Page 298 - Optical Switching And Networking Handbook

13_200023_Glossary/Bates 1/17/01 10:10 AM Page 283

Glossary 283

Multimode fiber An optical fiber with a core large enough to
propagate more than one mode of light. The typical diameter is
62.5 micrometers.
Multiplex (MUX) To transmit two or more signals over a single
channel.
Multiplexer A device for combining several channels to be
by one line or fiber.
Nanometer One billionth of a meter.

Nanosecond One billionth of a second.
Narrowband Services requiring up to 1.5 Mbps transport
capacity.
Network Element (NE) Any device that is part of a SONET
transmission path and serves one or more of the section, line,
and path-terminating functions. In SONET, the five basic
network elements are

Add/drop multiplexer
Broadband digital cross-connect
Wideband digital cross-connect

Digital loop carrier
Switch interface
Network Monitoring and Analysis (NMA) A fault manage-
ment system used by RBOCs to perform network monitoring
and surveillance. The NMA system has two types, facilities
management and switch management. NMA is capable of
performing an event correlation to determine the root cause,
create trouble tickets, and track the status of outstanding
tickets. NMA relies on topology information to perform event
correlation. This information can come from TIRKS (via NSDB)
or it can be manually entered.

Optical Carrier Level 1 (OC-1) The optical equivalent of an
STS-1 signal.