Page 221 - Optical Switching And Networking Handbook

09_200023_CH08/Batesx 1/17/01 8:20 AM Page 206

206 Chapter 8

Carriers planning their capacity for current or future needs also
find DWDM as an economical way to do the following:

Incrementally increase capacity
Rapidly provision new equipment for needed expansion

Future-proof their infrastructure against unforeseen bandwidth
demands
Wholesalers can take advantage of DWDM to lease capacity (rather
than entire fibers) either to existing operators or to new market
entrants. DWDM will be especially attractive to companies that have
low-fiber-count cables that were installed primarily for internal
operations but that could now be used to generate telecommunica-
tions revenue. In the past, many carriers were smug with the idea
TEAMFLY
that they installed plenty of spare fibers in their rights of way.There-
fore, these carriers stated that they could just light up another fiber
rather than install the DWDM multiplexers and switches. This may
have been true in the past, but as things progressed, the fibers were
consumed, and the demand for new bandwidth continued to escalate.
Using DWDM in the metropolitan area breathes new life into these
carriers’ networks.
DWDM system transparency to various bit rates and protocols
will enable carriers to tailor and segregate services to various cus-
tomers along the same transmission routes. DWDM enables a car-
rier to provide STM-4/OC-12 service to one customer and
STM-16/OC-48 service to another all on a shared ring. In regions
with a fast-growing industrial base, DWDM is one way to utilize the
existing thin fiber plant to quickly meet burgeoning demand.

Building Block of the Optical
Network

DWDM is now entrenched as the preferred method to relieve the
bandwidth constraint many carriers face. Several U.S. carriers have
settled on DWDM at 16 times the OC-48 rate to gain more capacity.
DWDM deployments throughout the carrier infrastructure will con-

®
Team-Fly