Pakistan Telecommunication Company Limited

INTERNSHIP REPORTHUAWEI C&C08SIEMENS EWSDZTE

PRESENTED TO:DIRECTOR PHONES DIGITAL ITR, PTCL ISLAMABAD

PRESENTED BY:● RABIA JAMIL ● SALEHA IQBAL

COMSATS Institute Of Information Technology, Islamabad

DEDICATED

To our dear Pakistan which is our identity & which deserves to be returned more than it gave us.

ACKNOWLEDGEMENT

First of all we would like to thanks to ALMIGHTY ALLAH by the grace &

help of which we have been able to complete this project.

Thank you to the wonderful people at PTCL who continue to provide

support, warm encouragement, patience and guidance.

Thanks to all the people who took the time to voluntarily send encouragements &

suggestions for this project. Your input and help is very much appreciated.

Truly thanks to our dear parents for genuine support & encouragements.

This task is dedicated to the covenant of God with man on earth.

Table Of Contents

Chapter1: EWSD EXCHANGE Structural Units Of EWSD Exchange

DLU (Digital Line Unit) LTG (Line Trunk Group) SN (Switching Network) CP (Coordination Processor)

Functional Units Of EWSD Exchange Control Switching Signaling Access Power

Chapter2: HUAWEI PRI EXCHANGE Over View & Background General Introduction Of C&C08 Switch System Overall Structure Modular Structure Central Module Alarm Box C&C08 Maintenance System Physical Characteristics Of The Switch Access Network Access Network IBA-I Islamabad (C&C08)

Chapter3: ZTE EXCHANGE General Introduction ZXJ10 (V10.0) System Description

System Over View Hardware Configuration

Peripheral Switching Module (PSM) Major Functions Of PSM Hardware Structure Of PSM

The Remote Switching Module (RSM) Message Switching Module (MSM) Central Switching Network Module (SNM) Operation & Maintenance Module (OMM) Mobile Peripheral Module (MPM) & VLR Module VPM Packet Handling Module (PHM) Internet Access Module (IAM)

EWSD (Eidal Widal Switch Digital)EWSD is the digital exchange made by German Company Siemens. This is the very reliable exchange which is mostly used in Pakistan.This type of digital exchange is used as local, tandem, transit as well as international gate way exchange.The most common switch is used as main exchange. This can operate as PSTN, ISDN (BRI), PRI, CMMERCIAL Subscriber (Pay phones). 

Structural Units of EWSD SwitchEWSD switch can be divided into following parts.

Digital line unit (DLU). Line trunk group (LTG). Switching network (SN). Coordination processor (CP).

DLU (Digital line unit)

DLU provides the gateway to the EWSD exchange. The data of home and commercial subscribers are stored in specific modules in

DLU. The telephone ring is generated in DLU. The metering of voltage is done in DLU. Provides contact with DIU (digital interface unit).

Functions Of DLU

Modules of Digital Line Unit

1- Subscriber Line Module (SLM)SLM modules store the data of all types of subscribers that includes PSTN, ISDN, PRI, home users and commercial users. In IBA1-A there are two types of SLM modules

SLMA COS. SLMA CMRL.The SLMA COS module supports 8 subscriber telephone lines and connects them to the exchange.

Digital Line Unit

Processor and

Controller

Interface

Subscriber line circuit

(SLC)

Power

BDCGRGMGDLUC

DCC-CR DIUBDBBDE

Testing

SLMACOSSLMACMRLSLMAITFSLMD

FMTU

LCMM

The SLMA CMRL module supports 6 commercial lines i.e. public call offices and connects them to main exchange.

2- Bus Distribution Base(BDB) The BDB module controls all the buses that are running throughout the DLU. The BDB modules are present in the first frame and they monitor the sub control units BDE’S that are control units of the bus in the other frames.

3- Bus Distribution Extension(BDE)The BDE modules are control units of different shelves of a single rack of the EWSD exchange. The BDE module is controlled by BDB.

4- Ring Generation and Measuring Module (RGMG)The RGMG module generates ring and it also acts as metering unit for voltage in the digital line unit.

5- Digital line Unit Control (DLUC):The DLUC module is the main control module in the DLU .it monitors all the functionalities of different modules of the DLU.

6- Bus Distribution Clock Generation (BDCG):This module generates the clock for bus distribution so that all the buses are synchronized.

