Scrigroup - Documente si articole

Username / Parola inexistente      

Home Documente Upload Resurse Alte limbi doc  


BulgaraCeha slovacaCroataEnglezaEstonaFinlandezaFranceza
GermanaItalianaLetonaLituanianaMaghiaraOlandezaPoloneza
SarbaSlovenaSpaniolaSuedezaTurcaUcraineana

AdministrationAnimalsArtBiologyBooksBotanicsBusinessCars
ChemistryComputersComunicationsConstructionEcologyEconomyEducationElectronics
EngineeringEntertainmentFinancialFishingGamesGeographyGrammarHealth
HistoryHuman-resourcesLegislationLiteratureManagementsManualsMarketingMathematic
MedicinesMovieMusicNutritionPersonalitiesPhysicPoliticalPsychology
RecipesSociologySoftwareSportsTechnicalTourismVarious

Fetex - digital switching system

comunications

+ Font mai mare | - Font mai mic





DOCUMENTE SIMILARE

Trimite pe Messenger
BUSINESS ETHICS
Means of efficient communication
MODEL OF INTERVENING IN A TEENAGERS’ PERSONAL DEVELOPMENT GROUP
Fetex - digital switching system
Receiver’s efficiency
GROUP COMMUNICATION - Communication Relation
Ethernet & RS232 Interface Guide
Telecommunications
A special answer: Feedback
Switches and LAN design requirements

TERMENI importanti pentru acest document

Fetex


 





The FETEX ś150 digital switching system has the latest design providing

easy  operation  and  maintenance,  advanced  capabilities,  and  highly  reliable

operation. The system has been designed to serve as the intelligent node for

ISDN  and  Intelligent  network (IN).  This  system  meets  the  demands  of  more

advanced  and  diversified  communication  networking  by  the  use  of  advanced

switches and PCM transmission technologies.

The  transmission  environment  influences  introduction  of  digital

switching system. As digitization of transmission facilities increases, the more

economical the introduction of digital switching system becomes.

Introduction  of  remote  line  concentrator  and  remote  line  multiplexers

greatly  reduces  subscriber  loop  cable  length  and  concentrates  several

thousand-subscriber  lines  on  to  a  few  PCM  lines.    This  enables  economical

expansion  in  urban  and  rural  areas,  and  allows  easy  introduction  of  new

services to a wide area.

Design concept

During  research  and  development  of  the  FETEX-150  system,  the

following basic design concepts are followed:

One-Machine concept

The system can serve for any of the following applications:

·    INTS: International Toll Switch

·    TS:    Toll Switch

·    MS:   Tandem Switch

·    LS:    Local Switch

·    STP:  Signal Transfer Point

Technology Independencen

The system‘s modularity and software functional blocks make it easy to

continuously incorporate new technology, innovations and additional new user

capabilities.

Standardization

The  FETEX-150  system  follows  ITU-T/Bellcore/T1/ETSI  standards,

allowing integration of the FETEX-150 system into a multi-vendor network.

The  modularity  of  equipment  and  software  function  blocks  and  well-

defined  interfaces  between  the  modules  are  essential  to  meet  the  design

concepts. In the FETEX-150 system, all the function modules are designed on

an open-ended feature basis to permit easy introduction of new capabilities, to

be  economically  configured  in  any  application  and  any  switch  size  over  the

entire switch range.

The basic services of the FETEX-150 system are as follows:

ISDN-oriented services

·    Multimedia/ multi-channel services

·    I-Series Signaling Base Advances Telephone Services

POTS

·    Conventional Signaling Base Telephone Services

Data Services


·


Conventional Data Switching Services

(Telex/Packet/Circuit Switched Data)

51



Outstanding features


Fetex 


The system provides a number of features, some of which are described

in the following paragraphs.

Wide range of applications

The  modular  construction  of  the  FETEX-150  in  both  hardware  and

software  gives  it  maximum  flexibility  for  a  variety  of  applications.  The  multi-

processor  system  has  1,800,000  BHCA  capacity  and  the  uniprocessor  system

has  250,00  BHCA  capacity.    In  addition,  the  FETEX-150  system  has  the

following capacities:

240,000 lines or 60,000 trunks

24,000 Erlangs

Processor organization

The  system  can  be  configured  with  a  single  processor  or  with  multi

processor, making it cost competitive for small to large-capacity applications. 

In  the  uniprocessor  configuration,  functions  of  the  Call  Processor  are

incorporated into the Main Processor. The hardware and software are designed

to  make  it  possible  to  change  from  uniprocessor  to  multiprocessor  system.

This conversion can be done on-line with minimum effect on call processing.

Installation

The  FETEX-150  system  is  designed  either  for  a  building  or  container

housing.  The  system  is  essentially  the  same  in  either  installation.  Because  of

the following features, installation is easy, simple, and quick:

·    Space-saving with high technology components.

·    Rapid and convenient wiring.

·    Software  is  thoroughly  tested  during  development,  and  hardware  is

completely tested in the factory. 

The Small-version, container type FETEX-150 system can provide 2000

lines with a basic container, and up to 10,000 lines with a basic container and

three expansion containers.

Modular Structure

All functional modules of the FETEX-150 system are connected through

a  unified,  universal  interface.  The  integrity  of  each  hardware  and  software

module  is  strictly  maintained.  System  organization  also  allows  smooth

upgrading and uninterrupted service as new devices are added

Advanced software

Advanced  software  technology  and  high  reliability  characterize  the

system software including the following development features:

·    Applications are programmed using a high-level language.

·    Man-machine language is based on ITU-T and Bellcore standards.

·    Functional  specification  and  description  language  is  used  to

document call-processing software. 

Simple network topologyl

The  FETEX-150  network  is  configured  as  a  TST  switch.  The  internal

speed  of  the  network  module  is  8Mbps  in  an  8-bit  parallel  configuration,

providing a high-speed, large-capacity switch module. Each switch module has

1,024  time  slots  and  380  Erlangs  of  through-traffic  capacity  with  virtually  no

blocking.  Additional  switch  modules  can  be  installed  by  interconnecting  them

with existing highways between modules during expansion.

Easy maintenancen

The maintenance and operation provides system supervision and control,

man-machine  interface,  and  automatic  testing  and  diagnostics.  Access

provided  through  intelligent  workstations  allows  maintenance  personnel  to

operate  and  maintain  the  system  without  the  assistance  of  specialized

personnel.

52



New features


Fetex 


The  FETEX-150  system  employs  a  number  of  features  like  Signaling

System No. 7 and ISDN.

