EPON System Research Articles

Crosslinking and interfacial behavior of carboxylic functionalized carbon nanotube Epon nanocomposites: a molecular dynamic simulation approach

We implemented molecular dynamics simulations to study the effect of single-walled carbon nanotube (SWCNT) and carboxylic (–COOH) functionalized SWCNT on the crosslinking and interfacial behavior of Epon 862 nanocomposite. Results showed that the introduction of control SWCNT in the Epon system reduced the crosslinking by 8–12% in comparison to control system (without CNT). The molecules of Epon 862 and Epikure-W changed their conformation and aligned themselves in the direction parallel to the surface wrapping the nanotubes. Also, no interfacial bonding was found between the polymer and SWCNT. However, the introduction of the –COOH functional groups on the surface of SWCNT lead to increase in crosslinking and resulted in a strong bond formation between the polymer and nanotube interphase. A significant increase in energy was found in Epon/COOH-SWCNT systems that lead to an increase of 33% in interfacial strength in comparison to Epon/SWCNT counterpart. The pullout simulations of Epon/SWCNT samples showed separation at the interphase with no polymer atoms attached to CNT. In contrast, bond stretching and breakage were observed in the polymer chain, whereas, a strong interphase was observed in Epon/COOH-SWCNT samples. This study reveals the nanolevel interactions between the nanotubes and polymers which otherwise not possible through experimental techniques, and lead to cognize that the functionalization of SWCNT with –COOH groups can establish a strong network with the epoxy chain and significantly enhance the interfacial properties particularly for applications where the interphase is critical.

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

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

Field-Trial of a High-Budget, Filterless, $\lambda$ -to-the-User, UDWDM-PON Enabled by an Innovative Class of Low-Cost Coherent Transceivers

We experimentally demonstrate an innovative ultradense wavelength division multiplexing (UDWDM) passive optical networks (PON) that implements the full $\lambda \text {-to-the-user}$ 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 $\text{6.25}\text{-}\text {GHz}$ grid), real-time GbE transmissions (by using either fully analog or light digital signal processing), multirate transmission ( $\text{1.25}\; \text{and}\; \text{10}\,\text {Gb/s}$ ), high optical distribution network loss (18–40 dB) as well as a bidirectional channel monitoring system.

Providing the full DDF link protection for bus-connected SIEPON based system architecture

Abstract Currently a massive amount of traffic per second is delivered through EPON systems, one of the prominent access network technologies for delivering the next generation network. Therefore, it is vital to keep the EPON optical distribution network (ODN) working by providing the necessity protection mechanism in the deployed devices; otherwise, when failures occur it will cause a great loss for both network operators and business customers. In this paper, we propose a bus-connected architecture to protect and recover distribution drop fiber (DDF) link faults or transceiver failures at ONU(s) in SIEPON system. The proposed architecture provides a cost-effective architecture, which delivers the high fault-tolerance in handling multiple DDF faults, while also providing flexibility in choosing the backup ONU assignments. Simulation results show that the proposed architecture provides the reliability and maintains quality of service (QoS) performance in terms of mean packet delay, system throughput, packet loss and EF jitter when DDF link failures occur.

Application of EPON Multicast Technology over IPTV

In this paper, we propose an IPTV controllable multicast solution, which combines the technology of SCB, IGMP and the extended OAM. SCB and IGMP are responsible for the distribution of multicast service. A method that based on the extended OAM multicast control packets is used to realize the functions of control and management in multicast service. We also explain the bandwidth design methods of the EPON system. In the end, the implementation scheme of EPON controllable multicast in IPTV application is proposed.

On the Use of the Doze Mode to Reduce Power Consumption in EPON Systems

Current networking equipment usually provides several energy profiles with different performance capabilities. For example, in EPON systems, ONUs are able to switch their transmitters off when there is no data to transmit. This low power mode, known as doze mode, can significantly reduce power consumption in EPONs if wisely used. In this paper, we evaluate through simulation the potential power savings that can be obtained using this mode in many different scenarios. In particular, we analyze the impact of the DBA algorithm and the mode governor on both energy efficiency and frame delay with different implementations of the doze mode.

