Glossary

A | B | C | D | E | F | G | H | I | J | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y

A

ADM

Add/Drop Multiplexer

Agent (SNMP)

A Software module that performs the network management functions requested by management stations. An agent module may be implemented in a network element that is to be managed, such as network element. Agents and network management stations communicate by means of SNMP.

AIS

Alarm Indication Signal : It is a code sent to downstream sites to indicate an upstream failure (used to prevent unnecessary downstream alarms).

ANSI

American National Standards Institute: American standards body that defines the characteristics and guidelines for telecommunications networks.

APTS

Assisted Partial Timing Support

ATM

Asynchronous Transfer Mode

AVAR

Allan Variance

B

B8ZS

Bipolar with 8 Zero Substitution: Code type belonging to DS1 signal

BC

Boundary Clock

BITS

Building Integrated Timing Supply: Generally, this is the North American term for a SASE.

BMCA

Best Master Clock algorithm

BPV

BiPolar Violation: Two consecutives bits of the same polarity

BTS

Base Transceiver Station

BVA

Boîtier à Vieillissement Amélioré: French expression meaning "Enclosure with Improved Ageing". The OSA BVA crystal oscillators employ special techniques to achieve stability performance, unmatched by any other crystal device, i.e. typically 1 x 10-11/day.

C

CC

Composite Clock: 64/8 kHz signal

CCITT

International Consultative Committee on Telephone and Telegraphy: Old name for ITU-T

CE

European Union regulatory community symbol

CES

Circuit Emulation Services

CRC

Cyclic Redundancy Check

Cs Clock

Cesium Clock: Primary reference source with a guaranteed accuracy of parts in 10E-12, using the resonance of Cesium atoms at 9.192631770 GHz

CTO

Compact Tracking Oscillator: Level III/Local Node Clock - model OSA 5542

D

D-PLL

Digital Phase Lock Loop: Phase lock loop technique used in the Oscilloquartz Tracking Oscillator equipment (e.g. 5540, 5542, 5544, 5546, 5548x, ...).

D4

Also called SF (Super Frame): A frame type belonging to the DS1 signal

dB

Abbreviation for decibel

DB

Data Base

DCE

Data Communication Equipment: Abbreviation for decibel: The devices and connections of a communications network that connect the communication circuit between the data source and destination (the Data Terminal Equipment or DTE). A modem is the most common kind of DCE.

DDS

Direct Digital Synthesis

DS1

Digital Service level 1: DS1 is the abbreviation for 1544 kbit/s signals

DTE

Data Terminal Equipment: A device which acts as the source and/or destination of data and which controls the communication channel. DTE includes terminals, computers, protocol converters, and multiplexers.

DTR

Data Terminal Ready: The wire in a full RS-232 connection that tells the Data Communication Equipment (DCE, typically a modem) that the Data Terminal Equipment (DTE, typically a computer or terminal) is ready to transmit and receive data.

DXC

Digital Cross-connect

E

E1

E1 is simply an abbreviated form of 2048 kbit/s

EEC

Ethernet Equipment Clock

EMC

Electro Magnetic Compatibility

EMI

Electro Magnetic Interference

EMP

Electro Magnetic Pulse: The electromagnetic radiation from a nuclear explosion. The resulting electric and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges.

ESD

ElectroStatic Discharge

ESF

Extended Super Frame: A frame type belonging to the DS1 signal

ESM

Embedded System Manager: The ESM ensures effective management of OSA solutions (5548 or 5548B) by providing a gateway to Oscilloquartz' central management system, SyncView™. All functions including its powerful 486 processor, embedded software and communications interfaces are integrated into a compact plug-in module, eliminating the need for additional external hardware.

ESMC

Ethernet Synchronization Messaging Channel

ETSI

European Telecommunications Standards Institute: European standards body that defines the characteristics and guidelines for telecommunications networks.

F

F3

Frequency, Flexibility, Functions: Oscilloquartz' modular equipment architecture, 19" rack standard.

Fault management

The Facilities that enable the detection, isolation, and correction of abnormal operation of the OSI environment.

fc

Cut-off Frequency

FCC

Federal Communications Commission

FDL

Facilities Data Link

fo

Oscillator Output Frequency

FQL

Forced Quality Level: Forced Quality Level is use to set the assumed quality level of an incoming (Synchronisation) signal when the Quality level can be determined (e.g. by SSM).

Free Run

Clock operating mode: A clock is said to be in free run mode when it has never had an external reference or is not operating from stored values acquired from a previously connected external reference.

