On dynamic multicast traffic provisioning with grooming capabilities support in light-trail networks

In recent years, because of the popularity of Internet and the rapid growth of multimedia applications, the requirements of bandwidth from users increase violently in optical networks. Various multicast multimedia services also bring challenges to next generation optical networks. As the rapid advance of DWDM, the bandwidth of a single fiber link is significantly improved. However, the traditional circuit switching architecture, lightpath, has the disadvantage with lower bandwidth utilization of a single wavelength. Light-trail has been proposed as an efficient solution to support optical networks. Compared with lightpath approach, a light-trail can achieve fast provisioning for multiple connections without optical switching. The support of sub-wavelength granularity in light-trial network increases the utilization of wavelength bandwidth effectively. The most distinctive feature is that light-trail allows multiple node access, so it possesses natural multicasting capability inherently. In a light-trail, the single send by one node will be received by the downstream nodes. In other words, light-trail has the advantage of natural multicasting. Furthermore, incorporating traffic grooming into light-trail, it can obviously become a strong candidate to support multicasting and multi-granularity bandwidth demands in the future. In this article, we propose a dynamic multicast routing algorithm with traffic grooming consideration in light-trail networks, named Dynamic Light-Trail-based Multicast Routing algorithm (DLTMR). For static traffic, we use a set of ILP formulations to calculate the optimal solution for minimizing the number of established light-trails. In the simulation, we use various network topologies and variant limitation of network resource to verify that DLTMR can efficiently improve blocking performance in the light-trail networks.