoS. In the simulation, a framework of combined Diffserv and Intserv model is employed in an EPON system, with a dynamic bandwidth allocation algorithm that adapts to it. The simulation results demonstrate that the EPON system with the combined models can provide more flexible, various control for user-oriented service quality.

Controllable multicast for IPTV over EPON

The character of 1 Gbps bandwidth and treebased structure make Ethernet passive optical network (EPON) very suitable for broadcast or multicast services such as Internet protocol television video (IPTV). The document proposed a novel scheme, based on the former research for controllable multicast over EPON system, mainly considering system security and maintainability. It can both control the IPTV program source’s and the receiver’s validity, improving the efficiency and precision.