Similar to the electronic domain in which packet switching networks are used to transport users' traffic (which is mostly Internet traffic), optical packet switching (OPS) networks must be set up for future worldwide communications in order to transport the huge traffic generated by so many Internet users and applications. The major problem for an OPS network is the contention of optical packets and the lack of optical buffering for resolving this contention. So far, many researchers and scientists have proposed practical solutions to overcome the problem of OPS networks; however this is the first book that collects all the techniques and studies them in depth. Focusing on the system level of OPS and quality of service (QoS) provisioning, the book covers: An introduction to OPS networks, OOFDM networks, GMPLS-enabled optical networks, QoS in OPS networks Techniques that either avoid contention, or resolve contention, or both, in a hybrid manner in both long-haul and metro OPS networks Methods by which an OPS network can be used in parallel with other optical switching mechanisms The most recent methods suitable for metro OPS networks Written by an expert in the field of OPS networking, this book provides a comprehensive study on the protocols and techniques developed for improving the operation of OPS.