All-optical networks (AON) facilitate the transportation of heterogeneous services made up of diverse technologies, protocols and formats with minimal impact to the network infrastructure. This is in contrast to the technologies in opaque networks that are typically protocol and format specific. Emerging solutions for next generation AON will simultaneously allow mesh connectivity of services with different bit rates and/or modulation formats over common fibre infrastructure, thus providing a flexible transport platform for current and future services. Consequently, it is an inefficient use of network resource to provision end- to-end lightpaths without considering the different optical performance requirements of the different service interfaces. This book is about a resource allocation mechanism that works in a heterogeneous environment. In particular, the focus is on the wavelength dependent nature of chromatic dispersion (CD) effect. Note that very high requirement is imposed on CD compensation capability in future reconfigurable network environment as the path changes dynamically.