An optical packet-switched IP-over-WDM metro ring network

In this paper, novel distributed medium access protocols for a time-slotted WDM metro ring employing optical packet switching and supporting variable-length data packets such as IP datagrams directly in the optical layer are proposed. A scalable multi-hop WDM ring is considered since we assume much more nodes than available wavelengths in the network. In the underlying control-channel based architecture, each node is equipped with three transmitters (two fixed-tuned and one tunable) and two fixed-tuned receivers. The new access control scheme relies on a frame-based slot reservation strategy including reservation of successive slots for data packets longer than the given slot size, and immediate access for packets shorter than the slot length. Thus, a highly efficient IP-over-WDM metro network with simple receiver hardware is obtained.