Page 295 - Optical Switching And Networking Handbook

13_200023_Glossary/Bates 1/17/01 10:10 AM Page 280

280 Glossary

expensive than regenerators and can typically be spaced 80—120
km apart at 2.5 Gbps, depending on the quality of the fiber plant
and the design goals of the DWDM system.
Enterprise systems connection (ESCON) A duplex optical
connector used for computer-to computer data exchanges.
Fiber Distributed Data Interface (FDDI) A dual counter-
rotating ring local area network or a connector used in a dual
counter-rotating ring local area network.
Far End Block Error (FEBE) A message sent back upstream
that a receiving network element is detecting errors, usually a
coding violation. See Remote Error Indication (REI).
Fiber The structure that guides light in a fiber optic system.
Fiber channel An industry-standard specification that origi-
nated in Great Britain that details computer channel communi-
cations over fiber optics at transmission speeds from 132 Mbps
to 1062.5 Mbps at distances of up to 10 kilometers.

Fiber-to-the-Curb (FTTC) Fiber optic service to a node con-
nected by wires to several nearby homes, typically on a block.

Fiber-to-the-Home (FTTH) Fiber optic service to a node located
inside an individual home.

Fiber-to-the-Loop (FTTL) Fiber optic service to a node that is
located in a neighborhood.

Fixed stuff A bit or byte whose function is reserved. Fixed stuff
locations, sometimes called reserved locations, do not carry over-
head or payload.
Framing A method of distinguishing digital channels that have
been multiplexed together.
Frequency The number of cycles of periodic activity that occur
in a discrete amount of time.
Gallium aluminum arsenide Generally used for short wave-
length light emitters.
Gallium arsenide Used in light emitters.

Gigabits per second (Gbps) One billion bits per second.