Optical cross connects for optical networking

As the transmission line rate supported by optical fibers increased from 45 Mb/s to 2.5 Gb/s during the 1980s, interexchange carrier networks introduc ed various digital cross connects to provision, groom, and restore DS0 (64- kb/s) DS1 (1.5-Mb/s), and DS3 (45-Mb/s) traffic. With the recent release of its WaveStar(TM) Optical Line System (OLS) 400G, Lucent Technologies has i ncreased the fiber transmission capacity more than one-hundred-fold using d ense wavelength division multiplexed (DWDM) 2.5- and 10-Gb/s signals. To me et the challenge of managing the bandwidth within emerging "terabit offices " enabled by DWDM, Lucent and other vendors are aggressively pursuing resea rch and development of optical cross connects capable of directing traffic on a per-wavelength basis. In this paper we explore the role of an optical cross connect (OXC) in evolving wavelength division multiplexed (WDM) optic al networks. We also examine various OXC architectures and address the tech nological challenges and practical tradeoffs that affect their port count ( size), functionality, and cost.