移动自组织网中基于最优距离的概率广播方案

广播是移动Adhoc网络提供路由发现、地址解析等网络功能的一项重要操作．为了减少了泛洪广播算法中的端到端延迟,有效利用有限的带宽资源,解决广播风暴问题,文中提出了一种距离感知的广播技术,即基于最优距离的概率广播方案．本方案通过结合概率算法和距离感知来解决广播风暴问题,以高可达率和低延迟在网络中传播广播数据包．仿真结果显示与主流的泛洪算法和概率广播算法相比,本方案在可到达率、端到端延迟及重播概率等方面的性能有所提高．     

移动Ad-hoc经典路由协议仿真与比较

路由协议选择的方法一般是通过网络仿真器对不同协议进行对比分析,其结果作为协议选取的依据。该文以DSR协议为例,介绍了仿真过程的详细步骤,并对Ad hoc网络经典路由协议DSR和AODV协议进行对比分析。结果表明,在动态的环境下,AODV的分组投递率和路由负载优于DSR路由协议。     

随机移动模型下移动自组网无序传输端到端延迟闭解分析

针对移动自组网端到端延迟在封闭形式分析方面的局限性,该文提出一种有效的针对无序传输,单副本两跳中继算法的网络延迟建模方案,并给出其严格的理论延迟上界。首先针对多种随机移动模型,证明了移动节点的相遇间隔时间可归纳为统一表达式。然后,综合分析了媒介竞争、流量竞争、排队延迟等问题,合理划分并精确求解出了各延迟关键时间段,从而构造了数据包排队服务模型。最后推导出移动自组网端到端延迟的封闭形式理论上界。仿真结果表明,该理论延迟与实验数据紧密吻合。     

An adaptive directional MAC protocol for ad hoc networks using directional antennas

A directional antenna can bring benefits in terms of power consumption,spatial reuse,etc.To exploit the advantage of directional antennas and improve the transmission throughput highest,this paper proposes an adaptive directional MAC protocol(ADMAC).By varying the transmission strategy according to the usage of the channel,nodes can send RTS and CTS packets omni-directionally or directionally.Also,this paper proposes a calculation method of virtual carrier sensing with collision avoidance.By the method,ADMAC protocol makes more pairs of nodes transmit and receive data simultaneously without interferences than other MAC protocols for directional antennas.The paper compares the simultaneous delivering nodes and network throughput of ADMAC with DMAC,DVCS and SDMAC under different experiment parameters.The simulation results show that the throughput of ADMAC is higher than the throughput of DMAC,DVCS and SDMAC protocols.     

适用于MANETs的前摄性门限签名协议

现有的门限签名方案存在大量动态的用户集合,不适用于移动Ad-hoc网络(MANETs)。为此,提出一种适用于MANETs网络的高效门限签名协议。该协议的安全性基于标准RSA假设,且满足通用可组合安全性。高效门限签名协议具有前摄性,能够同时提供“分享密钥”和“更新用户子密钥”的功能。安全性分析结果证明该协议的高效性。     

Virtual community-based video resource sharing solution in MANETs

The virtual community has emerged as a state-of-the-art technology, grouping the user with the common interest and providing a feasible solution for large-scale deployment of resource sharing services. Efficient sharing for video resources and low maintenance cost of overlay topology are key factors in MP2P video on demand systems. In this paper, a novel virtual community-based video resource sharing (VCVRS) solution in MANETs is proposed. VCVRS design a virtual community construction strategy to group the nodes with the common playback behavior and a flexible community maintenance mechanism so as to obtain the fast supplier discovery and low maintenance overhead. Simulation results show how VCVRS achieves higher lookup success rate, lower server stress, lower node load and less overlay maintenance overhead, in comparison with another state of the art solution.     

一种分布式混合预约多址(DHRMA)协议的研究

本文在D-PRMA协议的基础上对其进行改进,提出一种分布式混合预约多址(DHRMA)协议。DHRMA协议采用混合式预约机制,并配合使用时隙表,来减小业务竞争所造成的碰撞的概率,解决隐藏终端和暴露终端问题,从而改善系统的性能并提高系统的吞吐量;同时赋予实时业务较高的优先级以满足其服务质量(QoS)的要求。另外,本文还采用了一种互同步技术,用以解决网络中节点之间的同步问题。     

基于节点能量的主动路由维护算法

在无线自组织网（MANETs）中对于服务质量（QoS）的支持是一项很有挑战的任务，而路由算法是保证QoS的一种重要手段，路由维护又是路由算法的一个重要组成部分。文中在分析了已有路由维护算法的基础上，提出了一种基于AODV的主动路由维护算法，它能够满足延时的严格要求，并且仅需要相对较少的网络资源。     

On-Demand Utility-Based Power Control Routing for Energy-Aware Optimization in Mobile Ad Hoc Networks

In this paper, we propose a novel on-demand energy-aware routing protocol, UBPCR [utility-based power control routing], which reduces the trade-offs that arise in the other energy-aware route selection mechanisms that have recently been proposed for mobile ad hoc networks. Our approach is based on an economic framework that represents the degree of link's satisfaction (utility). With UBPCR, the utility function for any transmitter-receiver pair is defined as a measure of the link's preference regarding the signal-to-interference-and-noise ratio (SINR), the transmit power, and the transmitter's residual battery capacity. During a route-searching process, each intermediate node between the source and the destination is executed via two consecutive phases: the scheduling phase and the transmit power control phase. The scheduling algorithm finds the proper qualified data slot for the receiving channel so that the transmissions of independent transmitters can be coordinated. The transmit power control determines the optimal power, if one exists, that maximizes the corresponding link's utility. Extensive simulations show that the UBPCR protocol can achieve incompatible goals simultaneously and fairly. Chan-Ho Min received the B.S. degree in Industrial Management and the M.S. degree in Industrial Engineering from Korea Advanced Institute of Science and Technology (KAIST) in 2000 and 2002, respectively, where he is currently pursuing the doctoral degree in Industrial Engineering (Telecommunication Engineering Interdisciplinary Program) at KAIST. His research interests include the optimization problems of radio resource management for broadband wireless/cellular/ad hoc/satellite communication networks. In particular, he focuses on mobile ad hoc networking. Sehun Kim received the B.S. degree in Physics from Seoul National University, Seoul, Korea, and the M.S .and Ph.D. degrees in Operations Research from Stanford University. In 1982, he joined the faculty of the Korea Advanced Institute of Science and Technology (KAIST), where he is currently a Professor of Industrial Engineering. His research has been in the areas of combinatorial and nonlinear optimization. Recently, he is working on the application of optimization techniques to the design and analysis of computer and communication systems. He has published a number of papers in Mathematical Programming, Operations Research Letters, Journal of Optimization Theory and Applications, IEEE Trans. on Vehicular Technology, and International Journal of Satellite Communications.