Spectrally efficient and low cost time and wavelength division multiplexed passive optical network systems

The next-generation passive optical network stage 2 (NG-PON2) intends to support stacking 10 Gb/s wavelengths and maintaining the compatibility with the deployed legacy passive optical network (PON) systems. Essentially, Time and Wavelength Division Multiplexed-PON (TWDM-PON) is the best solution for NGPON2 that aims to support a symmetric 40 Gb/s data rate transmission, a split ratio of 1:64 and a distance up to 60 km. Unfortunately, most of the existing low cost and practical TWDM-PON solutions are still incapable to support remote users and inefficient for spectral bandwidth in higher services. Typically, low cost transceivers are avoided as they suffer from significant frequency chirp that seriously impact its transmission performance at the bit rate above 10 Gb/s. Therefore, the objectives of this thesis are to improve the current TWDM-PON power budget in supporting more access services reaching the remote customers to enhance the bandwidth capacity at lower cost and to reduce the complexity implementation problem. This is achieved by overcoming the significant frequency chirp of the low cost transceivers used such as reflective semiconductor optical amplifier (RSOA) and directly modulated lasers (DMLs), which are suitable for high data rate transmission. The RSOA chirp is mitigated using a single bi-pass delay interferometer (DI) at the optical line terminal (OLT) while the DML chirp is managed by ensuring its resulting current is in phase with the bandwidth enhancement factor, , at both optical network unit (ONU) and OLT. Apart from that, DML equipped with dispersion compensation fiber (DCF) technique for power budget improvement is also proposed. Furthermore, low cost schemes for even higher data rate TWDM-PON up to 56 Gb/s is proposed utilizing highly spectral efficient 16-quadrature amplitude modulation (16-QAM). The results are obtained from physical layer simulation, OptisystemTrademark and MatlabTrademark, where relevant significant parts are verified through theoretical analysis. The simulation results demonstrate a sufficient dispersion compensation with a record of 56.6 dB power bughet for DML-based TWDM-PON transmission system. While results are not absolute due to variations that can occur in practical implementation, analysis demonstrates the feasibility of the proposed methods

FTTx Access Networks: Technical Developments and Standardization

This chapter provides a review of factors driving technical development of broadband access networks, mostly toward higher bit rates and symmetrical services, together with a review of “fiber to the x” (FTTx) technologies for fixed access networks, including development and performance limitations of digital subscriber line (DSL) systems using twisted-pair copper cables, as well as fiber to the home systems. Characteristics and standardization of these systems are presented, together with a review of the two main competing broadband technologies: Data over cable service interface specification (DOCSIS) in coaxial cable TV networks and the 4G and 5G wireless networks. Additionally, a short list of recent developments in passive technologies (fibers, cables, and connectors) is included. Finally, the issues related to dismantling of the traditional copper telephone network and ensuring continuity of voice services in emergency situations are analyzed

