A light-trail is a generalization of a lightpath such that multiple nodes can take part in communication along the path. A light-trail exhibits properties of dynamic provisioning, optical multicasting and sub-wavelength grooming and architecturally is analogous to a shared wavelength optical bus with an Out-Of-Band (OOB) control channel. The bus feature results in a node that has a large pass-through loss, and hence restricts the size of a light-trail to metro environments. Within a bus the OOB control channel allows for dynamic real-time arbitration. Due to this limitation, it is difficult to extend the light-trail concept to regional and core networks. In this paper we propose a method to provide multihop communication in light-trails thereby relaxing the limitation in hop count, as well as enhancing reach of communications. We propose node architecture and protocol requirements for creating Multi-hop Light-trails (MLTs). We then discuss design issues for MLTs in regional area networks through problem formulation. A simulations study validates MLTs.
['Ashwin Gumaste', 'Jianping Wang', 'Abhay Karandikar', 'Nasir Ghani']
MultiHop Light-Trails (MLT) - A Solution to Extended Metro Networks