A PROPOSED SOLUTION TO THE BOTTLENECK AND CAPACITY PROBLEM FOR DATA TRANSFER

There is increased need for solution to communicate larger data over the PON network. In this study, two problems including bottleneck and the capacity load problem were investigated and based on this, a solution is proposed. For methodology, N number of Nodes is used for ringbased architecture which represent the complete PON system. The nodes are the save points are created for monitoring the nodes and tracking their network faults. The distance from each node is equal and there are N number of checkpoints. The source and receiver node are selected dynamically. A ring-based network model is proposed with the optimized solution, less data loss and higher speed. The proposed work sets a scenario which is based on ring topology with 08 number of nodes with same number of save points. 800 m * 800 m is the dimension of the topography. We found that time it took to transfer a packet is about 1.01 second.  For solving the bottleneck problem, the tree-based network model is used and accordingly, 4 sub-networks are taken in a hierarchal way.  Comparison of results based on packet delivery shows that proposed model has better time factor in terms of sending data compared to the existing system. 

Video Traffic Characteristics of Modern Encoding Standards: H.264/AVC with SVC and MVC Extensions and H.265/HEVC

abstract: Video encoding for multimedia services over communication networks has significantly advanced in recent years with the development of the highly efficient and flexible H.264/AVC video coding standard and its SVC extension. The emerging H.265/HEVC video coding standard as well as 3D video coding further advance video coding for multimedia communications. This paper first gives an overview of these new video coding standards and then examines their implications for multimedia communications by studying the traffic characteristics of long videos encoded with the new coding standards. We review video coding advances from MPEG-2 and MPEG-4 Part 2 to H.264/AVC and its SVC and MVC extensions as well as H.265/HEVC. For single-layer (nonscalable) video, we compare H.265/HEVC and H.264/AVC in terms of video traffic and statistical multiplexing characteristics. Our study is the first to examine the H.265/HEVC traffic variability for long videos. We also illustrate the video traffic characteristics and statistical multiplexing of scalable video encoded with the SVC extension of H.264/AVC as well as 3D video encoded with the MVC extension of H.264/AVC.View the article as published at https://www.hindawi.com/journals/tswj/2014/189481

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

Video Traffic Characteristics of Modern Encoding Standards: H.264/AVC with SVC and MVC Extensions and H.265/HEVC

Video encoding for multimedia services over communication networks has significantly advanced in recent years with the development of the highly efficient and flexible H.264/AVC video coding standard and its SVC extension. The emerging H.265/HEVC video coding standard as well as 3D video coding further advance video coding for multimedia communications. This paper first gives an overview of these new video coding standards and then examines their implications for multimedia communications by studying the traffic characteristics of long videos encoded with the new coding standards. We review video coding advances from MPEG-2 and MPEG-4 Part 2 to H.264/AVC and its SVC and MVC extensions as well as H.265/HEVC. For single-layer (nonscalable) video, we compare H.265/HEVC and H.264/AVC in terms of video traffic and statistical multiplexing characteristics. Our study is the first to examine the H.265/HEVC traffic variability for long videos. We also illustrate the video traffic characteristics and statistical multiplexing of scalable video encoded with the SVC extension of H.264/AVC as well as 3D video encoded with the MVC extension of H.264/AVC

Estudo e implementação de soluções de comunicação IP/GPON

Este trabalho visa abordar as temáticas essenciais ao projeto e implementação de redes de acesso Gigabit Passive Optical Networks (GPON), assim como os “tradicionais” serviços disponibilizados por este tipo de solução de comunicação, em aldeamentos turísticos e instalações empresariais. Os serviços que podem funcionar sobre uma rede GPON são variados, sendo que, qualquer tecnologia Internet Protocol (IP), pode ser colocada a funcionar sobre esta solução. De entre os vários serviços, o sistema de Internet Protocol Television (IPTV) é o que apresenta maiores desafios de implementação em redes GPON. O IPTV consiste na transmissão de sinais de televisão sobre o IP. Utiliza o conceito de IP Multicast para enviar os pacotes de informação dos canais de televisão pela rede, até as Set Up Boxes (STB), que são responsáveis pela receção do sinal e transmissão dos canais para as televisões. O facto de requerer uma largura de banda mínima, torna o IPTV suscetível a degradação, quando há alterações significativas nos débitos de transmissão da rede. Garantir a largura de banda mínima, adequada ao funcionamento do sistema, requer a utilização de técnicas de Quality of Service (QoS). No trabalho será abordado o estudo de dois projetos GPON distintos, cuja realização resultou da aplicação dos conhecimentos técnicos adquiridos, durante o estágio