Objetivo: Diseñar y construir un instrumento para medir el estrés laboral de acuerdo con Modelo Demanda- Control-Apoyo (MDCA) Karasek, así como estimar sus propiedades psicométricas. Material métodos: Las etapas efectuadas la construcción Escala Demanda-Control-Apoyo (EDCA) determinar psicométricas fueron las siguientes: a) Revisión sistemática a literatura, b) determinación los factores estruc...

IEEE 802.11 distributed coordination function (DCF) can alleviate the collision and hidden station problem, but it doesn’t differentiate traffic categories (TC). Therefore, it can’t provide sufficient QoS support for different traffic categories. Recently, a new contention-based enhanced distributed channel access (EDCA) scheme was proposed which provides a probabilistic QoS support. In this pa...

With the provisioning of high-speed wireless LAN (WLAN) environments, multimedia services (e.g., VoIP and video-conference) with different QoS requirements will be available in next generation WLANs. Multimedia services could be categorized into multiple traffic classes and different priorities will be applied to access the wireless medium. The IEEE 802.11 working group has been developing a ne...

IEEE 802.11e standard has been published to introduce quality of service (QoS) support to the conventional IEEE 802.11 wireless local area network (WLAN). Enhanced Distributed Channel Access (EDCA) is used as the fundamental access mechanism for the medium access control (MAC) layer in IEEE 802.11e. In this paper, a novel Markov chain based model with a simple architecture for EDCA performance ...

IEEE 802.11e standard has been published to introduce quality of service (QoS) support to the conventional IEEE 802.11 wireless local area network (WLAN). Enhanced Distributed Channel Access (EDCA) is used as the fundamental access mechanism for the medium access control (MAC) layer in IEEE 802.11e. In this paper, a novel Markov chain based model with a simple architecture for EDCA performance ...

The popular IEEE 802.11 WLAN today does not provide any quality-of-service (QoS) because of its contention-based channel access nature of the medium access control (MAC). Therefore, we proposed a simple software upgrade-based solution, called a dual queue scheme, to provide QoS to real-time services such as Voice-over-IP (VoIP) in our previous work [7]. The dual queue scheme operates on top of ...

There have been many performance studies on the original IEEE 802.11 distributed coordinated function using both simulation and analytical methods. However, the recent IEEE 802.11e standard has not yet been investigated extensively. This paper proposes an accurate analytical model for the enhanced distributed channel access (EDCA), which is the core protocol of 802.11e. The model captures the o...

Quality of service (QoS) provisioning is one of the most important criteria in newly emerging UWB-operated WPANs, as they are expected to support a wide variety of applications from time-constrained, multimedia streaming to throughput-hungry, content transfer applications. As such, the Enhanced Distributed Coordinated Access (EDCA) mechanism has been adopted by MultiBand OFDM Alliance in its UW...

With fast deployment of wireless local area networks (WLANs), the ability of WLAN to support real time services with stringent quality of service (QoS) requirements has come into fore. In this paper, we evaluate the capability of QoS support in Enhanced Distributed Channel Access (EDCA) mechanism of the IEEE 802.11e standard, which is the medium access control (MAC) enhancements for QoS support...

The problem of content delivery with a required QoS is currently one of the most important. In ad-hoc networks it is IEEE 802.11 EDCA which tries to face this problem. This paper describes several EDCA line topology configurations with mixed priorities of nodes. Detailed conclusions about the innovative results help to understand the behavior of EDCA in the presence of hidden and exposed nodes....