Next Generation Optical Access Networks: from TDM to WDM

Postprint (author’s final draft

Energy-saving mechanism in WDM/TDM-PON based on upstream network traffic

One of the main challenges of Passive Optical Networks (PONs) is the resource (bandwidth and wavelength) management. Since it has been shown that access networks consume a significant part of the overall energy of the telecom networks, the resource management schemes should also consider energy minimization strategies. To sustain the increased bandwidth demand of emerging applications in the access section of the network, it is expected that next generation optical access networks will adopt the wavelength division/time division multiplexing (WDM/TDM) technique to increase PONs capacity. Compared with traditional PONs, the architecture of a WDM/TDM-PON requires more transceivers/receivers, hence they are expected to consume more energy. In this paper, we focus on the energy minimization in WDM/TDM-PONs and we propose an energy-efficient Dynamic Bandwidth and Wavelength Allocation mechanism whose objective is to turn off, whenever possible, the unnecessary upstream traffic receivers at the Optical Line Terminal (OLT). We evaluate our mechanism in different scenarios and show that the proper use of upstream channels leads to relevant energy savings. Our proposed energy-saving mechanism is able to save energy at the OLT while maintaining the introduced penalties in terms of packet delay and cycle time within an acceptable range. We might highlight the benefits of our proposal as a mechanism that maximizes the channel utilization. Detailed implementation of the proposed algorithm is presented, and simulation results are reported to quantify energy savings and effects on network performance on different network scenarios

Validation platform implementation description - D5.2

This deliverable describes different test-beds for the validation of the architecture, algorithms and protocols for the operator governed opportunistic networking as defined in the OneFIT Project. Further on, this deliverable provides a description of the implementation of the OneFIT cognitive management systems CSCI and CMON as well as the C4MS protocol. Also, implementation of the blocks supporting the OneFIT system (JRRM, CCM, DSONPM, and DSM) is described. This document also describes the implementation of the OneFIT scenarios for opportunistic coverage extension, opportunistic capacity extension, infrastructure supported ad-hoc networking and device-to-device communication as well as opportunistic resource aggregation in the backhaul network

Results analysis and validation - D5.3

This deliverable describes the validation processes followed to assess the performance of the algorithms and protocols for the operator governed opportunistic networking as defined in the OneFIT Project. Therefore, this document includes the description of the set-up of the different validation platforms, the design of the test plans for each one of them, and the analysis of the results obtained from the tests. A per-scenario approach rather than a per-platform approach has been followed, so an additional analysis has been performed, gathering the results related to each scenario, in order to validate the premises stated to each one of them. The OneFIT concept has been therefore validated for all foreseen business scenarios

Statistical Models for MPEG Video Standard

. This paper introduces a statistical model for a variable bit rate MPEG output stream. The appropriate choice of the parameters (q, M, N ) that define a VBR MPEG codec is studied. The traffic is assumed to be generated on an ATM network. A VBR MPEG codec is simulated through an object-oriented programming environment written in C++. In this work a video luminance sequence of 3600 frames is used. The codec frame stream is separated according to the Intra, Predicted and Bidirectionally-Predicted coding algorithm. A statistical analysis of each stream is presented. It can be concluded that in all cases, the statistical behaviour approaches a binomial random variable. A composed multistage Markov chain is proposed to model the VBR MPEG output stream. The histograms comparing the empirical data and the model results are also shown. To generate video traffic stream an event-driven simulator was developed in C++. The frame bit-rate is controlled by semi-Markov chain model. In the chain state..

A New Hybrid Coding Method for Videoconferencing Applications

This paper presents a new hybrid coding method for low bit-rate videoconferencing transmission over ISDN. The use of both predictive and transform coding techniques along with motion compensation allows to obtain bit-rates suitable for ISDN applications. To that extend, a new quad tree based segmentation technique to detect stationary and moving parts of an image is introduced. On the other hand, to fully exploit the statistical properties of the signal to be encoded, an adaptive predictor is designed as well as a transform coding scheme to encode the prediction error. A buffer design that provides constant bit-rate is also introduced. Good visual results are obtained in the range of m x 64 Kbits/s, m = 1,2,3,... . 1. Introduction A video conferencing system is defined as a system that provides a mean to transmit moving images in real time from participants in a conference or in a meeting. The single person-camara (SPC) system is the most commonly used video conferencing system 1 . Thi..