Functional architecture of optical channel network

Atomic functional architecture model has been accepted by ITU-T to describe the functional architecture of transport networks as well as equipment specification in an implementation independent way. With the existing functional architecture components four different solutions have been proposed to model the complex optical channel (OCh) layer network. One approach is to assign 3-R to the OMS/OCh adaptation function; the second approach is to introduce dedicated transparent layers or to split single OCh layer into several sub-layers; the third is to be deployed by using an abstract characteristic information (CI) definition; the last is using super layer architecture component. This paper analyzes these four methods and presents a new approach by introducing virtual layer network and virtual CI. Virtual adaptation, virtual connection point and virtual link connection are also introduced in order to cover the different transparent connections within a layer network. In addition, examples of using virtual layer component to model the OADM with transparent pass-through and to provide the necessary transparent connections for optical network elements are presented in this paper.