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1.
1 .INTRODUCTIONMobile ad hoc networks ( MANET) , also calledthe infrastructureless mobile network or self-or-ganized network,consists of a collection of mobilenodes sharing a wireless channel without any cen-tralized control or established communication back-bone .ad hoc networks have no fixed routers ;allnodes are capable of movement and can be connect-ed dynamically in an arbitrary manner . Usually ,these nodes act as both end systems and routers atthe same ti me . Nodes of these netwo…  相似文献   

2.
With the rapid development of Internet, mobile networks and high-performance networking technology,multiple constrained QoS multicast routing optimization in networks with uncertain parameters has become a very important research issue in the areas of networks and distributed systems. It is also a challenging and hard problem to the next generation Internet and high-performance networks, and has attracted the interests of many people. This paper discusses the multiple constrained QoS multicast routing problem, which may deal with the delay, delay jitter,bandwidth and packet loss metrics, and describes a network model for researching the routing problem. The paper mainly presents multiple constrained QoS multicast routing algorithm (MCQMRA), a QoS multicast routing policy for Internet,mobile network or other high-performance networks, which is based on the genetic algorithm (GA) and can provide QoS-sensitive paths in a scalable and flexible wayin the network environment with uncertain parameters. The MCQMRA can also optimize the network resources such as bandwidth, delay, packet loss metrics and can converge to the optimal or near-optimal solution within few iterations, even for the network environment with uncertain parameters. Simulation results show that MCQMRA is an available approach to QoS multicast routing decision.  相似文献   

3.
QoS multicast routing algorithm based on GA   总被引:9,自引:2,他引:9  
1 .INTRODUCTIONTheprovisionofquality of service (QoS) guaranteesisofutmostimportanceforthedevelopmentofthemulticastservices .Multicastroutinghascontinuedtobeaveryimportantresearchissueintheareasofnet worksanddistributedsystems.Ithasattractedtheinterestsof…  相似文献   

4.
Reliable adaptive multicast protocol in wireless Ad hoc networks   总被引:1,自引:0,他引:1  
1.INTRODUCTIONA wireless ad hoc networkis a multi-hop wireless net-workformed by a collection of mobile nodes withoutthe intervention of fixed infrastructure.Because awireless ad hoc networkis infrastructureless and self-organized,it is used to provide i mpromptu communi-cationfacilities in harsh environments.Typical appli-cation areas of wireless ad hoc networkinclude battle-fields,emergency search,rescue sites and data acqui-sitionin remote areas.A wireless ad-hoc network isalso useful …  相似文献   

5.
针对现有多跳无线自组网路由协议以被动方式对拥塞进行处理,有可能导致更多的分组丢失、更长的时延和更大的网络开销问题,提出了一种基于辅助路由的拥塞自适应协议(congestion adaptive protocol based on aided-routing, CAPAR)。该协议以主动方式对拥塞进行处理,采取建立辅助路由的方法对发送给拥塞节点的业务流量进行分流,主动避免拥塞的发生,克服了以被动方式对拥塞进行处理所带来的不利影响。给出了CAPAR协议的建立过程,证明了CAPAR协议的正确性,并对其路由存储代价和路由更新代价进行了分析。结果表明,与其他按需路由协议相比,CAPAR减少了重新建立路由所带来的开销和时延,其路由更新代价明显降低。  相似文献   

6.
基于拓扑维护的自适应多信道OLSR路由协议   总被引:1,自引:0,他引:1  
OLSR是一种应用于无线移动Ad hoc网络的基于链路状态机制的先应式路由协议。在OLSR中,网络拓扑的动态变化会使节点掌握的拓扑信息失效,从而导致路由表项不全,影响路由性能。针对上述问题,提出了一种基于拓扑维护的自适应多信道路由协议MOLSR-TM,该协议把拓扑维护状况感知和自适应算法引入OLSR,以调整HELLO控制消息的发送频率和邻居记录表、拓扑记录表的刷新频率。性能分析和仿真结果表明,MOLSR-TM能改善节点的拓扑维护状况,增强动态拓扑适应能力,提高数据成功率、端到端时延和网络吞吐率等性能。  相似文献   

7.
基于遗传算法与模糊选择的多播路由优化   总被引:2,自引:0,他引:2  
遗传算法在优化计算特别是在多播路由问题中得到了广泛应用,但在进行大规模优化时,遗传算法存在着爬山能力差以及不成熟收敛等缺点。为此,提出基于启发式遗传算法和模糊选择机制的新型多播树计算方法,本算法采用树型结构编码和高效的遗传操作,同时优化时延、丢包率和带宽利用率等多个参数。仿真实验表明,这种算法用于多播路由多目标优化问题时,可以克服采用遗传算法进行多目标优化的缺陷。  相似文献   

