An optical layer protocol for lightpath management in WDM networks

This paper deals with an optical layer protocol designed for next generation lightwave networks, known as all-optical networks (AONs), where path between end-to-end nodes remains entirely optical. These paths are called lightpaths. Unlike OSI-RM, in the AON architecture, a new layer, called optical layer, has been introduced to manage the lightpath-related-functions. The optical layer lies in between physical layer and data link layer. The objective of this paper is to define a specification for the optical layer protocol for AONs. In order to study the dynamics of the optical layer protocol system, we first employ the communicating finite state machine model to represent the protocol. Then a reachability analysis of the model is performed to verify the protocol. This paper shows how the optical layer protocol can be specified formally and made errorfree by the step-wise refinement of an initial specification where validation is done after each refinement.