7- DCC:One DCC module provides the voltage to first eight modules of a shelf and the later eight modules are supported by an other DCC module at the end of the shelf.

Physical Rack Diagram of DLU (IBA 1-A):DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

RGMG

BDB

BDCG

DLUC

DIU

FMTU

LCMM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

RGMG

BDB

BDCG

DLUC

DIU

SLM

SLM

SLM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

BDE

BDE

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

BDE

BDE

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

BDE

BDE

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

BDE

BDE

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

BDE

BDE

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

DCC

DCC

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

BDE

BDE

SLM

SLM

SLM

SLM

SLM

SLM

SLM

SLM

DCC

Line Trunk Group (LTG)The line/trunk group (LTG) forms the interface between the digital environment of the node and the digital switching network (SN). The LTGs perform non-central control functions and thus relieve the coordination processor (CP) of routine work.

Functions of LTG: Following are the major functions of LTG

LTG provides direct connection of one exchange with the other exchanges of the same city or the other cities.

LTG generates telephone tone. LTG provides a gateway to the switching network. LTG provides interface between DLU and PCM.

FUNCTIONS OF LTG

Line Trunk Group

Interfacing

Trunk

Signaling

Memory Unit

Tone Generator

Code Receiving

Sync &SwitchingModule

Power

CRP

4 x DIU’s

TOG

PMUBPMUCPMUD

GSL

DCC-DE

SILC-BSILC-C

CGSM

 Several LTG types are available for optimal implementation of the various line types and signaling methods. The two main types of LTGs (differing in their functionality) used are:

LTG-B ● LTG-C

Physical Rack Diagram:DIU

DIU

DIU

DIU

CRP

TOG

GSL

CGSM

PMU

SILC

DCC

LTG-BThe LTGB is used for connecting:

Up to four digital transmission routes (PDCs) for DLUs at transmission rates of 2048 kbit/s

Up to four primary rate accesses (Pas) for medium-sized and large ISDN PABXs (ISDN subscribers with PA) at a transmission rate of 2048 kbit/s.

Main Components of an LTG-B Group processor (GP) Link interface unit between line/trunk group and switching network (LIU) Group switch (GS) Speech multiplexer (SPMXA) Signaling unit (SU) Line/trunk unit (LTU)

Switching Network (SN)By virtue of its high data transmission quality, the switching network can switch connections for various types of service (for example telephony, facsimile, teletext, data transmission).

This means that switching network is also ready for the Integrated Services Digital Network (ISDN).

Functions OF Switching Network: Duplicated (full redundancy) Highly-Integrated switching network modules One space stage module can handle up to 1024 simultaneous calls with full

redundancy Interfaces of 8,192 Kb/s available within Highly compact design from space-saving point of view An exchange of 10,000 subscribers may accommodate the SN in a single rack Two kinds of connections: Switched & Semi-permanent

Structure:In large and very large exchanges the capacity stages of the switching network (SN:504LTG, SN:252LTG and SN:126LTG) include

One time stage incoming (TSI) Three space stages (SS) One time stage outgoing (TSO)

Medium-sized and small exchanges (SN:63LTG and SN:15LTG) contain One time stage incoming (TSI) One space stage (SS) One time stage outgoing (TSO)

Physical Rack Diagram:TSM

TSM

TSM

TSM

LIS

LIS

SGC

LIS

LIS

TSM

TSM

TSM

TSM

DCC

TSM

TSM

TSM

TSM

LIS

LIS

SGC

LIS

LIS

TSM

TSM

TSM

TSM

DCC

Coordination Processor:

The CP performs the following functions in a network node: Call processing Operation and maintenance Safeguarding

The CP consists of the following processors: Base Processors Call Processors Input / Output Control Bus for Common Memory Common Memory Input / Output Processors

Coordination Processor Modules1. BAP: The BAPMs and the BAPSs provide the same software functional units. 2. CAP: The CAPs mainly include software for call processing functions. 3. IOC: IOCs have only firmware for communication with the call processing, O&M and data

communication peripheries.4. BCMY:The bus for common memory (BCMY) connects all processors (BAP, CAP), including the input/output controls (IOC), with each other and with the common memory (CMY).5. CMY:

The common memory (CMY) includes, among other things, the common database for all processors, plus the input and output lists for the IOP. The CMY is duplicated in order to ensure a high level of availability. 6. IOP:Different types of input/output processors (IOP) connect the CP113D with other units in the network node, the external bulk memories, the operation and maintenance terminal, the operation and maintenance center (OMC, via data lines) and computer centers (also via data lines).