UMA NOVA ABORDAGEM PARA DETECTAR TRÁFEGO P2P COM BASE NA ANÁLISE DE ASSINATURAS

In recent years, peer-to-peer (P2P) networks have gained more popularity in the form of file-sharing applications, such as uTorrent and eMule, that use BitTorrent and eDonkey protocols. With such popularity comes security risks and external attacks; the latter is often associated with information hacking. In this paper, we will introduce a new way to monitor and detect the use of each of the P2P applications within the corporate network. Based on the inspection of traffic packets in order to extract digital signatures of these applications using the open-source packet analysis program "Wireshark," in addition to using the well-known Snort intrusion detection system (IDS) with a number of adequate and new rules, this solution can allow us to receive powerful warning messages that detect the presence of P2P applications inside the network. We implemented our rules in Snort IDS. Over a period of time, this solution allowed us to achieve 96% effectiveness in detecting the presence of P2P applications.En los últimos años, las redes peer-to-peer (P2P) han ganado más popularidad en forma de aplicaciones para compartir archivos, como uTorrent y eMule, que utilizan los protocolos BitTorrent y eDonkey. Con tal popularidad vienen riesgos de seguridad y ataques externos; Este último a menudo se asocia con el pirateo de información. En este artículo, presentaremos una nueva forma de monitorear y detectar el uso de cada una de las aplicaciones P2P dentro de la red corporativa.Basada en la inspección de paquetes de tráfico con el fin de extraer firmas digitales de estas aplicaciones utilizando el programa de análisis de paquetes de código abierto "Wireshark", además de utilizar el conocido sistema de detección de intrusos (IDS) Snort con una serie de reglas adecuadas y nuevas, esta solución puede permitirnos recibir potentes mensajes de advertencia que detectan la presencia de aplicaciones P2P dentro de la red. Implementamos nuestras reglas en Snort IDS. Durante un período de tiempo, esta solución nos permitió alcanzar un 96% de efectividad en la detección de la presencia de aplicaciones P2P.In recent years, peer-to-peer (P2P) networks have gained more popularity in the form of file-sharing applications, such as uTorrent and eMule, that use BitTorrent and eDonkey protocols. With such popularity comes security risks and external attacks; the latter is often associated with information hacking. In this paper, we will introduce a new way to monitor and detect the use of each of the P2P applications within the corporate network. Based on the inspection of traffic packets in order to extract digital signatures of these applications using the open-source packet analysis program "Wireshark," in addition to using the well-known Snort intrusion detection system (IDS) with a number of adequate and new rules, this solution can allow us to receive powerful warning messages that detect the presence of P2P applications inside the network. We implemented our rules in Snort IDS. Over a period of time, this solution allowed us to achieve 96% effectiveness in detecting the presence of P2P applications.Nos últimos anos, as redes peer-to-peer (P2P) ganharam mais popularidade na forma de aplicativos de compartilhamento de arquivos, como uTorrent e eMule, que usam protocolos BitTorrent e eDonkey. Com tamanha popularidade, surgem riscos de segurança e ataques externos; este último é frequentemente associado à invasão de informações. Neste artigo, apresentaremos uma nova maneira de monitorar e detectar o uso de cada um dos aplicativos P2P dentro da rede corporativa.Baseada na inspeção de pacotes de tráfego para extrair assinaturas digitais dessas aplicações usando o programa de análise de pacotes de código aberto "Wireshark", além de usar o conhecido sistema de detecção de intrusão (IDS) Snort com uma série de regras adequadas e novas, esta solução pode nos permitir receber poderosas mensagens de aviso que detectam a presença de aplicações P2P dentro da rede. Implementamos nossas regras no Snort IDS. Ao longo de um período de tempo, esta solução permitiu-nos alcançar 96% de eficácia na detecção da presença de aplicações P2P

Wavelength reconfigurability for next generation optical access networks

Next generation optical access networks should not only increase the capacity but also be able to redistribute the capacity on the fly in order to manage larger variations in traffic patterns. Wavelength reconfigurability is the instrument to enable such capability of network-wide bandwidth redistribution since it allows dynamic sharing of both wavelengths and timeslots in WDM-TDM optical access networks. However, reconfigurability typically requires tunable lasers and tunable filters at the user side, resulting in cost-prohibitive optical network units (ONU). In this dissertation, I propose a novel concept named cyclic-linked flexibility to address the cost-prohibitive problem. By using the cyclic-linked flexibility, the ONU needs to switch only within a subset of two pre-planned wavelengths, however, the cyclic-linked structure of wavelengths allows free bandwidth to be shifted to any wavelength by a rearrangement process. Rearrangement algorithm are developed to demonstrate that the cyclic-linked flexibility performs close to the fully flexible network in terms of blocking probability, packet delay, and packet loss. Furthermore, the evaluation shows that the rearrangement process has a minimum impact to in-service ONUs. To realize the cyclic-linked flexibility, a family of four physical architectures is proposed. PRO-Access architecture is suitable for new deployments and disruptive upgrades in which the network reach is not longer than 20 km. WCL-Access architecture is suitable for metro-access merger with the reach up to 100 km. PSB-Access architecture is suitable to implement directly on power-splitter-based PON deployments, which allows coexistence with current technologies. The cyclically-linked protection architecture can be used with current and future PON standards when network protection is required

