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| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Narula-Tam, A. Modiano, E. Brzezinski, A. |
| Copyright Year | 1983 |
| Abstract | In a wavelength-division multiplexed (WDM)-based network, a single physical link failure may correspond to multiple logical link failures. As a result, two-connected logical topologies, such as rings routed on a WDM physical topology, may become disconnected after a single physical link failure. We consider the design of physical topologies that ensure logical rings can be embedded in a survivable manner. This is of particular interest in metropolitan area networks, where logical rings are in practice almost exclusively employed for providing protection against link failures. First, we develop necessary conditions for the physical topology to be able to embed all logical rings in a survivable manner. We then use these conditions to provide tight bounds on the number of physical links that an N-node physical topology must have in order to support all logical rings for different sizes K. We show that when K/spl ges/4 the physical topology must have at least 4N/3 links, and that when K/spl ges/6 the physical topology must have at least 3N/2 links. Subsequently, we generalize this bound for all K/spl ges/4. When K/spl ges/N-2, we show that the physical topology must have at least 2N-4 links. Finally, we design physical topologies that meet the above bounds for both K=4 and K=N-2. Specifically, our physical topology for embedding (N-2)-node rings has a dual hub structure and is able to embed all rings of size less than N-1 in a survivable manner. We also provide a simple extension to this topology that addresses rings of size K=N-1 and rings of size K=N for N odd. We observe that designing the physical topology for supporting all logical rings in a survivable manner does not use significantly more physical links than a design that only supports a small number of logical rings. Hence, our approach of designing physical topologies that can be used to embed all possible ring logical topologies does not lead to a significant overdesign of the physical topology. |
| Starting Page | 1525 |
| Ending Page | 1538 |
| Page Count | 14 |
| File Size | 729778 |
| File Format | |
| ISSN | 07338716 |
| Volume Number | 22 |
| Issue Number | 8 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2004-10-01 |
| Publisher Place | U.S.A. |
| Access Restriction | One Nation One Subscription (ONOS) |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Network topology Routing Intelligent networks Wavelength division multiplexing Protection Optical fiber networks Bandwidth WDM networks Optical network units Metropolitan area networks |
| Content Type | Text |
| Resource Type | Article |
| Subject | Computer Networks and Communications Electrical and Electronic Engineering |
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