Functionality of CP

Functional Units of EWSD exchange:The EWSD system is divided into different functional areas called subsystems coordinated by a central system. Following are the main functional units of EWSD exchange.

1. Control2. Switching3. Signaling4. Access5. Power

ControlControl belongs to the area which is responsible for the coordination of the various subunits. Control consists of the following: Coordination Processor (CP)

Message Buffer (MB)

COORDINATION PROCESSOR

BASE PROCESSOR

CALL PROCESSOR

INPUT/OUTPUT PROCESSOR

COMMON MEMORY

BUS FOR COMMON MEMORY

INPUT/OUTPUT CONTROL

System Panel (SYP) Central Clock Generator (CCG)

Message Buffer The task of MB is to control the exchange of messages between the following subsystems: 

Coordination Processor (CP) and line/trunk groups (LTG): Commands and Messages

CP and switch group controls (SGC) of the switching network: Setting commands for the SN

LTGs among one another: Reports LTGs and the common channel signaling network control

(CCNC):Orders

Message Buffer GroupThe message buffer is divided into functional groups called Message Buffer Groups according to the expansion concept. One message buffer group consists of one message buffer unit for Switch Group Control and two message buffer units for LTG. In the least configuration, at least one message buffer group may exist with at least one MBUL and one MBUS active where as the other MBUL may be inactive.In the highest configuration, there are up to 4 message buffer groups with 4 MBUS and 8 MBUL.  Central Clock GeneratorIn order to switch and transmit digital information, the sequence of operations must be synchronous throughout the equipment involved.This requires a clock supply with a high level of reliability, precision and consistency for all the nodes in the digital network. This task is fulfilled by the central clock generator (CCG).Depending upon the accuracy required, the following two modes of operation are possible.Control System PanelThe purpose of the system panel is to display alarms and advisories of internal and external supervisory units outside the system) both visually and acoustically. It is divided into two parts namely the System Panel Control and the System Panel Display unit.

SwitchingBy virtue of its high data transmission quality, the switching network can switch connections for various types of service (for example telephony, facsimile, teletext, data transmission).

This means that switching network is also ready for the Integrated Services Digital Network (ISDN).

SignalingThe EWSD digital electronic switching system can control connections to and from other network nodes using all the common signaling systems.

The signaling functions in a EWSD network-node are handled by the "common channel signaling network control (CCNC)". One system that is particularly suitable for stored-program-controlled digital nodes is signaling system no. 7. This transports signaling information separately from the user information (voice, data) on common-channel signaling links.

Advantages Higher speed signaling Very reliable signal transmission Flexibility to adapt to future requirements

Suitable transmission Medium Copper Wires Optical Fibers Digital Radio Links Satellite links

AccessThis includes:

Line / Trunk Group (LTG) Digital Line Unit (DLU) Digital Announcement System (DAS).

DAS explained:The digital announcement unit announces recorded messages to the subscriber relating to different matters such as reason for disconnection or the disability of a non STD phone to dial an outstation call. The necessary information for such an announcement is provided by CP and DLU.

HUAWEI PRI EXCHANGE (C & C08)

OVER VIEW & BACKGROUND

PRI stands for “Primary Rate Interface”. The PRI exchange connects the ISPs and the subscribers of the telephone line. C&C08 is the PRI exchange installed at IBA. It is manufactured by Chinese company Huawei.

This exchange is installed in the premises of the office of the general manager Islamabad Telecom Region. It is in the jurisdication of divisional engineer phones IBA-I Islamabad. Only PRI connections are provided to different ISPs working in Islamabad through this exchange.

The basic theme of installing a separate exchange for ISPs was to reduce the traffic from EWSD & ZTE exchanges through which PSTN services are being provided to normal subscribers in the communication division of IBA-I because these exchanges started being overloaded due to the increasing use of internet everyday.

Pakistan Telecommunication Company Limited decided to install a separate exchange for this purpose. Huawei Technologies, China a leading name among the manufacturers of telecommunication switches all over the world came forward to install this exchange as a gift to PTCL, strengthening the bridge of Pak-China friendship.

