Page 240 - Optical Switching And Networking Handbook

10_200023_CH09/Bates 1/17/01 9:45 AM Page 225

Cost Implications and Financial Trending 225

4 A/D of 16 channels 8 A/D of 32 channels
Figure 9-7
Cost ratios for
900
transparent and
opaque systems 800

700
in $ millions US 500
600

400
300

200
100
0
Transparent fixed Transparent Opaque
Configurable

to add and/or drop four OC-48 channels between DWDM terminals,
as seen in Figure 9-7.
This feature provides the flexibility of allowing some channels to
pass through the hub and create express channels. Carriers can tai-
lor services to specific customers, and revenue-generating traffic can
be distributed. All this is possible while costs are reduced for
installing end terminals at low-traffic areas.
In addition, DWDM systems with an open architecture can greatly
assist operators in keeping pace with the constantly changing indus-
try. These systems enable operators to provide SONET/SDH, asyn-
chronous/PDH, Fast Ethernet, and ATM traffic on the same fiber.
Operators will easily adapt to new technologies without adding opti-
cal transmitters for a specific protocol. Using a meshed network of
sorts, the optical mesh will enable an open architecture to simplify
the protocols and bandwidth-carrying capacities for the future. Fig-
ure 9- 8 shows an optical mesh network capable of providing the nec-
essary protection and added bandwidth for several protection
routes. Instead of having the carriers provide 100 percent redun-
dancy, a much lesser percentage of redundancy is possible with