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1.
The message delay in mobile ad hoc networks   总被引:1,自引:0,他引:1  
Robin  Philippe  Ger 《Performance Evaluation》2005,62(1-4):210-228
A stochastic model is introduced that accurately models the message delay in mobile ad hoc networks where nodes relay messages and the networks are sparsely populated. The model has only two input parameters: the number of nodes and the parameter of an exponential distribution which describes the time until two random mobiles come within communication range of one another. Closed-form expressions are obtained for the Laplace–Stieltjes transform of the message delay, defined as the time needed to transfer a message between a source and a destination. From this we derive both a closed-form expression and an asymptotic approximation (as a function of the number of nodes) of the expected message delay. As an additional result, the probability distribution function is obtained for the number of copies of the message at the time the message is delivered. These calculations are carried out for two protocols: the two-hop multicopy and the unrestricted multicopy protocols. It is shown that despite its simplicity, the model accurately predicts the message delay for both relay strategies for a number of mobility models (the random waypoint, random direction and the random walker mobility models).  相似文献   
2.
Ad Hoc网络的离散时间马氏链建模及分析   总被引:1,自引:0,他引:1  
Ad Hoc网络是一种非常有前途的自组无线网,该文通过对Ad Hoc网络作出一些合理假设,建立了Ad Hoc网络的离散时间马氏链模型,给出了模型的平稳分布,并进一步分析了节点相邻的概率、节点的平均邻居数、平均泛洪距离等网络重要参数。最后,给出了转移概率矩阵的一个具体定义方法,并得到了相应结果。  相似文献   
3.
王杉  魏急波  庄钊文 《电讯技术》2006,46(5):105-108
全球移动信息系统仿真平台(CloMoSim)在移动自组织网络仿真中得到了广泛的应用,尤其是对网络路由以及MAC协议的建模支持。在对自组网路由方式特点及协议设计思路进行分析的基础上.结合典型的自组网路由算法策略,重点介绍了GloMoSim仿真环境的特点及其目前所支持的路由层协议。通过多次仿真验证,分析比较了这些路由协议的相关性能并得出结论。  相似文献   
4.
王杉  魏急波 《电讯技术》2006,46(6):94-97
能量消耗是移动自组网(MANET)路由协议研究中的一介热点所在。区域路由协议作为混合式寻路机制,为移动自组网提供了一种灵活的路由选择方式。在其路由发现的过程中,存在着多径问题,合理地利用这些路径进行路由转发,可以降低节点间功耗的偏差,使得整介网络能量消耗比较均匀。仿真表明,区域内路由部分中,该算法可较大地延长网络生存周期,而区域间路由部分所受影响则较小。  相似文献   
5.
A multipath source self repair routing (MSSRR) algorithm for mobile ad hoc networks is proposed.By using multiple paths which can be repaired by themselves to transmit packets alternately, the network‘s load is balanced, the link state in the network can be checked in time, the number of the times the route discovery mechanism starts is decreased. If only one route which will be broken can be used to transmit the packets, the route discovery mechanism is restarted. The algorithm is implemented on the basis of dynamic source routing (DSR). The effect of MSSRR on lifetime of the access from the source to the destination and the overhead is discussed. Compared with the performance of DSR, it can be seen that the algorithm can improve the performance of the network obviously and the overhead almost does not increase if the average hop count is larger.  相似文献   
6.
An ants-based on-demand routing algorithm (AORA) specialized for mobile ad hoc networks is proposed. AORA measures the network's traffic information including delivery time, route energy etc. by the continuous delivery of data packets, then calculates the compositive parameter for each route which can be seen as the stigmity and uses it to choose the comparatively optimal route in real time. To adjust the weight of each traffic information, the algorithm can meet the different demand of the network's user. Multipath source self repair routing (MSSRR) algorithm and dynamic source routing (DSR) can be seen as the special samples of AORA. The routing overhead is not increased in this algorithm. By using simulation, it can be seen that the performance of AORA is better than that of DSR in all scenarios obviously, especially the delivery fraction is increased by more than 100 96.  相似文献   
7.
王申  陈曦  于宏毅 《电讯技术》2005,45(2):67-71
本文以基于3G技术的移动自组织网(MANET)的研究为背景,用现在较为流行的高速USB接口与DSP的主机接口HPI相连接,成功地解决了MANET移动终端与主机之间的数据交换问题。本文在介绍了TI公司DSP芯片TMS320C6416和CYPRESS公司的USB接口控制芯片CY7C68013特点以后,介绍了两者连接的一种硬件设计以及USB芯片的固件的编写和调试。  相似文献   
8.
胡赟鹏  刘波 《电讯技术》2005,45(6):77-79
针对一种基于UTRA TDD LCR时隙结构的ad-hoc网络的通信特点,给出了一种可在DSP上实现的基于FFT的M idamble码搜索算法,并给出了基于该算法的多径搜索实现方案。分析表明,该算法充分利用了DSP的特点,且其运算效率相比于传统的匹配滤波有大大的提高。  相似文献   
9.
李海涛  林孝康 《电讯技术》2004,44(5):144-147
近年来,有关移动Ad Hoc网络的关键技术研究已经取得了很大的进展,如何有效地提高其网络性能仍然是目前研究的热点问题。本文结合这种网络拓扑动态变化、路由易发生改变的特点,分析了传统TCP协议在应用上遇到的挑战,并从两个途径研究了针对TCP技术的各种改进方案,同时提出了今后可能的研究方向。  相似文献   
10.
DSR—Based Selective Repeat ARQ Protocol in MANET   总被引:1,自引:0,他引:1  
The efficient route algorithms involved in mobile ad hoc network(MANET)are studied.An arrange-ment of a combination of the traditional dynamic source routing(DSR)protocol is put forward and the selective re-peat ARQ protocol is put forward by analyzing and studying them in detail and providing the scheme.In net-works,especially in wireless networks,the nodes are capable to process data much faster that transmission,the DSR-based selective repeat ARQ protocol has real meanings in MANET.  相似文献   
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