摘要

Recent advances in wavelength division multiplexing (WDM) networks have helped enhance the popularity of multicasting services. However, as a single network failure may disrupt the information transmission to multiple end-users, protecting multicast requests against network failures becomes an important issue in network operation. This paper investigates the sub-wavelength level protection for dynamic multicast traffic grooming. A new method named lightpath-fragmentation based segment shared protection (LF-SSP) scheme is proposed. By carefully splitting primary/backup lightpaths into segments to improve resource sharing for both traffic grooming and protection, LF-SSP aims to minimize the network resources allocated for request protection. Extensive simulations are carried out to compare the performance of LF-SSP to some existing approaches, on sub-wavelength-level as well as wavelength-level multicast protections in different cases. Results show that LF-SSP steadily outperforms these existing methods as long as the network resources are not too limited. Influences of the add/drop port resources and the average number of destinations per connection request on the LF-SSP performance are also evaluated.