Feature

Ultrahigh-speed optical time-division multiplexing transmission (OPN Trends Supplement)

Satoki Kawanishi

All indicators are that the rapid growth in data traffic will continue. One particularly important trend is the increase in transmission speed of local area networks (LANs); the speed of the next generation Ethernet is 10 Gbit/s, the same as that of today’s backbone transmission systems. We are now living in what is substantially a distance-free world, in which connection with anyone on Earth can be achieved by means of optical communication networks. International commerce will generate greater interconnection between high-speed LANs, as well as more extensive use of the Internet. Indeed, Internet access is now so pervasive that the latest Internet-enabled devices include not only cellular phones but appliances such as refrigerators and microwave ovens. Society is becoming ever more dependent on the free flow of data. Backbone networks with huge capacity are essential to maintain our way of life. We have been able to increase the transmission capacity of digital communication networks by adopting and enhancing the technique of time-division multiplexing (TDM). With TDM, the binary signals associated with different channels are interleaved to form a higher-speed multiplexed signal.