Page 43 - Optical Communications Essentials

Optical Communication Systems Overview

Optical Communication Systems Overview 33

any other technology, the challenges to improve performance are never-ending.
Researchers are working to pack more and more wavelengths closer together in
a given spectral band, to increase the data rates per wavelength, and to go
longer distances by developing new types of optical amplifiers.
As a further step toward realizing the full potential of optical fiber transmis-
sion capacity, researchers are considering the concept of an intelligent WDM
network. The major activity in this area is the development of an optical cross-
connect (OXC) that will switch optical signals at line rates (e.g., at 10-Gbps OC-
192 or 40-Gbps OC-768 rates) without optical-to-electrical conversion. The
eventual creation of such a component will provide lower switching costs and
higher capacities than the currently used electrical cross-connects.
A key ingredient for the widespread implementation of optical fiber technology
is an extensive body of test, interface, and system design standards. For example,
the TIA has published over 120 fiber optic test standards and specifications for
testing the response of fibers, cables, passive devices, and electrooptic components
to environmental factors and operational conditions. Furthermore, within the
ITU-T G series there are at least 44 recommendations that relate to perform-
ance specifications for fiber cables, optical amplifiers, wavelength multiplexing,
optical transport networks, system reliability and availability, and management
and control for passive optical networks. In addition, within this G series there
are many recommendations referring to SONET and SDH. Table 2.1 lists a
sampling of ITU-T recommendations, which aim at all aspects of optical net-
working.

Further Reading

1. J. Hecht, City of Light, Oxford University Press, New York, 1999.
2. K. C. Kao and G. A. Hockman, “Dielectric-fibre surface waveguides for optical frequencies,”
Proceedings IEE, vol. 113, pp. 1151–1158, July 1966.
3. E. Snitzer, “Cylindrical dielectric waveguide modes,” J. Opt. Soc. Amer., vol. 51, pp. 491–498,
May 1961.
4. G. Keiser, “A review of WDM technology and applications,” Opt. Fiber Technol., vol. 5, no. 1,
pp. 3–39, 1999.
5. National Institute of Standards and Technology (NIST), 325 Broadway, Boulder, CO 80303
(http://www.nist.gov).
6. National Physical Laboratory (NPL), Teddington, Middlesex, United Kingdom (http://www.
npl.co.uk).
7. Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany (http://www.ptb.de).
8. Telecommunication Industries Association (TIA) (http://www.tiaonline.org).
9. Electronic Industries Association (EIA), 2001 Eye Street, Washington, D.C. 20006.
10. Telecommunication Standardization Sector of the International Telecommunication Union
(ITU-T), Geneva, Switzerland (http://www.itu.int).
11. International Electrotechnical Commission (IEC), Geneva, Switzerland (http://www.iec.ch).
12. American National Standards Institute (ANSI), New York (http://www.ansi.org).
13. Institute of Electrical and Electronic Engineers (IEEE), New York (http://www.ieee.org).
14. A. McGuire and P. A. Bonenfant, “Standards: The blueprints for optical networks,” IEEE
Commun. Mag, vol. 36, pp. 68–78, February 1998.

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