MANET中一种QoS模型的分析与改进

QoS模型是对QoS的一种综合解决方案.文章就MANET中一种扩展性强的QoS模型INSIGNIA进行了研究与分析,讨论了多种已有的对INSIGNIA模型改进方式的具体过程,总结归纳这些改进中的所要解决的问题和解决效果,考虑控制成本花费和借助路由协议和其他协议层的信息应对动态网络的方式,最后提出了合适的改进解决思路和步骤.     

基于负荷平衡的混合式中继选择新算法

现有的中继选择算法通常带来中继负荷失衡问题,可能导致中继节点资源的非公平利用。为解决这个问题,首先对中继负荷失衡问题进行了分析,接着使用链路信噪比和中继节点负荷作为模糊控制的输入参量,提出了负荷平衡中继选择(LBRS)算法;其次,针对LBRS算法中存在的低信噪比区域误比特率偏高的问题,进一步提出了LBRS的改进算法,即基于负荷平衡的混合式中继选择(HRS)算法。仿真结果表明,与典型的最优中继选择(BRS)算法比较,HRS算法在平衡中继节点负荷上具有非常显著的优势,在误比特率性能上稍逊,总的来说是一种性能优异的中继选择算法。     

Optimization of link load balancing in multiple spanning tree routing networks

In telecommunication networks based on the current Ethernet technology, routing of traffic demands is based on multiple spanning trees: the network operator configures different routing spanning trees and assigns each demand to be routed in one of the selected spanning trees. A major optimization issue in this solution is the combined determination of (i) a?set of appropriate spanning trees, and (ii) assignment of demands to the trees, in order to achieve an optimal load balancing on the links of the network. In this paper we consider models and solving techniques for lexicographical optimization of two load balancing objective functions. The first objective is the min-max optimization of the n worst link loads (with n up to the total number of network links), and the second objective is the minimization of the average link load (when n is smaller than the total number of network links). Besides exact methods, a heuristic technique that can compute both feasible solutions and lower bounds for the addressed optimization problem is proposed. Finally, we discuss effectiveness of different solution using results of a numerical study of realistic case studies.     

异构分层无线网络中的混合动态流量均衡算法研究

结合信道借用和流量转移技术提出了一种混合动态流量均衡算法。使用该算法热点小区可以向紧凑模式中的同类型轻负载小区借用信道，同时还可以按一定条件将呼叫转移到与热点小区重叠覆盖的异构轻负载小区中，每个流量周期借用的信道数和转移的呼叫数将根据热点小区的剩余可用信道数和新呼叫到达率来计算。仿真结果表明，该流量均衡算法能够显著降低热点小区系统和整个异构系统的新呼叫阻塞概率、切换呼叫掉线率，而且整个异构系统的利用率也得到了相应提高。     

Gateway Selection Protocol in Hybrid MANET Using DYMO Routing

In this paper, we propose a novel gateway (GW) selection protocol in hybrid Mobile Ad hoc Networks (MANETs). We focus on the situation that occurs when specialized, sensitive data is sent to the Internet from MANET nodes. These special data types are especially susceptible to security risks such as information leak and data falsification. Therefore, it is necessary for such special data to be forwarded by a secure/trusted GW which is controlled by a trusted network administrator. However, there should be multiple GWs deployed in a MANET, where the cost ineffectiveness makes it difficult for a network administrator to simultaneously manage every GW. Because of the risk of forwarding special data through an unmaintained GW, we propose a routing protocol which allows a source node to have sensitive data forwarded to the Internet through a trusted GW. To achieve this desirable performance, we improve upon one of the newest routing protocols, Dynamic MANET On-demand (DYMO), which works in consideration of application data. Through simulations, we evaluate our protocol in comparison with the conventional DYMO protocol. The results show that our protocol can make MANET source nodes choose GWs for specific data.     

Secured and QoS Based Energy-Aware Multipath Routing in MANET

Wireless Personal Communications - In MANET, energy aware multipath routing is major concern for securable transmission which is possible by avoiding the attackers or selfish nodes from the...     

Improved Priority Aware Mechanism for Enhancing QoS in MANET

Wireless Personal Communications - Priority Aware mechanism utilizing connection-oriented approach doesn't offer uniform throughput and low end-to-end delay when the velocity of mobile nodes is...     

