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1.
Mobile ad hoc networks (MANET’s) popularly uses ad hoc on-demand distance vector (AODV) routing protocol. Past research has identified certain limitations on performance on AODV. This work discusses the results of a new protocol, improved directional AODV (ID-AODV) routing protocol; that has succeeded in improving the performance of MANET’s for energy, delay, packet delivery ratio and overheads as compared with networks using AODV. In ID-AODV, improvements are carried out in both network layer, and data link layer. The directionality is introduced based on hop count of its position from the source. The dual sensing directional media access control protocol is used to eliminate the hidden terminal, exposed terminal, and deafness issue. Participation of nodes in forming route is decided by checking remaining energy level of the node and also checking its load. A modified algorithm is used to reduce the delay. This algorithm reduces the delay by changing the time to live, wait time, and using expanded ring search technique. The simulation results show that the ID-AODV offers improved performance on average Energy consumption in the range of 17–20%, average end to end delay is lower by 61 to 95%, Overheads improved in the range of 10–13%, Jitter 6–21%, link break 43–52%, packet delivery ratio is 6–21% lower as compared to MANETS deploying AODV.  相似文献   

2.
International Journal of Wireless Information Networks - Nodes in Mobile Ad hoc Networks (MANETs) communicate wirelessly without any dedicated infrastructure and administrative control. In MANETs,...  相似文献   

3.
本文提出了一种新的快速收敛的基于距离矢量(DV)的路由协议.该协议是在MIL-STD-188-220C路由协议的基础上,结合DSDV的优点,并提出了局部拓扑变化感知、全局拓扑变化感知等思想,加快了拓扑变化的收敛过程,提高了应用层分组传榆率.通过仿真分析对比表明,改进后的整体性能优于DSDV,使之更适合应用于快速移动的无线自组织网络中.  相似文献   

4.
Ad hoc是近年来热门的无线分组网络。路由协议是Ad hoc网络的关键技术,决定了Ad hoc网络的寻址效率并为数据传输提供可靠的Qo S保证。在小型化网络、低带宽条件下,使用改进的基于链路状态路由协议可以有效的提高寻址效率和网络可靠性。  相似文献   

5.
The goal of our work is to establish chosen scenario metric parameters for ad hoc on demand distance vector (AODV) routing protocol by both simulation and statistical analysis. In first part of our work, we have carried out simulation of AODV on NS2 under different topological conditions. AODV’s performance for end to end delay, energy consumption and packet delivery rate as a function of area, packet rate and packet size is recorded. Based on evaluation of statistical data & graphs, range of scenario metric parameters at which AODV performs best is chosen. Also, Random topology with mobility is considered as chosen topology for AODV after evaluating performance. Performance of MANET is highly influenced by parametric settings for speed, area, packet rate, packet size. Based on our analysis of goodness of fit, residual and prediction bounds we conclude that the regression analysis equation for performance parameters is acceptable predictive empirical model for the range of values obtained from the experimental data. The simulation results show that our empirical model is capable of producing good estimates as statistical parameters values are well within limits. Therefore, we may infer that for the experimental set up under consideration, the chosen scenario metric parameters are packet rate of 35 packets per second, area 500 m2, packet size 512 bytes. With the range chosen for scenario metric, the performance metric parameters range obtained was, Energy Consumption 0.1–3.2 J, end to end delay 3.2–4.8 ms, PDR 90–100 which demonstrated the capability of predictable and repeatable performance.  相似文献   

6.
Wireless Personal Communications - Cognitive performance is associated with learning ability and academic success of a student. Since an individual student may lose attention during class, a study...  相似文献   

7.
Ad Hoc networks are prone to link failures due to mobility. In this letter, a link perdurability based routing scheme is proposed to try dealing with this problem. This scheme uses signal strength measurements to estimate the route life time and hence chooses a stable route, and is implemented in two typical ad hoc routing protocols to evaluate its performance.The simulation results have shown that this scheme can improve these protocols‘ packet delivery ratio in cases where there are frequent link failures.  相似文献   

8.
Ad Hoc网络中,组播路由协议具有广泛的应用前景.但由于网络拓扑的变化,设计具有可靠数据传输能力的组播路由协议比较困难.综合考虑Ad Hoc网络中节点的移动性和节点能量对路由稳定性的影响,选取具有较高性能的链路,使得路由具有较好的稳定性.仿真结果证明,与MAODV协议相比,设计的路由协议明显提高了数据投递率,并大大降低了丢包数.  相似文献   

9.
一种新型的 Ad Hoc 网络按需加权分簇算法   总被引:4,自引:0,他引:4  
王钢  单琦  徐妍  赵洪林 《无线电工程》2005,35(12):23-26
提出了一种新型的适用于 Ad Hoc 网络的按需加权分簇算法,根据节点的权值来进行簇 的划分,在计算权值时,综合考虑节点度,节点的能量和移动性等多方面因素。为了提高网络体系结构 的稳定性,减少计算和通信开销,采用按需策略来完成簇结构的维护。首先介绍了2种典型的分簇算 法,然后详细说明了新型的按需加权分簇算法并利用仿真实验对3种分簇算法进行了比较。仿真结果 表明,按需加权分簇算法的性能优于另外2种分簇算法。  相似文献   

10.
Wireless Personal Communications - The Mobile Ad Hoc Network (MANET) dominates the wireless network environment and the output of MANET is significantly affected by the...  相似文献   

11.
Nodes in a mobile ad hoc network are battery constrained devices and energy efficiency becomes an important consideration. In a multi-hop mobile ad hoc network the most common method to achieve energy efficiency is the transmission power control scheme in which a node transmits the data packets to its nearest neighbor which is at minimum required power level. However this scheme minimizes only the transmission power within the node’s neighborhood and energy efficiency at the link level is possible. With this scheme it is not possible to minimize the overall energy consumption of the network and the communication overhead of the network is not minimized. An analysis has been performed and our results have proved that instead of using low transmission power, the routing strategy needs to be controlled and only certain nodes are to be allowed to receive and process this routing request based on the received signal strength, then the overall energy consumption of the network can be minimized and the communication overhead is also minimized. The modified routing strategy is applied to the basic ad hoc on-demand distance vector (AODV) routing protocol and a maximum transmission range based ad hoc on-demand distance vector routing protocol named AODV range routing (AODV_RR) is proposed and studied under different network sizes. Measurable difference in performance is realized and the proposed AODV_RR perform better than normal AODV with respect to all the selected metrics.  相似文献   

12.
In this paper, we study medium access control (MAC) protocols with quality-of-service (QoS) support, that is, topology-independent link activation transmission scheduling, for mobile code-division multiple-access (CDMA) ad hoc networks. QoS provisioning for each communication link is guaranteed without the need to adopt transmission schedules in mobile environments. An interference model, which captures the difference between transmission and interference ranges, is considered. Under this interference model, an approach to guaranteeing conflict-free transmission slots in each frame (QoS provisioning) for each communication link is proposed. Compared with the previously known method, superior performance is obtained. We then present a topology-independent link activation scheduling framework based on the theory of group-divisible (GD) designs. By the mathematical properties of GD designs, the proposed framework guarantees conflict-free transmission slots in each frame for each communication link, without the overhead due to the recomputation of transmission schedules when the network topology changes. With the proposed framework, we study and evaluate one series of GD design constructions. Based on the results derived, topology-independent link activation scheduling algorithms are then presented. The proposed schemes are designed for different objectives: maximizing the minimum system throughput and/or minimizing the schedule frame length. Numerical results show that the proposed algorithms outperform previously known schemes. The average performance of the proposed schemes is also derived.  相似文献   

13.
We have designed an authenticated link-level ad hoc routing protocol and integrated it with the Portland State University implementation of Mobile-IP. The routing protocol addresses link security issues. In our protocol, mobile nodes, as well as agents, broadcast ICMP router discovery packets. The router discovery packets are authenticated and bind the sender's MAC and IP addresses. Problems caused by tying IP subnet schemes to routing on radio links are eliminated. Security problems associated with ARP spoofing are also reduced. This link-level protocol is integrated with Mobile-IP on links where increased security is needed. The protocol replaces ARP, and may be integrated with higher-level multi-hop ad hoc routing protocols.  相似文献   

14.
Ad Hoc网中链路连通性的概率评估   总被引:1,自引:0,他引:1  
Ad Hoc网将在未来的商用和军用通信方面起着非常重要的作用.网内节点的随机移动将会导致网络拓扑的动态变化.任一对节点之间链路连通性的分析对提前预测网络拓扑变化起着关键作用.文中基于不同的初始条件通过数学推导的方法来分析任一对节点之间随时间变化的链路连通性空间平均概率.  相似文献   