8.
In recent years, QoS multicast routing has continued to be a very important research topic in the areas of networks. This paper presents a heuristic algorithm for the QoS multicast routing (HAQMR). This heuristic algorithm deals with delay and bandwidth constraints and has low cost. The HAQMR attempts to significantly reduce the overhead for constructing a multicast tree, the proof for correctness of the HAQMR is given, and the performance of the HAQMR is evaluated by simulations. The study shows that HAQMR provides an available approach to QoS multicast routing.  相似文献   

9.
1 .INTRODUCTIONA mobile Ad hoc network refers to a temporal multi-hop autonomy system,whichis constituted by a groupof mobile nodes containing wireless send-receive equip-ments[1].It possesses manycharacteristics-fast-deploy-able,self-organized,acentric , movable and of multi-hop.It can be wildly applied to many fields ,such asnational defense,emergency and disaster ,scientificin-vestigation and exploration etc .,and uponthat ,it hasgreat prospects[1 ,3 6]. With the wide spread of mo-bile…  相似文献   

10.
针对传统卫星网络中业务类型多样化导致的网络配置复杂和业务服务质量(quality of service, QoS)无法得到有效保障的问题,研究了基于软件定义网络(software-defined networking, SDN)的卫星网络架构,提出了一种能够满足多种QoS需求的自适应路由算法。首先,建立了软件定义卫星网络多约束条件路由选择优化模型;然后,使用拉格朗日松弛法对模型进行松弛处理;最后,使用梯度法进行迭代求解,搜索出满足带宽、时延、丢包率等多种QoS的最优路径。研究结果表明,该优化算法在QoS满意度方面相比近地轨道卫星路由算法提高了64%,在时延满意度和丢包率满意度方面相比软件定义路由算法提高了28%。  相似文献   

11.
1.INTRODUCTION WiththerapiddevelopmentofInternet,mobilenet worksandhigh performancenetworkingtechnology,itbringsoutextensiveinterestsofpeopleinproviding multimediaandreal timeservicessuchasvideoconfer ence,distanceeducation,entertainmentandsoon.Theseservicesrequirecertainquality of service(QoS)fromthenetworks.Thatis,thereshouldbe guaranteesastobandwidth,delay,delay jitter,ratio ofpacket lossandlowcostduringthedatatransmis sion.Meanwhile,multicastserviceshavebeenused invariousmultimediaap…  相似文献   

12.
Tactical mobile ad hoc network (MANET) is a collection of mobile nodes forming a temporary network, without the aid of pre-established network infrastructure. The routing protocol has a crucial impact on the network performance in battlefields. Link reliability based hybrid routing (LRHR) is proposed, which is a novel hybrid routing protocol, for tactical MANET. Contrary to the traditional single path routing strategy, multiple paths are established between a pair of source-destination nodes. In the hybrid routing strategy, the rate of topological change provides a natural mechanism for switching dynamically between table-driven and on-demand routing. The simulation results indicate that the performances of the protocol in packet delivery ratio, routing overhead, and average end-to-end delay are better than the conventional routing protocol.  相似文献   

13.
基于禁忌搜索的负载均衡组播路由算法   总被引:1,自引:0,他引:1  
提出了一种基于禁忌搜索策略的能实现网络负载均衡的QoS组播路由优化算法。该算法在满足业务带宽和时延的基本要求下,将网络费用和负载均衡分布作为目标函数进行优化,达到网络费用较小和负载均衡分布的目的。仿真结果表明,该算法是一个有效、可行的算法。  相似文献   

14.
针对由卫星光网络拓扑动态变化、业务多样化和负载不均引起的路由收敛慢和波长利用率低的问题, 提出了一种基于深度强化学习的卫星光网络波长路由分配方法。基于软件定义中轨/低轨(medium earth orbit/low earth orbit, MEO/LEO)双层卫星网络架构, 利用深度强化学习算法动态感知网络当前的业务负载和链路状况, 构造基于时延、波长利用率和丢包率的奖励函数进行选路决策。为了解决单跳链路对整个光路的影响, 引入链路瓶颈因子, 搜索符合服务质量(quality of service, QoS)约束的最优路径。研究结果表明, 与传统卫星网络分布式路由(satellite network distributed routing algorithm, SDRA)算法和Q-routing算法相比, 所提算法降低了网络的时延、丢包率, 提高了波长利用率, 同时也降低了高优先级业务的阻塞率。  相似文献   