The most popular & widely used switch of Huawei Technologies, C&C08 is installed & giving extremely remarkable performance in PRI exchange IBA-I Islamabad. Initially there is a provision of one hundred (100) PRI connections but it is expandable & PTCL is planning to extend it.

Let us now discuss the important features of C&C08 in detail.

GENERAL INTRODUCTION OF C&C08 SWITCH SYSTEMTHE MEANING OF C&C

City & Countryside Computer & Communication China & Communication

PROFILE OF C&C08Universal frames & racks are used in C&C08 digital SPC switching system. The boundary dimensions of a rack are “2100×800×550mm, & such a rack can hold six “620×300×279mm” standard-sized frames with each frame being able to hold 26 plug-in-units (boards).This kind of modular structure can facilitate the installation & capacity expansion of the system as well as adding of new devices to introduce new functions.

Different functional boards can be chosen to handle various signaling networks, & through the adding new functional frames or modules, a wide variety of new functions & technologies can be introduced to expand the system application area.

OVERALL STRUCTURE

A C&C08 system is composed of a central module & multiple switching modules. The central module is composed of the administration module/communication module (AM/CM).

HardwareIt is a state of the art telecom technology which proves the skills of Chinese engineers.A schematic sketch of C&C08 is given as under.

MODULAR STRUCTURE

BAM: Back administration moduleLIM: Line interface moduleSM: Switching moduleSPM: Service processing moduleLAN: Local area networkPDF: Power distribution frame

BAM: It is a super computer It is a powerful administration plat form. State of the art computer functioning as server. User through background i.e LAN can implement maintenance, test, billing & other

features.

LIM:

Mainly it is in the charge of Multiplexing & demultiplexing the services & signaling data.

It is connected to SM through a 40.96 Mbps Interface. STM-1:Trunk Interface E-1:Trunk Interface

SM: It is the hardcore of C&C08 It has distributed relational data base management. It handles call processing. Operation & Maintenance It has alone switching capacity. Stand alone single module exchange. SM & AM/CM are interconnected via fiber optics. Maximum 128 SMs can be connected to a AM/CM. It consists of 6 frames It consists of 1 to 8 racks.

SPM: It is in charge of handling various & V5 services. Equal in functions to SM but with much more powerful capacity. Working with interfaces of E-1 It is connected with BAM via 10M/100M interface using TCP/IP protocol.

SRM: Shared Resource Module Provides shared resources of entire system ( DTR,MFC Transceiver, FSK, CONF,

SPD) required by SPM such as: Signal tones DTMF device MFC device Conference telephone device CID display

AM: It is comprised of FAM ( Front administration Module) & BAM (Back

administration module) BAM interconnects SMs & client server FAM performs following functions

Inter modules call connections Real time switching control & management Ticket processing Traffic statistics

FAM & BAM are interconnected via 1 to 6 10/100M TCP/IP ports EthernetLAN BAM(FAM) Link (Super Computer)

CM

It is the communication module: It is responsible for Inter-SM speech channels & signaling links

CENTRAL MODULE The collection of AM/CM, SPM, SRM is known as Central Module. It can contain a maximum of 9 racks. AM/CM - CPM, CNET, CCM, STM, LIM, BAM & integrated alarm box

STM: It is the synchronization timing system Its function is synchronizing the system with higher level networks

CPM: It is the central processing module Its purpose is storage & processing of local office data & management of boards on

AM/CM HDLCCPM CCM Other Modules Link

CCM:- Central communication module 112 incoming high ways 112 outgoing high ways forming signaling switching network transmission rats is 2.048 MBPS

CNET:- Central switching network Incharge of switching regarding voice & narrow band communication It has 64 high speed Optical Fiber Links(HOFL) Its capacity is 128 K

MPU:- Main processing unit It is the brain of SM Directly controls the boards of MCF through BUS It controls user & trunk circuits via nodes It also controls sending of tone & voice by SIG board It can control NET board to handle call connection It communicates with AM/CM, Operation & maintenance system & Load MPU software operates through HDLC synchronous serial port

NOD:- This card is responsible for the communication between MPU & User frame &

trunk frame There are 11 NOD slots for each SM The communication between Main NODE & MPU is through Mail box. Mail Node & Sub Nodes exchange messages through serial ports

NODES forward the commands to Sub Nodes that are issued by MPU & reports the states of Sub Nodes to MPU

SIG:- This is Digital signal tone board It provides 64 paths of signal tones

BNET-A:-As the name indicates this card (module) is used for the switching purposes.

