Page 160 - Optical Switching And Networking Handbook

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Optical Switching Systems and Technologies 145

work configuration enables one to construct a fully nonblocking
cross-connect with up to 1,024 1,024 channels by linking together
2
32 32 switch modules. Alternatively, instead of using n mirrors,
each with two-controlled positions, to form an n n switch, one can
use 2n mirrors each having n controllable positions to achieve the
same functionality. This architecture, called the steered beam config-
uration, is used to construct large optical cross-connect switches
within a single switch stage.
Switching is accomplished by manipulating the free-space propa-
gation paths of the light beams directly. Consequently, MEMS
switches are optically transparent. In other words, they can be used
in networks with widely varying data rates, modulation formats, and
signal wavelengths. Moreover, changes in the network properties
have no effect on switch functions. Therefore, no hardware modifica-
tion is needed when the communication service providers upgrade
the other parts of their networks or systems.

Easy Upgrades

This last feature will increase in importance as high-bandwidth con-
nections become more popular with consumers. With the large vari-
ety of data traffic passing through the ever more complicated
communication links from local-area to global networks, the ability
to work with existing equipment while accommodating future
upgrades will be the key feature that makes all-optical switches the
preferred choice of carriers.“Forklift” technological decisions are out-
dated with the carriers.
As high-speed data networks further penetrate the consumer
market, network service providers are turning to technology
solutions that will enable them to offer diverse services with
varying bandwidth demands. The vision of a future all-optical
network that can deliver these potentials seems less and less like a
distant dream. All-optical switches and MEMS-based optical
switches in particular are going to be the key enablers for the future
of ultra-high-bandwidth, all-optical communication networks.