共查询到16条相似文献，搜索用时 218 毫秒
1.
In this paper, the security technology of ad hoc networks is studied.To improve the previous multi-receiver signcryption schemes, an ID-based multi-message and multi-receiver signcryption scheme for rekeying in ad hoc networks is proposed.In this scheme, a sender can simultaneously signcrypt n messeges for n receivers, and a receiver can unsigncrypt the ciphertext to get his message with his own private key.An analysis of this scheme indicates that it achieves authenticity and confidentiality in the random oracle model while being of lower computation and communication overhead.Finally, for the application of our scheme in ad hoc, a threshold key updating protocol for ad hoc networks is given. 相似文献
2.
An adaptive load balancing scheme is proposed to balance the load in ad hoc networks. The new scheme can be applied in most on-demand routing protocols resulting in significant performance improvement. The proposed scheme is applied to the ad hoc on-demand distance vector (AODV) routing protocol. Simulation results show that the network load is balanced on the whole, and performance in packet loss rate, routing overhead and average end-to-end delay is also improved. 相似文献
3.
ZUO Dong-hong DU Xu YANG Zong-kai 《浙江大学学报(A卷英文版)》2007,8(8):1191-1198
Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks. 相似文献
4.
This paper proposes a novel multichannel medium access control(MAC)protocol based on CDMA that improves network performance and reduces collision probability in wireless ad hoc networks.In the scheme,the code channel is divided into common channel,broadcast channel and several data channels.Simulation results show that the proposed protocol can achieve significantly better performance than the IEEE 802.11 standard. 相似文献
5.
The flooding distance is an important parameter in the design and evaluation of a routing protocol,which is related not only to the delay time in the route discovery,but also to the stability and reliability of the route.In this paper, the average flooding distance (AFD) for a mobile ad hoc network (MANET) in a random graph model was given based on the dynamic source routing (DSR) protocol.The influence of spatial reuse on the AFD was also studied.Compared with that in the model without the spatial reuse,the AFD in the model with the spatial reuse has much smaller value,when the connetivity probability between nodes in the network is small and when the number of reused times is large.This means that the route discovery with the spatial reuse is much more effective. 相似文献
6.
Optimal congestion control algorithm for ad hoc networks： Penalty function-based approach 总被引：2，自引：0，他引：2
XU Wei-qiang WU Tie-jun 《浙江大学学报(A卷英文版)》2006,7(12):2110-2117
INTRODUCTION Congestion control is a critical issue for ensuring the efficient and fair allocation of network resource among communication flows. In wireline networks, TCP has resolved this issue of concern. However, it was reported that TCP performance in a multihop ad hoc environment degrades severely (Xu and Wu, 2006). Thus, some optimization-based congestion control schemes have been proposed to improve TCP performance in ad hoc networks (Chiang, 2005; Chen et al., 2005; Lee et a… 相似文献
7.
Throughput of mobile ad hoc network （MANET） is limited by collision avoidance. In CDMA-based MANET, this limitation can be overcome by multiuser detection （MUD） because conventional colliding packets can be detached and detected by MUD so that multi-packet reception （MPR） is possible. This paper introduces the principles of MUD algorithm for MANET, and proposes an adaptive blind MUD algorithm. A special medium access control （MAC） protocol is designed to make MANET more efficient. This is achieved by sending more packets to a destination simultaneously. The proposed MUD algorithm and MAC protocol allow CDMA-based MANET to support MPR. Simulations show a remarkable improvement in the throughput performance of MANET. 相似文献
8.
TANIYAMA Kenta MORII Takeshi KOIZUMI Shinya NOGUCHI Kazuhiro KOTANI Yukihiro KATTO Jiro 《浙江大学学报(A卷英文版)》2006,7(Z1)
We propose an on-demand multiparth routing algorithm in a mobile ad hoc network for video transmission and evaluate its real world performance in video streaming application. There have been a number of multipath routing protocols extended from AODV which is a well-known single path routing protocol. Multipath routing protocols indicate good performance in the reduction of route discovery latency and unnecessary routing packets in simulations. We show that the route establishment using source route lists provided by us (Hu and Johnson, 2002) can reduce the route discovery latency, select stable routes automatically, and work well for live video streaming without limitation of the hop count based approaches. We evaluate this proposed method compared with the original AODV by using eight laptop PCs and demonstrate live streaming experiments. 相似文献
9.
