Integrated Broad-Band Communication Using Optical Networks--Results of an Experimental Study

This paper reports on an experimental system of an integrated communication network built with components representing the state-of-the-art in the area of optical fiber transmission and large-scale integration of logic functions. These components make it possible to apply new concepts for signal processing, transmission, and switching in the experimental system. The large bandwidth of optical channels allows the transmission of all kinds of communication services including data, audio, and video, while semiconductor technology offers low cost realization and mass production of complex signal processing and switching functions to handle all these services within one network. The concept of the system is presented and results on system components and subsystems are given.     

Uni- and bidirectional 4λ×560 Mb/s transmissionsystems using WDM devices based on wavelength-selective fusedsingle-mode fiber couplers

Four-wavelength-channel wavelength-division multiplexing (WDM) lab transmission system experiments with buried heterostructure (BH) lasers at 1200-, 1240-, 1280-, and 1320-nm wavelengths, all-fiber WDM devices, and 20-km single-mode link fiber at a 560-Mb/s bit rate demonstrated that unidirectional and bidirectional WDM transmission systems could be operated successfully by using all-fiber 4λ multiplexing, 4λ demultiplexing, or 4λ multiplexing/demultiplexing devices with a low insertion loss per wavelength channel (2.1-4.7 dB), enough optical far-end crosstalk attenuation (18-37 dB), and high optical near-end crosstalk attenuation (43-49 dB). It is concluded that the four-wavelength-channel WDM lab transmission system at 560 Mb/s mainly used as a test bed is not representative of future unidirectional trunk WDM systems. Such systems favor distributed feedback (DFB) lasers in the 1500-1560-nm wavelength range where fiber attenuation is lower than in the 1200-1320 nm wavelength range and where 1500-nm DFB lasers with a smaller linewidth do not limit the repeater distance as much because of mode partition noise     

Feasibility of a 1 Gbit/s/ 565 Mbit/s bidirectional single-mode-fibre subscriber line for B-ISDN using 1279 nm/ 1315 nm wavelength division multiplexing

A laboratory system, transmitting 1 Gbit/s signals to a subscriber station and 565 Mbit/s signals back to a head station via one 20 km-long single-mode fibre, has been realised. Wavelength division multiplexing via two 3 dB fibre couplers of selectivity ?0.04 dB/nm has been used. The experiment demonstrates that bidirectional single-mode-fibre transmission is applicable to a future B-ISDN subscriber network.     

Services Integration and Multiplexing for Broad-Band Communication Systems

In broad-band communication networks, a number of services are simultaneously available to the subscriber. The issues of service integration and multiplexing techniques, and their impact on network topologies, are addressed in this paper. Alternative realizations of broadband networks, together with necessary electrical and optical components, are discussed. A comparison between the different alternatives is also made.