System applications

The  FETEX-150  system  can  be  applied  to  any  switching  node  in  the

public switching network. Summaries of system specifications and applications

are as provided:


Item

Processor architecture

Application

Capacity

   Terminations

   Traffic

   Attempts

Speech path network

Main Memory (MM)

File Memory (FM)

Floor Loading

System configuration


Specification

Distributed multiprocessor hierarchy

INTS: International Toll Switch

TS   :  Toll Switch

MS  :  Tandem Switch

LS   :   Local Switch

STP :   Signal Transfer Point

·    240,000 lines or 60,000 trunks

·    24,000 Erlangs 

·    1,800,000 BHCA

·    TST

·    1,024 Time Slots per module

·    380 Erlangs per Module

·    8 Megawords per Central Controller

·    32-bit word + Error Check and

Correct / parity.

·    4 Mw per FM

·    4 Mw x 4 per Central Controller

·    32-bit word + Error Check and

Correct.

300 kg/m2 (single cabinet)


The system is composed of modular hardware and software systems.

Software  is  organized  hierarchically  into  system,  subsystem,  block,

component, and unit levels. Units are compatible and linkable entities.

The  FETEX-150  system  has  an  effective  division  of  functions  between

hardware and software, providing great flexibility for future function additions.

All  functional modules, whether hardware  or software provide unified  internal

interfaces.

The hardware system comprises the following three functional subsystems:

·    The  speech  Path  Subsystem  (SPS)  forms  the  actual  switching  fabric  for  a

cell under control of the Central Processing Subsystem (CPS).

·    The CPS controls all switching system functions and is interconnected with

the SPS and the MOS

·    The  MOS  provides  man-machine  communication,  system  supervision,  and

testing functions for maintenance and operation of the system.

Multiplexi

The  FETEX-150  system  employs  a  TST  Digital  Switch  Module  (DSM).

The  input  to  the  DSM  is  8  links  with  an  8  Mbps  serial  bit  stream.  This  is

multiplexed  in  the  DSM  at  8 Mbps  on  an  8-bit  parallel  basis,  providing  1,024

TS.

The  maximum  system  configuration  is  64  DSMs,  which  is  65536  TS.

Within the 1024 TSs, 960 are used for call connections and the remaining 64

for internal processing. 

Processor configuration

The  FETEX-150  system  employs  a  hierarchical  processor  arrangement.

The highest level is the duplicated Main Processor (MPR) which controls overall

system  operation.  A  maximum  of  8  duplicated  Call  Processors  (CPR)  can  be

53



Fetex 

equipped  under  one  duplicated  MPR.  At  the  lowest  level,  duplicated  Line

Processors (LP) control the line concentrator stage.

Inter-processor communications of various types that are used are:

·    MPR  and  CPR  communication  is  performed  through  a  unified

interface.

·    CPR and LPR communication is via the SGC and CSE using duplicated

SS7 channels.

·    CPR to CPR communication is performed via MPR.

Communication between LPR and CPR

The signaling controller on the LPR side and Common channel signaling

equipment  on  the  CPR  side  performs  communication  between  the  LPR  and

CPR.  This  communication  is  passed  through  a  pair  of  64  KBPS  signaling

channels  on  the  8  Mbps  highway  for  the  LC  and  on  the  PCM  lines  for  RLC,

acting on a load-sharing basis.

SS7 is employed as signaling protocol for the following reasons:

·    Flexibility for future modification

·    Compatibility with the D-channel protocol of ISDN lines.

·    Layered and message based signaling.

Line concentrator (LC)

The  FETEX-150  system  has  2  types  of  LCs.  Type  A  is  economical  for

small systems. The type B has more capacity and features than A.

Subscriber interfaces

A point of LC-As can accommodate analog subscriber lines. The LC-B

can accommodate both basic rate ISDN subscriber lines (2B+D) and primary

rate access and digital subscriber loop carrier interface in addition to analog

subscriber lines.

Traffic usage and call attempt capacityi 

The LC-A has one internal highway 8 Mbps connected to the DSM with

120 channels available for user channels. The LC-A uses an 8-bit processor for

call handling.

The LC-B has up to 8 internal highways connected DSM with a

maximum of 960 channels available for user channels. Intra-LC calls are

connected within the LC reducing the number of channels to the DSM. This is

an especially important benefit for the Remote Line Concentrator (RLC)

application of the LC-B because it reduces a number of channels necessary

between the RLC and the host switch. The LC-B uses a 32-bit processor for

call handling.

Remote concentrator (RLC)

The  FETEX-150  system  has  2  types  of  RLCs  for  cost-effective

applications  in  a  local  plant.  RLC-A  is  economical  even  for  a  small  number  of

lines. RLC-b has more capacity and features.

RLC-A

The RLC-A depends on a host switch for call processing functions as well

as  maintenance  and  administration.  The  arrangement  provides  a  low  cost

system. 

     Call processing features

The following are the major call processing features:

·    Ordinary subscriber lines long lines and coin lines such a variety of line

types but analog are supported.

54


Fetex 

·    Intra-RLC connections can be provided at RLC-A by looping back the link to

the host, which reduces the links to the host.

·    The RLC-A can operate in a stand-alone mode with stand-alone equipment.

When the links  to the host fail, the RLC-A and the stand-alone equipment

provide  basic  call  processing.  Stand-alone  equipment  can  cover  up  to  5

RLC-As.

     Maintenance and administration featuresr

The  RLC-A  depends  on  the  host  for  the  following  maintenance  and

administration  processing  functions,  as  well  as  the  man-machine  interface

device.

·    Charge  recording:  performed  at  the  host  and  also  stored  at  the  host

storage device.

·    Man-machine  interface:  command  input  and  message  outputs  related  to

the RLC-A are performed through the host man-machine interface devices.

     Stand-alone features

When  RLC-host  links  fail,  the  RLC-A  automatically  moves  to  a  stand-alone

mode.

·    Charging  recording:  During  stand-alone  operation,  charging  data  is

recorded in extension memory cards.

·    Emergency access trunks: access is provided to specified destinations or

other central offices using outgoing trunks.

·    Stand-alone  announcement:  the  system  can  notify  subscribers  of  the

stand-alone operation mode at call origination.

RLC-B

RLC-B  depends  on  a  host  switch  for  call  processing  functions  as  well  as

maintenance  and  administration.  This  arrangement  provides  a  low  cost

system.

     Call processing features

The following are the major call processing features:

Small  call  processing  features  which  are  provided  for  the  LC-B  are  also

prepared for the RLC-B

The RLC-B can operate intra RLC connections in a stand-alone mode.

