Optical Burst Switching

Optical burst switching (OBS) is an experimental switching paradigm representing an intermediate solution between circuit (wavelength) and packet switching in optical networks.

Purpose

Its purpose is to dynamically provision sub-wavelength granularity by optimally combining electronics and optics. OBS considers sets of packets with similar properties called Bursts. Therefore, OBS granularity is coarser than OPS. OBS provides more bandwidth flexibility than wavelength routing but requires faster switching and control technology. On the other side, OBS require less complex technology than optical packet switching (OPS) because it extensively uses aggregation and control signals are processed out of band. OBS can be used for realizing end-to-end all optical communications.

Method

In OBS, packets are aggregated into data bursts at the edge of the network. Various assembling schemes based on time and/or size exist. OBS features the separation between control and data planes. A control signal (CS) is associated to each data burst (DB). The CS is signaled out of band and processed electronically, whereas the DB is transmitted optically. The DB can cut through intermediate nodes, where data buffers are consequently not required (contrary to OPS). Full transparency of the data plane can, moreover, be achieved: no Electro-Optical (E/O) and no O/E conversion of the data flows occur.

Additional resources

*Baldine I, "et al"., 2003, "Just-in-Time Optical Burst Switching Implementation in the ATDnet All-Optical Networking Testbed" "Proceedings of the Global Telecommunications Conference (GLOBECOM 2003)", San Francisco, USA.
*Chen, Yang; Qiao, Chunming and Yu, Xiang; "Optical Burst Switching (OBS): A New Area in Optical Networking Research", "IEEE Network Magazine", Vol. 18 (3), pp.16–23, May–June 2004.
*Gauger, C.; 2003, "Projects and Test Beds Related to OBS in Europe", "Proceedings of the 2nd International Workshop on Optical Burst Switching, IEEE Globecom", San Francisco, USA.
*Jue, Jason P. and Vokkarane, Vinod M.; "Optical Burst Switched Networks", Springer, Optical Networks Series, 2005 ISBN 0-387-23756-9.