VOIP WITH ADAPTIVE RATE IN MULTI- TRANSMISSION RATE WIRELESS LANS

“Voice over Internet Protocol (VoIP)” is a popular communication technology that plays a vital role in term of cost reduction and flexibility. However, like any emerging technology, there are still some issues with VoIP, namely providing good Quality of Service (QoS), capacity consideration and providing security. This study focuses on the QoS issue of VoIP, specifically in “Wireless Local Area Networks (WLAN)”. IEEE 802.11 is the most popular standard of wireless LANs and it offers different transmission rates for wireless channels. Different transmission rates are associated with varying available bandwidth that shall influence the transmission of VoIP traffic

VOIP WITH ADAPTIVE RATE IN MULTI- TRANSMISSION RATE WIRELESS LANS

“Voice over Internet Protocol (VoIP)” is a popular communication technology that plays a vital role in term of cost reduction and flexibility. However, like any emerging technology, there are still some issues with VoIP, namely providing good Quality of Service (QoS), capacity consideration and providing security. This study focuses on the QoS issue of VoIP, specifically in “Wireless Local Area Networks (WLAN)”. IEEE 802.11 is the most popular standard of wireless LANs and it offers different transmission rates for wireless channels. Different transmission rates are associated with varying available bandwidth that shall influence the transmission of VoIP traffic

User-Centric Quality of Service Provisioning in IP Networks

The Internet has become the preferred transport medium for almost every type of communication, continuing to grow, both in terms of the number of users and delivered services. Efforts have been made to ensure that time sensitive applications receive sufficient resources and subsequently receive an acceptable Quality of Service (QoS). However, typical Internet users no longer use a single service at a given point in time, as they are instead engaged in a multimedia-rich experience, comprising of many different concurrent services. Given the scalability problems raised by the diversity of the users and traffic, in conjunction with their increasing expectations, the task of QoS provisioning can no longer be approached from the perspective of providing priority to specific traffic types over coexisting services; either through explicit resource reservation, or traffic classification using static policies, as is the case with the current approach to QoS provisioning, Differentiated Services (Diffserv). This current use of static resource allocation and traffic shaping methods reveals a distinct lack of synergy between current QoS practices and user activities, thus highlighting a need for a QoS solution reflecting the user services. The aim of this thesis is to investigate and propose a novel QoS architecture, which considers the activities of the user and manages resources from a user-centric perspective. The research begins with a comprehensive examination of existing QoS technologies and mechanisms, arguing that current QoS practises are too static in their configuration and typically give priority to specific individual services rather than considering the user experience. The analysis also reveals the potential threat that unresponsive application traffic presents to coexisting Internet services and QoS efforts, and introduces the requirement for a balance between application QoS and fairness. This thesis proposes a novel architecture, the Congestion Aware Packet Scheduler (CAPS), which manages and controls traffic at the point of service aggregation, in order to optimise the overall QoS of the user experience. The CAPS architecture, in contrast to traditional QoS alternatives, places no predetermined precedence on a specific traffic; instead, it adapts QoS policies to each individual’s Internet traffic profile and dynamically controls the ratio of user services to maintain an optimised QoS experience. The rationale behind this approach was to enable a QoS optimised experience to each Internet user and not just those using preferred services. Furthermore, unresponsive bandwidth intensive applications, such as Peer-to-Peer, are managed fairly while minimising their impact on coexisting services. The CAPS architecture has been validated through extensive simulations with the topologies used replicating the complexity and scale of real-network ISP infrastructures. The results show that for a number of different user-traffic profiles, the proposed approach achieves an improved aggregate QoS for each user when compared with Best effort Internet, Traditional Diffserv and Weighted-RED configurations. Furthermore, the results demonstrate that the proposed architecture not only provides an optimised QoS to the user, irrespective of their traffic profile, but through the avoidance of static resource allocation, can adapt with the Internet user as their use of services change.France Teleco

