Study on Performance Analysis of Multimedia Traffic and Access Methods in Mobile Communication Systems

在本研究中：(1)我们首先评估了蓝牙的性能。接下来，我们评估了短距离运行的WLAN和蓝牙系统的特性。这意味着基本服务区域彼此重叠。当同时运行WLAN和蓝牙系统时，观察到显著的性能下降。(2)提出了一种新的现实的用于分布式控制的多层细胞结构，其中可以有一个或多个细胞层类型。根据细胞结构中的细胞半径固定选择每个细胞层类型的细胞大小。我们也提出了一个有效的分析，以评估这种移动蜂窝无线系统的性能，用ARP方法。(3)提出了一种基于7个单元重复的递归搜索算法。该方法在满足最小相邻干扰的条件下，比其他方法在最短时间内找到最优或半最优信道分配。我们还证明了该方法的有效性。然后，我们将该技术应用于几个不同的信道分配环境。我们也提出了在这种方法中遇到的困难和进一步的改进。(4)提出了一种基于非持久载波感知多址免碰撞（CSMA/CA）协议的语音和数据集成无线局域网的分析方法，以精确推导出输出过程中数据包间隔时间的矩生成函数。数值算例包括通过微分矩生成函数，比较单交通系统模型和多交通系统模型中数据包间隔时间的变异系数。(5)研究了半马尔可夫环境下系统的最优替换问题。讨论了马尔可夫环境的一种特殊情况，将状态空间等效化简为有限，从而使问题的实际计算是可行的。最后通过数值算例验证了分析的正确性和有效性。(6)在模型定义良好且最优性方程成立的弱条件下，研究了具有期望总奖励折现的离散时间马尔可夫决策过程的最优性方程和最优策略的性质。(7)我们考虑了信道分配的两种干扰条件：两个小区距离内的同信道干扰和同一小区和相邻小区内的相邻信道干扰。提出了递归搜索算法和邻域改进结构。然后，我们最小化或不允许这两种类型的干扰，以实现最佳的信道分配。少

In this study :(1) We first evaluated the performance of Bluetooth. Next, we evaluated the characteristics of both WLAN and Bluetooth systems that are operating at short range. This means the basic service areas overlap with each other. Significant performance degradation was observed when operating both WLAN and Bluetooth systems simultaneously.(2) We presented a new realistic multi-layer cell architecture for distributed control, in which there could be one or more cell layer types. The cell size for each cell layer type was fixedly selected according to cell radius in the cellular structure. We also presented an efficient analysis to evaluate the performance of such mobile cellular wireless systems by using ARP method.(3) We suggested a new method using recursive search algorithm based on a 7 cells repetition. In this assignment method, it takes shorter time to find an optimal or a semi-optimal channel assignment than in other methods, which satisfies minimum adjacent interference. … More We also showed that the method is valid. We then applied the technique to several different channel assignment environments. We also presented the difficulties encountered in this method and further improvements.(4) We presented an analysis method for an integrated voice and data wireless LAN with non-persistent carrier sense multiple access with collision avoidance (CSMA/CA) protocol to exactly derive the moment generating function of the packet interdeparture time for the output process. Numerical examples included comparisons between the single and multiple traffic system models in term as the coefficient of variation of packet interdeparture time by differentiating the moment generating functions.(5) We investigated an optimal replacement problem of a system in a semi-Markov environment. A special case of Markov environment was discussed, and the state space could be simplified equivalently to be finite, so the real computation of the problem is feasible. Finally, a numerical example was given to prove the correctness and validity of the analysis.(6) We investigated the properties of the optimality equation and optimal policies in discrete time Markov decision processes with expected discounted total rewards under the weak conditions that the model is well defined and the optimality equation is true.(7) We considered two types of interference conditions for channel assignment : a co-channel interference within distance of two cells and a adjacent channel interference within the same and the adjacent cells. We presented our recursive search algorithm together with the neighborhood improvement structure. Then we minimized or disallowed these two types of interference in order to achieve optimal channel assignment. Less