Virtual Optical Bus: An Efficient Architecture for Packet-Based Optical Transport Networks

The virtual optical bus (VOB) is presented as a novel architecture for packet-based optical transport networks. The VOB is an evolutionary networking architecture based on the optical burst/packet switching (OBS/OPS) paradigm with a higher performance-in terms of packet loss rate and network throughput. The achieved gain comes at a cost of a marginal increase in the delay that packets experience at the ingress edge of the network, where we can still use inexpensive electrical buffers. In the VOB architecture, flows of traffic between nodes in the network are grouped into clusters and within each of the clusters a special form of coordination on packet transmission is introduced. This coordination ensures collision-free packet transmission within each cluster. Additionally, clustering of flows and selection of paths for clusters are done in a way that the interaction among routes of clusters in the network is minimized. This leads to a reduction of packet collisions in the network and also an increase in the network throughput. Design issues related to the VOB architecture are discussed and two design examples are presented that illustrate the high potential of this approach.