Photonics Maintaining Competitiveness in the Information Era (1988) / Chapter Skim
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2. Opportunities in Telecommunications
2. Opportunities in Telecommunications
Pages 9-22
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From page 9... ...
Until that time, the media used for transporting information from place to place were copper cables and radio (including terrestrial microwave links and satellites)
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From page 10... ...
The ability to transmit information for long distances without repeaters or with fewer repeaters (and without the interference and security problems of radio) made it possible to build transmission systems with lower initial equipment costs, lower right-of-way costs, and lower maintenance costs.
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From page 11... ...
data rates of several gigabits per second and repeaterless spans beyond 100 km, for a data rate times distance product more than 10 times that of the commercially available equipment cited above. Local Area Networks In the context of this report, a local area network is defined as a communications interconnection system deployed in an office, a factory, or a multibuilding campus (distances typically < 1 mile)
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From page 12... ...
can be attached. Since the computing devices to be attached might cost only a few hundred or a few thousand dollars each, and since there are more places to attach computing devices than there are attached devices themselves, each access port must be very inexpensive compared to the cost of the accessing device.
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From page 13... ...
Thus the BISDN marketplace represents a very important application for photonic technologies. Key to this marketplace will be low-cost fiber cables, low-cost transmitter and receiver modules, and possibly novel approaches to the distribution network architecture to reduce the need for active electronic components in the outside plant (in unattended locations)
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From page 14... ...
Photonic Technologies Within Equipment As telecommunications moves toward the higher data rates associated with BISDNs, the ability to perform functions such as multiplexing, switching, and internal component interconnects at these high data rates becomes a limiting factor in cost and practicality. Higher-speed electronic circuits consume more power, which creates the thermal management problem of keeping components from overheating.
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From page 15... ...
Among such attributes are immunity to electromagnetic interference, relative security from eavesdropping, spanning of long distances without electronic repeaters, and low cable weight. Military applications also impose additional requirements on fiber-optic systems, e.g., wider operating and storage temperature ranges; ability to withstand severe vibration, shock, and other mechanical stress; and robustness of system performance in the presence of multiple simultaneous subsystem failures.
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From page 16... ...
Long-Distance and Moderate-Distance Point-to-Point Connections Enabling Technologies Ripe for Development · Fiber cables with low loss and low dispersion (variation of group velocity with wavelength) at 1.3-micron wavelength, and with low microbending loss and high strength.
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From page 17... ...
These are needed to deploy wavelength-multiplexed systems with moderate numbers of concurrent wavelengths. Enabling Technologies Requiring Continuing Research · Transmitter and receiver subsystems incorporating very narrow line width, single-frequency lasers for coherent communications systems (coherent detection)
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From page 19... ...
companies successfully market transmitter and receiver modules for point-to-point interconnections within equipment and between pieces of equipment, continued diligence to increase reliability and reduce cost is required as this market grows. Enabling Technologies Requiring Continued Research · Optical traces ("conductors")
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From page 20... ...
By taking advantage of standard or open interfaces (e.g., interfaces with publicly documented and stable specifications) between major components of a system, network providers can purchase optical fiber cables from one manufacturer, optical line and span-terminating repeaters from another manufacturer, and multiplexing equipment from yet another manufacturer.
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From page 21... ...
Numerous areas requiring continued research activity necessary to enable certain new markets or to reduce costs in existing or emerging markets have also been identified. The impact of standards and open interfaces on increasing competition and preventing particular technologies from becoming bottlenecks to competition in larger system procurements was also discussed.
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From page 22... ...
1988. Special Issue on Fiber Optic Local and Metropolitan Area Networks.
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