Light-trains: A Cross-Layer Delivery Mechanism for High Bandwidth Applications in Moving Metro-Trains
2006 IEEE International Conference on Communications
Trains as a mass transport system are a strong application case for coarsely granular bandwidth-on-demand networking. Multiple trains time-sharing the same track, traveling at a significant speed and containing a large number of bandwidth savvy users represents a premier motivation for the merger of optical and wireless communications. Wireless delivery methods alone cannot suffice the need for such a large moving mass of bandwidth intensive users. We propose a method to efficiently integrate a
... wireless network over a flexible optical backbone. The proposed method is built upon the light-trails optical platform and involves a unique control layer that adapts to an overlaid wireless network. Here, we propose a cross-layer protocol that enables seamless communication for these "lighttrains". We also show benefits in terms of throughput, end-to-end delay, bandwidth efficiency and scalability of such a scheme through a simulation study. Power based hand-off is the typical technique used for maintaining ubiquity. Hand-off occurs in the provisioning zones. Since multiple trains share the same track we are compelled not to use the track as a medium for data transport. Instead, an underlying optical network serves as a good choice, as track operators generally tend to have rights of way along their routes. In order to support the communication to moving trains, the underlying optical network needs to meet certain characteristics. The principle requirement on the optical network is dynamic provisioning of bandwidth. Data paths must be provisioned for wireless gateways along the track through the optical network on an on-demand basis. This timesensitive requirement, coupled with the fact that multiple This full text paper was peer reviewed at the direction of IEEE Communications Society subject matter experts for publication in the IEEE ICC 2006 proceedings.