Modelo de Calidad de Servicio a Nivel de Enlace de Datos para Tráfico de Misión Crítica sobre Redes IEEE 802.11g en Modo Infraestructura

This article presents a synthesized review as state of the art of the study of QoS for mission-critical traffic in wireless local area networks that use the IEEE 802.11g protocol. This is to highlight previous research for their contribution will constitute a reference to guide a proposed new approach to ensuring the quality of service for this type of traffic using the above protocol. The review is based on academic and business items made during the current five years. As a result of this review it is evident that there have been many efforts to address the issue but there are still gaps in the characterization of mission-critical traffic and ensuring quality of service for the same, due the new applications and the large host of WiFi networks in business and government, which has led to increased demand for access channels and, therefore, a challenge to the progress already known, such as IEEE 802.1q.Este artículo presenta en forma sintetizada una revisión del estado del arte del estudio de la Calidad de Servicio para tráfico de misión crítica en redes de área local inalámbricas que utilizan el protocolo IEEE 802.11g. Esto con el fin de resaltar investigaciones previas que por su aporte se constituyan en un referente para orientar la propuesta de una nueva forma de abordar el aseguramiento de la calidad de servicio para este tipo de tráfico utilizando el protocolo mencionado. La revisión se basa en artículos académicos y empresariales elaborados durante el presente lustro. Como resultado de dicha revisión se evidencia que han sido muchos los esfuerzos para abordar el tema pero aún existen vacíos en la caracterización del tráfico de misión crítica y la garantía de la calidad del servicio para el mismo, debido a las nuevas aplicaciones informáticas y a la gran acogida de las redes WiFi en el ámbito empresarial y gubernamental; lo que ha generado un aumento en la demanda de los canales de acceso y, por ende, un desafío para los avances ya conocidos en la materia, tal como IEEE 802.1q

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

A QoS guaranteeing MAC layer protocol for the "underdog" traffic

<p>Abstract</p> <p>With the tremendous boom in the wireless local area network arena, there has been a phenomenal spike in the web traffic which has been triggered by the growing popularity of real-time multimedia applications. Towards this end, the IEEE 802.11e medium access control (MAC) standard specifies a set of quality-of-service (QoS) enhancement features to ensure QoS for these delay sensitive multimedia applications. Most of these features are unfair and inefficient from the perspective of low priority (non-real time) traffic flows as they tend to starve the non-real time flows depriving them of appropriate channel access, hence throughput. To that extent, this article proposes a MAC protocol that ensures fairness in the overall network performance by still providing QoS for real-time traffic without starving the "underdog" or non-real-time flows. The article first presents analytical expressions supported by Matlab simulation results which highlight the performance drawbacks of biased protocols such as 802.11e. It then evaluates the efficiency of the proposed "fair MAC protocol" through extensive simulations conducted on the QualNet simulation platform. The simulation results validate the fairness aspect of the proposed scheme.</p

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen