共查询到20条相似文献,搜索用时 15 毫秒
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无线自组网中的路由协议AODV没有提供流控和拥塞避免机制,当网络负载较重时,多媒体业务或产生较大的延时,或分组被大量丢弃,使网络性能下降.在AODV协议的基础上,提出一种基于带宽接入控制的改进协议BAC-AODV,对节点和路径的可用带宽进行估算,修改路由建立机制,使路径满足业务流对带宽的需求,保证网络的QoS质量.分析和仿真结果表明,改进后的协议相比原有AODV,能更有效地控制业务流量,提高吞吐量,降低延时. 相似文献
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针对无线传感器网络能量受限和路由协议中节点能量消耗不均衡的问题,提出一种新的无线传感器网络的分区异构分簇协议(PHC协议).该协议的核心是将3种不同能量等级的节点根据能量的不同分别部署在不同区域,能量较高的高级节点和中间节点使用聚类技术通过簇头直接传输数据到汇聚点,能量较低的普通节点则直接传输数据到汇聚点.仿真结果表明,该协议通过对节点合理的分配部署,使簇头分布均匀,更好地均衡了节点的能量消耗,延长了网络的稳定期,提高了网络的吞吐量,增强了网络的整体性能. 相似文献
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提出了一种综合考虑链路安全、链路冲突、链路可靠度与链路可用带宽的路由判据SIEB。SIEB包括链路安全和链路性能2个方面,在SIEB的链路安全权值计算中,为了抵御各种洞攻击,提出了基于两跳邻居反馈的链路信任值计算方法。在此基础上,提出了链路安全权值计算算法LSWC和链路性能权值计算算法LSPC,提出了分布式满足QoS约束的路由协议SIEBP,SIEBP的目标是:构造安全的路由路径,并且最大化网络吞吐量。仿真结果表明,SIEBP能达到预定目标,构造的路径能抵御黑洞、灰洞、虫洞等攻击,并且获得了较高的网络吞吐量。 相似文献
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Farshad Javadi Kumudu S. Munasinghe Abbas Jamalipour 《Wireless Communications and Mobile Computing》2012,12(9):782-796
In wireless mesh networks (WMNs), real time communications (e.g., Voice over IP (VoIP) and interactive video communications) may often be interrupted as packets are frequently lost or delayed excessively. This usually happens due to the unreliability of wireless links or buffer overflows along the routing paths. The mesh connectivity within the WMN enables the capability to enhance reliability and reduce delay for such applications by using multiple paths for routing their packets. The vital components in multi‐path routing for achieving this are the pre‐determined formation of paths and the technique that the paths are deployed for packet traversal. Therefore, we propose a novel multi‐path routing protocol by introducing a new multi‐path organization and a traffic assignment technique. The designed technique dubbed as FLASH (Fast and reLiAble meSH routing protocol) discovers one primary path between a pair of source and destination based on a new proposed metric, and thereafter selects mini‐paths, which connect pairs of intermediate nodes along the primary path. The primary path and mini‐paths are concurrently deployed, as multiple copies of packets are routed through. This technique compensates for possible outage at intermediate wireless nodes or their corresponding wireless links along the primary path. Routing along mini‐paths is performed in such a way that redundant copies do not cause an excessive congestion on the network. The effectiveness of the proposed scheme is evaluated analytically and through extensive simulations under various load conditions. The results demonstrate the superiority of the proposed multi‐path organization in terms of reliability and satisfactory achievements of the protocol in enhancing delay and throughput compared to the existing routing protocols, especially for long distances and in congested conditions. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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多接口多信道无线Mesh网中,提出了一种基于信号干扰监测的路由度量机制(ISB)。现有的路由度量机制如WCETT、iAWARE等均存在各自的不足。通过对iAWARE深入分析,发现其并不能正确地反映背景噪声这一重要因素。为此改进了该度量机制,使其更加正确地反映背景噪声,并且具有了等分性,即可以在路由协议中使用如Bellman-Ford或Dijkstra路径计算方法。理论分析和网络仿真表明,新度量机制下的网络性能如网络吞吐量和端到端延迟均优于HopCount、ETT、WCETT和iAWARE。 相似文献
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为了延长无线传感网络的生存时间,需要设计满足高效率、低功耗的路由算法。一种CMRA(intercluster head multi-hop routing algorithm)算法被提出来,这种算法通过节点通信能量消耗模型建立最小能量路径树,但CMRA对于簇头选择的能量分配不均衡,造成簇头结点负载过重。提出一种新的路由算法CMRA-EE(CMRA-energy efficient),在簇头选举阶段引入节点能量参数,同时将簇头节点能量与距离作为代价参数,从而平衡了网络节点能耗。通过仿真对CMRA-EE算法进行性能分析与评价,结果显示,CMRA-EE算法在延长无线传感网有效生存时间方面比CMRA算法有了明显的改善。 相似文献
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Dave Cavalcanti Carlos Cordeiro Anup Kumar Dharma P. Agrawal 《Wireless Communications and Mobile Computing》2007,7(3):375-397