Handoff optimization and load balancing in wireless LANs using association control

As users move around in wireless local area networks, they associate with different access points in succession to maintain connectivity. Without the carefully designed association control policy, it may lead to frequent handoffs and imbalanced load, which can potentially incur unacceptable delays and poor throughput. While existing works to this issue mainly focus on minimizing the number of handoffs over time, in this paper, we propose a new association control scheme with the goal of reducing the frequency of handoffs and balancing load among access points. The defined problem, handoff optimization and load balancing (HOLB,) is mathematically described as a minimum–maximum programming. Since the HOLB problem is a nondeterministic polynomial‐time hard, two constant approximation algorithms are presented to resolve it. First, we propose an α‐approximation() centralized algorithm CHOLB. CHOLB employs a novel method to simplify the original problem to the minimum‐cost maximum‐flow problem, which is solved in polynomial time. On the sis of CHOLB, we then put forward a β‐approximation () distributed algorithm DHOLB for the purpose of scalability and lightweight. DHOLB partitions the network into clusters and uses CHOLB as its local centralized algorithm within each cluster. Extensive evaluations show that the proposed algorithms outperform the existing schemes in terms of the handoff frequency and traffic load. Copyright © 2013 John Wiley & Sons, Ltd.     

Queue‐based multiple path load balancing routing protocol for MANETs

Congestion in the network is the main cause for packet drop and increased end‐to‐end transmission delay of packet between source and destination nodes. Congestion occurs because of the simultaneous contention for network resources. It is very important to efficiently utilize the available resources so that a load can be distributed efficiently throughout the network. Otherwise, the resources of heavily loaded nodes may be depleted very soon, which ultimately affects network performances. In this paper, we have proposed a new routing protocol named queue‐based multiple path load balancing routing protocol. This protocol discovers several node‐disjoint paths from source to destination nodes. It also finds minimum queue length with respect to individual paths, sorts the node‐disjoint paths based on queue length, and distributes the packets through these paths based on the minimum queue length. Simulation results show that the proposed routing protocol distributes the load efficiently and achieves better network performances in terms of packet delivery ratio, end‐to‐end delay, and routing overhead. Copyright © 2016 John Wiley & Sons, Ltd.     

一种新的自适应负载均衡的QoS多径路由机制

针对MANET中AODV,DSR等典型按需路由协议未考虑负载均衡导致网络拥塞和性能急剧下降的严重不足,提出了新的路由机制-ALBQM(Adaptive Load Balance QOS Multipath).ALBQM主要包括:(1)QoS可用带宽的负载感知模型,减少网络冲突和拥塞;(2)采用最大不相关多径并行通信,自适应分配数据流量,提高数据递交率.基于OPNET网络仿真平台对ALBOM应用于DSR进行性能验证,与DSR及其多径路由SMR相比,在重负载网络中有更好的性能表现-在不增加额外控制开销的条件下提升数据递交率,减少端到端平均延迟及路由错误总数.     

Dynamic load balancing among multiple fabrication lines through estimation of minimum inter-operation time

We propose a load balancing method which balances all processing operations of products among multiple semiconductor wafer fabrication lines (fabs) by using predictive scheduling results. Through a simulation experiment we confirmed that the proposed method enabled improved load balancing (compared to conventional methods) among multiple fabrication lines each of which can independently fabricate wafers and has different wafer processing capacity. The load balancing feature effectively reduces the waiting time at each process step and the lead time of all products in multiple fabs. Another promising application of the proposed method is performance evaluation of automated material handling systems (AMHS) in terms of inter-operation time, and we have used the method to evaluate the transportation efficiency of actual fabs.     

A Novel Technique for Gateway Selection in Hybrid MANET Using Genetic Algorithm

Integration of Mobile Ad hoc NETworks (MANETs) with the Internet has been paid immense attention in the field of heterogeneous networks. In MANET some intermediate nodes called Internet Gateways (IGs) are responsible for sending the data traffic of source nodes towards the fixed nodes in the Internet. The key issue considered while selecting IG nodes is its optimised throughput with the reduced delay in resource constraint mobile nodes. In this paper, a genetic algorithm inspired Delay Sensitive Gateway Selection (DSGS) scheme is proposed considering the issue of network delay by minimising the total distance travelled by the source nodes to the gateway. The performance of the proposed GA-based DSGS scheme is studied using a comparative approach. The simulation results demonstrate that the proposed scheme significantly outperforms the conventional schemes and is capable of achieving higher network throughput while minimising the end-to-end delay.

     

Multipath Delay Analysis Using Queuing Theory for Gateway Selection in Hybrid MANET

Wireless Personal Communications - Hybrid Mobile ad hoc network (H-MANET) is a network in which MANET is connected to the Internet using some special nodes called Internet Gateways (IGs). Previous...     

