An approach towards a singlemode local loop is presented in which each customer is given a dedicated wavelength channel by taking different wavelength slices from identical LEDs. This is accomplished by means of wavelength division multiplexing (WDM) components. Results from a fourchannel system operating at 2 Mbits over 2.2 km, together with a theoretical analysis of a tenchannel system, are presented Published in: Electronics Letters (Volume:24 , Issue: 7 ) Page(s): 389 390 ISSN : 00135194 INSPEC Accession Number: 3151136 long haul specifications for distances between 6 and 11 km (Table 2). The bit error rate of the DS1 data stream was measured and found to be better than Table 2 VIDEO PERFORMANCE MEASUREMENTS No. of video No. of DS1 Length channels channels SNR DG DP km % deg 0 1 0 67.0 1.9 0.5 6 1 1 62.0 1.8 1.2 6 2 1 61.0 1.8 1.05 11 1 1 57.0 1.2 1.9 11 2 1 56.0 4.8 33 Acknowledgments: We acknowledge the assistance of L. Curtis, R. E. Spicer, P. W. Shumate and C. W. Lundgren, all of Bellcore, and J. Koscinski and M. Eros of General Optron ics Corp. for their assistance during this study. P. S. VENKATESAN P. S. NATARAJAN J. OROST Bell Communications Research 331 Newman Springs Road Red Bank, NJ 077017020, USA 4th February 1988 References OLSEN, G. H. : ‘Long wavelength LEDs, a challenge to laser diodes’, Photonics Spectra, 1985, 17, pp. 121124 PERSONICK, s. D. : ‘Fiber optics: technology and applications’ (Plenum Press, New York, 1985) SHUMATE, P. w., et al.: ‘Transmission of 140Mbs signals over single mode fiber using surface and edgeemitting 1.3pm LEDs’, Electron. Lett., 1985, 21, pp. 522524 WAKABAYASKI, T., KIHARA, T., and MURASE, T.: ‘4590135 Mbits optical fiber transmission system’, Fujitsu Sci. d? Tech. J., 1985, 21, CIMLETT, J. L., et a.: ‘Dispersion penalties for single mode fiber transmission using 1.3 and 1.5pm LEDs’, Electron. Lett., 1985, 21, pp. 21 1223 pp. 668670 TANIFUII, T., MATSUURA, M., and YAMAMOTO, Y.: ‘42km analogue video signal transmission in single mode fibers using 1.3 pm edge emitting LEDs’, Electron. Lett., 1986, 22, pp. 192193 POPHILLAT, L.: ‘Video transmission using a 1.3pm LED and monomode fiber’. Proc. 10th ECOC, Stuttgart, Germany, Septem ber 1984, pp. 238239 Electrical Performance Standards for Television Relay Facilities, EIA Standard RS250B, Sep., 1976, Electronic Industries Associ ation, 2001, I Street, N.W., Washington, D.C. 20006, USA Preliminary generic requirements for PFM video and data trans mission on single mode fiber, Bell Communications Research Technical Advisory, TATSY000384, April 1986, obtainable from Information Manager, 435 South Street, Room 27147, Morris town, NJ 07960, USA LED SPECTRAL SLICING FOR SING LEM 0 DE LOCAL LOOP APPLICATIONS Indexing terms: Optical communications, Networks, Multi plexing, Optical fibres An approach towards a singlemode local loop is presented in which each customer is given a dedicated wavelength