Page 142 - Optical Switching And Networking Handbook

07_200023_CH06/Batesx 1/17/01 10:04 AM Page 127

Optical Switching Systems and Technologies 127

Optical Switching in the
Metropolitan Network

Before we see the full deployment of metropolitan SONET and
DWDM systems and before long-haul optical switches experience
wide-scale deployment, the equipment vendors must introduce opti-
cal switches for metropolitan networks. This market ignited in a rel-
atively short time. The abundance of options solidifies the fact that
the metropolitan network is so different that new solutions are
required to satisfy the escalating data demand regardless of the
progress made with optical networking in the past.The metropolitan
area is exploding. As much as 80 to 90 percent of corporate traffic is
moving outward from corporate networks and must traverse the
metropolitan networks to get to the wide-area long-distance market.
The typical features and functions that we incorporate into the
long-haul network are significantly different from those of the met-
ropolitan networks. Initially, the rather sluggish provisioning of met-
ropolitan DWDM by carriers was perplexing. However, in the year
2000, a number of vendors announced optical cross-connects for the
metropolitan market. Optical switches will manage the monstrous
bandwidth needs to support new services in the metropolitan net-
work. Several specialty consulting firms dealing with optical switch-
ing and networking predict that the market is growing exponentially
from a mere $200 million in 1998 to an astounding $4 billion by
2004, as shown in Figure 6-1.
The metropolitan optical switch market as described by the vari-
ous providers includes two main classifications of optical switching
systems:

1. Opaque Systems that perform regeneration, reshaping, and
resynchronization of the optical signal electronically.

2. Transparent Systems that perform all switching optically.