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Cost Implications and Financial Trending 227

Streaming audio and video files
LAN to WAN communications

These new DWDM systems will be able to transport a massive
amount of video, telephony, and voice traffic over a single fiber. This
type of system will multiply the capacity up to 128 or more times,
with anticipated cost savings compared with traditional fiberoptic
network architectures.
A 128 DWDM system meshes well with cable operators’ current
requirements. In one scenario, five optical wavelengths are dedicated
to 80 video channels, one for pay per view premium channels and
two for cable modem, telephony, and other two-way traffic. DWDM
technology not only lowers initial costs but also represents efficient
revenue-generation capability by enabling traditional core services
to operate on the same network with two-way DS-3 and Ethernet-
based services.When these advantages are combined with the latest
optical amplifier technology, DWDM becomes a powerful solution for
meeting the bandwidth needs of today’s cable networks, as well as
providing tremendous capacity for the future.

Optical Cross-Connects

Digital cross-connect systems have been around for two decades.
These were based on the use of electrical communications using
standard TDM strategies. The cross-connect systems were designed
to handle the provisioning, protection (automatic protection switch-
ing), and restoration of the larger networks. The volumes of traffic
passing through a digital cross-connect system (DCS) required active
monitoring and maintenance capabilities on the signals passing
through. Newer cross-connect systems are now using an optical
WDM architecture to satisfy the larger capacities and traffic vol-
umes on the network. The size of these networks mandates that
attention be paid to signal attrition (attenuation) and careful design
efforts in using them. Carriers are actually demanding initial cross-
connects that will support several hundred OC-48s today. However,
in the future these carriers will be looking for systems with thou-
sands of ports as the network grows and the wavelength manage-