Page 154 - Optical Switching And Networking Handbook

07_200023_CH06/Batesx 1/17/01 10:05 AM Page 139

Optical Switching Systems and Technologies 139

Figure 6-8
The OPTera core
switch (Nortel
Networks)

Source: Nortel Networks

Nortel Networks’ (Xros’s) system, on the other hand, handles up to
1,152 pairs of inputs and outputs with a transparent all-optical
pathway. The cross-connects consist of two facing 6 6 inch arrays
of 1,152 mirrors each. Incoming beams of light are directed to their
destinations by these movable mirrors. Thus an entire incoming
fiberoptic channel can be switched as a whole to any output port.
This scheme also facilitates redundancy by allowing network plan-
ners to create an architecture where multiple alternate paths can be
made available to protect each link.A sample of this system is shown
in Figure 6-9.
Port-provisioning ease further enhances MEMS switches because
of the inherent transparency of the system. In telecommunications
networks of the past, it took months to get high-speed circuits provi-
sioned and installed. Newer systems can perform this function on
the same day.