Abstract: The method of placing regenerators along a trail connecting a source network node with a destination network node of an automatically switched optical network first identifies N tentative regeneration sites and n+1 optical paths along the trail. Wavelengths are assigned to each optical path, and the performance of the trail is assessed based on regenerator placement data and wavelength assignment data.

Abstract: The method of placing regenerators along a trail connecting a source network node with a destination network node of an automatically switched optical network first identifies N tentative regeneration sites and n+1 optical paths along the trail. Wavelengths are assigned to each optical path, and the performance of the trail is assessed based on regenerator placement data and wavelength assignment data.

Abstract: The method of placing regenerators along a trail connecting a source network node with a destination network node of an automatically switched optical network first identifies N tentative regeneration sites and n+1 optical paths along the trail. Wavelengths are assigned to each optical path; and the performance of the trail is assessed based on regenerator placement data and wavelength assignment data. The data identifying this regenerator path, namely regenerator placement data, the wavelength assignment data and the performance parameter of the trail are stored in a list, if the performance parameter is over a threshold. Selection of the tentative sites is revised whenever the initial placement fails due to a reach problem, a wavelength-blocking problem or a path quality problem. If the time for revising the initial placement, or the cost of a regenerator path is unacceptable, the regenerator path is abandoned and a further placement is initiated.

Abstract: The routing cycles method establishes a connection between a source network node and a destination network node based on a cycles graph. For each connection request, the network identifies ‘k’ valid solution cycles on the cycles graph, taking into account any constraints imposed by the type of routing requested. Each valid solution cycle is then split into a pair of routes, which are validated against explicit constraints received with the request, if any. The performance of each pair is then estimated and the pairs are ordered in a list based on their performance. The pair ordering is carried out based on the cost of the routes and on the chance of a successful set-up, which is given by an estimated Q factor. The network attempts to set up the connection according to the class of service for the respective request, first along the best route(s) from the list. Failing this, it will try the second best route(s), etc.