Date Added: Aug 2010
Routing and wavelength assignment under availability constraints has been extensively researched recently. Availability (or more precisely, steady-state availability) can be defined as the average probability of a connection operating over a time window that tends to infinity. However, Service Level Agreements (SLAs) commit a minimum connection uptime fraction over a finite contract duration. This random variable is known in reliability engineering as interval availability. If the minimum agreed interval availability is not honored, the service provider is penalized. In order to balance the risk of non-compliance fines against asset protection costs, network planners must know the interval availability distribution.