QoS Guaranteed and Adaptive Downstream Bandwidth Utilization Scheme for Ethernet Passive Optical Networks

Dynamic bandwidth allocation（DBA） is an open and hot topic in the Ethernet passive optical network（EPON） ,which is regarded as one of the best choices for next-generation access networks. However,most proposed DBA schemes ignore the quality of service（QoS） guarantee on maximum delay and delay jitter for the real-time traffic and the downstream bandwidth utilization under light upstream load in EPON. In this paper,a new DBA scheme,QoS guaranteed adaptive downstream bandwidth utilization（QoS-ADBU）,is proposed. This scheme can provide better QoS assurance by determining the maximum transmission cycle time according to the maximum acceptable packet delay and delay jitter for real-time traffic. Besides,the downstream utilization can also be improved by adapting the polling frequency to downstream traffic load.

Implementation of access controller for Ethernet passive optical network

This paper presents the design and implementation of access controller used for Ethernet passive optical network （ EPON）. As a first step to develop an ASIC product, the entire system is designed on a field programmable gate array （FPGA） with an embedded CPU. To reduce working frequency of the FPGA, the byte-to-word conversion is proposed. Propagation delays are equalized by ranging procedure so as to avoid data collision. Implementations of synchronization, classification, as well as Linux porting are illustrated in detail. The interface between the FPGA and CPU are also presented. Experimental results show that the proposed system can properly function in a relatively low cost FPGA.

Quality of Service Analysis of Ethernet Network Based on Packet Size

Ethernet network, standardized by IEEE 802.3, is vastly installed in Local Area Network (LAN) for cheaper cost and reliability. With the emergence of cost effective and enhanced user experience needs, the Quality of Service (QoS) of the underlying Ethernet network has become a major issue. A network must provide predictable, reliable and guaranteed services. The required QoS on the network is achieved through managing the end-to-end delay, throughput, jitter, transmission rate and many other network performance parameters. The paper investigates QoS parameters based on packet size to analyze the network performance. Segmentation in packet size larger than 1500 bytes, Maximum Transmission Unit (MTU) of Ethernet, is used to divide the large data into small packets. A simulation process under Riverbed modeler 17.5 initiates several scenarios of the Ethernet network to depict the QoS metrics in the Ethernet topology. For analyzing the result from the simulation process, varying sized packets are considered. Hence, the network performance results in distinct throughput, end-to-end delay, packet loss ratio, bit error rate etc. for varying packet sizes.

Echo-state-network classification based multi-services awareness in high-speed optical passive networks

With the challenge of great growing of services diversity,service-oriented supporting ability is required by current high-speed passive optical network( PON). Aimed at enhancing the quality of service( Qo S) brought by diversified-services,this study proposes an echo state network( ESN)based multi-service awareness mechanism in 10-Gigabite ethernet passive optical network( 10GEPON). In the proposed approach,distributed architecture is adopted to realize this ESN based multi-service awareness. According to the network architecture of 10G-EPON,where a main ESN is running in OLT and a number of ESN agents works in ONUs. The main-ESN plays the main function of service-awareness from the total view of various kinds of services in 10G-EPON system,by full ESN training. Then,the reservoir information of well-trained ESN in OLT will be broadcasted to all ONUs and those ESN agents working in ONUs are allowed to conduct independent service-awareness function. Thus,resources allocation and transport policy are both determined only in ONUs. Simulation results show that the proposed mechanism is able to better support the ability of multiple services.

A novel algorithm for Ethernet-passive-optical-network dynamic bandwidth allocation based on threshold

The Ethemet passive optical network （EPON） is the next generation of broad-band network technique. A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units （ONUs）. This article provides a novel dynamic bandwidth allocation algorithm, i.e. threshold dynamic bandwidth allocation （TDBA）, which is based on adaptive threshold, to increase resource utilization. The algorithm uses ONU data-transmitting rate to adjust optical line terminal （OLT） receiving data threshold from an ONU. Simulation results show that this algorithm can decrease average packet delay and increase network throughput in a l 0G EPON system.

Design and implementation of ethernet passive electronic network over coax

To increase the limit of ethernet over coax （EoC） technology in the bidirectional reform of the hybrid fiber coaxial （HFC） network, an ethernet passive electronic network （EPEN） system based on Coax is proposed and experimentally demonstrated in this paper. The proposed EPEN exploits the existing capabilities of the MAC layer in the ethernet passive optical network （EPON） for reduction of cost of the HFC network. As the MPCP （multi-point control protocol） is introduced in the EPEN, bandwidth control and higher efficiency can be achieved. The experimental results exhibit the throughput of system up to 100Mbps, which meet the requirements of HFC network. To improve the performance of EPEN, frequency division multiplexing （FDM） can be used for further increase of the throughput and more hardware processing modules in the future. can be implemented to enhance the capacity

Study Application of RADIUS Protocol on Ethernet

This paper presents how to apply the RADIUS (Remote Authentication Dial In User Service)protocol ,which is generally applied to dial-up network, to the authentication & charge of Broad Band accessing control system on Ethernet. It is provided that the Broad Band accessing control system included a self-designed communication protocol is used in communicating between an terminal user and Network Access Server .The interface module on the servers side and the Radius system is also given in this article.

Ring Network Technology for Carrier Ethernet

The fast development of IP services forces the traffic flow in the networks to move gradually from Time Division Multiplexing(TDM) services to packet data services.To adapt to the change,low-cost Ethernet technologies are introduced into the Metropolitan Area Network(MAN).Ring network control protocols and ring network protection technologies are applied to guarantee manageability and reliability required in the telecom networks.The Ethernet Ring Protection(ERP) and Resilient Packet Ring(RPR) are two different ring protection technologies.The Transport Multi-Protocol Label Switching(T-MPLS) network uses the T-MPLS Shared Protection Ring(TM-SPRing) technology to provide ring protection.Carriers can expand the protection as needed and use appropriate ring technologies to meet the requirements of Carrier Ethernet(CE).