Paper] Dynamic Bandwidth Allocation with PID-Based Request Threshold Controller for EPON Systems

Paper] Dynamic Bandwidth Allocation with PID-Based Request Threshold Controller for EPON Systems

Design of Dual PON-MAC ONU Dedicated for Communication System of Power Distribution and Utilization

With the development of smart power grid technology, EPON has become a popular communications technology both in power distribution and utilization automation. The article analyses several communication path protection methods of EPON system, then introduces the development of a dual PON-MAC ONU for such application, both hardware and software design are discussed. At last, A group of test data which verify the performance of fast protect switchover is given..

Application of IEEE802.1x Protocol Based on EPON System

IEEE 802.1x is a port-based network access control protocol, the one of the newest authentication protocols. With the MD5 algorithm as an example, this paper introduces the type of protocol packets and the authentication process in detail. The authentication port is apart from the business stream based on the logical port. The business stream is transmitted over the controlled port, but the authentication stream is transmitted over the uncontrolled port. Therefore, the port control and authorization for users can be carried out. In this paper, two authentication methods based on EPON system are studied in detail. The 802.1x authentication protocol has many advantages, such as low-cost, simply and so on. It can satisfy the requirement of intelligent distribution network communication system.

Study on Electrical Power EPON System

In IEEE8023ah Protocols, the uplink bandwidth allocation algorithm is not clearly defined, which depends on the telecommunication device providers. Combined with the strong and multiples services requirements of smart distribution grid, the State Grid developed an OLT chip with QoS mechanism and responded EPON system. Compared with nowadays OLT chip in market, the highlight of our OLT chip is its multiple QoS mechanism. On the respect of dynamic bandwidth allocation, the priority allocate and bandwidth statistic multiplexing functions have been added..

Study on Dynamic Bandwidth Allocation Algorithms Based on EPON

The use of EPON for network allocation is gradually becoming the main stream for broadband network. This technology makes full use of the features of optical network and passive optical splitter to reduce equipment costs, operation and maintenance costs for network operators and to provide faster and more stable broadband network for users. The article introduces the working principle of EPON, establishes EPON system based on OPNET technology, analyzes the current bandwidth allocation algorithm, and proposes improvement to the algorithm. Experimental emulation finds that the new algorithm can provide good QOS service and is greatly improved in the aspects of packet delay, average queue and bandwidth utilization rate.

Flexible scheduling ensuring inter-ONU-group fairness in 1G/10G EPON coexistence system

In recent years, 10 Gbit/s Ethernet passive optical networks (10G EPON) have been gaining considerable interests because of its high bandwidth capability. To ensure smooth transition from 1 Gbit/s to 10 Gbit/s equipment and to avoid a significant one-time investment into such a cost-sensitive market, coexistence of gigabit Ethernet passive optical networks (GEPON) and 10G EPON system are necessary. In this article, coexistence system architecture and a novel bandwidth allocation algorithm called weight-optimized dynamic bandwidth allocation for coexistence EPON (WOCE-DBA) for the system is proposed. The simulation results show that this algorithm can guarantee fair bandwidth sharing among different optical network unit (ONU) groups, without ignoring the inter-ONU and intra-ONU fairness. Most importantly, it can flexibly adapt to the system composition variations and save efforts needed to modify the bandwidth scheduling mechanism during the migration process from GEPON to 10G EPON.

On triplexer design for next generation Ethernet passive optical network systems

The standardisation effort targeting 10 Gbit/s EPON systems, together with the requirement for coexistence with the legacy IEEE 802.3ah compliant equipment, impose a set of very tight requirements in terms of wavelength allocation plan for future EPON systems and significant limitations in terms of triplexer design for optical network unit (ONU) modules, where two wavelength channels (or three, when an analogue video overlay is used on the downstream) must be properly separated with minimum power and quality loss, providing also a high quality transmission window for the upstream 1310 nm signal. In this paper, we look closer at the possible triplexer and filter design for emerging 10 Gbit/s EPON systems in the light of current IEEE 802.av Task Force activities and technical limitations of the wavelength division multiplexing (WDM) filter design process.

