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The MAC access delay in a saturated IEEE 802.11 DCF wireless LAN is analyzed. We develop a unified analytical model and obtain explicit expressions for the first two moments as well as the generating function. We show via comparison with simulation that our model accurately predicts the mean, standard deviation, and distribution of the access delay for a(More)
This paper provides a scalable framework for analysis and performance evaluation of optical burst-switching (OBS) networks. In particular, a new reduced load fixed point approximation model to evaluate blocking probabilities in OBS networks is introduced. The model is versatile enough to cover known OBS reservation policies such as just-enough-time,(More)
This paper provides new loss models for a hybrid optical switch (HOS) combining optical circuit switching (OCS) and optical burst switching (OBS). Exact blocking probabilities are computed when 1) no priority is given to either circuits or bursts and 2) circuits are given preemptive priority over bursts. Because it is difficult to exactly compute in(More)
This paper provides a framework for analysis and performance evaluation of Optical Burst Switching (OBS) networks. In particular, a new reduced load fixed point approximation model to evaluate blocking probabilities in OBS networks is introduced. The model is versatile enough to cover known OBS reservation policies such as Just-Enough-Time (JET),(More)
Transmission of the acknowledgement frame after a packet reception is optional in the IEEE 802.15.4 standard. Considering a set of sensor nodes, each of which has a packet to transmit at the beginning of an active period, we provide an analysis that yields the packet loss statistics of the nonacknowledgement mode of the standard. The analysis is based on a(More)
We analyze the MAC access delay of the IEEE 802.11e EDCA mechanism under saturation. We develop a detailed analytical model to evaluate the influence of all EDCA differentiation parameters, namely AIFS, CWmin, CWmax and TXOP limit, as well as the backoff multiplier beta. Explicit expressions for the mean, standard deviation and generating function of the(More)
A comprehensive energy model for wireless sensor networks is provided by considering seven key energy consumption sources some of which are ignored by currently available models. We demonstrate the importance of using such a comprehensive model by comparing it to other existing energy models in terms of the lifetime of a sensor node. We use our model to(More)
In this paper, we evaluate and improve the performance of the medium access control (MAC) protocol for safety applications in a dedicated short range communication (DSRC) environment. We first develop an analytical model to study the IEEE 802.11 distributed coordination function (DCF) MAC protocol that has been adopted by the IEEE 802.11p standard for DSRC.(More)
The IEEE 802.16 standard is a promising technology for the fourth-generation mobile networks and is being actively promoted by the Worldwide Interoperability for Microwave Access (WiMAX) Forum: an industry-led consortium. Among the various service classes supported in the standard, best-effort service is expected to be the major service class subscribed to(More)