Review on Dynamic Bandwidth Allocation of GPON and EPON

The passive optical network(PON)technology has been drastically improved in recent years.In spite of using the optical technology,the utilization of the entire bandwidth is a very challenging task.The main categories of PON are the Ethernet passive optical network(EPON)and gigabit passive optical network(GPON).These two networks use the dynamic bandwidth allocation(DBA)algorithm to attain the maximum usage of bandwidth,which is provided in the network dynamically according to the need of the customers with the support of the service level agreement(SLA).This paper will provide a clear review about the DBA algorithm of both technologies as well as the comparison。

Optical local area network emulations over Ethernet passive optical networks:A survey

As a promising solution to efficiently achieving fiber to the home （FTTH）, Ethernet passive optical network （EPON） is currently improved to provide intercommunication among customers, together with normal traffic delivery, via optical local area network emulation. It is a new research direction and expected to enhance the normal EPON performances. The purpose of this article is to review the state-of -the-art solutions to emulating optical local area networks （OLANs） over EPON. We discuss the major problems involved, e.g., network architecture, control mechanisms, and other potential enhancements. We also outline areas for future researches.

Dynamic Wavelength and Bandwidth Allocation Using Adaptive Linear Prediction in WDM/TDM Ethernet Passive Optical Networks

Hybrid wavelength-division-multiplexing(WDM)/time-division-multiplexing(TDM) ethernet passive optical networks(EPONs) can achieve low per-subscriber cost and scalability to increase the number of subscribers. This paper discusses dynamic wavelength and bandwidth allocation(DWBA) algorithm in hybrid WDM/TDM EPONs.Based on the correlation structure of the variable bit rate(VBR) video traffic,we propose a quality-ofservice (QoS) supported DWBA using adaptive linear traffic prediction.Wavelength and timeslot are allocated dynamically by optical line terminal(OLT) to all optical network units(ONUs) based on the bandwidth requests and the guaranteed service level agreements(SLA) of all ONUs.Mean square error of the predicted average arriving rate of compound video traffic during waiting period is minimized through Wiener-Hopf equation.Simulation results show that the DWBA-adaptive-linear-prediction(DWBA-ALP) algorithm can significantly improve the QoS performances in terms of low delay and high bandwidth utilization.

Upstream Channel Utilization of CSMA/CD-Based Ethernet over Passive Optical Networks

We demonstrate that an asynchronous CSMA/CD protocol with an optical loop-back star coupler can achieve high upstream channel utilizatbn in an Ethernet PON, readily supporting a large installed base of Ethernet 10BaseT and 100BaseT interfaces.

AN IMPROVED EPON UPSTREAM TRANSMISSION SCHEME WITH ZERO INTER-PERIOD IDLE LOSS

Existing Ethernet Passive Optical Network(EPON) Dynamic Bandwidth Allocation(DBA) algorithms suffer from the disadvantage of idle time loss,which lower the upstream bandwidth utili-zation.This letter proposes an improved upstream transmission scheme with idle-time eliminating mechanism.Theoretical analysis and numerical calculation prove that the improved scheme can ef-fectively eliminate the idle time and enhance the efficiency of upstream link utilization.Simulation results have shown that the bandwidth utilization can be raised up to 15% in heavy-load scenarios while the time delay performance of Assured Forwarding(AF) and Best Effort(BE) services are improved simultaneously.

Real-time performance analysis of non-saturated and non-slotted Ethernet based on a two-dimensional collision state model

This paper proposes a new method to analyze Ethernet performance. Currently, most studies on Ethernet performance assume that the channel is divided into time slots, or the network load is saturated with little attention to a non-slotted channel and the non-saturation status. However, this situation is more consistent with the practical application of Ethernet. This paper first calculates the original collision probability and the retransmission collision probability in the original load, then obtains the retransmission load of the network based on those two collision probabilities, and finally acquires the actual load of the network by an iterative method. In addition, the accuracy of the analysis is checked against simulation results.

Heuristic polling sequence to enhance sleep count of EPON

Next-generation passive optical networks(PONs)demand power conservation to create a green environment.A reduction in power consumption of the traditional Ethernet passive optical network(EPON)can be achieved by increasing the sleep count in optical network units(ONUs).In this paper,this is accomplished by introducing a first-in-last-out(FILO)polling sequence in the place of a fixed polling sequence to increase the number of ONUs entering sleep mode(sleep count).In a fixed polling sequence,the optical line terminal(OLT)allocates idle time to the ONUs based on the overall load of the ONUs.This leads to a situation that whenever the idle time does not meet the wakeup time threshold of sleep mode,the ONUs are put into doze/active mode,which consumes more power.In the FILO polling sequence,the first polled ONU in the current cycle is made to be polled last in the following cycle.Polling continues in this way,and by this rearrangement,the idle time of delayed poll ONUs increases;hence,it helps to reduce the power consumption.Additionally,a modified load adaptive sequence arrangement(MLASA)method is suggested,where the ONUs are categorized into doze ONUs and sleep ONUs.A numerical simulation of the FILO polling sequence with a vertical cavity surface emitting laser(VCSEL)ONU shows a maximum reduction in power consumption of 15.5 W and a 20%improvement in energy savings compared with the traditional fixed polling sequence.The MLASA method results in better power consumption with minimum delay than that of the proposed FILO and existing LASA methods.