     Stand-alone features


·

·

·


During  stand-alone  operation,  charge  recording  is  provided  using

optional FM for intra-RLC calls. 

Connecting  a  portable  workstation  to  the  RLC-B  provides  limited

maintenance features.

The system can notify subscribers of the stand-alone operation mode

at call origination.


Reliability

The  FETEX-150  system  is  very  reliable  because  of  the  following  design

features:

Modular design

Duplicated architecture

55



Fetex 

Quality control performed throughout manufacturing of all components and

equipment.

Software system reliability

     Hierarchical memory structuret

Memory is organized into the following levels:

1)Main memory (MM) 2) File memory (FM) 3) Magnetic tape (MT)

     Restart process

Four phases of system restart, each selected according to the fault

conditions, minimize the effect of system restart on call processing.

     Post analysis dump

On the occurrence of a software fault, the contents of temporary data

areas in MM are transferred to FM.

     Audit

The software system provides a built-in audit facility to detect software

faults, such as program maze or abnormalities in data. The audit facility

enables early detection of software faults.

     Fault detection methodt

For maintenance of stability of continuous call processing services, the

system employs a rotation method for isolating faults in which doubtful

equipment is replaced with a standby one.

     External supervision facility

System operation is continuously checked through the External

Supervisory Equipment. If any abnormality is detected the emergency action

circuit activates a system restart.

Hardware system reliability

The FETEX-150 system provides full redundancy throughout the system

except at the terminal end. This is used to safeguard operation in areas in

which a failure can influence a large number of calls.

Maintenance and operation

The maintenance and operation features of the FETEX-150 system are:

High reliability

High reliability supported by an automatic reconfiguration system, which

uses the built in redundancy.

Easy maintenancen

The  maintenance  and  operation  subsystem  provides  automatic  testing

and diagnosis.

Software featuresr

The FETEX-150 system software is composed of real time and

multiprocessing program modules.

Software based on ITU-T recommendations

     Specification description language (SDL)

     Man-machine language (MML)

     High level language (HLL)

Flexible software

     Generic standard program

System software is composed of the following:

Operating system subsystems common to all FETEX series switching systems

Application subsystem controls specific switching functions.

Office data specifies the conditions of a particular office.

56


Subscriber data specifies conditions of each subscriber such as class of

service, numbering, equipment location, features, etc.

     Modular structure


Fetex 


A program module is provided for each switching function. Each module

is interconnected by means of a data table. This structure allows each

program to be independent, resulting in program reliability and flexibility.

     File updating

Office files are loaded by command for updating existing files. Files of a

working office can be updated with only a slight effect on the cal processing.

1.   TYPES OF SUBSCRIBER LINE


1.1

     1.2

2.


TYPES OF TELEPHONE 

·    Rotary telephone (10PPS or 20PPS)

·    Push button telephone 

·    ISDN terminal

SUBSCRIBERS LINE CLASS

·    Individual, PBX, and party lines

·    Unit fee coin telephone 

·    Multi-fee coin telephone

·    ISDN basic rates access line

·    ISDN primary rate access line (B/H channel interference)

SUBSCRIBER SERVICES


2.1       TYPE OF CALL

·    Intra-office calls

·    Local call

·    Subscriber toll dialing (STD) call

·    International direct dialing (IDD) call

·    Toll call via operator

·    International call via operator

·    Special service call

2.2       BASIC SUBSCRIBER SERVICES

a)   PBX facility

The extension in a PBX group can be accompanied with non-consecutive

circuit locations. The following additional facilities are provided.

·    Night line service of PBX

Number of PBX terminating lines is reduced by a request signal from the

PBX. The lines to be blocked are given by the command

·    PBX  in ś dialing

This service allows a calling party to be directly connected to a desired PBX

extension by dialing the directory number of the extension. Digit

translation for identification of DID (direct in dialing) PBX is 5 or less.

b)   Coin telephone facility

c)   Malicious call trace facility                        

Malicious call tracing by printing out the calling subscribers number, called

subscribers number, and other  relevant information when the called

subscribers flashes his hook switch. An audible alarm is used at the same

time. The call is held under the control of called party.


d)


Changed number interception (CNI)


Calls to subscribers whose directory number has changed are rerouted to

operator or an announcement machine.

e)   Denied service

·    Denied service (originating)

Call origination is denied by sending busy tone to a subscriber who has this

service class when he picks up the handset.

·    Denied service (terminating)

57



Fetex 

Call termination is denied by sending a special tone to subscriber

who dials the number in this service class.

f)    Semi-permanent connection

A 64KBps connection can be setup between 2 network inlets

designated by a command.

g)   Tone and talkie service

h)   Charging free connection

i)    Trunk offering (TKO)

This service is provided to permit operators to access a busy line

2.3       SUPPLEMENTARY SUBSCRIBER SERVICE

a)   Abbreviated dialing

Subscriber with push button telephones make calls, including IDD

by dialing only a 3 digit dialing code

b)   Call transfer

c)   Call waiting

d)   3 way calling

Allows conversation among 3 subscribers 

e)   Telephone rest service

Calls to this subscriber will be routed to an announcement

system. The service can be registered or cancelled by dialing

special codes.

f)    Absentee service

All calls to this subscriber are terminated to a special

announcement

g)   Automatic wake up service

h)   Hot line 

Can connect to pre-determined number by just picking up the

hand set.

i)    STD call and/or IDD call barring


3.


SIGNALING

The FETEX-150 system can handle the following signaling systems :

Subscriber line signaling

·    Dial Pulse

·    Dual Tone Multifrequency

·    ISDN D-channel protocol

      Junction line signaling

·    DC loop signaling

·    E & M signaling

·    Digital line signaling


                   Register signaling

·    DP signaling

·    RVP signaling

·    MF signaling

·    MFC signaling

                    Common channel signaling

·    ITU-T signaling system no.7 (SS7)


4.


SWITCHING FEATURES


4.1       NUMBERING PLAN

·    Directory number independent of location

Directory numbers can be assigned independently of

equipment location

·    Non-consecutive numbering on PBX

No restrictions on using non-consecutive directory numbers

to make a PBX group

·    Various numbering plans can be adapted for any custom as

numbering processing is controlled by software.

4.2       TRANSLATION AND ROUTING

·    Translation

58



Fetex 

Digit translation of up to 8 digits within a maximum of 24

stored digits, including  prefix and/or special codes.

·    Route size

Outgoing route: Max 1,024 including DID, PBX routes and

talkie

Incoming route: Max 1,024

·    Alternative routing within 8 routes

·    Digit deletion of 0 to 7 or all digits and digit insertion and

substitution of up to 5  digits within 63 patterns.

