Implementation schemes of multihop lightwave networks

The paper compares two implementation schemes of multihop virtual topologies in a WDM passive star network. The first implementation scheme, denoted by link mapping is the traditional one-to-one mapping of the virtual topology links to the system wavelengths. In the second scheme, denoted by node mapping, a unique wavelength is assigned to each node (transmitter) in the system. The comparison is given in terms of the system hardware (number of wavelengths, number of transmitters and receivers and their cost), the system performance (average delay, average queue length and capacity) and capacity per unit cost which reflects the system hardware, its cost and the system performance. The authors have shown that unless the receiver cost dominates the system cost it is always possible that the capacity per unit cost of the node mapping scheme is better than that of the corresponding link mapping scheme