Dynamic Capacity Allocation in OTN Networks

A dynamic Optical Transport Network (OTN) has the advantage of being able to adjust the connection capacity on demand in order to respond to variations on traffic patterns or to network failures. This feature has the potential to reduce operational costs and at the same time to optimize networks resources. Virtual Concatenation (VCAT) and Link Capacity Adjustment Scheme (LCAS) are two techniques that when properly combined can be used to provide improved dynamism in OTN networks. These techniques have been previously standardized in the context of Next Generation SDH/SONET networks. VCAT is used to tailor the capacity of network connections according to service requirements, while LCAS can adjust dynamically that capacity in a hitless manner. This paper presents an overview of the application of VCAT/LCAS techniques in the context of OTN. It explains in detail how these techniques can be employed to resize the connection capacity and analyses its use in network protection solutions. Furthermore, a detailed analysis of the time delays associated with different operations is provided and its application to some reference networks is undertaken. The obtained results provide an idea about the time delays of the capacity adjustment processes and define potential scenarios for implementing VCAT/LCAS techniques.