It forms Intra Module Switching Network 4K * 4K switching network provides 128 High Ways 64 are used by own system resources 64 are freely distributed in users & trunks

CKV:- It drives the differential clocks of the functional units i.e ASL & trunks CKV is a part of the BNETA board Either board alone, BNETA, or CKV can not work normally

ASL:- This is Analog subscriber Line card This card provides all the telecommunication services to the normal subscribers i.e

analog subscribers or the internet service providers It is present in SM 1 ASL frame has 19 ASL cards 1 ASL card has 16 subscribers 1 ASL frame has 304 subscribers

ET-16 Card:- This type of cards are present in Line interface module Each ET-16 card has 16 E-1s Each E-1 has 32 channels One PRI ( Primary rate interface) means One E-1 When it is about normal telephone subscribers we can provide 16 telephone

lines(connections) from one E-1 & 256 from one ET-16 cards, but when itcomes to ISPs one or more PRIs are provided to them, that means one or more E-1s.One E-1 or PRI means 32 communication channels similarly two PRIs means 64 channels of communication.

DSL:- Digital subscriber line card The subscribers who need digital services are accommodated here It provides digital services like ISDN(Integrated services digital network) In case of ASL PRI is provided & in case of DSL, BRIs (Binary rate interface) are

provided There can be a maximum of 8 users in one DSL card. This means 8 BRIs can be

provided at a time from a single card Each BRI has 64 communication channels Currently no BRI is provided to any subscriber from this exchange (switch) in the

territory of IBA-I

PWC:- Power card Its major function is as secondary power supply 4 PWC boards can power 2 frames, that means each frame has 2 PWC boards Its output is 5 V/ 20A D.C

ALARM BOX It alarms a system fault It is connected to BAM & work stations via serial ports Presenting audible & visual system Categorically we can say that alarms are related to four types of systems, these are

namely: Power supply system Exchange functions Self alarms Exchange related environment

C&C08 MAINTENANCE SYSTEM

This is the software which is being used for the subscriber administration, fault maintenance & controlling the operation of this switch. This same software is installed in the FAM (LAN) & BAM (Super computer). The version of this maintenance system currently in use is V 6.1.0.This is a very user-friendly windows based system that allows the administrator to allow a number of operators to administer the switch & to restrict them from certain operations. Every user has its own login name & password to achieve the authority of administering the switch. This software provides the user the ability to test or detect the fault in any part of the switch as well as a particular user’s line. Also the administrator can add value aided services to subscriber’s service e.g., CLI, Call waiting, Conference calling etc.

Access Net Work

This net work topology is used to access & control the system being operated at a distance through optical link by means of an administration terminal. The idea of Utilising this type of net work in Public switched telephone net work came from the problems caused by the copper plantation such as maintenance, fault locating & heavy in cost etc.To have a better understanding of this net work let us consider an example of such a system installed & being used in communication division IBA-I of Pakistan Telecommunication Company Ltd.

ACCESS NET WORK IBA-I ISLAMABAD (C&C08)

About four thousand customers (4000 telephone connections) of PTCL are located in Saudi Pak Tower, one of the largest business empires in Islamabad. For this purpose eight