·    Trunks are fully accessible without grading

·    Random selection of trunk in a route

4.3       RELEASE CONTROL

·    Normal calls are held under the control of calling party.

·    Emergency calls such as Fire, Police are held under the

control of called party.

·    Connection is forcibly released if the called party does not

respond within a pre-determined time.

4.4       TIME SUPERVISION

·    Permanent signal partial dialing (PSPD) timing

PSPD timing is applied for detection of permanent signal

and partial dialing.

·    Inter digit (ID) timing

ID timing is applied for detection of last digit when

numbers of different digits are sent on the same route.

·    Reanswer time supervision

Time supervision is applied from the receipt of clear-back

signal to the receipt of clear forward signal

4.5       OTHERS

·    Automatic number identification (ANI)

Identification and sending of calling subscribers directory

number in response to a request signal from the

succeeding exchange.


5.

5.1

5.2

5.3

6.


CHARGING FEATURES

Charging system

·    Flat rate

·    Message rate

·    Measured rate

Charging by call duration and charging rate.

CHARGING SYSTEM 

·    Periodic pulse metering (Bulk accounting)

·    Automated message accounting (LAMA/CAMA)

AUTOMATIC CHARGING INFORMATION 

After the conversation, the duration of call and/or charge are

reported to the calling subscriber by the operator, voice response

equipment or output to the printer.

MAINTENANCE AND OPERATION FEATURES


6.1       SYSTEM STATUS MANAGEMENT

·    System status identification

·    Alarm facility

·    Route alarm indication

Equipment status and alarms are indicated on the TCNS (test console)

by function key operation and detailed information is displayed when

commanded. On detection of an abnormal state the visual and audio alarms

are blown. Routes are also displayed on TCNS when commanded.

6.2       FAULT PRCESSING AND DIAGNOSIS

·    Automatic fault processing

Auto detection and isolation of faulty equipment is done

and system is reconfigured automatically.

·    Diagnosis

59



Fetex 

Diagnosis is carried on an on-line basis and the location of

faulty equipment is displayed on the SCWS/VDU.

6.3       TRAFFIC CONTROL

·    Automatic load control

In case of a system overload, calls originating from

subscribers and incoming calls are gradually restricted

according to priority of subscriber and incoming trunks.

·    Routing control

For outgoing congestion, outgoing calls are restricted by

command activation.

·    Dynamic 

The system periodically decides a maximum number of

calls to be handled by the system. Even under overload

condition, the system accepts calls as much as possible for

the processor.

6.4       TRAFFIC MEASUREMENT

Traffic data such as junction traffic, number of calls, and occupancy

of control equipment, is collected. The data can be displayed on the

VDU, SCWS, MT or LP. The following 3 measurements are provided.


a)   Routine measurement:


Carried out on a routine basis


b)   Special measurement: Carried out to measure more detailed

characteristics of a specific equipment or item such as

incoming route than routine measurement only when

activated by command.

c)   Fluctuation measurement:   This command is activated by

command, to supervise traffic fluctuation.

6.5       OBSERVATION


·

·


Subscribers dialing

Designating subscribers through the SCWS/VDU collects

subscriber-dialing behavior.

Charge observation

Detailed charging data including the detailed number,

time answered, time disconnected, and metering

information are collected for each call by designating

subscribers through the SCWS/VDU.


6.6       SUBSCRIBER DATA & OFFICE DATA CHANGE


·

·


Subscriber data change (Service order)

Subscriber data such as class of service, directory

number, etc. can be changed using a command input

without disturbing the call processing.

Office data change (Recent change)

Office data such as routing and signaling can be

changed by a command input, without disturbing call

processing.


6.7       CENTRALIZED MAINTENANCE & OPERATION (OPTION)

The CMOC (Centralized Maintenance and Operation) facilities are

provided for effective use of manpower and overall supervision of

network.

SYSTEM DESCRIPTION

Overview

The FETEX-150 system consists of the following major subscriber-

systems 


·

·

·


Speech path sub system (SPS)

Central processing sub system (CPS)

Maintenance & Operation subscriber system (MOS)


SPEECH PATH SUBSCRIBER SYSTEM  (SPS

The  major  function  of  the  SPS  is  to  interface  analog  lines,  digital  lines,

integrated services Digital Network (ISDN) subscriber lines, analog trunks,

and to provide switching functions.

     For  line  interfaces,  a  line  Concentrator  (LC)  or  a  remote  Line

Concentrator  (RLC)  is  employed  to  concentrate  customer  traffic  for

60



Fetex 

connection to a Digital Switch Module (DSM). Trunks are connected to the

DSM by trunk interface circuits without concentration.

DSM  controls  switching.  Peripheral  equipment,  e.g.,  LCs,  Analog  Trunk

Shelves  (ATSH),  Digital  terminal  Shelves  (DTSH),  and  receiver  Shelves

(RECSH), are connected to the DSM via optical  8Mbps highways. This  is a

common  interface  used  throughout  the  system  and  is  also  used  for

peripheral/application  modules  connected  to  the  LC  or  RLC,  such  as

Subscriber  Line  Circuit  Shelves  (SLCSH),  Digital  Subscriber  Line  Circuit

Shelves  (DLSH),  and  DTSHs.  The  optical  highways  are  used  for  the

following reasons:


·

·

·


High data rate capacity

Immunity from Electromagnetic interferences

Reduction in the number of transmission cables


  The  SPS  is  connected  to  the  CPS  via  a  duplicate  Speech  Path  (SP)  bus.

The  Call  processor  (CPR)  of  the  CPS  controls  the  DSM  and  the  peripheral

modules.

LINE CONCENTRATOR TYPE A (LC-A)

LC-A  provides  the  line  interface,  front-end,  and  pre-processing  for  call

control  between  subscriber  lines  and  the  DSM.  LC-A  contains  following

equipments:

a)   Line Processor Shelf (LPRSH)

·    Line Processor (LPR)

·    Line Control Memory (LCM)

·    Sending Signal Memory/Receiving Signal Memory (SSM/RSM)

·    Scanner/Signal Distributor (SCN/SD)

b)   Subscriber Line Circuit Shelf (SLCSH)

·    Line Concentrator Time Switch (LCTW)

·    Analog Subscriber Line Circuit (SLC)

LINE CONCENTRATOR TYPE B (LC-B)

LC-B contains following equipments:

a)   Central Processor Shelf

·    Line Processor (LPR)

·    Signaling Controller (SGC)

b)   Line Switch Shelf (LSWSH)

·    Signal Receiver And Distributor (SRD)

·    Scanner/Signal Distributor (CSN/SD)

·    Signaling Interface (SGIF)

·    Network Interface (NWIF)

The line interface equipment consists of:

a)   Subscriber Line Circuit Shelf (SLCSH)

·    Analog Subscriber Line Circuit (SLC)

b)   Digital Subscriber Line Circuit Shelf (DSLCSH)

·    Digital Subscriber Line Circuit (DLC)

c)   Digital Terminal Shelf (DTSH)

·    Digital Terminal (DT)

Line Processor

The  LPR  consists  of  a  duplicated  32-bit  processor,  Main  Memory  (MM),

and  a  Channel  Controller  (CHC).  The  LPR  performs  call  processing  and

maintenance and administration functions in cooperation with the CPR. The

LPR  communicates  with  the  subscriber  equipment  and  the  CPR  via  the

SGC.

