Traffic grooming is the name given to a family of optical network design problems that has attracted significant attention from both academia and industry in the last decade or so. Traffic grooming has grown from a narrow research area to a mainstream requirement for real world practitioners. This book presents the practical motivation, theoretical description, and extant techniques for traffic grooming in optical networks. The description of the various topics of research is authored by leading researchers in this area, and contains comprehensive description of related literature for each area. This book is intended to be a definitive reference and text for traffic grooming both for the practitioner in industry and the student in academia.