Broadband Packet Switching Technologies: A Practical Guide to ATM Switches and IP Routers

CHAPTER 11

OPTICAL PACKET SWITCHES

Introduction of optical fibers to communication networks has caused a tremendous increase in the speed of data transmitted. The virtually unlimited bandwidth of optical fibers comes from the carrier frequency of nearly 200 THz [1]. Optical networking technology, such as add-drop multiplexers [2, 3], reconfigurable photonic switches [4], and wavelength division-multiplexing (WDM), has progressed well and facilitated optical networking [5, 6]. Especially, recent advances in dense wavelength multiplexing division (DWDM) technology have provided tremendous bandwidth in optical fiber communications [7]. However, the capability of switching and routing packets at this high bandwidth (e.g., 1 Tbit/s) has lagged far behind the transmission capability. Building a large-capacity packet switching system using only electronic technology may lead to a system bottleneck in interconnecting many electronic devices or modules, mainly caused by the enormous number of interconnection wires and the electromagnetic interference they would generate. With the advancement of optical devices technology, several packet switch architectures based on WDM technology have been proposed for large-capacity packet switches. Although today's optical packet switching technology is ...