دانلود رایگان مقاله انگلیسی ارزیابی قابلیت اطمینان عملکرد برای شبکه های ادهاک تلفن همراه - الزویر 2018

Abstract

The reliability of the mobile ad hoc network (MANET) is receiving increasing attention. Previous works are mainly focused on the connectivity reliability of the MANET; however, its performance reliability has not been considered. In the MANET, the paths connecting two nodes are prone to continuous changes due to the mobility of nodes, which can result in a huge uncertainty on the transmission performance. Thus it is necessary to research the evaluation method of the performance reliability of the MANET. In this study, the transmission reliability is defined to measure the reliability of the transmission performance of the MANET. The impact of interference on the transmission reliability is considered. The topology optimization of the MANET is studied based on the transmission reliability, and genetic algorithm is adopted to solve the optimization problem. In the numerical example, the effects of the involved parameters on the transmission reliability are discussed, and some applicable conditions of the optimal design are analyzed for practical applications.

Conclusions

This study considers the performance reliability of the MANET. The transmission reliability is defined to measure the reliability of the transmission performance of the MANET. The evaluation method is provided based on the assumptions of the random direction mobility model with constant velocity, a single-path and on-demand routing protocol, the CSMA/CA protocol and the singular path loss model. Taking the number of nodes and the communication range as the decision variables, the topology optimization problem of the MANET is solved by GA. It is revealed that the transmission reliability is a monotonically decreasing function of the number of nodes. There exists a critical maximum hop count. If the used maximum hop count is less than the critical maximum hop count, the transmission reliability is a non-monotonic function of the communication range. However, if the used maximum hop count is no less than the critical maximum hop count, the transmission reliability is a monotonically increasing function of the communication range. Using over many hops is not suggested in practice, because the growth of the maximum hop count can decrease the maximum achievable transmission reliability. Moreover, different deployments of the MANET have been discussed in detail under different considerations for practical applications. From the macroscopic point of view, the transmission reliability is used as a performance reliability index for the overall transmission performance of the MANET, and does not describe the effect of the locations of nodes at a specific time point. Thus, on the micro level, time dependent reliability indices and location dependent reliability indices can be investigated in the future research.