A growing need to have ubiquitous connectivity has motivated our research to provide continuous connection between various wireless platforms such as cellular networks, wireless local area networks (WLANs), and mobile ad hoc networks (MANETs). In this paper, we consider integration at the routing layer and propose two adaptable routing protocols (IRP‐RD and IRP‐PD) that exploit topology information stored at the fixed network components (cellular base stations and WLAN access points) for the route discovery and maintenance processes. Our proposed protocols can provide connectivity to the cellular network and/or WLAN hotspots through multihop routing, while differ in the gateway discovery approach used. In IRP‐RD, multihop routes to gateways to the cellular network or WLAN hot spots are discovered on demand, while in IRP‐PD out of coverage users proactively maintain routes to the gateways. Furthermore, proposed protocols can be used in any heterogeneous scenario, combining a cellular network and WLANs operating in infrastructure or ad hoc (MANET) mode. We provide simulation results that demonstrate the effectiveness of the proposed integrated routing protocols and show the advantages and drawbacks of each gateway discovery approach in different heterogeneous scenarios. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Noureddine Moussa Abdelbaki El Belrhiti El Alaoui 《International Journal of Communication Systems》2019,32(16)
Energy conservation and fault tolerance are two critical issues in the deployment of wireless sensor networks (WSNs). Many cluster‐based fault‐tolerant routing protocols have been proposed for energy conservation and network lifetime maximization in WSNs. However, these protocols suffer from high frequency of re‐clustering as well as extra energy consumption to tolerate failures and consider only some very normal parameters to form clusters without any verification of the energy sufficiency for data routing. Therefore, this paper proposes a cluster‐based fault‐tolerant routing protocol referred as CFTR. This protocol allows higher energy nodes to become Cluster Heads (CHs) and operate multiple rounds to diminish the frequency of re‐clustering. Additionally, for the sake to get better energy efficiency and balancing, we introduce a cost function that considers during cluster formation energy cost from sensor node to CH, energy cost from CH to sink, and another significant parameter, namely, number of cluster members in previous round. Further, the proposed CFTR takes care of nodes, which have no CH in their communication range. Also, it introduces a routing algorithm in which the decision of next hop CH selection is based on a cost function conceived to select routes with sufficient energy for data transfer and distribute uniformly the overall data‐relaying load among the CHs. As well, a low‐overhead algorithm to tolerate the sudden failure of CHs is proposed. We perform extensive simulations on CFTR and compare their results with those of two recent existing protocols to demonstrate its superiority in terms of different metrics. 相似文献
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We investigate the problem of joint downlink wireless backhaul bandwidth (WBB) and power allocation in heterogeneous cellular networks (HCNs). A WBB partitioning scheme is considered, which allocates the whole bandwidth between the macrocell and small cells for data transmission and backhauling. We formulate an optimization problem to maximize the weighted sum logarithmic utility function by jointly optimizing WBB portion and fronthaul power allocation of each base station with consideration of the backhaul capacity limitation on each small cell. In order to solve this joint optimization problem, we propose a hierarchical two‐level approach and decompose the original problem into two independent subproblems: the WBB allocation