共查询到17条相似文献,搜索用时 453 毫秒
1.
2.
一种带物理约束的光网络业务量疏导方法 总被引:1,自引:0,他引:1
提出了基于最大收益的捆绑疏导算法(MRA)来解决光网络中具有多种物理约束的业务量疏导问题。MRA首先在物理拓扑上逐个放置业务, 随后捆绑细粒度业务、实现管道实例化。即考虑业务的路由情况, 将其在物理拓扑上的路由都视为单跳的细粒度管道, 然后使用基于深度优先搜索的方法来检查哪些业务能够捆绑到一起形成多跳粗粒度的潜在管道, 以节省中间节点的细粒度交换容量。再从这些粗粒度的潜在管道中, 使用最大收益的方法遴选出具有最大成本收益的无冲突集合, 并加以实例化。仿真结果显示, 在处理多个物理约束时, MRA在容量和实现成本上均优于现有的算法, 并且它能处理多达百个节点以上的大网络中的业务量疏导问题。 相似文献
3.
4.
5.
6.
基于节能的绿色光网络路由算法的研究 总被引:1,自引:0,他引:1
在传统的网络路由算法中,一般采用最短路径算法进行路由选路,最短路径算法以节点间的距离为权重,计算一条由源节点至目的节点的权重最小的路径以完成路由。最短路径算法虽然最小化了距离长度代价,却没有考虑能耗问题,所以使用最短路径算法所得出路径的能耗并不一定是最小的。针对这一问题,提出一种新型的综合性绿色路由算法,设定能耗作为节点间的权重,融合光旁路及业务量疏导,同时考虑路由和波长分配(RWA)问题,将完成每个业务所需要的能耗最小化,实现节能。仿真结果表明,与最短路径算法相比,绿色路由算法在较大规模网络中能够节省约40%的能耗,节能效果相当显著。 相似文献
7.
8.
疏导可以增加多播业务请求成功传输概率并提高光纤链路带宽利用率,但波分复用光网络中所有节点具有疏导能力则会增加网络造价和复杂度.本文研究了稀疏疏导网络中疏导节点选择策略,提出基于最小代价最大节点度数的疏导节点选择策略;根据疏导节点和非疏导节点功能差别,改进了稀疏疏导网络中多播请求的疏导传输方法.结合最小代价最大度数疏导节点选择策略和多播业务稀疏疏导传输方法,提出一种根据网络业务阻塞率限定值指标实现多播请求所需最少数目疏导节点的稀疏路由方法.仿真结果表明:在网络给定波长数和光收发器端口数目情况下,所提策略能够节约所需疏导节点数目并优化疏导节点位置,降低网络节点构造造价. 相似文献
9.
10.
11.
In IP over WDM networks, since there is a large bandwidth gap between a wavelength capacity and the actual bandwidth required by each user, it is necessary to multiplex low-rate traffic streams (LRSs) into lightpaths by traffic grooming. However, with the number of wavelengths increases, a large number of all optical (OOO) transmitting ports are consumed. Meanwhile, the multi-hop grooming with incorporating full-wavelength conversion capacity in each node requires too many optical-electrical-optical (OEO) ports inevitably. To solve theses problems, waveband switching and intra-band wavelength conversion are proposed. By integrating traffic grooming and waveband switching, this paper devises a new multi-granularity traffic grooming mechanism with the function of intra-band wavelength conversion. Based on the proposed mechanism and integrated grooming policy (IGP), a new heuristic routing algorithm called multi-granularity traffic grooming based on integrated auxiliary graph (MGIAG) is also proposed since the traffic grooming problem is NP-hard. Simulation results show that, compared to traditional integrated grooming algorithm (IGA), MGIAG can save more ports and obtain lower blocking probability. Compared to traditional single-hop traffic grooming algorithm (SHA), lower blocking probability and more savings in transmitting ports can be achieved by multi-hop grooming in MGIAG and IGA although they consume more OEO ports. 相似文献
12.
Since optical network carries a lot of traffic, survivability is very important to ensure the service continuity against network failures. Recently, multicast services become more popular to meet the huge multimedia demand in network, so that multicast survivability in optical network has got more attention. However, multicast survivability may lead to more energy consumption due to more redundant backup resources allocated. Since greening network is particularly important with the energy crisis keeping growing, green multicast survivability in optical network is a challenging issue. This paper focuses on the green multicast grooming protection problem in optical network and designs two auxiliary graphs that includes a virtual topology graph and an integrated graph to address the survivable multicast grooming, routing and wavelength assignment. Based on the auxiliary graphs, this paper proposes an efficient heuristic called green multicast grooming algorithm based on spanning path dedicated protection (GMG-SPDP), in which the network reliability and the energy efficiency are jointly taken into account. Simulation results show that, compared to other algorithms, the proposed GMG-SPDP not only has lower blocking probability and higher bandwidth utilization ratio, but also saves more energy. 相似文献
13.