Developing multi-path routing protocol in MANET using hybrid SM-CSBO based on novel multi-objective function

One of the infrastructure-free networks is mobile ad hoc networks (MANETs) that are built with limited battery life using wireless mobile devices. This restricted battery capability in MANETs creates the necessity of considering the energy-awareness constraint in designing them. As routing protocols, the major aim of MANETs is to create the energy awareness in the network; it improves the network's lifetime through effectively utilizing the available restricted energy. Moreover, it creates some limitations like the mobility constraint, wireless link's sensitivity to environmental impacts, and restricted transmission range and residual energy of nodes that causes rapid modifications in the network topology and frequent link failure. By taking those problems, this paper plans to develop a new multipath routing protocol, where the hybrid optimization algorithm with the integration of cuckoo search optimization (CSO) and butterfly optimization algorithm (BOA) is proposed and named sensory modality-based cuckoo search butterfly optimization (SM-CSBO) for determining the optimal path between the source and destination. The main goal is to select the path with better link quality and more stable links to guarantee reliable data transmission. The multi-objective function is considered with the factors regarding distance, normalized energy, packet delivery ratio, and control overhead to develop an effective routing protocol in MANET. The proposed model of SM-CSBO algorithm has superior than 5.8%, 30.4%, 36.7%, and 39.3%, correspondingly maximized than PSO, SFO, CSO, and SFO algorithms while considering the number of nodes as 150. The simulation outcomes proved that it enhances network performance when compared with the other traditional protocols.     

Gateway Placement Optimization in Wireless Mesh Networks With QoS Constraints

In a wireless mesh network (WMN), the traffic is aggregated and forwarded towards the gateways. Strategically placing and connecting the gateways to the wired backbone is critical to the management and efficient operation of a WMN. In this paper, we address the problem of gateways placement, consisting in placing a minimum number of gateways such that quality-of-service (QoS) requirements are satisfied. We propose a polynomial time near-optimal algorithm which recursively computes minimum weighted Dominating Sets (DS), while consistently preserving QoS requirements across iterations. We evaluate the performance of our algorithm using both analysis and simulation, and show that it outperforms other alternative schemes by comparing the number of gateways placed in different scenarios     

无线Mesh网络多网关选播QoS路由模型研究

无线Mesh网络中网关常常成为网络的瓶颈.为了解决网关的选取问题和提高QoS性能,根据多网关选取问题与选播路由的相似性,提出了一种基于选播机制的网关选取模型.该模型将所有网关节点抽象成一个选播组,带QoS约束的用户端通过有效的选播机制能够自适应地选择最优的网关节点为其服务,以保证无线Mesh网络良好的接入性能.仿真结果表明了该算法的正确性和有效性.     

软件定义网络中基于Q-学习的负载均衡算法

针对软件定义网络(Software Defined Network,SDN)的负载均衡问题,为使网络的资源分配更加合理,防止网络拥塞,设计了一种基于Q-学习的负载均衡(Q-learning Load Balance,QLLB)算法,可根据网络环境自行作出决策,避免网络拥塞,实现网络资源的合理分配.与最短路径算法Dijk...     

An ACO and position information based intelligent QoS routing mechanism in MANET

Quality of service (QoS) routing technology, which can find the available route, is an important way to realize the end-to-end QoS provisioning for networks. Intelligent routing discovery, establishment and maintenance, which take use of ant colony algorithm, have been widely researched in the past years. But the ant colony algorithm has two obvious shortcomings, which are low convergence rate and algorithm stagnation in local optimum. As the topology of mobile ad hoc network (MANET) is always changing, the information of network status is hard to collect in time. So the enhancement of the convergence rate of the QoS routing algorithm is quite important in MANETs. Based on the AntHocNet algorithm previously designed for ad hoc networks, this paper proposes a position-based intelligent QoS routing algorithm. The position constraints are added in the procedures of tabu list forming and pheromone updating. Compared with AntHocNet, the proposed mechanism can greatly reduce the convergence rate in the premises of searching an available path with QoS guarantee according to the simulation results.     

一种微服务架构下的负载均衡策略

基于一致性哈希算法的负载均衡技术,常被用于解决分布式系统的横向扩展问题。微服务架构与传统的分布式软件架构不同,采用了客户端负载均衡策略,由于一致性哈希算法本身并没有相关的负载均衡措施,在请求过度集中的情况下,会导致服务节点间的数据倾斜。文章提出基于线性同余法的一致性哈希访问策略,结合了随机算法和哈希算法的优势,为解决客户端负载均衡问题提供了一种新的思路。     

一种基于MSTP的负载均衡算法设计

负载均衡是提高网络性能的重要技术,多实例生成树协议MSTP提出了在不改变网络交换基本方式的前提下,在不同的虚拟局域网VLAN中采用不同的生成树拓扑进行通信,通过控制各VLAN使用的生成树拓扑来达到选路的目的,为利用冗余链路实现负载均衡提供了条件。文中确定了一种链路负载函数作为衡量网络负载的依据,提出了一种基于MSTP的负载均衡选路算法,利用该算法可以选择链路负载最小的生成树映射,充分利用了冗余线路,实现负载均衡的目的。