Signaling Con troller

SGC  is  a  High  level  Data  Link Control  Procedure  (HLDC)  handler.  SGC

acts as an interface for communication with the following equipments:


a)   DLCSH     b) DTSH


c) CPR

Line Switch


The  LSW  is  a  one-stage  time  switch  performs  concentration  and

provides  intra-LSW  connections.  It  consists  of  6  switching  network

modules.  Each  module  consists  of  1,024  time  slots.  Thus,  LSW  can

accommodate up to 6,144 time slots (1,024x6=6,144).

61



Fetex 

Each  switching  module  consists  of  8 optical  8Mbps  (128 time  slots  per

highway). Up to 48 highways can be connected to one LSW.

Signal Receiver & Distributort

SRD is hardware to software interface. Under control of LPR it controls

LSW and the SCN/SD signal sending and receiving between line interface

equipment.

Scanner/Signal Distributort

The SCN/SD is a memory for signal receiving and sending between the

line  interface  equipment  and  the  SRD.  The  SC/SD  communicates  with  the

following equipment:


a)   SLCSH


b)DTSH

Network Interface


NWIF connects LSW to DSMs via duplicated 8Mbps highways. NWIF has

following main functions:

·    Electrical and Optical signal conversion

·    NRZ to and from CMI code conversion

·    Clock extraction from received data

Signal Interface

SGIF connects SGC to LSW. It also converts 64Kbps highways from the

SGC to interface with the LSW and vice versa.

ANALOG SUBSCRIBER LINE CIRCUIT (SLC) and ANALOG SUBSCRIBER LINE

CIRCUIT SHELF (SLSCH)

Subscriber Line Circuit

Each SLC, depending on class of service, is equipped with a per-channel

CODEC and a software selectable hybrid-balancing network.

Subscriber Line Circuit Shelf

The SLCSH is a shelf to accommodate SLC. One SLCH can accommodate

a maximum of 240 circuits.

DIGITAL SUBSCRIBER LINE CIRCUIT (DLC) & DIGITAL SUBSCRIBER LINE

CIRCUIT SHELF (DLCSH)

Digital Subscriber Line Circuit (DLC)

DLC provides basic rate access to ISDN lines (2B+D) and an interface to

DLCC.  DLC  uses  echo  cancellation  methods  (ECM),  performs  activation/

deactivation  control,  and  multiplexes/De-multiplexes  B-Channels  and  D-

Channels.

Digital Subscriber Line Shelfh    (DLSH)

One DLC card accommodates one (2B+D) circuit. Thus, 1 DLCSH can

accommodate up to 56 circuits.

REMOTE LINE CONCENTRATOR (RLC)

The FETEX-150 has 2 types of RLC‘s viz; Type A and Type B.

REMOTE LINE CONCENTRATOR TYPE A (RLC-A)

RLC-A is LC-A, which is located at a remote location and connected via

PCMs.

RLC-A and LC-A have similar configurations. A single RLC-A can

accommodate up to 4 PCM-30 systems or 5 PCM-24 systems to host.

REMOTE LINE CONCENTRATOR TYPE B (RLC-B)

RLC-B is LC-B, which is located at a remote location and connected via

PCMs.

RLC-B and LC-B have similar configurations. RlC-B can accommodate up to

88 PCM-30 systems or 110 PCM-24 Systems to host.

62



DIGITAL SWITCH MODULE (DSM)


Fetex 


DSM  is  a  3  stage  (Time-Space-time)  switching  network,  virtually  non-

blocking, and duplicated in hot standby mode. Each module can handle up to

380Erlangs of traffic (960 CH) and the total traffic handling capacity of system

is  24,320Erlangs  (61,400  CH).  It  has  a  8Mbps  (8 bit  parallel)  interface.  Each

network has the following:

·    Secondary Multiplexers (SMPX)

·    Primary Time Switch (PTSW)

·    Space Switch (SSW)

·    Secondary Time Switch (STSW)

·    Secondary De-multiplexers (SDMPX)

·    Control Memory (CM) for the control of PTSW, SSW, and STSW

·    PCM code Conversion (PCC)

ANALOG TRUNK CIRCUIT (AT) & ANALOG TRUNK SHELF (ATSH)

ANALOG TRUNK CIRCUIT (AT)

AT circuit is an interface between analog trunks and the DSM. Trunk

circuit converts analog signals to digital form, and vice versa. A per channel

CODEC and metallic test access are provided for each AT circuit.

ANALOG TRUNK SHELF (ATSH)

It is used for analog trunks. An optical 8 Mbps highway with 128 time slots

is  used  between  the  ATSH  and  DSM.  In  addition  to  the  various  analog  trunk

cards  for  interoffice  trunks,  the  ATSh  accommodates  miscellaneous

equipment,  such  as  3-way  calling  circuits,  interface  trunks  for  the

announcement system, test equipment.

DIGITAL TERMINAL (DT) & DIGITAL TERMINAL SHELF (DTSH)

DIGITAL TERMINAL (DT)

DT is used for PCM line interface interoffice trunks, links for RLCs, RLMs

and ISDN primary rate interface.

DIGITAL TERMINAL SHELF (DTSH)

It consists of Digital Terminal Common (DTC) and Digital Terminals (DT).

DTCs are duplicated and connected to DSM via a pair of duplicated 8Mbps

highways. DTC acts as an interface circuit between DT and DSM.

TONE GENERATOR (TNG) & SIGNAL RECEIVER (REC)

FETEX-150  system  employs  technology  independent  tone  distribution  and

signal  receiving  techniques.  The  Tone  Generator  and  Signal  Receiver  are

mounted  on  the  RECSH.  Optical  8Mbps  highways  are  used  for  links  between

DSM  and  RECSHs.  One  RECSH  can  terminate  up  to  120  channels/128  time

slots.

