An encryption scheme for high speed passive optical networks

Ethernet passive optical networks (EPONs) have emerged as the one of the most promising candidates for next-generation access networks. These new architectures couple low-cost optics with advanced edge electronics to offer vastly improved scalability over competing digital subscriber line and cable modem offerings. This paper proposes several novel architectural enhancements for EPON, which will help increase the viability of optical access over a broader range of subscriber access scenarios. Specifically, this paper proposes a two-stage EPON architecture that allows more end-users to share an optical line terminal link, and enables longer access reach/distances (beyond the usual 25 km distance). In addition, a new dynamic bandwidth allocation (DBA) algorithm is proposed to effectively allocate bandwidths between end users. This DBA algorithm can support differentiated services in a network with heterogeneous traffic. We conduct detailed simulation experiments to study the performance and validate the effectiveness of the proposed architecture and algorithms.

The exponential growth of Internet data traffic pushes hard the telecommunication infrastructure for upgrading the transmission data rate. At the optical access level, a passive optical network (PON) is the most popular and lowest cost architecture which enables high speed access for enter prise and private users as well as various backhauling and fronthauling functionalities. Standardized PONs have undergone a number of upgrades in data rates. In order to guarantee a stable return of investment for operators, the co-existence of different generations of PONs on the same fiber infrastructure is ensured via a wavelength division multiplexing (WDM) approach. This leads to a spectrum shortage for future allocations if full co-existence is required. Today's fastest 40 Gb/s TWDM PONs [1] support 10 Gb/s lane rate non-return-to-zero (NRZ). Looking forward, the bandwidth demands continue to rise, thus increasing the per-wavelength bit rate is necessary for a future upgrade beyond 40 Gb/s. For such high data rates, the conventional NRZ format becomes demanding with respect to the required transceiver bandwidth and the acceptable fiber dispersion. As an alternative, advanced modulation formats and efficient signal processing can address the upgrade issue. Recently, research efforts have been focusing on 25 Gb/s or 40 Gb/s per wavelength next generation PONs using either NRZ with chirp management [2], or electrical/optical Duobinary [3–7], PAM-4 [3, 6–8], as well as more complex ODFM [9]. Considering PONs are cost-sensitive applications, intensity modulation and direct detection is highly desirable. Compared to DSP intensive OFDM, electrical/optical Duobinary and PAM-4 with low complex DSPs are potentially costeffective solutions. This paper aims to review and compare a number of implementation options for 40 Gb/s per wavelength high speed PONs using electrical/optical Duobinary and PAM-4. Optical link power budget performance, transceiver cost and power dissipation will be analyzed based on numerical approaches. Experimental demonstrations will also be presented.

We reviews optical access technologies for 5G mobile communication networks such as mobile data compression, high-speed passive optical network (PON), and analog radio over fiber (RoF) technologies. Recent feasibility studies for future optical access network with optical mobile convergence are discussed.

Maximum likelihood sequence estimation in high-speed PONs using machine learning-based pre-equalizers

Circuit Emulation Services (CES) technology has emerged as an option to mitigate traditional TDM circuits supporting legacy applications across managed packet networks. Since Ethernet Passive Optical Network (EPON) is becoming a major technology for pervasive access. The primary benefits of CES over EPON (CESoEPON) are the low cost and simplicity of deployment to support all types of legacy TDM applications across EPONs. Thus, the QoS-guarantee for highly delay-sensitive services on EPONs could be enhanced. This paper investigates a preemptive priority transmission technique that works on MAC and PHY layer of EPONs. The proposed novel scheme effectively reduces the frame queuing delay as well as jitter, so as to enhance precise time synchronization in EPONs. Through simulation experiments, we show that the proposed method achieves superior and precise QoS control compared to existing non-preemptive methods. Finally, we present a general conclusion of the paper.

Radio over Fibre (RoF) technology provides distribution of broadband signals to base station using an optical access network. This technology reduces the complexity at base station. On the other hand, giga bit passive optical network (GPON) has gained much of the interest in today's network due to its high data rate (1.2 GHz-2.4 GHz), simplicity, flexibility and low costs. The combination of GPON with RoF technology provides high capacity and high data rate solution. This paper provides characterization of RoF GPON by various simulations performed on OPTSIM software. The statistical analysis of simulation results are based on received signal strength and eye pattern obtained for various modulation schemes at different distances.