thousand copper lines (one pair for each connection) were planed under ground which were originating from Divisional office of IBA-I & terminating in the premises of Saudi Pak Tower at a distance of about five to seven kilometers from IBA-I. It is obvious that copper plantation of eight thousand lines of this much length is very much expensive & also a tough job to do. The maintenance of this plantation requires the services of a line staff dedicated particularly for this business estate. In case of line fault in any of the connections the earth has to be dug out for even kilometers to locate the fault. Line losses are also of great significance in this respect. Many a time lines become noisy due to many external & internal factors affecting the signaling which results in distortion & disturbance in voice & data communication. As a remedy for this problem ,access net work technique is employed using a well known & state of the art switch by HUAWEI TECHNOLOGIES, brand name C&C08.This switch is being used as the accessing tool in the net work. The telephone connections to Saudi Pak Tower building are provided by the IBA-IA exchange, which is a SIEMENS most famous & widely used switch, brand name EWSD. Since SIEMENS EWSD has CCS7(Common channel signaling) type signaling & HUAWEI C&C08 employs V5.2 signaling so there is a mechanism in between that decodes & converts CCS7 to V5.2 mode. A pair of optical fibre is originated from digital Interface Unit of EWSD Exchange passing through the digital distribution frame it enters the trunk frame of C&C08 switch. This trunk is placed with another truck in Access Net Work Room in IBA-I. From other side of the trunk frame the optical fibre pair goes into the AV-5 frame of the second trunk placed beside it. The signaling was CCS7 up to here. Now from this frame an optical link originates & terminates in the premises of Saudi Pak Tower. There it enters the module SBA 155/622 H, from MDF four thousand pairs of copper wire are planted & taken to the desired locations where the telephone connections are to be provided. This net work has reduced the length of copper wire as it is used between the MDF (S.P.T) & desired locations in Saudi Pak Tower. These four thousand connections are being administrated from IBA-I by means of an administration terminal (PC) which is connected to the main control frame of the switch C&C08.The administration of the connections includes fault location & rectification, billing, disconnection & provisioning of different value aided services e.g., CLI, Call waiting & Code barring for nation wide is international dialing etc., the employment of this net work has reduced the line staff which was appointed before & also increased the efficiency of the PSTN services provided by PTCL. The switch C&C08 is used on testing basis which is a gift from the HUAWEI technologies China Inc. to the PTCL. The office of the HUAWEI Technologies is also located in the premises of the Saudi Pak Tower, this switch is working efficiently & has shown a remarkable performance regarding fault occurrence till date, PTCL is planning to install this type of net works through out the country to reduce the expenditures & problems faced due to copper plantation. A trunk diagram shown below will give a better understanding of the net work topology.

ZTE EXCHANGEZTE is a Chinese telecommunication company that was founded in 1985.Initially it had its network limited in different cities of China later on ZTE extended its network to different countries of Asia and Africa. Unlike EWSD, ZTE is modular based exchange and in each module we have its own control system, switching network and signaling network.

At IBA exchange a ZTE exchange named ZXJ10 is installed. It has capability of supporting 10000 lines. A detailed diagram of ZTE’s module is shown in the next page.

The main advantage of having a ZTE exchange is its low cost. The ZTE exchange costs almost eight times less than that of Siemens, Ericsson or Alcatel. That is the reason why ZTE is becoming so popular in the developing and poor countries of Asia and Africa.

The disadvantage of ZTE exchange is that it is not as reliable as EWSD, Ericsson, Alcatel or even Huawei. ZTE exchange suffers from more errors than other exchanges.

DIUs

L

T

G

EMPTY

EMPTY

EMPTY

AV-5 FRAME

SBS 155/622 H

RAM

M AIR CONDITIONI- NG UNIT

SBS 155/622 HD SUBSCRIBER LINE CARD

SUBSCRIBER F LINE CARD

D

F

F

TRUNK FRAME EMPTY

CLOCK FRAME

MAIN CONTROL FRAME

MCF

BAM

CCS 7SIGNALING

V5.2SIGN

OPTICA-L

LINK

IBA-IAEXCHANGE

PCM HALL

ACCESS NET WORK ROOM SAUDI PAK TOWER

10

ALARM-48+5-5

ALARM-48+5

-5

DSPU

DSPU

DSPU

DSPU

PP

TSLC

TSLC

TSLC

TSLC

MasterStandbyOfflineAlarmPower

SwitchResetOn/off

MasterStandbyOfflineAlarmPower

DT

DT

DT

DT

DT

10

10

ALARM-48+5

-5

SwitchResetOn/off

ALARM-48+5-5

10

DSPU

DSPU

COMA

COMA

MPPP

MPPP

SLC

SLC

SLC

SLC

SLC

SLC

PP

PP

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

SLC

ZTE ZXJ10 MODULE

CKG

NET

CKG

NET

ZXJ10 (V10.0) SYSTEM DESCRIPTION

SYSTEM OVERVIEW

The ZXJ10(V10.0) digital SPC switching system employs an open architecture with full distribution between modules, hierarchical control, inside modules & centralized administration. It is based on general purpose computers & is supported by local area network. It employs the client/server mode as its control structure, so that the system is flexible in networking & powerful in call handling with high reliability & good compatibility & expandability.