15.
Ad Hoc网络中基于距离的机会频谱接入方案   总被引:1,自引:0,他引:1       下载免费PDF全文
孙君  朱洪波 《电子学报》2011,39(7):1679-1682
本论文研究ad hoc网络中的机会频谱接入(OSA)技术,建立一种既能够抑制次用户对主用户的干扰,又能够在非合作次用户间进行公平、无冲突的资源共享的接入机制.解决了在自组织的多用户ad hoc网络中,主次用户以及次用户之间共享频谱资源,次用户选择最佳频谱接入,并确保抑制对主用户的干扰以及自身性能优化的问题.为此,建立次...  相似文献   

16.
黄晓斌  华蓓 《电子技术》2011,38(8):64-66,63
文章针对节点数量多、密度大的一类移动自组网提出了一种跨层联合设计的MAC/路由协议.在MAC层上采用基于调度的信道分配算法以减少通信冲突,在网络层上结合使用表驱动路由和基于地理位置的路由来提高协议适应动态拓扑的能力,并设计了适合TDMA MAC协议的高效的消息交互机制.在OPNET仿真平台上与AODV/802.11和G...  相似文献   

17.
Ad Hoc网络中基于双向收敛蚁群算法的QoS路由算法   总被引:1,自引:0,他引:1  
蚂蚁算法是一种新型随机优化算法,能有效解决Ad Hoc网络多约束的QoS路由问题,但存在收敛速度慢和易陷入局部最优等缺点.针对于此,在借鉴精英策略的基础上提出了一种基于双向收敛蚁群算法,并将该算法应用于Ad Hoc网络的QoS路由问题中.仿真结果表明,算法可明显提高数据包的投递率,降低端到端的传输时延.  相似文献   

18.
为了延长Ad Hoc网络的生存周期,提出了一种基于蚁群优化和能量有效的Ad Hoc网络多路径动态路由算法ACOERA。该算法根据路径的有效能量率进行路由选择,路径建立后通过蚁群优化算法动态收集路径信息,并对路由表进行更新。仿真结果表明,该算法能有效延长网络生存时间,增强通信网络的自适应能力。  相似文献   

19.

Higher layer applications, such as routing protocols and robot navigation systems, commonly depend upon link quality (LQ) estimates for improving the efficiency and reliability of wireless communications. LQ estimation is especially critical for maintaining connectivity in mobile ad hoc networks, which tend to be less reliable than infrastructure networks due to their decentralized and dynamic nature. However, estimating LQ for applications higher than the physical layer is challenging due to the underlying dynamics of wireless propagation and the mismatched temporal perspectives between the layers. Due to its relevance and difficulty, a significant research effort has been devoted to developing empirical methods for accurately estimating LQ. The goal of this survey is to provide a comprehensive review of the existing approaches to LQ estimation in IEEE 802.11-based ad hoc and mesh networks, with some exceptions that include sensor networks. The survey organizes the literature according to the different fundamental techniques, and also compares them in terms in terms of strengths and weaknesses. Finally, we conclude with the latest developments in LQ estimation, which involve machine learning, and provide recommendations for future work in the field.

  相似文献   

20.
任智  朱其政  付泽亮  周舟  周杨 《电讯技术》2023,63(10):1546-1552
优化链路状态路由(Optimized Link State Routing,OLSR)协议是一种先验式路由协议,网络中的所有节点通过周期性地发送控制消息来计算全网路由信息。在短波自组织网络中,节点周期性地发送控制消息会占据大量的信道资源,大幅增加网络的控制开销,浪费短波有限的带宽资源,导致网络通信性能急剧下降。其次,受到地形地貌、天线方向和接收性能的个体差异等影响,造成无线链路不稳定,导致网络中存在非对称链路,增加了通信端到端时延。为此,提出了一种低时延的短波自组网OLSR协议。该协议在执行MPR(Multipoint Relay)选择算法时综合考虑了节点的连接度和链路可靠性,在优化MPR节点个数的同时选择链路可靠性较大的节点作为MPR节点,在进行路由选择时能够利用网络中的非对称链路。仿真结果表明,该协议能优化数据包投递成功率、吞吐量、端到端时延和网络控制开销等性能指标。  相似文献   

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