Optical fibre step by step substitutes existing copper cable infrastructure in the carriers' access networks, enabling new broadband services. One common approach, a passive optical network (PON) infrastructure, basically consists of optical fibres and splitters, which are lit up by G-PON (Gigabit/s-PON) or XG-PON (10 Gigabit/s-PON). These systems are attenuation limited, therefore the loss budget of a PON is of high importance. For the deployment process the total attenuation of the PON, between Central Office (CO, OLT) and customer site (ONT), must be accurately monitored and kept below the values specified in G.984.x and G.987.x standards. In FTTH scenarios the PON attenuation measurements must include the in-house networks up to the subscriber fibre cable termination unit. During operation, the Optical Line Supervision (OLS) parameters (e.g. G.984.2, Amd2) are continuously monitored, processed and correlated for appropriate alarm generation. In the case of a fibre failure, additionally non-intrusive in-service measurements from the CO site must be supported for fault localisation. This is enabled by an appropriate WDM-filter per PON in the CO, providing access to the PON for OTDR measurements at wavelengths of 1625/1650 nm. In this paper possible solutions for PON measurement and monitoring for the deployment and operation of FTTH networks will be described in detail from a carrier's perspective. All these activities must be carried out in a minimum of time and with low operational efforts in order to guarantee a cost efficient network operation.

DOI: 10.1049/ic:20070284 ISBN: 978-3-8007-3042-1 Location: Berlin, Germany Conference date: 16-20 Sept. 2007 Format: PDF We derive the performance and critical design issues of optical-coding based centralized live PON monitoring technique allowing more than 512 clients. We consider PON geographical distribution models in our performance evaluation. (2 pages) Inspec keywords: condition monitoring; encoding; optical fibre networks Subjects: Optical fibre networks; Codes

Broadband Passive Optical Access Networks

Advances in high speed network communications have raised the bar of delivering demanding multimedia and data services through Ethernet passive optical networks (EPONs). At their relatively low cost, EPONs have become an attractive solution to providing essential services like voice, video, and data communications reliably, while at the same time providing expected guarantees of the delivery of those services in terms of defined quality of service measures. A continuous theme throughout EPON research has been the study of efficient dynamic bandwidth allocation (DBA) as a key factor in achieving fairness in distributing bandwidth amongst remote network units. In our research, we investigate another factor and its effect of network performance and service delivery: cycle demand proportionality (CDP). By observing the patterns of demand in the network on an individual network unit basis cycle after cycle, we can deduce load characteristics of some units over others. We can then make decisions about subsequent grant allocations based on this factor and aim to achieve better results in the process. We simulate EPONs under varying loads and incorporate the use of CDP in conjunction with currently used DBA schemes. In this paper we present results of achieving improvements in delay performance under light-load circumstances for the cyclic polling DBA scheme

While in recent years backbone bandwidth has experienced substantial growth, little has changed in the access network. “Last mile” still remains the bottleneck between a high capacity LAN or home network and the backbone. Passive optical network (PON) is a technology viewed by many as an attractive solution to this problem. In this study, we discuss and evaluate design issues for PON access networks. Specifically, to drive the cost of an access network down, it is very important to have an efficient, scalable solution. We believe that a PON based on polling, with data encapsulated in Ethernet frames, possesses the best qualities, such as dynamic bandwidth distribution, use of a single downstream and a single upstream wavelength, ability to provision a fractional wavelength capacity to each user, and ease of adding a new user. To support dynamic bandwidth distribution, we propose an interleaved polling algorithm. We then suggest a scheme for in-band signaling that allows using a single wavelength for both downstream data and control message transmission. To obtain realistic simulation results, we generated synthetic traffic that exhibits the properties of self-similarity and long-range dependence. We then analyzed the network performance and its effect on various types of traffic, e.g., best-effort data traffic, VBR video traffic and CBR streams.

