IEEE 802.11 distributed coordination function （DCF） is a distributed medium access scheme based on carrier sense multiple access with collision avoidance （CSMA/CA） protocol. Many literatures have analyzed the perf...IEEE 802.11 distributed coordination function （DCF） is a distributed medium access scheme based on carrier sense multiple access with collision avoidance （CSMA/CA） protocol. Many literatures have analyzed the performance of IEEE802.11 DCF. However, such literatures either used simulation methods or built the analytical models under the assumption that the saturation condition was satisfied. To overcome such a problem, in this paper, a hi-dimensional Markovian model has been introduced to depict the DCF mechanism. The proposed model introduced an idle stage and a discrete time M/G/1 queue to deduce the channel throughput under finite load traffic. Simulation results proved the accuracy of the proposed model.展开更多
网格计算技术正在成为计算机领域的新热点。在网格服务的研究开发中,Globus Toolkit是首选的网格中间件。Globus Toolkit和Linux均为开放源代码软件,加上Linux系统良好的稳定性和兼容性,因此两者的结合是很自然的。详细讨论了利用Globus...网格计算技术正在成为计算机领域的新热点。在网格服务的研究开发中,Globus Toolkit是首选的网格中间件。Globus Toolkit和Linux均为开放源代码软件,加上Linux系统良好的稳定性和兼容性,因此两者的结合是很自然的。详细讨论了利用Globus Toolkit 3.2(GT3.2.1)和Red Hat Linux 9.0在局域网内搭建网格计算平台的安装配置过程,展示了利用Globus Toolkit3.2在Red Hat Linux 9.0下开发网格服务的方法。展开更多
This paper presents an analytical saturation throughput model of IEEE 802.11 DCF (distributed coordination function) with basic access in ad hoc mode. The model takes into account freezing of the backoff timer when a ...This paper presents an analytical saturation throughput model of IEEE 802.11 DCF (distributed coordination function) with basic access in ad hoc mode. The model takes into account freezing of the backoff timer when a station senses busy channel. It is shown that taking into account this feature of DCF is important in modeling saturation throughput by yielding more accurate and realistic results than models known from literature. The proposed analytical model also takes into account the effect of transmission errors. All essential features of the proposed analytical approach are illustrated with numerical results. The presen-tation of the model is proceeded by an overview of approaches to IEEE 802.11 network performance evaluation presented in the literature.展开更多
文摘IEEE 802.11 distributed coordination function （DCF） is a distributed medium access scheme based on carrier sense multiple access with collision avoidance （CSMA/CA） protocol. Many literatures have analyzed the performance of IEEE802.11 DCF. However, such literatures either used simulation methods or built the analytical models under the assumption that the saturation condition was satisfied. To overcome such a problem, in this paper, a hi-dimensional Markovian model has been introduced to depict the DCF mechanism. The proposed model introduced an idle stage and a discrete time M/G/1 queue to deduce the channel throughput under finite load traffic. Simulation results proved the accuracy of the proposed model.
文摘网格计算技术正在成为计算机领域的新热点。在网格服务的研究开发中,Globus Toolkit是首选的网格中间件。Globus Toolkit和Linux均为开放源代码软件,加上Linux系统良好的稳定性和兼容性,因此两者的结合是很自然的。详细讨论了利用Globus Toolkit 3.2(GT3.2.1)和Red Hat Linux 9.0在局域网内搭建网格计算平台的安装配置过程,展示了利用Globus Toolkit3.2在Red Hat Linux 9.0下开发网格服务的方法。
文摘This paper presents an analytical saturation throughput model of IEEE 802.11 DCF (distributed coordination function) with basic access in ad hoc mode. The model takes into account freezing of the backoff timer when a station senses busy channel. It is shown that taking into account this feature of DCF is important in modeling saturation throughput by yielding more accurate and realistic results than models known from literature. The proposed analytical model also takes into account the effect of transmission errors. All essential features of the proposed analytical approach are illustrated with numerical results. The presen-tation of the model is proceeded by an overview of approaches to IEEE 802.11 network performance evaluation presented in the literature.