FTP

File Transfer Protocol

G

G.703

ITU-T recommendation: Defines the electrical characteristics for interfaces, e.g. G.703-2, G.703-6, G.703-10. The suffix -n denotes the recommendation's paragraph number.

G.704

ITU-T recommendation: Defines the frame structure/functional characteristics of interfaces associated with network nodes, synchronous digital multiplex equipment, PCM multiplexing equipment (i.e. 1544, 2048, 8448 kbit/s, etc.).

G.811

ITU-T recommendation: Defines requirements of Primary Reference Clock systems (PRC).

G.812

ITU-T recommendation: Defines requirements of slave clocks (types I,II, III, IV, V and VI).

G.813

ITU-T recommendation: Defines requirements of slave clocks suitable for operation of SDH equipment.

G.823

ITU-T recommendation: Defines control of jitter and wander in digital networks based on the 2048 kbit/s hierarchy.

G.824

ITU-T recommendation: Defines control of jitter and wander in digital networks based on the 1544 kbit/s hierarchy.

G.825

ITU-T recommendation: Defines control of jitter and wander in digital networks based on the synchronous digital hierarchy (SDH).

GPS

Global Positioning System: Satellite based navigation and timing system.

GPS-I

GPS Receiver Interface: GPS interface integrated into front end of OSA 5548 or 5548B SASE.

GPS-I2

GPS Receiver Interface: The new generation of GPS-I. (See above)

GPS-M

GPS Receiver Module: GPS module used in OSA SSU 5546 and GRU 5581.

GPS-x1-y

GPS Input & Holdover module: GPS module used in the OSA 5581C GPS.
x indicates the kind of auxiliary input (E=E1, T=T1)
y indicates the holdover quality (A=Rubidium, B=OCXO)

GUI

Graphical User Interface

H

Holdover Mode

Clock operating mode: A clock operates in holdover mode when it has lost its controlling sync input (external reference) and is using stored data to control its output. Holdover terminates when the clock is once again controlled by an external reference.

HOU

Hold Over Unit: This is a module with internal oscillator which is normally locked to the selected input reference by means of a Digital PLL Filter and provide highly stable outputs in holdover mode.

HyperTerminal

Terminal application delivered with any Windows 95,98 or NT 4.0 operating system. You can use HyperTerminal with a modem to connect two computers so You can send and receive files or connect to computer bulletin boards and other information programs. For example, You can use HyperTerminal to connect to an online service and to download files from a bulletin board on the online service. You can also use HyperTerminal to connect a computer directly to another computer.

I

I/O

Input/Output Interface

IEEE

Institute of Electrical and Electronic Engineers

IETF

Internet Engineering Task Force

IIU

Input Interface Unit: A family of plug-in modules to interface Oscilloquartz'equipment with several types of input signals (e.g. G.703-2, G.703-6, G.703-10).

ILS

Input Line Selector: The ILS is a plug-in module normally used in a protected arrangement that provides selection of the input synchronisation feeds using one of several operating modes: Automatic, Manual, Forced or Performance modes.

INC

INput Card

ISDN

Integrated Services Digital Network: A set of communications standards allowing a single wire or optical fiber to carry voice, digital network services and video. ISDN is intended to eventually replace the plain old telephone system.

ISO

International Standards Organization

ITU-T

International Telecommunications Union: New name for CCITT. International organisation that defines the characteristics and guidelines for telecommunications networks.

J

Jitter

Short-term non-cumulative variations of the significant instants of a digital signal form their ideal positions in time, expressed in seconds or in UI (unit interval).

L

LAN

Local Area Network

LED

Light Emitting Diode

LM

Local Manager: Local management application for OSA systems.

LOF

Loss Of Frame

LOS

Loss Of Signal

M

MAC

Monitoring and Alarms Controller: Plug-in module concentrates all alarms in OSA equipment, provides a visual summary of the alarms, relay contacts and an RS232 port for local or remote control.

MADDS

Manual & Automatic Direct Digital Synthesis

ME

Managed Equipment: Equipment that is remotely manageable.

MGW

Media Gateway

MIB

Management Information Base

MML

Man-Machine Language

MML server

A server application that performs MML requests

MRTIE

Maximum Relative TIE: Maximum TIE relative to local reference, e.g. time error measured between output and input of a slave clock.