at the macrocell base station (MBS) and the power allocation at both the MBS and small cell base stations (SBSs). Accordingly, the optimal WBB portion and power allocation solutions are obtained, respectively. Furthermore, we develop a distributed algorithm to implement the joint WBB and power allocation. Numerical results verify the effectiveness of the proposed approach and analyze the impact of the weighted coefficient and backhaul capacity limitation on the network performance. In addition, significant performance gains can be achieved by the proposed approach over the benchmark. 相似文献
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Rahim Khan Muhammad Zakarya Zhiyuan Tan Muhammad Usman Mian Ahmad Jan Mukhtaj Khan 《International Journal of Communication Systems》2019,32(18)
Heterogeneous wireless sensor networks (WSNs) consist of resource‐starving nodes that face a challenging task of handling various issues such as data redundancy, data fusion, congestion control, and energy efficiency. In these networks, data fusion algorithms process the raw data generated by a sensor node in an energy‐efficient manner to reduce redundancy, improve accuracy, and enhance the network lifetime. In literature, these issues are addressed individually, and most of the proposed solutions are either application‐specific or too complex that make their implementation unrealistic, specifically, in a resource‐constrained environment. In this paper, we propose a novel node‐level data fusion algorithm for heterogeneous WSNs to detect noisy data and replace them with highly refined data. To minimize the amount of transmitted data, a hybrid data aggregation algorithm is proposed that performs in‐network processing while preserving the reliability of gathered data. This combination of data fusion and data aggregation algorithms effectively handle the aforementioned issues by ensuring an efficient utilization of the available resources. Apart from fusion and aggregation, a biased traffic distribution algorithm is introduced that considerably increases the overall lifetime of heterogeneous WSNs. The proposed algorithm performs the tedious task of traffic distribution according to the network's statistics, ie, the residual energy of neighboring nodes and their importance from a network's connectivity perspective. All our proposed algorithms were tested on a real‐time dataset obtained through our deployed heterogeneous WSN in an orange orchard and also on publicly available benchmark datasets. Experimental results verify that our proposed algorithms outperform the existing approaches in terms of various performance metrics such as throughput, lifetime, data accuracy, computational time, and delay. 相似文献
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无线传感器网络地理路由协议要求节点根据少量本地路由信息将数据分组传输路由到目标节点。为了消除路由环,地理路由算法通常需要将网络拓扑平面化。然而现有的平面化算法要么假设节点的通信半径是一固定值,在实际应用中不适用;要么对每一条链路都进行检测是否有交叉链路,路由维护代价很高。针对以上问题,提出一种具有高可靠性和低维护成本的地理路由协议RPR(region partitioning-based routing),其基本思想是将网络划分为规则多边形区域,并在贪心路由失败时将多边形区域内的所有节点看作一个虚拟节点进行周边路由。多边形区域间通信能够降低平均路由路径长度,从而提高了路由的可靠性。基于区域划分的网络平面化策略不需要检测和删除相交链路,因此减少了路由维护开销。模拟实验结果显示,RPR协议比现有方法的平均路由路径长度更短,路由维护开销更低。 相似文献
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对目前AdHoc无线移动网络中存在的路由问题进行分析,并从多路径路由的要求出发,讨论把动态源路由协议DSR改造成多源路径协议的可行性,并提出了具体的实现算法。文中所提出的多径源路由协议为无线网络的路由协议的研究提供了重要的理论支持。 相似文献
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针对无线Mesh网络的网络特性,提出了一种基于链路负载估算的拥塞控制策略LLECC。LLECC算法计算有效链路带宽和链路负载估算确定RED算法中的调整因子,通过调整因子调整RED算法中的参数从而实现动态的对无线网络拥塞控制。详细讨论了LLECC算法的实现过程和相关参数的计算方法,通过仿真分析验证了该算法对无线Mesh网络性能的提高。 相似文献
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提出一种基于传输速率自适应的动态带宽分配算法,为异构无线网络中的多业务提供服务质量保证。根据所提的传输速率优先级决策模型,在传输速率QoS需求和异构网络容量约束的条件下,通过动态调整不同网络中各个移动终端所支持业务的传输速率来得到最优带宽重分配矩阵,以最大化整个异构网络的效用函数;将自适应带宽重分配问题描述为一个优化问题,采用动态优化的迭代算法自适应调节用户传输速率来进一步最大化该效用函数。理论分析和数值仿真结果表明,所提算法在给定传输速率且满足QoS需求的基础上,能够最大化网络的效用函数并减小新呼叫的阻塞概率。 相似文献