We present for the first time remote powering of a 3-D MEMS for optical switching using light over fibre. The low power switch with integrated optical splitters is suitable at non-powered remote PON distribution sites. Introduction The rapid deployment of fibre-to-the-home (FTTH) poses a number of new operational challenges in managing fibre due to the growing outside fibre plant infrastructure and the inherent churn in access networks [1]. Automating fibre management using remotely controlled optical switches has been proposed to efficiently manage subscriber connectivity and fault localization without human intervention, and to reduce the number of network and test equipment [2]. Early field trials have confirmed the benefits to operate and maintain fibrebased networks [3]. The deployment of switches in Central Offices (CO) for FTTH point-to-point networks is relatively simple. The insertion of optical switches, however, in Passive Optical Networks (PON) at Fibre Distribution Hub (FDH) sites in the field is much more difficult because those sites are usually not powered. We demonstrate in this paper a remotely powered fibre management solution using a low-power 3DMEMS optical switch and a light-over-fibre powering technique. We also report improved environmental performance for field switch operation. Integrated PON 3-D MEMS Switch Fig.1 shows a typical FDH layout in a PON: a first bay with optical splitters is connected to the Optical Line Terminal (OLT) at the CO; a second bay with fibre terminations is connected to residential homes. Optical splitters Patch-cords OLT ONU CO Homes Outside Plant Truck-rolls for patching Field OTDR measurements ONU FDH Fig. 1. PON FDH with discrete splitters and manual fibre management requiring technician dispatch to connect subscriber to OLT or test fibres with OTDR. Each time a subscriber is added, a technician must be dispatched at the FDH site to connect it to an unused OLT port. If subscribers are connected up-front, additional OLTs are required due to limited market penetration, thus increasing greatly the initial investment cost per paying subscribe. Technicians also go in the field to perform OTDR measurements to certify fibre installation or to trouble-shoot faults. All those costly and error-prone human interventions can be alleviated by the insertion of an optical switch at the FDH sites (Fig.2). The software-controlled switch connects a subscriber to the desired splitter port, packing subscribers onto the minimum number of OLTs in real time. All the home run fibres can be checked using a test fibre connected to an OTDR at the CO that can be shared among multiple FDH sites. Optical switch with splitters OLT ONU CO Outside Plant

The main objectives of this paper is to improve knowledge of multimode fiber transmission over step-index plastic optical fiber SI POF with 1000 μm core. The thick SI POF fibers seem a very attractive alternative in local computer networks for the “classic” (thin) single- and multimode fibers because of their low price and easy installation. In the paper we show measurements of bandwidth and attenuation of various SI POF optical paths. In particular, there was investigated a cascade of passive components (couplers, patchcords) which can be part of transparent (passive) optical networks. Keywords : plastic optical fibre, passive optical network, multimode coupler. 1. INTRODUCTION Recently there has been publish a number of papers concerning optical data transfer over plastic optical fiber [1][2]. Both point-to-point and WDM passive network configurations are considered. The concept of passive network is well known as it comes to the access networks based on single mode fiber. Such networks were proposed in several standards (APON, BPON networks). Commercial solution have been developed and deployed since. We would like to extend benefits of this network type to home networks based on multimode optical fiber. We consider such networks as a viable solution of the optical home network architecture. Along with a multimode optical cable only multimode compatible elements (couples/splitters, connectors, etc.) may be used in the network. Once deployed the upgrade of such a network should be relatively easy. Unlike to the single mode PON where the bandwidth is not an issue, the multimode network maximum operational range is defined by the fiber bandwidth (related to the intermodal dispersion) rather than by the fiber attenuation [3]. The relation among the modal bandwidth of the fiber, the launching condition and mode coupling is fairly well known for silica GI optical fibers (

Investigation of high-speed optical FSK generation scheme based on carrier suppression and phase modulation

This article describes Ethernet passive optical networks, an emerging local subscriber access architecture that combines low-cost point-to-multipoint fiber infrastructure with Ethernet. EPONs are designed to carry Ethernet frames at standard Ethernet rates. An EPON uses a single trunk fiber that extends from a central office to a passive optical splitter, which then fans out to multiple optical drop fibers connected to subscriber nodes. Other than the end terminating equipment, no component in the network requires electrical power, hence the term passive. Local carriers have long been interested in passive optical networks for the benefits they offer: minimal fiber infrastructure and no powering requirement in the outside plant. With Ethernet now emerging as the protocol of choice for carrying IP traffic in metro and access networks, EPON has emerged as a potential optimized architecture for fiber to the building and fiber to the home.