MSC

Mobile Switching Center

MTIE

Maximum Time Interval Error: Maximum peak to peak phase change

MUX

Multiplexer

N

NE

Network Element

NEBS

Network Equipment Building Systems: NEBS describes about the environment of a typical United States RBOC Central Office. NEBS is the most common set of safety, spatial and environmental design guidelines applied to telecommunications equipment in the United States.
NEBS was developed by Bell Labs in the 1970s to standardize equipment that would be installed in a central office. The objective was to make it easier for a vendor to design equipment compatible with a typical Regional Bell Operating Company (RBOC) central office (CO). This would result in lower development costs and ease the equipment's introduction into the network. Telcordia now manages the NEBS specifications.

NG

Next Generation

NGN

Next Generation Networks: In NGNs the data of all services, be it real-time services (e.g. voice) or pure data services, are transported as IP packets over a packet switched network infrastructure. Despite the asynchronous nature of the switching or routing of packets, many network element types in NGNs require accurate and stable synchronization supply. Where SDH and SONET are used for transport, traditional synchronization technology is adequate. However, Ethernet technology is now gaining terrain especially in the access and metro domains.

NM

Network Manager: Network management level within the SyncView™ hierarchy.

NMI

Network Management Interface

NMS

Network Management System

NSM

Network Synchronisation Management System: See also SyncView™.

NTP

Network Time Protocol

O

OCXO

Oven Controlled Crystal Oscillator: Clock oscillator using oven technique, e.g. OCXO 8665.

OIU

Output Interface Unit

ONP

Open Network Provision

OSA

Oscilloquartz SA

OUC

OUtput Card

P

PCM

Pulse Code Modulation

PDH

Plesiochronous Digital Hierarchy

PDU

Protocol Data Unit: A data structure containing SNMP message components and used for communication between SNMP entities.

ppm

Parts per million

pps

Pulse per second

PRC

Primary Reference Clock

PSN

Packet Switched Network

PSTN

Public Switched Telephone Network

PSU

Power Supply Unit

PTP

Precision Time Protocol

PTSG

Precise Time Stamp Generator

Q

Q3

A software agent (or adapter) which provides a standard way to integrate telecommunication equipment in a TMN system.

QL

Quality Level: Quality Level is defined by ITU-T to be one of (for SDH network):
PRC = desc. In G.811
SSU-A = desc. In G.812 (I & V)
SSU-B = desc. In G.812 (VI)
SEC = desc. In G.813
DNU = Do Not Use

QoS

Quality of Service

R

RAM

Remote Access Manager: An add-on package allowing remote use of any Oscilloquartz' Local Manager, either through modems and POTS/ISDN connections or through TCP/IP networks.

RAN

Return Authorization Number: Also called RMA – Number required to return material for factory repair

Rb

Rubidium: Clock oscillator using Rubidium.

RFC

Request For Comment: The Requests for Comments (RFCs) form a series of notes, started in 1969, about the Internet (originally the ARPANET).
The notes discuss many aspects of computer communication, focusing on networking protocols, procedures, programs, and concepts but also including meeting notes, opinion, and sometimes humor. The document series edited by the Internet Engineering Task Force (IETF) describes the Internet suite of protocols and related experiments.

RJ-45

Registered Jack 45: 8 pin-connector for data transmission

RM

Regional Manager: Regional management level within the SyncView™ hierarchy.

RMU

Remote Management Unit: This module is present in 5581C and 5533C equipments.

RNC

Radio Network Controller

RS422

Specification for electrical parameters of an interface only. RS422 is compatible with V11 and X21.

RS449

Specification for mechanical parameters of an interface together with pinout and connector gender (DTE male, DCE female).

RTC

ReTiming Card

RTU

Re-Timing Unit: A plug-in module that re-times traffic signals (i.e. E1/T1 signals) affected by excessive jitter and wander. An RTU physically fits into an OIU slot and needs specifically designed connector tiles.

S

SASE

Stand-alone Synchronisation Equipment: OSA model 5548 or 5548B synchronisation system for SONET/SDH or PDH, Transit or Local Node Clock.

SCI

Standard Control Interface: SCI is the standard software embedded in the Oscilloquartz SSU MAC processor card.

SDA

Synchronisation Data Acquisition: Oscilloquartz' data acquisition software utility for use with TTS, T/O, CTO, DTO & SSU. Normally incorporated in SDR & SMA (see below).

SDH

Synchronous Digital Hierarchy

SDR

Synchronisation Data Reduction: Oscilloquartz' post processing software designed for use with OSA Tracking Oscillators or TIE Test Sets for analysis of timing signals with respect to ITU-T (CCITT) and other parameters (e.g. TIE, MTIE, AVAR, TVAR).

