Optimal Design of Optical Ring Networks with Differentiated Reliability (DiR)
Optimal Design of Optical Ring Networks with Differentiated Reliability (DiR)
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DOI：
10.1007/3-540-44554-4_20
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发表时间：
2001-12
期刊：
影响因子：
--
通讯作者：
A. Fumagalli;M. Tacca
中科院分区：
文献类型：
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作者：
A. Fumagalli;M. Tacca
目前的光网络通常提供两种程度的服务可靠性：在网络中存在单一故障时提供完全保护，以及根本不提供保护。这种情况反映了历史上的双重性，其根源在于曾经分裂的电话和数据环境。面向电路的业务需要保护，即，提供随时可用的备用资源，以在故障的情况下替换工作资源。面向数据报的服务依赖于恢复，即，通过路由表更新等动作，动态搜索和重新分配受影响的资源。然而，当前的发展趋势正逐渐推动网络设计朝着统一解决方案的方向发展，该解决方案将共同支持传统的语音和数据业务以及各种新颖的多媒体应用。随着服务质量（QoS）和区分服务（Differentiated Services）等概念在同一网络中提供不同级别的服务性能的重要性的增加，证明了这一趋势。与这种模式相一致，本文正式引入了区分可靠性（DiR）的新概念，并将其应用于在同一网络层中使用公共保护机制提供多个可靠性等级（类），即，路径切换根据DiR概念，考虑层中的每个连接都保证最小可靠度，定义为该连接允许的最大故障概率。因此，为一个给定的连接选择的可靠性程度是由应用程序的要求，而不是由实际的网络拓扑结构，设计约束，网络组件的鲁棒性，和跨度的connection.A有效的算法，提出了设计的波分复用（WDM）层的DiR环。
Current optical networks typically offer two degrees of service reliability: full protection in presence of a single fault in the network, and no protection at all. This situation reflects the historical duality that has its roots in the once divided telephone and data environment. The circuit oriented service requiredprotection, i.e., provisioning of readily available spare resources to replace working resources in case of a fault. The datagram oriented service relied uponrestoration, i.e., dynamic search for and reallocation of affected resources via such actions as routing table updates.The current development trend, however, is gradually driving the design of networks towards a unified solution that will jointly support traditional voice and data services as well as a variety of novel multimedia applications. The growing importance of concepts, such Quality of Service (QoS) and Differentiated Services that provide varying levels of service performance in the same network evidences this trend.Consistently with this pattern, the novel concept ofDifferentiated Reliability(DiR)is formally introduced in the paper and applied to provide multiple reliability degrees (classes) in the same network layer using a common protection mechanism, i.e., path switching. According to the DiR concept, each connection in the layer under consideration is guaranteed a minimum reliability degree, defined as the Maximum Failure Probability allowed for that connection. The reliability degree chosen for a given connection is thus determined by the application requirements, and not by the actual network topology, design constraints, robustness of the network components, and span of the connection.An efficient algorithm is proposed to design the Wavelength Division Multiplexing (WDM) layer of a DiR ring.