
A.1 Numerics
1+1 protection
An architecture that has one normal traffic signal, one working SNC/trail, one protection
SNC/trail and a permanent bridge. At the source end, the normal traffic signal is
permanently bridged to both the working and protection SNC/trail. At the sink end, the
normal traffic signal is selected from the better of the two SNCs/trails. Due to the
permanent bridging, the 1+1 architecture does not allow an extra unprotected traffic
signal to be provided.
100BASE-T
IEEE 802.3 Physical Layer specification for a 100 Mb/s CSMA/CD local area network.
100BASE-TX
IEEE 802.3 Physical Layer specification for a 100 Mb/s CSMA/CD local area network
over two pairs of Category 5 unshielded twisted-pair (UTP) or shielded twisted-pair
(STP) wire.
10BASE-T
An Ethernet specification that uses the twisted pair cable with the transmission speed as
10 Mbit/s and the transmission distance as 100 meters.
1:N protection
An architecture that has N normal service signals, N working SNCs/trails, and one
protection SNC/trail. It may have one extra service signal.
1PPS
Pulse per second, which, strictly speaking, is not a time synchronization signal. This is
because 1PPS provides only the "gauge" corresponding to the UTC second, but does not
provide the information about the day, month, or year. Therefore, 1PPS is used as the
reference for frequency synchronization. On certain occasions, 1PPS can also be used
on other interfaces for high precision timing.
3R
Reshaping, Retiming, Regenerating.
A.2 A
ABR
Available Bit Rate
AC
Alternating Current
ACAP
A channel configuration method, which uses two adjacent channels (a horizontal
polarization wave and a vertical polarization wave) to transmit two signals.
Active/Standby
switching of cross-
connect board
The process in which the standby cross-connect board automatically takes the place of
the active one. If there are two cross-connect boards on the SDH equipment, which are
in hot back-up relation of each other, the operation reliability is improved. When both
the cross-connect boards are in position, the one inserted first is in the working status.
Unplug the active board, the standby one will run in the working status automatically.
When the active cross-connect board fails in self-test, the board is pulled out, the board
power supply fails or the board hardware operation fails, the standby cross-connect board
can automatically take the place of the active one.
add/drop multiplexer
Network elements that provide access to all or some subset of the constituent signals
contained within an STM-N signal. The constituent signals are added to (inserted), and/
or dropped from (extracted) the STM-N signal as it passed through the ADM.
ADM
OptiX OSN 550 Multi-Service CPE Optical Transmission
System
Configuration Guide
A Glossary and Acronyms
Issue 02 (2011-06-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
A-3