HARDWARE CONFIGURATION

Aided by a full contribution control system, ZXJ10 can hold one to several dozens of modules in accordance with the exchange capacity. Besides, in terms of services demands & geographical locations, this system can be expanded with different modules. Except the OMM module, each module consists of a pair of active/standby MPs ( Master processor ), several SPs ( Slave processor ) & some single boards, PSM SNM, MSM, RSM, RLM are the basic modules of the ZXJ10 foreground network, while OMM makes up the background network.

PHM PSM

Figure: System structure diagram

OMM: Operation & Maintenance Module PSM: Peripheral Switching ModuleRLM: Remote Line Module RSM: Remote Switching ModuleSNM: Switching Network Module MPM: Mobile Peripheral ModuleVPM: Visitor Peripheral Module MSM: Message Switching ModuleIAM: Internet Access Module PHM: Packet Handling Module

In the whole ZXJ10 system, all the important equipment is in active/standby mode, including MP, T net, NETD, COMM, FBI, clock equipment & subscriber unit processors, etc.

PERIPHERAL SWITCHING MODULE (PSM)

Major functions of PSM: In a single module office, it performs the PSTN, ISDN subscriber access & call

handling In a multi-module office, it is connected into the central modules one of the

module offices As the mobile switching system ( MSC ) , it is connected into the central

exchange

SNM

RLM

IAM

MSM

OMM

PSM PSM RLM

RSM

RSM RLM

PSM

MPM VPM

As the service switching point ( SSP ) of IN, it is connected into the SCP

Hardware Structure of PSM The core of the TS switching network pf PSM module is of an active/standby non-blocking switching network of 8K*8K or 32K*32K, the peripheral interface units & the signaling units. The internal message paths are established through the intramodule communication boards (COMM) & the monitoring boards (MONI).The clock employs the loose-coupling method with its possible maximum accuracy of Stratum 2 & degree A. It can provide built-in Bits systems too.

The full system configuration is of 12480L ( 12480 subscriber lines) + 26700DT ( 26700 trunks) . In every group of 960 subscribers, it interchanges with 240 trunks. Each module holds 48 NO. 7 links or 24 V5.2 interfaces.

8 Mb/s

2

Figure: PSM structure diagram

FBI

8 Mb/sSNM

2 Mb/s2 Mb/s

Digital trunk unit

Subscriber unit SWITCHING UNIT

8K * 8KMFC

DTMF

TONE

V5.2 NO. 7 COMM COMM

MP0 MP1

SIGNALING UNIT

Control unit

PSM employs multiprocessor hierarchical control mode, consisting of the following basic units.

Control unit: MP, COMM, & MONI, Namely, a single COMM board can process 32 64Kb/s HDLC, with 8K-byte & dual-port RAM. It can serve as MP-PP, MP-MP COMM, no.7 signaling boards, V5.2 C channel board & 30b + D D channel board. Moreover, it can monitor the power supply, synchronization unit, & FBI ( fiber interface ), for instance, the MONI & the PEPD( peripheral environment parameter detection ) boards

Switching unit: 8K DSN ( digital switching network ) & some DSNIs Synchronization unit: clock reference card CKI ( if the bits interface required ),

synchronous oscillator SYCK Peripheral interface unit: DTI, FBI, as well as subscribers & analog trunk boards Signaling unit: ASIG ( analog signaling board ), TONE, MFC, DTMF, & CID ( caller identification ) board Subscriber unit: in every 960 subscribers lines, there are 40 ASLCs ( or DSLC ),

each containing 24 analog subscriber lines ( or 12 digital subscriber lines for each DSLC ). Each unit is equipped with 4 analog subscriber test boards MTT ( or digital subscriber test boards DMTT ). ASLC & DSLC boards can be inter-inserted, so can the MTT/DMTT. All the single boards have processors. The subscriber unit is monitored by two active/standby SPs

Analog trunk unit: the analog trunk unit is controlled by two active/standby SPs with 22 trunk boards, including the single frequency trunk ( SFT ), the loop trunk ( TRT ), the A/B wire trunk ( ABT ), & the magnetic trunk ( MT )

THE REMOTE SWITCHING MODULE ( RSM )

The internal structure of RSM module is exactly the same as that of PSM except more TSs from PSM to the central network & their fixed no. is of 2040. However the no. of TSs from RSM to the central network is comparatively smaller & can be increased at the rate of every 32 TSs, flexible as well as adjustable.

