Efficient multicast schemes for optical burst-switched WDM networks

In this paper, we study several multicast schemes in optical burst-switched WDM networks taking into consideration of the overheads due to control packets and guard bands (GBs) of bursts on separate channels (wavelengths). A straightforward scheme is called Separate Multicasting (S-MCAST) where each source node constructs separate bursts for its multicast (per each multicast session) and unicast traffic. To reduce the overhead due to GBs (and control packets), one may piggyback the multicast traffic in bursts containing unicast traffic using a scheme called Multiple Unicasting (M-UCAST). The third scheme is called Tree-Shared Multicasting (TS-MCAST) whereby multicast traffic belonging to multiple multicast sessions can be mixed together in a burst, which is delivered via a shared multicast tree. The multicast schemes (M-UCAST and TS-MCAST) are compared with S-MCAST in terms of bandwidth consumed and processing load.