Pre-Congestion Notification (PCN) Architecture

This document describes a general architecture for flow admission and termination based on pre-congestion information in order to protect the quality of service of established, inelastic flows within a single Diffserv domain.\u

A QoS-enabled resource management scheme for F-HMIPv6 micro mobility approach

In the near future, wireless networks will certainly run real-time applications with special Quality of Service (QoS) requirements. In this context micro mobility management schemes such as Fast Handovers over Hierarchical Mobile IPv6 (F-HMIPv6) will be a useful tool in reducing Mobile IPv6 (MIPv6) handover disruption and thereby to improve delay and losses. However, F-HMIPv6 alone does not support QoS requirements for real-time applications. Therefore, in order to accomplish this goal, a novel resource management scheme for the Differentiated Services (DiffServ) QoS model is proposed to be used as an add-on to F-HMIPv6. The new resource management scheme combines the F-HMIPv6 functionalities with the DiffServ QoS model and with network congestion control and dynamic reallocation mechanisms in order to accommodate different QoS traffic requirements. This new scheme based on a Measurement-Based Admission Control (MBAC) algorithm is effective, simple, scalable and avoids the well known traditional resource reservation issues such as state maintenance, signaling overhead and processing load. By means of the admission evaluation of new flows and handover flows, it is able to provide the desired QoS requirements for new flows while preserving the QoS of existing ones. The evaluated results show that all QoS metrics analyzed were significantly improved with the new architecture indicating that it is able to provide a highly predictive QoS support to F-HMIPv6

Advances in Internet Quality of Service

We describe recent advances in theories and architecture that support performance guarantees needed for quality of service networks. We start with deterministic computations and give applications to integrated services, differentiated services, and playback delays. We review the methods used for obtaining a scalable integrated services support, based on the concept of a stateless core. New probabilistic results that can be used for a statistical dimensioning of differentiated services are explained; some are based on classical queuing theory, while others capitalize on the deterministic results. Then we discuss performance guarantees in a best effort context; we review: methods to provide some quality of service in a pure best effort environment; methods to provide some quality of service differentiation without access control, and methods that allow an application to control the performance it receives, in the absence of network support

Theories and Models for Internet Quality of Service

We survey recent advances in theories and models for Internet Quality of Service (QoS). We start with the theory of network calculus, which lays the foundation for support of deterministic performance guarantees in networks, and illustrate its applications to integrated services, differentiated services, and streaming media playback delays. We also present mechanisms and architecture for scalable support of guaranteed services in the Internet, based on the concept of a stateless core. Methods for scalable control operations are also briefly discussed. We then turn our attention to statistical performance guarantees, and describe several new probabilistic results that can be used for a statistical dimensioning of differentiated services. Lastly, we review recent proposals and results in supporting performance guarantees in a best effort context. These include models for elastic throughput guarantees based on TCP performance modeling, techniques for some quality of service differentiation without access control, and methods that allow an application to control the performance it receives, in the absence of network support

Systematic review of African-American women’s identity struggle in American drama

This article carries out a review of the literatures of the related materials that approach the main area of my study which is African American women's lack of identity. As a result, black women in America experience various kinds of oppressions throughout their live but this issue has been changed in the second half of 20th century because of many social, political and literary movements. In conclusion, postmodern drama and Civil Right Movement provide the fertile background for many playwrights at that time to promote the development of a political, literary and social agendas

Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

The role of admission control in assuring multiple services quality

Considering that network overprovisioning by itself is not always an attainable and everlasting solution, Admission Control (AC) mechanisms are recommended to keep network load controlled and assure the required service quality levels. This article debates the role of AC in multiservice IP networks, providing an overview and discussion of current and representative AC approaches, highlighting their main characteristics, pros and cons regarding the management of network services quality. In this debate, particular emphasis is given to an enhanced monitoring-based AC proposal for assuring multiple service levels in multiclass networks.Centro de Ciências e Tecnologias da Computação do Departamento de Informática da Universidade do Minho (CCTC

Per-Priority Flow Control (Ppfc) Framework For Enhancing Qos In Metro Ethernet

Day by day Internet communication and services are experiencing an increase in variety and quantity in their capacity and demand. Thus, making traffic management and quality of service (QoS) approaches for optimization of the Internet become a challenging area of research; meanwhile flow control and congestion control will be considered as significant fundamentals for the traffic control especially on the high speed Metro Ethernet. IEEE had standardized a method (IEEE 802.3x standard), which provides Ethernet Flow Control (EFC) using PAUSE frames as MAC control frames in the data link layer, to enable or disable data frame transmission. With the initiation of Metro Carrier Ethernet, the conventional ON/OFF IEEE 802.3x approach may no longer be sufficient. Therefore, a new architecture and mechanism that offer more flexible and efficient flow and congestion control, as well as better QoS provisioning is now necessary

Multimedia courseware for interactive teaching and learning: students’ needs and perspectives

Education faces many new challenges in meeting the demands of teaching and learning for the 21st century. One of the new challenges is to integrate ICT (Information and communication technologies) in teaching and learning as a means of delivering alternative teaching. Multimedia technology, for example, has the potential to transform a traditional classroom into an unlimited imaginary world. This paper report on development and evaluation of a multimedia courseware for Design and Technology (RBT). An interactive CD was developed using the Adobe Flash CS6 software. Alpha and Beta testing have been carried out in the development process. 6 experts were assigned to evaluate the functionality of the interactive CD. In order to identify the usability of interactive CD, 103 respondents were involved in the survey by filling four-point Likert scaled questionnaire. The findings show that, the level of interactive CD usability is at a high level. Based on this study, there are positive effects that we can see based on the use of multimedia elements in the education system. The meaningful benefits of using multimedia elements for learning include the presentation of various learning styles. The presentation of information usually integrates multimedia elements such as text, graphics, audio and video