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1.
We present a decentralized auction-based scheme for bandwidth allocation and pricing in a differentiated service-based network. Different classes of clients provide their own expected bandwidth price and required amount of bandwidth. A service provider decides the admission price and differentiated service provided for each class of clients. We introduce mathematical formulations and provide a solution approach to maximize the service provider's revenue. For a single bottleneck link case, a polynomial-time algorithm is developed to obtain an optimal solution. For a multiple bottleneck link case, a heuristic algorithm is developed to solve the problem. The effectiveness of our solution approach is validated by simulation results, which compare our algorithms against the traditional flat-rate pricing approach.  相似文献   

2.
To ensure an intelligent engineering of traffic over entire satellite networks, a distributed routing scheme for low-earth orbit (LEO) satellite networks, agent-based load balancing routing (ALBR), is presented. Two kinds of agents are used. Mobile agents migrate autonomously to explore the path connecting source and destination, to gather inter-satellite link (ISL) cost, identifier and latitude of visited satellites. Meanwhile, stationary agents employ exponential forgetting function to estimate ISL queueing delay, calculate ISL cost using the sum of propagation and queueing delays; evaluate path cost considering satellite geographical position as well as ISL cost, finally update routing items. Through simulations on a Courier-like system, the proposed scheme is shown to achieve better load balancing, and can especially decrease packet loss ratio efficiently, guarantee better throughput and end-to-end delay bound in case of high traffic load. Furthermore, results from the implementation complexity analysis demonstrate that with the aid of agent technology, ALBR has lower on-board computation, storage, signaling requirements than other on-board routing schemes.  相似文献   

3.
文俊浩  宋鹏飞  王静 《计算机应用》2010,30(6):1638-1641
服务查找是面向服务架构(SOA)中一个非常重要的环节,但目前的服务查找算法一般并未考虑到服务查找节点间的负载均衡,在请求频繁条件下不能满足查找效率的要求。提出一种分布式的、综合考虑节点处理能力和网络延时、适用于SOA中分布式服务注册中心的服务查找请求路由算法HaFA。该算法利用负载度实现对服务节点计算能力的度量,解决了负载度均衡后任务仍可能分配到弱计算能力节点上的问题,提高了服务注册中心计算资源的利用率;利用节点负载波动率估量下一个离散时间点的负载度,解决了网络延时期间负载波动对实现均衡造成影响的问题。实验结果表明,HaFA在分布式服务查找中能有效提高系统吞吐率,缩短结果响应的平均等待时间。  相似文献   

4.
多信道无线Mesh网络负载均衡路由算法研究   总被引:1,自引:0,他引:1       下载免费PDF全文
针对无线网状网的网络容量问题,在多信道无线网状网模型的基础上,利用线性规划公式对无线网状网的路由问题进行描述,在此基础上提出了一个负载均衡的路由算法,在对业务请求的路由跳步数进行约束的前提上,通过减少网络链路上的负载,达到提高网络的吞吐量的目的。仿真结果表明,提出的算法能显著提高网络性能。  相似文献   

5.
Multi-path routing in the optical burst switching(OBS) networks can reduce the burst loss probability(BLP) by distributing the data burst traffic to multiple paths, compared with single path routing. Unlike the other multi-path routing schemes without considering the carrying capability of the routes, a new multi-path routing scheme based on effective voids(MPEV) is proposed to balance the load of multi-path and reduce the BLP in the paper. MPEV scheme first obtains the information on effective voids of the bottleneck link of multipath by sending a probe packet periodically. The effective voids can accommodate data bursts and accurately represent the available channel resource that is the main determinant of the BLP for OBS networks without optical random access memory. Then MPEV scheme distributes the burst traffic between an ingress node and an egress node to multiple link-disjoint paths by the ratio of the effective voids. More traffic is distributed to the path that has more effective voids, and vice versa. And the distributed amount is proportional to the effective voids of the bottleneck link. So MPEV scheme can balance the load of multi-path routes and can effectively reduce the BLP by avoiding the high load of a single path. And it is easy to implement and agilely adapt to dynamic network traffic. The performance of MPEV scheme is analyzed by queuing theory and is evaluated by simulation. The numerical results show that the proposed scheme can effectively reduce the BLP and balance the traffic load over multiple paths at the same time.  相似文献   