ACUTA Journal of Telecommunications in Higher Education

This Is Issue Voice over lP: Still Emerging After All These Years Unified Messaging: A Killer App tor lP State-of-the-Art Communications at SUNY Upstate Medical OptlPuter Enables More Powerful Collaborative Research Wireless Technology: A Major Area of Telecommunications Growth Ready for Convergence: lT Management and Technologists Innovation Culture Clashes Speech Recognition Solves Problems Interview President\u27s Message From the Executive Directo

ACUTA Journal of Telecommunications in Higher Education

This Is Issue Voice over lP: Still Emerging After All These Years Unified Messaging: A Killer App tor lP State-of-the-Art Communications at SUNY Upstate Medical OptlPuter Enables More Powerful Collaborative Research Wireless Technology: A Major Area of Telecommunications Growth Ready for Convergence: lT Management and Technologists Innovation Culture Clashes Speech Recognition Solves Problems Interview President\u27s Message From the Executive Directo

Sistema de monitoramento de qualidade em serviços de telefonia IP

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência da Computação, Florianópolis, 2015.A telefonia IP é um serviço consolidado que tem crescido de forma constante, impulsionada por suas diversas vantagens, como redução de custos, facilidade de integração com outros serviços, dentre muitas outras. No entanto, manter a qualidade deste serviço ainda é um desafio principalmente em locais de redes congestionadas. Como a telefonia é um serviço essencial para várias organizações, é fundamental manter as chamadas em níveis razoáveis de qualidade. Para tal, a qualidade oferecida pela telefonia IP deve ser constantemente monitorada de maneira a orientar as ações de novos investimentos e manutenção. Nesta direção, a presente dissertação propõe um sistema de monitoramento da qualidade fim-a-fim para os serviços de telefonia IP com base no pacote de relatórios de qualidade RTCP XR (Real Time Control Protocol - Extended Reports) e no protocolo de sinalização SIP (Session Initiation Protocol). Um caso de uso do sistema proposto, em um serviço de produção de telefonia IP de uma universidade, utilizando métricas objetivas e metodologias de monitoramento não intrusivas, demonstrou a efetividade e versatilidade do sistema proposto.Abstract : IP telephony is a consolidated service that has been growing steadily, driven by its various advantages, such as cost reduction, ease of integration with other services, among many others. However, maintaining the quality of this service is still a challenge especially in places of congested networks. As the telephony is an essential service for various organizations, it is essential to maintain the call quality at reasonable levels. To this end, the quality offered by IP telephony should be constantly monitored in order to guide the actions of new investments and maintenance. In this direction, this thesis proposes a quality end-to-end monitoring system for IP telephony services based on quality reporting package RTCP XR (Real Time Control Protocol - Extended Reports) and SIP signaling protocol (Session Initiation Protocol). A use case of the proposed system in an IP telephony production service of a university, using objective metrics and non-intrusive monitoring methodologies, demonstrated the effectiveness and versatility of the proposed system

Error Probability in Redundant Packet Sending over IP Network

In this paper we calculate error probability of packetized signal when method of redundant packet sending is used in IP network. The number of repeated signaling packets from each interval of packetization is determined to achieve the desired error probability. The method for management of this number of repetitions is developed based on the new analysis. This method is especially important in the case of sending signaling criteria of classic telephony network over IP network, because it makes possible to reach the same error probability as in classic telephony network

A-Interface Over Internet Protocol For User-Plane Connection Optimization In GSM/EDGE Radio Access Network

This thesis will cover a detailed study about the main motivations and benefits from using IP as a transport protocol for specifically A-interface in GERAN for Circuit Switched User-Plane (CS-UP) connection, in addition to the required protocols. The main study in this document will be around Real Time Protocol (RTP), Real Time Control Protocol (RTCP) negotiation for RTP packets multiplexing, for both cases, with and without RTP header compression. The focus will be about the communication between the Base Station Controller (BSC) and the Media GateWay (MGW), the bandwidth gain in accordance to the multiplexing delay for processing and buffering, the voice Quality of Service (QoS) and some other parameters