摘要

The increase of multimedia applications results in the growing popularity of multicast demands. At the same time, survivability in an optical network is very important because of its very high transmission rate. Therefore, it is necessary to provide survivability for multicast demands in an optical network. Previous works have proposed multicast protection schemes for single-fiber link failure, in which the preconfigured protection cycle, known as the p-cycle, is an efficient method to overcome the long restoration time and the complicated protection switching procedure in comparison with other schemes. However, most previous schemes are applied only to static multicast protection. Although some schemes are extended to dynamic multicast protection, they do not consider the protection for straddle links. To overcome the shortcoming, this paper improves the existing p-cycle-based dynamic multicast protection and proposes an enhanced intelligent p-cycle (EIpC) scheme, in which all working light-trees of multicast demands can be protected by a p-cycle in the network. For each multicast demand, EIpC can compute a set of high-efficient p-cycles to provide dynamic protection. By combining the existing p-cycles for meeting certain conditions, EIpC can reduce the wavelength usage of p-cycles. Simulation results show that EIpC can obtain performance improvement compared to conventional schemes.

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