SDU

Synchronisation Distribution Unit

SEC

Synchronous (SDH) Equipment Clock

SGC

Signal Generator Card

SMA

Software Management: Oscilloquartz craft terminal utility for local control and maintenance of CTO, DTO, SSU or other equipment fitted with MAC.

SMC

SONET Minimum Clock

SNMP

Simple Network Management Protocol: The application protocol offering network management service in the Internet suite of protocols. Abbreviation used for both SNMP v1 and SNMP v2

SNTP

Simple Network Time Protocol

SONET

Synchronous Optical Network

SQL

Structured Query Language: A standard interactive and programming language for getting information from and updating a database. Queries take the form of a command language that lets the user select, insert, update, find out the location of data, and so forth.

SSM

Synchronisation Status Message

SSMB

Synchronisation Status Message Byte

SSU

Synchronisation Supply Unit or Synchronisation Source Utility

ST2

Stratum 2 clock

ST3

Stratum 3 clock

ST3E

Stratum 3E clock

STM-N

Synchronous Transport Module of level N

STS

Synchronisation Test Set: High-resolution phase/frequency measurement equipment for analysis of timing signals with respect to ITU-T and other parameters (e.g. TIE, MTIE, AVAR, TVAR).

SyncE

Synchronous Ethernet

SyncView™

Oscilloquartz’ network management system (NMS). SyncView™ offers considerable savings by rationalising operation and maintenance tasks. It manages the Oscilloquartz synchronisation network from a single point and optionally enables control at regional level.

T

T1

T1 is simply an abbreviated form of 1544 kbit/s

tau or t

Loop Time Constant: t is the TOM loop time constant which can be programmed by the user to a value between 100 and 100,000 seconds. Appropriate setting of t optimises TOM's jitter and wander filtering characteristics.

TC

Transparent Clock

TCP / IP

Transmission Control Protocol / Internet Protocol

TCU

Timecode Unit: The NTP (Network Time Protocol) provides a standard timing protocol for computer systems (e.g. any IP-based networks). Time synchronisation is important for the accuracy of system logs and for correct time stamps on files that may be accessed by more than one computer via NFS (Network File System). The NTP server implemented in this module provides a GPS-derived time reference to all system clocks on individual machines in the associated network.

TDEV

Time Deviation: Square root of TVAR, expressed in nano seconds.

TDM

Time Division Multiplexing

TEX-P

Passive Time Extraction: Passive in-line device normally mounted external to the equipment, used to couple 64 or 1544 or 2048 kbit/s links to the equipment.

THC

Tracking & Holdover Card

TIE

Time Interval Error: Variation in time delay of a given timing signal with respect to an ideal timing signals over a particular time period. Time interval error over an observation time S (seconds).

TL1

Transaction Language 1: TL1 was defined in the 80's by Bellcore (now Telcordia) and is the dominant management protocol for controlling telecommunications networks in North America, China and other parts of the world.

TMN

Telecommunications Management Network

TNC

Transit Node traCeable

ToD

Time of Day

TOM

Tracking Oscillator Module: TOM and its associated VCO (e.g. OCXO or BVA) form the core of OSA's synchronisation solutions. TOM phase locks the VCO to the selected input, effectively filtering and regenerating the timing signal. This combination also provides highly stable outputs in holdover mode.

TS0

Time Slot 0 (Zero)

TSG

Timing Signal Generator

TU-12

Tributary Unit 12

TVAR

Time Variance: Measure of the expected time variation of signal as a function of integration time. See also TDEV.

U

UL

Underwriter’s Laboratories, Inc

V

V11

See RS422

VCO

Voltage Controlled Oscillator: Voltage controlled oscillator normally used in the OSA equipment (e.g. BVA 8695, OCXO 8665, etc.).

W

WAN

Wide Area Network

Wander

Long-term non-cumulative variations of the significant instants of a digital signal form their ideal positions in time, expressed in seconds or in UI (unit interval).

X

X.25

Communication protocol for levels 1 to 3 in a WAN.

X21

Interface electrically compatible with V11/RS422.

XINMAX

XINMAX is the TOM threshold for phase error which can be programmed by the user to a value between 1 ns and 60 us. See also TOM above.

XO

Crystal Oscillator

Y

y(t)

Fractional frequency offset, normalised instantaneous offset from a reference, in function of time.

YINMAX

YINMAX is the TOM threshold for detection of fractional frequency difference. YINMAX can be programmed by the user but is normally set to a value equal to the OCXO's pulling range.

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