Dynamic Bandwidth Allocation Algorithm with Fairness in 1G/10G Coexistence EPON System

Gigabit Ethernet Passive Optical Networks (GE-PON) systems have been deployed widely as a broadband access solution for the optical access network, the so-called FTTx networks. 10 Gigabit EPON (10G-EPON) is about to be standardizing by a task force (802.3av). To provide the next FTTx solution with 10G-EPON systems, one of the key technologies is how to migrate from 1G-based to 10G-based. In this paper, we present Dynamic Bandwidth Allocation (DBA) algorithm which considered a fair policy for 1G/10G coexistence EPON system to achieve a smooth migration.

Development of 10 Gb/s EPON in IEEE 802.3av

The interest in the evolution of current PON systems toward high-data-rate systems capable of providing a future-proof platform for delivery of truly subscriber-oriented and personalized triple-play services resulted in the recent kickoff of the 10 Gb/s Ethernet PON system standardization effort in the IEEE . Ethernet PON has become a network of choice for low-cost subscriber-oriented digital service delivery, taking over the market previously dominated by DSL and cable modems. In this article we examine the current development process of 10 Gb/s EPON systems in more detail, standardized in the framework of the IEEE 802.3av task force, looking at the technical challenges, drivers, and possible evolution scenarios of the emerging high-data-rate access systems..

An introduction to PON technologies [Topics in Optical Communications

Passive optical networks are the most important class of fiber access systems in the world today. This article first reviews the reasons why the PON as a general architecture is so important. We then outline in some depth the technologies used to implement this architecture, including the G-PON and E-PON systems being deployed today, and the advanced PON systems that provide the evolution path to ever higher bandwidths

Fault discovery protocol for passive optical networks

Feature Issue on Passive Optical Network Architectures and TechnologiesAll existing flavors of passive optical networks (PONs) provide an attractive alternative to legacy copper-based access lines deployed between a central office (CO) of the service provider (SP) and a customer site. One of the most challenging tasks for PON network planners is the reduction of the overall cost of employing protection schemes for the optical fiber plant while maintaining a reasonable level of survivability and reducing the downtime, thus ensuring acceptable levels of quality of service (QoS) for end subscribers. The recently growing volume of Ethernet PONs deployment [Kramer, IEEE 802.3, CFI (2006)], connected with low-cost electronic and optical components used in the optical network unit (ONU) modules, results in the situation where remote detection of faulty/active subscriber modules becomes indispensable for proper operation of an EPON system. The problem of the remote detection of faulty ONUs in the system is addressed where the upstream channel is flooded with the cw transmission from one or more damaged ONUs and standard communication is severed, providing a solution that is applicable in any type of PON network, regardless of the operating protocol, physical structure, and data rate.

Media access control for Ethernet passive optical networks: an overview

Medium access control is one of the crucial issues in the design of Ethernet passive optical networks. To ensure efficient transmission, an EPON system must employ a MAC mechanism to arbitrate access to the shared medium in order to avoid data collisions in the upstream direction and at the same time efficiently share the upstream transmission bandwidth among all ONUs. The purpose of this article is to provide a good understanding of the MAC issue, discuss the major problems involved (e.g., multiple access, bandwidth allocation, transmission scheduling, and quality of service support), and present an overview of the state-of-the-art solutions proposed thus far to the problems. It is also our purpose to motivate further studies on the problems described in this article

Synchronization solution with clock automatic protection switching ability for the Ethernet passive optical network

Synchronous timing is a key technology in EPON system. This paper firstly analyzes the current three timing mechanisms and points out the disadvantages of them. And then, it puts forward a clock automatic protection switching scheme with more efficiency to resolve the clock problem in EPON, and proves the practicability of this timing scheme by simulation and FPGA confirmation.