Teletraffic Analysis for the Design and Performance Evaluation of Seamless Communication Networks

(1)移动通信网络中的呼叫接纳控制我们基于半马尔可夫决策过程理论，针对语音和数据业务的移动通信网络中的语音呼叫提出了一种新的呼叫接纳控制(CAC)方案。我们的最佳策略限制新的语音呼叫，以便长期将总预期成本(阻塞和强制终止概率)降至最低。(2)IEEE 1394串行总线接口的性能分析IEEE 1394接口允许实时应用的同步传输模式和延迟不敏感的应用的异步传输模式。提出并分析了一个排队模型来评估等时业务对异步分组等待时间的影响。(3)光网络中波长转换器的优化配置在光网络中，需要波长转换器来提高波分复用的效率。我们开发了一种遗传算法来确定装有变流器的节点的最优位置。我们的算法已经应用于由NTT在茨城和关东地区的办事处位置构成的现实网络。(4)排队模型分析利用应用随机过程的理论，我们研究了几个排队模型。

(1) Call Admission Control in Mobile Communication NetworksWe have proposed a new call admission control (CAC) scheme for voice calls in mobile communication networks with voice and data traffic, on the basis of the theory for semi-Markov decision processes. Our optimal policy restricts new voice calls in order to minimize the total expected costs (blocking and forced termination probabilities) over a long term.(2) Performance Analysis of the IEEE 1394 Serial Bus InterfaceThe IEEE 1394 interface allows both isochronous transfer mode for real-time applications and asynchronous transfer mode for delay-insensitive applications. We have proposed and analyzed a queueing model to evaluate the waiting time of asynchronous packets affected by the isochronous traffic.(3) Optimal Wavelength Converter Placement in Optical NetworksIn optical networks, wavelength converters are required to improve the efficiency of wavelength division multiplexing. We have developed a genetic algorithm to determine the optimal locations of the nodes equipped with converters. Our algorithm has been applied to realistic networks constructed from the locations of NTT offices in Ibaraki and Kanto areas.(4) Analysis of Queueing ModelsUsing the theory of applied stochastic processes, we have studied several queueing models.