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排序方式: 共有143条查询结果,搜索用时 15 毫秒
1.
Next generation backbone networks will likely consist of IP routers as well as optical cross connects (OXCs) and will deploy an optical control plane protocol. Generalized Multi Protocol Label Switching (GMPLS) has been proposed as the candidate of choice for the control plane. Optical fibers may carry large volumes of traffic and therefore adequate mechanisms must exist to enable the network to automatically recover from failures of fiber. In mission critical networks survivability becomes very important. We investigate the problem of autonomous recovery in such networks. The literature contains work in this area that investigates the problem of multilayer recovery. Such recovery had only been sequential in the sense that the published work recovers first in the optical domain, assuming the availability of redundant resources, and then proceeds to recover packet label switched paths. We report a recovery procedure for recovering packet label switch paths (packet LSPs) and lambda label switch paths (λLSP) concurrently. We have conducted an OPNET-based simulation study that compares the performance of the concurrent scheme with the previously published sequential two-layer recovery scheme. The study shows that the concurrent two-layer recovery scheme performs as much as forty-four percent faster than the sequential two-layer recovery scheme. 相似文献
2.
武装直升机抗坠毁设计研究 总被引:5,自引:0,他引:5
介绍了武装直升机抗坠毁的概念设计原理 ,提出了抗坠毁设计中的一些关键问题 ,为武装直升机抗坠毁设计提供理论指导。 相似文献
3.
S. Sygletos C. Skoufis C. Matrakidis A. Stavdas N. LeSauze D. Chiaroni 《Optical Switching and Networking》2005,2(1):19-33
This paper investigates the problem of dynamic survivable lightpath provisioning against single-node/link failures in optical mesh networks employing wavelength-division multiplexing (WDM).We unify various forms of segment protection into generalized segment protection (GSP). In GSP, the working path of a lightpath is divided into multiple overlapping working segments, each of which is protected by a node-/link-disjoint backup segment. We design an efficient heuristic which, upon the arrival of a lightpath request, dynamically divides a judiciously selected working path into multiple overlapping working segments and computes a backup segment for each working segment while accommodating backup sharing. Compared to the widely considered shared-path protection scheme, GSP achieves much lower blocking probability and shorter protection-switching time for a small sacrifice in control and management overhead.On the basis of generalized segment protection, we present a new approach to provisioning lightpath requests according to their differentiated quality-of-protection (QoP) requirements. We focus on one of the most important QoP parameters—namely, protection-switching time—since lightpath requests may have differentiated protection-switching-time requirements. For example, lightpaths carrying voice traffic may require 50 ms protection-switching time while lightpaths carrying data traffic may have a wide range of protection-switching-time requirements. Numerical results show that our approach achieves significant performance gain which leads to a remarkable reduction in blocking probability.While our focus is on the optical WDM network, the basic ideas of our approaches can be applied to multi-protocol label switching (MPLS) networks with appropriate adjustments, e.g., differentiated bandwidth granularities. 相似文献
4.
5.
随着反坦克武器数量的增多、威力的增大,使坦克防护的内函由原来的装甲防护演变成了坦克生存力。这一变化反映了西方对坦克防护的重视。与国际先进水平相比,我国在坦克生存力研究方面还存在着明显的差距。急需采取有效措施,迅速提高我国坦克的防护水平。该文对上述几个问题进行了论述。 相似文献
6.
This article presents a novel protection approach using Generalized Multi-Protocol Label Switching (GMPLS). This strategy
provides protection at the Wavelength Division Multiplexing (WDM) layer, meaning that all Internet Protocol Label-Switched
Path (IP LSPs) nested inside a lightpath are protected in an aggregated way. It uses resources efficiently since spare capacity
of working primary lightpaths can be used for backup purposes whenever necessary. The IP and WDM layers are treated together
as a single integrated network from a control plane point of view, so that network state information from both layers can
be used. Besides discussing the strategy proposed and the key features of GMPLS that will allow its implementation, we mathematically
formulate the maximum throughput problem. Thereafter, we propose and compare heuristic algorithms for IP-over-WDM networks
using three protection approaches: WDM lightpath protection, IP LSP protection, and the proposed protection scheme. Their
throughputs and recovery times are analyzed and compared. Our results show that, for a representative mesh network, the proposed
aggregated protection scheme presents better protection efficiency and good scalability properties when compared with the
other two schemes. 相似文献
7.
Protection vs. redundancy in homogeneous parallel systems 总被引:1,自引:1,他引:0
The article considers defense resource allocation in a system exposed to external intentional attack. The defender distributes its resource between deploying redundant elements and their protection from attacks. The attacker distributes its effort evenly among all of the elements or among elements from a chosen subset. The vulnerability of each element is determined by an attacker–defender contest success function. The expected damage caused by the attack is evaluated as system unsupplied demand. The article considers both the cases without and with performance redundancy. 相似文献
8.
Lei Hongfang Yu Lemin Li 《AEUE-International Journal of Electronics and Communications》2006,60(6):467-470
This letter studies the protection problem in WDM mesh networks and proposes a new scheme called improved path-based shared protection (IPSP) to tolerate double-link failures. Differing from previous path-based shared protection (PSP), IPSP allows some primary and backup paths to share resources. Simulation results show that IPSP outperforms PSP. 相似文献
9.
The paper considers vulnerable multi-state series-parallel systems operating under influence of external impacts. Both the external impacts and internal failures affect system survivability, which is determined as the probability of meeting a given demand. The external impacts are characterized by several destructive factors affecting the system or its parts simultaneously.In order to increase the system's survivability a multilevel protection against the destructive factors can be applied to its subsystems. In such systems, the protected subsystems can be destroyed only if all of the levels of their protection are destroyed.The paper presents an algorithm for evaluating the survivability of series-parallel systems with arbitrary configuration of multilevel protection against multiple destructive factor impacts. The algorithm is based on a composition of Boolean and the Universal Generating Function techniques.Illustrative examples are presented. 相似文献
10.
Lei Guo Xingwei Wang Xiaobing Zheng Yu Zhang Xuekui Wang 《Photonic Network Communications》2008,16(3):245-252
In this paper, we study the path-based shared protection (PBSP) and the link-based Hamiltonian cycle protection (LBHCP) schemes
for tolerating single-link failures in survivable wavelength-division-multiplexing networks. Although previous work indicated
that PBSP can perform better than link-based shared protection including the case of LBHCP, from theoretical analysis and
simulation results in this paper, we can clearly see that this indication of previous work is not suitable for LBHCP since
it can have a better resource utilization ratio and a faster recovery time than PBSP. Therefore, the new result of this paper
is a modification for the previous inaccurate idea and it also can well guide future work of researchers.
相似文献
Xingwei WangEmail: Email: |