15.
杨盘龙  田畅  于雍 《系统仿真学报》2005,17(7):1538-1542
战术互联网条件下的网络应用环境与民用网络相比,具有其特定的拓扑连接关系、移动方式和流量特征,而上述特点对于路由协议性能评估结果影响较大,针对应用背景结合路由协议评估体系,对自组织网络路由协议性能进行了仿真与评估,并得到如下结论:战术互联网环境下,移动性对路由协议的影响小于网络负载对协议性能的影响;同时,先应式路由协议比反应式路由协议更适合在网络负载较大的战术互联网环境中使用。  相似文献   

16.
Due to their characteristics of dynamic topology, wireless channels and limited resources, mobile ad hoc networks are particularly vulnerable to a denial of service (DoS) attacks launched by intruders. The effects of flooding attacks in network simulation 2 (NS2) and measured performance parameters are investigated, including packet loss ratio, average delay, throughput and average number of hops under different numbers of attack nodes, flooding frequency, network bandwidth and network size. Simulation results show that with the increase of the flooding frequency and the number of attack nodes, network performance sharply drops. But when the frequency of flooding attacks or the number of attack nodes is greater than a certain value, performance degradation tends to a stable value.  相似文献   

17.
卫星网络中由于卫星高动态拓扑和地面用户分布不均,导致卫星网络易出现区域负载失衡。设计高效的动态路由算法是当前卫星网络的研究热点,为此,提出了一种面向双层卫星网络的多业务负载均衡算法。该算法根据卫星链路上的数据传输量进行拥塞判断,根据链路时延因素和链路负载因素进行负载代价计算,不同服务质量(quality of service, QoS)需求的业务进行不同路径选择,通过分流均衡网络流量。仿真结果表明,该算法能够减少数据包的排队时延和丢包率,提高整网吞吐量。  相似文献   

18.
Multiple constraints-based QoS multicast routing: model and algorithms   总被引:5,自引:0,他引:5  
1.INTRODUCTION Multicastserviceshavebeenusedbyvariouscontinu ousmediaapplications.Forexample,themulticast backbone(Mbone)oftheInternethasbeenusedto transportrealtimeaudio/videofornews,entertain ment,videoconferencing,anddistancelearning.The provisionofQoSguaranteesisofutmostimportance forthedevelopmentofthemulticastservices.Multi castroutinghascontinuedtobeaveryimportantre searchissueintheareasofnetworksanddistributed systems[1~4].Itattractstheinterestsofmanypeo ple. Afrequently…  相似文献   

19.
一种Ad Hoc网络信道接入退避算法及仿真分析   总被引:3,自引:1,他引:3  
移动自组网络的应用环境以及其在商业上的潜在应用要求它支持QoS,高效合理的MAC协议对于保障Ad Hoc网络QoS具有重要的意义。在分析现有典型MAC协议及退避算法的基础上,提出了一种支特动态服务区分兼顾公平性的退避算法——服务区分动态退避(SDDB)算法。分析和仿真结果证明,与IEEE802.11等协议采用的退避算法相比,该算法在信道公平性和提供服务区分方面有较好的改善,并且在信道的吞吐量和提供服务区分、改善信道接入公平性之间能达到较好的折衷。  相似文献   

20.
分簇路由协议能够提高系统性能,但也存在不足之处,维护簇结构需要复杂的簇选择算法,带来簇结构维护开销。提出了一种新的Ad hoc网络分簇路由协议,该协议利用簇的层次结构,并采用基于异常度的簇结构调整方案提高簇结构稳定性,减小路由协议开销。分析和仿真表明该协议具有控制开销小、网络性能高的特点。
Abstract:
The clustering hierarchical routing protocol have been developed to increase the system performance.Hierarchical structure has inevitably brought some drawbacks,maintaining the hierarchical structure needs more complicated cluster heads selection algorithm,which may result in the cost of maintaining cluster structure.A novel clustering structure based routing Protocol for ad hoc network was explored.It could reduce the route cost by adopting the hierarchical structure and could improve ad hoc network stability by introducing a configuration strategy based on "Exception Degree".Analysis and simulation show that the protocol is characterized with its low maintenance costs of routing and high network performance.  相似文献   

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