TONE GENERATOR

TNG  is  a  digital  tone  generator  for  DTMF (Dual  Tone  MultiFrequency)  and

MultiFrequency  (MF)  signals,  providing  mixed  tones.  It  can  accommodate  up



to  26  tones  other  than  DTMF  &  MF  tones  which  are  sent  to  DSM  via  the

Upward Sub highway (USHW) of the DSM.

SIGNAL RECEIVER

Signal processing of MF signals from associated switches and DTMF signals

from subscribers is carried out in RECSH. The primary MUX/DeMUX are located

in  RECSH  and  provide  digital  type  MF receivers.  A  single  RECSH  can  process

up to 120 channels/128 time slots. The 120 multiplexed channels of MF signals

in the Downward Sub highway (DSHW) are demultiplexed in the PDMPX of the

RECSH to provide up to 8 receivers (REC).

DIGITAL ANNOUNCEMENT MACHINE (ANM)

63



Fetex 

The ANM is installed as an option when announcements to subscribers are

to be supplied. It can handle up to 8 messages with a storage capacity of 253

seconds (variable) per message.

VOICE RESPONSE EQUIPMENT

The voice response equipment, available as an option, is used for services

that  indicate  charging  information,  change  of  directory  number  to  calling

subscribers,  etc.  the  voice  response  equipment  can  compose  messages  for

these services. The specifications of VRE are as follows:


ITEM

Control Method

Loading of Voice data

Segment length

Multi-frequency tones

Total voice messages

Voice channels 

Voice memory device

Voice segments per message


SPECIFICATION

Microprogram Control

Loading from floppy disk or

Winchester disk

Max 33 min

Max 60

Max 400

Max 72 channels (PCM-24)

Max 90 Channels (OCM-30)

IC Memory

Max 400


CENTRAL PROCESSING SUBSCRIBER SYSTEM (CPS)

The  CPS  consists  of  the  Main  processor  (MPR)  and  the  Call  processor

(CPR).  MPR  performs  overall  functions  including  O&M  while  CPR  is

dedicated  for  call  processing  and  makes  use  of  the  LPR  in  the  LC  or  RLC.

MPR  is  the  highest  while  the  LPR  is  the  lowest  in  the  processor  hierarchy.

The configuration of a CPS is shown below.

Communication between CPR and MPR through the Channel-to-Channel

adapter (CCA). For uniprocessor switches, the call processing functionality

is  included  in  the  MPR  itself.  The  Common  Channel  Signaling  Equipment

(CSE) is a protocol handler for SS7 level 2.

The CPR and MPR developed for telecommunication purposes consists of

the  Central  Controller  (CC),  CHC,  MM  and  FM.  Central  processing  is

performed  on  a  stored  program  control  basis  similar  to  that  of  general

purpose computer. All CPS units are duplicated to cope the failures.

CENTRAL CONTROLLER (CC)

Specifications of the CC are given in the table below.

SPECIFICATION

ITEM

General Register  Micro program control with customer VLSI

processor

Instruction Set            162 instructions


Interruption

Level

Word length


2 levels. CLASS A=25/ CLASS B=12

32 bits + 7 bit error check and correct

(ECC) / 1 parity bit


The following are the functions of the CC:


a)


System control operation: Controls connections among the CC,


CHC and SPS


b)

c)


Arithmetic operation

Interrupt operation: fault interrupts, real time interrupts,


interrupts from the CHC, etc.


d)


Emergency  operation:  When  program  processing  becomes


impossible because of faults, the emergency circuit establishes a new

system  configuration.  The  operation  mode  of  CC  is  based  on  hot-

standby operation.

64



MAIN MEMORY


Fetex 


The MM stores the system program and data. It consists of one package

with control part and a memory part. Its capacity is 4Mw (32-bit word)

The  MM  is  duplicated  and  the  operation  mode  of  MM  is  based  on  hot-

standby operation. The specifications of MM are as given below.


FILE MEMORY


ITEM

Capacity MEMORY Unit

               MAXIMUM

Memory Component


SPECIFICATION

4Mw X 32 bits

words/MM

4Mbit per Chip MOS LSI


It  serves  as  a  highly  reliable  random  access  file  for  the  storage  of

program  and  data.  It  consists  of  a  File  Memory  Controller  (FMC)  and  a  File

Memory  Unit  (FMU)  that  has  a  capacity  of  4Mw.  The  CC  can  connect  up  to

4FMs.

The  FMC  and  FMU  are  duplicated  and  operation  of  FM  is  based  on  hot-

standby operation.

The specifications of FM are tabulated below.


ITEM

Capacity     Memory

Unit

                   Maximum

Control Feature

Data Check

Memory Component

CHANNEL CONTROLLER (CHC)


SPECIFICATION

   4Mw X 32 bits words

16 Mw X 32 bits words

Micro program control

Single bit error   Detected and

Corrected

Double bit error Detected (ECC)

1 Mbit per Chip MOS LSI


The  CHC  transfers  data  between  the  MM  and  the  FM  or  input/output

(I/O)  equipment  on  receiving  instructions  from  the  CC.  It  can  execute

programs  independently  of  the  CHC  during  CHC  data  transfer.  It  is  also

duplicated and can be connected with a maximum of 60 I/O devices.

CHANNEL-TOT -CHANNEL ADAPTER (CCA)

When  multiprocessor  configurations  are  employed  CCA  acts  as  an

interface  between  CPR  and  MPR.  It  is  connected  to  CHC  through  a  common

bus  interface,  and  also  connected  to  the  mate  CCA  through  a  CCA  interface.

CCA transfers information required for call processing between MPR and CPR.

CCA  on  instruction  from  CC,  autonomously  transfers  data  between  CCA  and

MPR. CCA is duplicated for each CPR for higher reliability.

COMMON CHANNEL SIGNALING EQUIPMENT (CSE) AND RELATED EQUIPMENT

The FETEX-150 system employs SS7 signaling for communication between

CPR and LPR.

The use of SS7 signaling in FETEX networks has the following features:

· Full implementation of CCITT recommendations

· Flexibility  in  application  fields  not  limited  to  interoffice  signaling  of

telephone calls

· Large capacity

· Variety of signaling interfaces

· Minimum effect on processor load

The  functions  of  SS7  are  divided  into  4  levels.  In  the  FETEX-150  system,

these 4 levels are implemented separately as follows:


· Level 1:

· Level 2:

· Level 3:

· Level 4:


 DSM and DT, or modems for analog links

 CSE

 CPR software

 CPR software


Modems,  CSEs,  and  CSE  Interface  (CSEI)  are  required  by  external  SS7

interfacing.

