Granularity in WDM networks: the role of fiber nonlinearities

Granularity is emerging as a central issue for WDM optical networks, as the added cost of optical components could be more than offset by the added flexibility and the savings on the electronics. In this letter, the issue of granularity is addressed from a transmission point of view. As an example, two ways to achieve an aggregate capacity of 100 Gb/s over a given point-to-point connection are considered: ten channels at 10-Gb/s and twenty channels at 5 Gb/s. It is found that the impact of optical fiber nonlinearities is lower in the second system.