6.
Well-known ‘routing hole’ problem of geographic routing is hardly avoided in wireless sensor networks because of various actual geographical environments. Existing geographic routing protocols use perimeter routing strategies to find a detour path around the boundary of holes when they encounter the local minimum during greedy forwarding. However, this solution may lead to uneven energy consumption around the holes since it consumes more energy of the boundary sensors. It becomes more serious when holes appear in most of routing paths in a large-scale sensor network. In this paper, we propose a novel distributed strategy to balance the traffic load on the boundary of holes by virtually changing the sizes of these holes. The proposed mechanism dynamically controls holes to expand and shrink circularly without changing the underlying forwarding strategy. Therefore, it can be applied to most of the existing geographic routing protocols which detour around holes. Simulation results show that our strategy can effectively balance the load around holes, thus prolonging the network life of sensor networks when an existing geographic routing protocol is used as the underlying routing protocol.  相似文献   

7.
针对考虑负载均衡的LEO卫星网络路由算法存在控制网络开销偏大、路由更新不及时以及流量调节机制分配不均等问题,提出了一种基于负载均衡的动态LEO卫星网络路由算法DRLB。根据卫星节点路径记录信息以及后向Agent读取策略设计新的路由机制,获得动态卫星拓扑结构;分析前向Agent的分组格式并删除冗余字段,达到减小网络开销目的;根据数据发送时间间隔构造前向Agent选址策略,提高路由更新效率,通过考虑卫星所处纬度流量分配不均问题,改进流量调节因子,获得更好的负载均衡效果。仿真结果表明,与SDRZ-MA算法相比,DRLB算法在减缓星地之间的控制开销、平均端到端时延等方面具有较好的优势。  相似文献   

8.
The Journal of Supercomputing - In a large sensor network, the data are usually routed back to the static base station (BS) using multi-hop communication. The sensor nodes near the BS suffer from...  相似文献   

9.
10.
A load balancing framework for adaptive and asynchronous applications   总被引:1,自引:0,他引:1  
We describe the design of a flexible load balancing framework and runtime software system for supporting the development of adaptive applications on distributed-memory parallel computers. The runtime system supports a global namespace, transparent object migration, automatic message forwarding and routing, and automatic load balancing. These features can be used at the discretion of the application developer in order to simplify program development and to eliminate complex bookkeeping associated with mobile data objects. An evaluation of this system in the context of a three-dimensional tetrahedral advancing front parallel mesh generator shows that overall runtime improvements of 15 percent compared to common stop-and-repartition load balancing methods, 30 percent compared to explicit intrusive load balancing methods, and 42 percent compared to no load balancing are possible on large processor configurations. At the same time, the overheads attributable to the runtime system are a fraction of 1 percent of the total runtime. The parallel advancing front method is a coarse-grained and highly adaptive application and therefore exercises all of the features of the runtime system.  相似文献   

11.
12.
In recent years, there have been rapid advances in network infrastructure and technologies for end-user communication. However, because of network dynamics and resource limitation, providing scalable end-user communication services is challenging when the applications are utilized on a large-scale. To address this challenge, a replica-aided load balancing scheme (RALB) is proposed for enabling the nodes in an overlay networks to support the communication applications for a large number of users. This paper makes three unique contributions. First, we study the existing load balancing schemes and identify their weakness in handling time-varying workloads with frequent load fluctuations. Second, we introduce a sophisticated cost model for load balancing cost estimation, which captures the dependencies between the factors (e.g., the load, message number, and link latency). Third, we propose a performance tuning technique to minimize the load balancing cost. The extensive experiments show that RALB effectively reduces the load imbalance and eliminates the load balancing cost when compared to the existing load balancing schemes.  相似文献   

13.
We propose a new link metric called normalized advance (NADV) for geographic routing in multihop wireless networks. NADV selects neighbors with the optimal trade-off between proximity and link cost. Coupled with the local next hop decision in geographic routing, NADV enables an adaptive and efficient cost-aware routing strategy. Depending on the objective or message priority, applications can use the NADV framework to minimize various types of link cost.We present efficient methods for link cost estimation and perform detailed experiments in simulated environments. Our results show that NADV outperforms current schemes in many aspects: for example, in high noise environments with frequent packet losses, the use of NADV leads to 81% higher delivery ratio. When compared to centralized routing under certain settings, geographic routing using NADV finds paths whose cost is close to the optimum. We also conducted experiments in Emulab testbed and the results demonstrate that our proposed approach performs well in practice.  相似文献   

