Video traffic : characterization, modelling and transmission

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A packet scheduling algorithm using traffic policing in LTE downlink networks

Orientador: Lee Luan LingDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: Neste trabalho, melhoramos o desempenho dos tradicionais algoritmos de escalonamento de pacotes na rede LTE (Long-Term Evolution) para aplicações de serviços multimídia, usando mecanismos de policiamento de tráfego conhecidas como reguladores de balde furado (do inglês, Leaky bucket). Busca-se atingir a equidade entre classes de serviços, controlando as taxas de chegada de pacotes nas filas de transmissão do escalonador. O cenário de simulação considera múltiplos usuários movimentando-se aleatoriamente a duas velocidades diferentes envolvendo os fluxos de tráfego de vídeo e VoIP. A avaliação de desempenho foi realizada em termos de parâmetros de qualidade de serviço, como atraso de pacotes, taxa de perda de pacotes e vazão média para tráfego de vídeo e VoIP. Os resultados da simulação confirmam que os escalonadores com tráfego de entrada policiado fornecem melhor desempenho para serviços em tempo real, especialmente aqueles que envolvem tráfego de vídeoAbstract: In this work, we improve the performance of traditional packet-scheduling algorithms in Long-Term Evolution (LTE) for multimedia service applications, using traffic policing mechanisms known as leaky bucket regulation. It seeks to achieve fairness between classes of services, controlling the arrival rates of packets in the transmission queues of the scheduler. The simulation scenario considers multiple users randomly moving at two different speeds using video and VoIP traffic flows. The performance evaluation was performed in terms of quality of service parameters, such as packet delay, packet loss rate and average throughput for video and VoIP traffic. Simulation results confirm that schedulers with polled input traffic provide better performance for realtime services, especially those involving video trafficMestradoTelecomunicações e TelemáticaMestra em Engenharia Elétric

Estimação de Probabilidade de Perda de Dados em Redes Através de Modelagem Multifractal de Tráfego e Teoria de Muitas Fontes

Neste artigo, propomos uma abordagem para estimação da probabilidade de perda de bytes em enlaces de redes de computadores considerando propriedades multifractais dos fluxos de tráfego. Mais especificamente, deduzimos uma expressão matemática para o cálculo da probabilidade de perda para servidores com buffer finito alimentados com fluxos multifractais de tráfego. A abordagem proposta se baseia na teoria das muitas fontes e na modelagem multifractal de tráfego baseada em cascatas multiplicativas. Por fim, avaliamos a proposta de estimação de probabilidade de perda através de simulações computacionais utilizando séries de tráfego real, verificando assim sua eficiência como ferramenta relacionada à provisão de qualidade de serviço em redes de computadores

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Determining Additional Modulus of Subgarde Reaction Based on Tolerable Settlement for the Nailed-slab System Resting on Soft Clay.

Abstract—Nailed-slab System is a proposed alternative solution for rigid pavement problem on soft soils. Equivalent modulus of subgrade reaction (k’) can be used in designing of nailed-slab system. This modular is the cumulative of modulus of subgrade reaction from plate load test (k) and additional modulus of subgrade reaction due to pile installing (∆∆∆∆k). A recent method has used reduction of pile resistance approach in determining ∆∆∆∆k. The relative displacement between pile and soils, and reduction of pile resistance has been identified. In fact, determining of reduction of pile resistance is difficult. This paper proposes an approach by considering tolerable settlement of rigid pavement. Validation is carried out with respect to a loading test of nailed-slab models. The models are presented as strip section of rigid pavement. The theory of beams on elastic foundation is used to calculate the slab deflection by using k’. Proposed approach can results in deflection prediction close to observed one. In practice, the Nailed-slab System would be constructed by multiple-row piles. Designing this system based on one-pile row analysis will give more safety design and will consume less time

Machine Learning based RF Transmitter Characterization in the Presence of Adversaries

The advances in wireless technologies have led to autonomous deployments of various wireless networks. As these networks must co-exist, it is important that all transmitters and receivers are aware of their radio frequency (RF) surroundings so that they can learn and adapt their transmission and reception parameters to best suit their needs. To this end, machine learning techniques have become popular as they can learn, analyze and even predict the RF signals and associated parameters that characterize the RF environment. In this dissertation, we address some of the fundamental challenges on how to effectively apply different learning techniques in the RF domain. In the presence of adversaries, malicious activities such as jamming, and spoofing are inevitable which render most machine learning techniques ineffective. To facilitate learning in such settings, we propose an adversarial learning-based approach to detect unauthorized exploitation of RF spectrum. First, we show the applicability of existing machine learning algorithms in the RF domain. We design and implement three recurrent neural networks using different types of cell models for fingerprinting RF transmitters. Next, we focus on securing transmissions on dynamic spectrum access network where primary user emulation (PUE) attacks can pose a significant threat. We present a generative adversarial net (GAN) based solution to counter such PUE attacks. Ultimately, we propose recurrent neural network models which are able to accurately predict the primary users\u27 activities in DSA networks so that the secondary users can opportunistically access the shared spectrum. We implement the proposed learning models on testbeds consisting of Universal Software Radio Peripherals (USRPs) working as Software Defined Radios (SDRs). Results reveal significant accuracy gains in accurately characterizing RF transmitters- thereby demonstrating the potential of our models for real world deployments

Quality of Service for Multimedia and Control System Applications in Mobile Ad-hoc Network

A Mobile Ad-Hoc Network (MANET) is a collection of randomly distributed infrastructure-less mobile nodes that form a wireless network. These Mobile nodes have the capability to act as a host or relay. As a host, the mobile nodes can be the source and/or destination of traffic, and when acting as a relay, they can be an intermediate node that forwards the traffic to its destination. Some of the challenges of a MANET include the dynamic network topology, device discovery, power constraints, wireless channel conditions and limited network resources. These challenges degrade the network performance and thus affect the network stability and robustness. Therefore, it is difficult for a MANET to attain the Quality of Service (QoS) of a wired network. This thesis aims to address the problem of the limited wireless network resources by proposing two adaptive scheduling algorithms that can adapt in real-time to the changes in the network. To achieve the aim; this thesis first analyses the behaviour of various application profiles in a queue. It models Voice, Email, and Internet Browsing traffic (by specifying packet sizes, and inter-arrival rates based on various distributions) separately and then simultaneously in a common network for uncongested and congested conditions, after which scheduling is applied in order to improve the overall network performance. The Voice traffic profile is then added to the UDP/IP protocol stack and the network performance is compared to a simple node without the UDP/IP protocol stack. A realistic wireless propagation model for the simulation is developed from a point-to-point open-field outdoor experiment. This thesis proposes two adaptive priority fuzzy based scheduler for a MANET, the priority of packets in the queue are determined based on the real-time available network resources. The methodology for transmitting a live-feed video stream over OPNET to validate the scheduler is also presented. An interface between the simulation and hardware is created to send real-time video traffic through the simulation network. This thesis concludes by showing that the performance of a MANET network can be improved by applying an adaptive scheduler