In optical code path networks a cycle attack phenomenon has been reported. Cycle attack is caused by multiaccess interference (MAI) among different optical code (OC) paths carried by the same wavelength. A previous study proposed a heuristic wavelength assignment scheme to avoid this unintended cycle attack problem. However, the wavelength assignment retry in the previous proposal may impose an overhead on OC path establishment latency, and furthermore it was not a complete solution to eliminate cycle attacks. In this paper, we propose a cycle-attack-free logical topology design to eliminate the unintended cycle attack problem in the network planning phase instead of the wavelength assignment. The basic idea is to convert the physical network topology into some tree-based logical topologies in which OC paths are routed. Simulation results show that (a) using the tree-based topologies with smaller average hop count helps to obtain better blocking performance and (b) in distributed optical path establishment our proposed approach performs better in terms of blocking and delay performance under the relative dynamic traffic condition.
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