14.
In this paper we present a general strategy for finding efficient permutation routes in parallel networks. Among the popular parallel networks to which the strategy applies are mesh networks, hypercube networks, hypercube-derivative networks, ring networks, and star networks. The routes produced are generally congestion-free and take a number of routing steps that is within a small constant factor of the diameter of the network. Our basic strategy is derived from an algorithm that finds (in polynomial time) efficient permutation routes for aproduct network, G×H, given efficient permutation routes forG andH. We investigate the use of this algorithm for routingmultiple permutations and extend its applicability to a wide class of graphs, including several families ofCayley graphs. Finally, we show that our approach can be used to find efficient permutation routes among the remaining live nodes infaulty networks.This research was supported in part by a grant from the NSF, Grant No. CCR-88-12567.  相似文献   

15.
For the problem of routing and wavelength assignment in Wavelength Division Multiplexing (WDM) optical transport network, an algorithm based on the state of links is proposed, which is named Tradeoff_LSDRAW, and which can select a path with the higher state level between a pair of nodes in a network. Finally, by an example network, we show that the algorithm has the stronger capability of selecting a better path between a pair of nodes, and can achieve the load balancing and reduce the congestion probability in WDM optical transport networks.  相似文献   

16.
在基于IEEE 802.11的宽带无线局域网中,随着终端STA的接入、移动和无线信道的时变性,各个接入点(AP)的负载将会产生差异,需要负载均衡优化机制平衡各个AP的差异,以达到网络资源的最大利用率。详细讨论了无线局域网中用到的几种负载均衡机制,分析了各自的优缺点,结合这些特点给出一种新的负载均衡机制。该机制能较准确地统计终端业务信息,降低切换失败风险,快速达到APs之间的负载均衡,优化提高网络整体性能。  相似文献   

17.
对多协议标签交换(MPLS)流量工程负载均衡问题,提出了两种多路径基于约束的负载均衡方法,在LSP建立初期就融入负载均衡思想。在通常的CSPF算法中,对于一个大带宽约束很可能无法找到可行路径,文中所提方法在没有单一路径满足带宽约束时,能将带宽约束划分为两个或多个子约束,并为每一子约束找到约束路径。实验结果表明,所提方法能增加路径建立的成功率,提高网络资源利用率,达到流量均衡。  相似文献   

18.
In modern computer networks, loading and bandwidth of communication links are optimized for providing high-quality service of network traffic, new services and technologies. As a rule, for this task the protocols of dynamic routing based on Dijkstra’s algorithm are used. Protocols of multipath routing for ensuring reliability and accuracy of the provided information allow to divide critical traffic and to execute load balancing along several routes at the same time. The purpose of the work is development and research of the improved multipath adaptive routing model in computer networks with load balancing. In this work, we focused on indicator of jitter optimization between the paved paths and a deviation value of reserve routes from an optimal route. Comparison and estimation of the offered algorithm with some existing approaches, and also modeling and analysis on various topologies of computer networks have been carried out.  相似文献   

19.
This paper studies the problem of balancing the demand for content in a peer-to-peer network across heterogeneous peer nodes that hold replicas of the content. Previous decentralized load balancing techniques in distributed systems base their decisions on periodic updates containing information about load or available capacity observed at the serving entities. We show that these techniques do not work well in the peer-to-peer context; either they do not address peer node heterogeneity, or they suffer from significant load oscillations which result in unutilized capacity. We propose a new decentralized algorithm, Max-Cap, based on the maximum inherent capacities of the replica nodes. We show that unlike previous algorithms, it is not tied to the timeliness or frequency of updates, and consequently requires significantly less update overhead. Yet, Max-Cap can handle the heterogeneity of a peer-to-peer environment without suffering from load oscillations. Mema Roussopoulos is an Assistant Professor of Computer Science on the Gordon McKay Endowment at Harvard University. Before joining Harvard, she was a Postdoctoral Fellow in the Computer Science Department at Stanford University. She received her PhD and Master’s degrees in Computer Science from Stanford, and her Bachelor’s degree in Computer Science from the University of Maryland at College Park. Her interests are in the areas of distributed systems, networking, and mobile and wireless computing. Mary Baker is a Senior Research Scientist at HP Labs. Her research interests include distributed systems, networks, mobile systems, security, and digital preservation. Before joining HP Labs she was on the faculty of the computer science department at Stanford University where she ran the MosquitoNet project. She received her PhD from the University of California at Berkeley.  相似文献   

20.
通过改进ACO算法达到一种能实现通信网络负载平衡的群体智能路由策略。采用的主要方法为:将蚁群划分为若干个子群,不同子群的蚂蚁释放不同类型的信息素。通过不同类型信息素之间的相互制约作用,以及链路负载的测量,提出了三种策略实现负载平衡路由。在模拟网络上进行了不同策略的对比实验,以及与已有的群体智能路由算法的运行测试比较。实验结果表明,本文的路由策略具有较好的效果和一定的优势。  相似文献   

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