The sys configuration of the FETEX-150 sys is as shown below.

65



COMMON CHANNEL SINALING EQUIPMENT


Fetex 


The  CSE  provides  level  2  functions.  CSE  manipulates  various  signaling

bit rates (i.e. 64 Kbps, 56Kbps, 48Kbps). One CPR can connect up to 32 CSEs

and one CSE can accommodate up to 8 signaling data links. The specifications

of CSE are tabulated as follows.


ITEM

Call processing Interface

Function

Number of CSEs

Number of signaling data

Processor

Signaling bit rate


SPECIFICATION

Common Bus DMA mode

SS7 level 2

32 CSEs per CPR

256 CSEs per system

8 links per CSE

16-bit processor

PCM: 24/30:64Kbps/56Kbps/48Kbps


COMMON CHANNEL SIGNALING INTERFACE (CSEI)

The CSEI is located between the CSE and the DSM to convert the data

transmission spaced between the data on a time slot of optical 8Mbps highway

to the DSM and the 64 Kbps to or from the CSE.

MAINTENANCE AND OPERATION SUBSYSTEM (MOS)

The  MOS  executes  various  maintenance  and  operation  tasks  under

control  of  MPR  together  with  a  man-machine  interface  terminal,  storage

deices,  alarm  supervision  equipment,  and  line/trunk  testing  equipment.

Following table gives an description of the MOS equipment.


ITEM

Workstation (SCWS/TWS)

Magnetic tape unit

CMOC interface equipment

WORKSTATION (WS)


DESCRIPTION

·    Command input

·    Message output

·    System supervision and control

·    Test functions

-     Line/line circuit test

-     Trunk/trunk circuit test

·    System software backup

·    Mass data storage for off-line

transfer

Interface to centralized maintenance

and operation center


The WS is an intelligent man-machine language interface terminal which

s composed of 

·    Processor

·    CRT display

·    Keyboard and Printer

·    HDD and FDD

·    Multi-telephone set (MTS)/Handset

System control WS (SCWS) or Test WS(TWS) may be configured for

various different types of works.

The various functions of the WS are tabulated as follows:


TYPE

SCWS

TWS


VARIATION

I

II

III

I

II

III


*

·

·

·


TRUNK TEST     LINE TEST

·

·                          ·

·

·


* System Supervision & Control


66



The following table gives the various equipments associated with

TWS/SCWS and the functions associated with each.

EQUIPMENT                                              FUNCTION


Fetex 


Alarm Indication Panel Unit

(ALIPU)

Alarm Control Shelf (ALMSH)

Analog Line & Trunk Test Interface

(ALTI)

Automatic Test Trunk Equipment

(ATTE)

Complaint & Transfer Service Unit

(CATS)

CAT Interface (CATI)

Communication Box (CBOX)

Digital LTE (DLTE)

External Supervisory Equipment

(ESE)

External Supervisory Equipment

for LPR (ESEL)

Junction test Equipment (JTE)

Line SCN/SD equipment (LSCD)

Line Supervisor (LSUP)

Line Test Adapter (LTAP)

Line Test Equipment (LTE)

OCE (Office Communication

Equipment)

System Test Adapter

MAGNETIC TAPE UNIT (MTU)


Trouble notification with buzzer

tone and flashing LED indication

Alarm data processing, including

detection, analysis, transfer to

CMOC and indicators

Protocol conversion to/from

LTE/WS

Trunk test circuit for loop back

establishment

Complaint call receiving & transfer

it to others CATS, TCNS, CBOX

and exiting console

Complaint call receiving from

subscriber. Sending of holding

tone

Complaint call receiving. AC jack

for transmission measurement

LTE function for digital subscriber

lines

Supervisory equipment for CPR

Supervisory equipment for LPR

Automatic junction test equipment

with automatic call generator and

responder

Scan signaling transfer from LP to

LPR

SD signaling transfer from CPR to

LC

Faulty subscriber line supervision

from MDF

Interface facility between

controlled exchange and MTWS

Automatic Line/line testing circuit.

Office communication between

CBOXs and exiting consoles

Interface facility between

controlled exchange and MSCWs


The MTU is used for mass data storage, and for input and output

of programs and data.

SERIAL INTERFACE ADAPTER (SIA)

The  SIA  is  used  between  the  CHC  and  I/O  devices.  The  SIA  is

connected  to  CHC  through  a  common  bus,  and  is  connected  to  an  I/O

device through the RS232C or V11 interface. The SIA main from houses

a  microprocessor  providing  a  firmware  control.  The  system  control

workstation  (SCWS)  and  may  types  of  MODEMs  can  be  used  as  I/O

devices  with  the  FETEX-150  system.  The  various  features  of  SIA  are

tabulated as follows:


ITEM

I/O interface

I/O cable length

I/O Bit Rate


SPECIFICATION

·    RS232C

·    V11

15 meters (maximum)

·    300/600/1200/2400/4800/9600

67



       Character Length

       Stop Bit Length

Communication

Synchronization

VISUAL DISPLAY UNIT (VDU)


bps

·    7/8

·    ˛ bit

Full Duplex

Asynchronous/Synchronous


Fetex 


It  is  controlled  by  SIA  and  is  the  most  effective  part  of  man-

machine  communication.  The  hard  copier  (HP)  can  be  connected  to

VDU.  The  VDU  displays  responses  to  commands  sent  from  CC  through

CHC.

TEST CONSOLE (TCNS)

The TCNS consists of system maintenance part and test part. The

system maintenance part displays the operating status of system alarm,

etc. with lamps and LCD. The various tests functions it performs are :

·    System Supervisory

·    Subscriber Line Circuit Test

·    Trunk Circuit Test

·    Junction Test

·    Tone Check

·    Call Origination & Termination

·    Subscriber Line Test

·    Telephone Set Test

·    Howler Sending

·    Time Set

Call connecting procedures

Call origination

Call origination is described in the following steps:

1.   When  subscriber  originating  goes  off  hook,  the  Line  Processor  (LPR)

detects the change in loop state.

2.   The LPR notifies the call processor (CPR) of subscriber being off hooked

using  SS7  signaling  system  through  communication  protocol.  The  CPR

then assigns an idle time slot between the LC and digital switch module

(DSM) for the speech channel. The CPR then connects dial tones to the

line  concentrator  (LC)  and  sends  a  message  to  the  LPR  to  begin

receiving dialed digits.