Fiber-Wireless (FiWi) access network is now becoming a promising architecture for access networks. Survivability is one of the key issues in the planning of FiWi access network because many high-rate traffic flows may be interrupted in case of a single fiber failure, which can cause a huge traffic loss. In addition, the users need ubiquitous broadband access that can be provided by FiWi access network. In this paper, we propose the protection approach called Maximum Covering Planning with Survivability (MCPS), including Integer Linear Programming (ILP) solution and heuristic solution, for the planning of survivable FiWi access network against single distribution fiber failure. The proposed approach aims at maximum coverage under the constraints of network connectivity. When a distribution fiber is broken, the interrupted Optical Network Unit (ONU) can transmit traffic to its backup ONU through the wireless paths between them. Simulation results show the network coverage of clients for different number of ONUs in different urban areas, and demonstrate the relationship between network coverage and the cost represented by the number of WiFi routers. 相似文献
14.
In order to provide cost-efficient and rapid protection against the key link failures dynamically, an intelligent p-cycle protection strategy based on network coding is proposed. Data units are combined from different links using network coding method at the on-cycle nodes, and then they are transmitted downstream for recovering data units lost due to failures. Under static traffic, an integer linear program (ILP) is formulated to provision the optimal p-cycles. Furthermore, according to the dynamic variation of the link importance degree, a heuristic cycle construction algorithm for generating, extending and contracting p-cycle is introduced to achieve intelligent and self-adaptive protection. The key of the proposed protection strategy is how to set the key link as a straddling link of the p-cycle as possible. The experiments demonstrate that the proposed strategy can guarantee instantaneous recovery of data units upon the failure of a key link with a low blocking rate and resource cost. 相似文献
15.
With the number of wavelengths in fibers increasing, the number of optical switching ports in conventional Optical Cross-Connect (OXC) keeps enhancing, so that waveband grooming technique is proposed to save the switching ports in OXC. Most of previous works focused on waveband grooming in single-domain optical network. Since the current optical backbone is actually divided to multiple domains according to the different network providers, it is necessary to study the waveband grooming in multi-domain optical networks. However, waveband grooming in multi-domain optical networks is more challenging than that in single domain networks because of the routing scalability and security issues. Therefore, in this paper, we propose a new heuristic Hierarchical Multi-domain Waveband Grooming (HMWG) algorithm based on Hierarchical Integrated Grooming Auxiliary Graph (H-IGAG) to reduce the total number of optical switching ports. The H-IGAG is compared of the Intra-domain Waveband Integrated Auxiliary Graph (Intra-WIAG) and the Inter-domain waveband Virtual Topology Graph (Inter-VTG). For the demand in single-domain, HMWG directly computes the route from the source node to destination node in the single-domain with waveband grooming on Intra-WIAG. For the demand spanning different domains, HMWG first computes the route from the source node to the selected border node in source domain and computes the route from the selected border node to the destination node in destination domain with waveband grooming on Intra-WIAG, respectively. Then, HMWG computes the route from the selected border node in source domain to the selected border node in destination domain with waveband grooming on Inter-VTG. Simulation results show that, compared with previous grooming algorithm, HMWG can obtain better performance. 相似文献
16.
基于组播树的多粒度波带静态疏导算法 总被引:1,自引:0,他引:1
研究了波带交换中的静态业务疏导算法。波带交换可以有效地减少波长交换的端口数量,但是当波带粒度值取固定值时,波带的粒度难以取得合适值。波带的粒度大,有助于减少交换端口的数量,但是波带利用率低;波带粒度小,有助于提高波带利用率,但是交换端口的数量多。为此,提出了多粒度的波带取值方法。根据静态业务疏导与组播路由的相似性,提出了利用构造组播树解决静态疏导问题的方法。另外,为了减少波带与波长交换平面互联的端口数量,采用了同目的地的波带疏导策略,并针对这一疏导策略提出了一种新的波带疏导辅助图。仿真结果表明,相对于固定粒度的波带取值,可以有效地减少交换端口的数量,并提高波带利用率。 相似文献
17.
A routing and wavelength assignment algorithm is proposed to minimize the number of wavelengths and transceivers required simultaneously under static traffic in translucent optical networks design. 相似文献