A Quality of Service framework for upstream traffic in LTE across an XG-PON backhaul

Passive Optical Networks (PON) are promising as a transport network technology due to the high network capacity, long reach and strong QoS support in the latest PON standards. Long Term Evolution (LTE) is a popular wireless technology for its large data rates in the last mile. The natural integration of LTE and XG-PON, which is one of the latest standards of PON, presents several challenges for XG-PON to satisfy the backhaul QoS requirements of aggregated upstream LTE applications. This thesis proves that a dedicated XG-PON-based backhaul is capable of ensuring the QoS treatment required by different upstream application types in LTE, by means of standard-compliant Dynamic Bandwidth Allocation (DBA) mechanisms. First the design and evaluation of a standard-compliant, robust and fast XG-PON simulation module developed for the state-of-the-art ns-3 network simulator is presented in the thesis. This XG-PON simulation module forms a trustworthy and large-scale simulation platform for the evaluations in the rest of the thesis, and has been released for use by the scientific community. The design and implementation details of the XGIANT DBA, which provides standard complaint QoS treatment in an isolated XG-PON network, are then presented in the thesis along with comparative evaluations with the recently-published EBU DBA. The evaluations explored the ability of both XGIANT and EBU in terms of queuing-delay and throughput assurances for different classes of simplified (deterministic) traffic models, for a range of upstream loading in XG-PON. The evaluation of XGIANT and EBU DBAs are then presented for the context of a dedicated XG-PON backhaul in LTE with regard to the influence of standard-compliant and QoS-aware DBAs on the performance of large-scale, UDP-based applications. These evaluations disqualify both XGIANT and EBU DBAs in providing prioritised queuing delay performances for three upstream application types (conversational voice, peer-to-peer video and best-effort Internet) in LTE; the evaluations also indicate the need to have more dynamic and efficient QoS policies, along with an improved fairness policy in a DBA used in the dedicated XG-PON backhaul to ensure the QoS requirements of the upstream LTE applications in the backhaul. Finally, the design and implementation details of two standard-compliant DBAs, namely Deficit XGIANT (XGIANT-D) and Proportional XGIANT (XGIANT-P), which provide the required QoS treatment in the dedicated XG-PON backhaul for all three application types in the LTE upstream are presented in the thesis. Evaluations of the XGIANT-D and XGIANT-P DBAs presented in the thesis prove the ability of the fine-tuned QoS and fairness policies in the DBAs in ensuring prioritised and fair queuing-delay and throughput efficiency for UDP- and TCP-based applications, generated and aggregated based on realistic conditions in the LTE upstream

Modified GIANT Dynamic Bandwidth Allocation Algorithm of NG-PON

Gigabit passive optical networks have been widely deployed due to the fact that the cost of their implementation is still decreasing. What is more important, we are facing theproblem with increasing demands on the transmission bandwidth. Regarding this issue, the ITU develops another two standards supporting higher downstream bitrate. The XG-PON standard is the first platform under the developing, and the NG-PON2 is the second standard. The first one provides compatibility and increases the downstream capacity of 10 Gbit/s and the second standard has the same assumptions, but does not have backward compatibility. In this article, we discuss only XG-PON networks. We choose amendment as the dynamic bandwidth allocation algorithms, and we have compared it with the original specification and with our modification. The primary intention of that modification is to reduce the delay of Triple Play (data, video, and voice) services. These services are represented by TCONT (Transmission Container), which is used to improve the PON system upstream bandwidth allocation and transmission status dynamically. As NS-3 simulator does not support the direct mapping of Triple Play services into T-CONT and their labeling. We focus on a delay value for Triple Play services which was reduced by own modification in a GIANT algorithm. On the other hand, we cannot reduce the delay value for VoIP services because it has the highest priority by T-CONT