And light signals corresponding to the 3 division multiplexing, optical switching is also divided into air, sky and wave 3, complete air separation channel, Sky Channel and channel switching.
Types of business support, optical switching can be divided into a circuit-switched (wavelength-routing) and packet-switched in two ways. As early as in the middle of in the early 1990 of the 20th century, people began to study Photonic switching technology, ATM optical switching, packet optical switch became a hot research topic. Expected optical breakthrough e-rate restrictions, improving the throughput of the switching unit. But these high-speed optical switch in optical switching needs to achieve, plus light logic device is still immature, unable to complete the complex logic functions, we can only implement electronically controlled optical switch, that is in the electric field recognition letter head, controlled by the signal light switch action. Due to the electronic exchange did not get rid of electronic "bottleneck" restriction, which limits their development and application. So far, high speed optical switch and optical logic device technology is still not a major breakthrough.
Based on wavelength division switching or wavelength-routed all-optical networks in the past few years, there is a considerable development and progressive scale of being. All optical network is defined as a customer signals provide optical transmission network, including optical transmission and multiplexing, routing, monitoring, and survival functions. Complete the Exchange is mainly the function of optical cross connectors (OXC) and optical add-drop multiplexer (OADM). After several years of research, experiment, all optical networks are the intelligent direction, automatic switched optical network (ASON) is its contribution to the development of intelligent mainstream direction.