Sparsely hubbed light-trail grooming networks

Recently, a new architecture called light-trails has been proposed that provides a novel control and management solution to address IP-centric issues at the optical layer. By inclusion of simple hardware that performs drop and continue functionality, overlaid with a light-weight control protocol, light-trails enable efficient sharing of network resources, improve bandwidth utilization and minimize network costs. Due to power budget constraints in such networks, it may not always be possible to have end to end communication in pure optical domain and requests may be required to traverse multiple intermediate transit points called hub nodes before reaching the final destination. The hub nodes need to be equipped with special hardware for switching and grooming connections. We investigate the problem of designing networks where such hubs are sparsely located. We show through our simulation results that by carefully designing heuristics for hub node placement and trail routing, it is possible to achieve high throughput with minimal number of hub nodes.