WDM/SCM MAC protocol suitable for passive double star optical networks

A new WDM/SCM access protocol with node-grouping scheme suitable for passive double star packet networks is proposed. Combining SCM with WDM enables us to place control and data channels on the same wavelength resulting in large bandwidth and high data rate transmission. In the proposed protocol, packet delay is reduced in a large scale because the parts of access control should be done for the number of groups rather than the number of network nodes. Furthermore, additional reduction of the packet delay is achieved by limiting the propagation paths of control packets to the roundtrip between source nodes and sub-hub based on double star network configuration.