移动Ad Hoc网络AODV路由协议的研究与优化

无线移动自组网是仅由移动节点所组成的网络,具有分布式控制、自组织、多跳等特点,由于该网络具有抗毁性能高、易铺设等性质,越来越受到业界的广泛关注。原始的路由协议已经满足不了现有网络不可预测、频繁变化的拓扑结构的需要,因此,在之前研究的基础上,对现有Ad Hoc网络AODV路由协议进行了研究,并设计出一种基于AODV协议的改进路由协议——基于认知的AODV协议(Cognitive-based AODV,CAODV)。通过NS2进行试验仿真,结果表明,CAODV协议具有比AODV协议更加优良的性质,可以有效降低重启路由发现频率,增加断裂链路的修复成功率,降低协议的控制负载,对现有网络的动态变化具有很强的适应能力。     

Distributed Generation of Shared RSA Keys in Mobile Ad Hoc Networks

Mobile Ad hoc NETworks(MANET) is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner,without needing any fixed physical infrastructure and centralized organizational/administrative infrastructure.However,the nature of ad hoc networks makes them very vulnerable to security threats.Generation and distribution of shared keys for CA(Certification Authority)is challenging in security solution based on distributed PKI/CA.Those solutions that have been proposed in the literature and some issues are discussed.This paper propose the solution of distributed generation of shared CA keys based on threshold RSA cryptosystems,with which the security and robustness of system is enhanced.     

Intrusion Detection Technology in Ad Hoc Network

With the rapid development of wireless network and mobile computing,the security of network becomes more important.As one of wireless mobile network,mobile Ad hoc network has new vulnerabilities that do not exist in a fixed wired network,and is susceptible to attacks.This paper introduces some methods which used in intrusion detection system and provides a new model of system based on multi-layer integrated distributed technology,especially recommend the protocol analyzing method in this system.     

Analysis and verification of TCP goodput of poisson distribution station over WLANs

By analyzing the throughput model of IEEE 802.11 MAC DCF put forward by Bianchi G, the retransmitting limit is extended and the state of direct transmission with no backing off is added in its discrete Markov chains to refine and perfect the classic model. The following assumption is proposed: the number of wireless stations accessing to AP in BSS met poisson distribution within a certain period of time. Under this assumption, both of the corresponding model and the quantified expression of calculating its goodput are provided. The rationality and effectiveness of the proposed model are verified with emulation of unidirectional TCP flow from AP to wireless stations.     

Using Agent Server to Enhance the Performance of Remote Data Service Based on HFC Network

The bi-directional Hybrid Fiber/Coaxial (HFC), which has almost 1GHz frequency bandwidth to transmit information, is the best access mode except Fiber to the Home (FTTH). Initial experiences indicate that real-world HFC networks are susceptible to a variety of radio-frequency impairments that significantly reduce the benefits of using high-speed cable modems. In this paper, the performance of data services in the TCP sub-layer of a HFC network is discussed and an agent server is used to enhance the performance of remote data transmission.[WT5HZ]