3.   The  LPR  establishes  a  path  between  the  originating  and  the  selected

time slot, and dial tone is provided to the calling subscriber.

Digit reception

Dial pulse (DP) subscriber 

The digit reception from DP subscribers is as described below

After receiving the dial tone the subscriber dials the calling subscriber number.

The  dialed  pulses  are  scanned  and  counted  by  the  LPR.  The  corresponding

digits  are  transmitted  to  the  CPR.  The  CPR  begins  the  translation  of  the

received digits and the customer class of service. The CPR also determines the

types of call.

Dual tone multil -frequency (DTMF) subscriber

Digit  reception  from  DTMF subscriber  can be  completed  in  three  steps. If  the

caller  is  a  DTMF  subscriber,  a  call  from  the  line  is  connected  to  a  DTMF

receiver  and  dial  tone  is  returned  to  the  line.  DTMF signals  are  received  and

interrupted by the DTMF receiver. The corresponding digits are transferred to

the  CPR  through  the  receiving  signal  memory  (RSM)  digit  by  digit.  The  CPR

translates  received  signals  for  customer  class  of  service  and  type  of  call  (i.e.

outgoing, interoffice etc.).

Ringing of an intra-office call

The  CPR  determines  the  called  party  (destination)  route  by  analyzing

the dialed digits as they are received. If sufficient digits are not yet received it

waits  for  the  succeeding  digits  to  be  dialed.  When  all  necessary  digits  are

68



Fetex 

received and translated as an  intra-office call, the CPR sends the terminating

call information to the appropriate LPR. The LPR connects and controls ringing

current to the called subscriber.

Audible  ring  tone  is  sent  to  the  caller  subscriber  by  the  same  connection

method used to send dial tone.

Intra-office call through connection

When the called subscriber goes off hook (answers), the subscriber line

card  automatically  stops  ringing.  The  LPR  detects  the  off-hook condition  and

sends the state change information to the CPR. The CPR stops sending audible

ringing tone to the caller subscriber. A through connection path is established

between the subscribers according to the instructions from the CPR.

DP signaling

In the digit outpulsing with DP signaling for outgoing calls, the CPR selects an

idle outgoing trunk (OGT) and sends seizure signal and digit information to the

OGT  via  the  sending  signal  memory  (SSM).  The  OGT  sends  a  seizure  signal

and subsequent DP signals to the succeeding office based on information sent

from the CPR.

MFC signaling

If the call is an outgoing call to an MFC signaling route, the CPR selects an idle

OGT  and  sends  a  message  with  seizure  information  to  the  OGT  via  the  SSM.

Then  the  OGT  sends  a  seizure  signal  to  the  succeeding  office.  Using

instructions from the CPR, MFC forward signals stored to the succeeding office.

At  the  same  time,  the  CPR  establishes  a  connection  between  OGT  and  MFC

receiver. MFC receiver receives the backward signals sent. The MFC backward

signals  are  detected  on  a  digital  signal  basis  and  the  received  information  is

sent to the CPR using a specially assigned time slot RSM.

Outgoing call through connection

When  MFC/DP  out  pulsing  is  completed,  an  acknowledgement  is

received and a through connection path is established between the subscriber

calling and the OGT by the CPR.

Incoming digit receptioni

DP signaling

When  a  seizure  signal  is  detected  on  an  incoming  route,  the  system

acknowledges and prepares to receive DP digits. The digit signals sent from a

DP  signaling  route  are  received  at  the  incoming  trunk  (ICT).  The  digit

information received is sent to the CPR for translation via the RSM.

MFC signaling

When a seizure signal is detected at the ICT, a seizure message is sent to the

CPR via RSM. The CPR establishes a connection between the ICT and the idle

MFC  receiver  while  the  MFC  receiver  detects  the  forward  signals  sent.  The

received MFC signals are decoded and formatted on a digital basis and sent to

CPR through RSM using a special assigned time slot. Using instruction fro CPR

the backward signals are stored.

Ringing for incoming call

When  the  last  digit  has  been  received,  the  CPR  determines  if  the  call  is

destined  for  the  local  office  or  any  other  services.  If  the  call  is  for  the  local

office  it  send  the  call  information  of  the  called  subscriber  through  the  CPR  to

the appropriate LPR. The LPR connects the controls the ringing current in the

other  end.  At  the  same  time  CPR  sends  audible  ringing  tone  to  the  calling

party.

Incoming call through connection

When  the  called  subscriber  goes  off  hook,  the  subscriber  line  card

automatically stops ringing. The LPR detects the condition and sends the state

change information to the CPR. The CPR stops sending ringing tone to caller. A

69


Fetex 

through  connection  path  between  the  called  subscriber  and  the  ICT  is

established.

Operation and maintenance features

Philosophy of O&M

The  FETEX-150  system  was  developed  with  the  concept  of  a  systemized  and

automated  maintenance  philosophy  to  ensure  a  highly  reliable  system.  The

FETEX- 150 system M&O features are as described below:

1.   High system reliability: - Highly reliable components, automatic system

reconfiguration,  and  system  redundancy  assure  high  reliability  of  the

system.

2.   Easy  Maintenance:  -  The  maintenance  and  operation  subsystem

provides  built-in  automatic  testing,  diagnosis,  reconfiguration,  and

recovery.  The  man  machine  interface  is  through  intelligent  workstation

(WS)  using  a  standardized  command  format  and  autonomous

messages.

Thus, the system M&O is systematized and simplified.

Man machine communication

Most  man  machine  communication  is  performed  through  the  system  control

workstation (SCWS) or VDU, visual display unit. Input commands are used to

retrieve data concerning traffic, alarms etc. output  messages can be directed

to the SCWS/VDU or magnetic tapes (MT) on request.

System Supervision

System  Supervision  and  control  facilities  assure  smooth  system  operation

through hardware and software integration.

System  Supervision  is  organized  hierarchically  based  on  the  fault  detection

functions. The structure is as shown:

The  FETEX  is  so  designed  that  the  vast  majority  of  troubles  are  detected

automatically  and  rapidly  by  external  and  self-detecting  supervision.  It  also

allows  supervising  and  overriding  external  and  self-detecting  methods  when

program control goes away.






Politica de confidentialitate



DISTRIBUIE DOCUMENTUL

Comentarii


Vizualizari: 1444
Importanta: rank

Comenteaza documentul:

Te rugam sa te autentifici sau sa iti faci cont pentru a putea comenta

Creaza cont nou

Termeni si conditii de utilizare | Contact
© SCRIGROUP 2022 . All rights reserved

Distribuie URL

Adauga cod HTML in site