Hypercube connected rings: a scalable and fault-tolerant logical topology for optical networks

A new, fault-tolerant, scalable, and modular virtual topology for lightwave networks employing wavelength division multiplexing is proposed. The propo sed architecture is based on a hypercube connected ring structure that enjo ys the rich topological properties of a hypercube, but it also overcomes on e of its drawbacks. In a hypercube, the nodal degree increases with the num ber of nodes. Hence, the per-node cost of the network increases as the netw ork size grows. However, in a hypercube connected ring network (HCRNet) the nodal degree is small and it remains constant, independent of the network population. A HCRNet, like a hypercube, is perfectly symmetric in the sense that the average internodal distance in an N-node HCRNet is the same from any source node. Its average internodal distance is in the order of log N a nd it is comparable to other regular structures such as the Trous and Shuff leNet. The HCRNet is based on the Cube Connected Cycle (CCC) interconnectio n pattern proposed for multiprocessor architectures. However, the HCRNet im proves on CCC by rearranging its hypercube links, which results in a signif icantly lower average internodal distance. In this paper we present the str uctural properties of HCRNet, and address the issues of scalability, and fa st routing in complete as well as incomplete HCRNet. (C) 2001 Elsevier Scie nce B.V. All rights reserved.