Dynamic traffic grooming algorithms for reconfigurable SONET over WDM networks - Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE

Most of today's optical networks are built on E:ONET rings [I]. Using WDM technology, multiple rings can be sup ported on a single fiber ring [3]. In this architecture, each wavelength independently carries a SONET ring. Each SONET ring can further support multiple low speed streams (e.g. an OC48 SONET ring can support 4 OC-12 or 16 OC-3 streams at the same time). At each node a WDM Add/Drop Mulliplexer (WADM) adds and drops or bypasses traffic on any wavelength. At each node, there are SONET adddrop multiplexers (SADM) on each wavelength to adddrop low speed streams. So the number of SADMs per node will increase linearly with th,: number of wavelengths that a single fiber ring can carry. The cost of SADMs will dominate the total cost of the optical network. But in fact, it is not necessary for each node to be equipped with SADMs on each wavelength. The problem of combining different low speed traffic streams into high-speed traffic streams in such a way that the number of SADMs is minimized is called traffic grooming. Several studies have been done on