Internet key exchange (IKE) is an automated key exchange mechanism that is used to facilitate the transfer of IPSec security associations (SAs). Public key infrastructure (PKI) is considered as a key element for providing security to new distributed communication networks and services. In this paper, we concentrate on the properties of the protocol of Phase 1 IKE. After investigating IKE protocol and PKI technology, we combine IKE protocol and PKI and present an implementation scheme of the IKE based on PKI. Then, we give a logic analysis of the proposed protocol with the BAN-logic and discuss the security of the protocol. The result indicates that the protocol is correct and satisfies the security requirements of Internet key exchange. 相似文献
10.
The standardized IEEE ,802. II distributed coordination function （ DCF） provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium. However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802. II protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters. 相似文献
11.
一种增强移动自组网Internet连接的改进型方案 总被引：1，自引：0，他引：1
针对移动自组网因单向链路以及盲目转播网关发现分组而造成的与Internet互联性能下降,提出了一种增强型互联方案.同时结合了先应和后应网关发现策略优点的混合网关发现策略被用来获取良好的Internet连接并保持低开销.而通过交换携带有额外增加的对称邻居节点列表和非对称邻居节点列表字段的AODV hello分组,单向链路得以从路由计算中予以清除而广播风暴也同时得到抑制.基于ns-2的仿真结果表明此改进型Internet连接方案在单向链路数量及节点移动速度均变化的应用环境下能取得较其他方案为优的互联性能. 相似文献
12.
针对AdHoc网络的视频传输,提出了一种新的网络带宽预测及控制方案．该方案基于跨层、接收端反馈以及贝叶斯网络等技术．对视频传输过程进行公式化描述,从而推导出影响视频传输质量的几个主要因素,这些因素可以通过跨层机制或接收端反馈的方式获取．根据这些影响因素,确定变量集和贝叶斯网络拓扑结构,从而构建贝叶斯网络预测模型．预测结果作为AdHoc网络带宽,根据该带宽值来控制视频编码器,动态调节输出的实时视频流码率．为验证该方案,对整个视频通信系统进行了仿真．结果显示,跟传统的传输方案相比较,夺方案能更好地利用网络带宽,减少了数据包的丢失,提高了实时视频质量． 相似文献
13.
葛文英 《安阳师范学院学报》2006,(5):45-48
目前,移动Ad Hoc网络越来越受到人们的重视。在Ad Hoc网络中,路由协议的性能优劣是一个很重要的问题。目前的协议大体可分为两类:表驱动类和按需驱动类路由协议。研究表明:表驱动类的路由协议带来了大量的路由开销,对于网络带宽比较紧张的Ad hoc网络环境,按需路由协议是更好的选择。 相似文献
14.
无线ad hoc网络最小均方负载均衡路由算法 总被引：1，自引：0，他引：1
Routing algorithm is a challenge for a mobile ad hoc network (MANET), but current routing protocols for MANETsconsider the path with minimum number of hops as the optimal path to a given destination. This strategy does not balancethe traffic load over a MANET, and may result in some disadvantages such as creating congested area, depleting power fasterand enlarging time delay in the nodes with heavy duties. In this paper, we propose a routing scheme that balances the loadover the network by selecting a path based on its mean load-square, the proposed routing metric can reflect not only the loadof the path, but also the load distribution along the path. Simulation results show effectiveness of this routing scheme onbalancing the load over all nodes in the network. 相似文献
15.
移动自组网多路径路由具有有效使用带宽、均衡负载和增加传输可靠性等方面的优势。路由发现是路由协议的重要组成部分,分析了设计多路径路由协议的路由发现部分的关键问题及不同策略,对近几年国内外提出的多路径路由协议在路由发现部分进行了比较,指出了多路径路由发现中需要进一步研究的问题。 相似文献
16.
余丽华 《广东广播电视大学学报》2011,20(2):104-107,111
针对分布式无线网络多跳、移动的特点,要实现整个网络的快速部署以及拓扑结构变化后的动态重建,最有效的方法是采用分群协议,并在linux环境下,利用基于图论的ANMP分群算法,实现自组网的分群。 相似文献