MESSAGE SWITCHING MODULE ( MSM )

SNM usually employs 4*8K planes, with the maximum expansion capability of 8 * 8K. Its switching TSs amount to 64K, applicable to various sorts of markets. The HWs from RSM, PHM are averagely distributed to 8 planes. Considerably the configuration flexibility of RSM , the PCM links from RSM can be connected to the multi-plane via the switching of a single T net. Since the connection of each plane can be controlled through a pair of MPs & two COMM boards with the 256 Kb/s HDLC link, that pair of MPs in SNM can also be connected with NT server of OMM via Ethernet so as to serve the message transmission between OMM & other related modules.

Figure: MSM structure diagram

PSM+ PHM

PSM+

MP0 MP1

COMM COMM COMM COMM

COMM COMM

MP0 MP1

MSM

...........

n * 64Kb/s

CENTRAL SWITCHING NETWORK MODULE ( SNM )

The major function of SNM is to perform not only the TS switching between PSM & PSM but also the B-channel connection between PSM & PHM.

Figure: Multi-module Test connection diagram

After the semi-permanent connection, SNM will transmit the TSs from the multi-module to MSM to support the n * 64kb/s switching. It can be applied to the ISDN H0 channel transmission, making the alternation of the communication bandwidth n * 64kb/s ( n≤32 ) become possible. It can also provide the background with the information channel.

PSM ( Tn )

PSM ( Tn )

PSM ( Tn )

PSM ( Tn )

PSM ( Tn )

PSM ( Tn )

S T

S T

S T

.

.

.

S netMulti-Plane

.

.

Figure: SNM structure diagram

SNM usually employs 4 * 8K planes,with the maximum expansion capability of 8 * 8K planes. Its switching TSs amount to 64K, applicable to various sorts of markets. The HWs

512 Kb/s512 Kb/s

.

.

16 * 8Mb/s

Built-in fiber

Built-in fiber

PSM

s

PSM

COMM COMM

MP0 MP1

OMM

RSMSingle T net 8K * 8K

Single T net

8K * 8K

COMM

RSM

32 * 8Mb/s

32 * 8Mb/s

16 * 8Mb/s

SingleTnet8K*8K

SingleTnet8K*8K

LAN

2 Mb/s HDLC

MSM

Built-in fiber E3 E1

COMM

SNM

from RSM, PHM are averagely distributed to 8 planes. Considering the configuration flexibility of RSM, the PCM links from RSM can be connected with the multi-plane via the switching of a single T net. Since the connection of each plane can be controlled through a pair of MPs & two COMM boards with the 256Kb/s link, that pair of MPs in SNM can also be connected with NT server of OMM via Ethernet so as to serve the ,message transmission between OMM & other relevant modules.

THE OPERATION & MAINTENANCE MODULE ( OMM )

According the size of modules, SNM can be such types as of 32K, 64K, 128K, 256K, of which 13K network can be employed to connect with 13 PSMs & 35 RSMs. The ZXJ10 SPC exchange follows the centralized maintenance management mode. Its maintenance management network has applied not only the client/server structure which is based on the TCP/IP protocol, but also the WINDOWSNT4.0 operation system. Its contents contain such things as data, statistical traffic, billing, system measurement, system alarm, etc, which are substantial for the management & the maintenance of the exchange. The handling of the software & the data of the whole system is executed in OMM. Then SNM transmits the results to each peripheral module, & can be under remote operation as well as maintenance management.

Figure: OMM connection diagram

NT clientNT

clientNT client

MP

DDN PSTN/PSPDN

NT Server

NT client

NT client router

..............

The main processor of MSM ( or other PSM modules ) can be connected into Ethernet via the standard TCP/IP protocol. As a result, the message interworking between OMM & the foreground processor is available.

MOBILE PERIPHERAL MODULE ( MPM ) & VLR MODULE VPM

MPM & VPM are developed on the advanced ZXJ10 ( V10.0 ) platform by adding mobile switching modules MSC & VLR modules, forming the core of the ZXG10 mobile switching network. The major function pf MPM is to realize the relevant functions of MSC, that is, providing the voice trunk, the signaling link to BSS, the tone trunk to PSTN, providing the link interface to PLMN, at the same time, supporting the message interaction among the VPMs. In addition , MPM is similar to pure wired trunk module. Within 8KTSs ( eg. 2KTSs to SNM, 2KTSs to BSS ), 4K TSs are for the incoming & outgoing office trunks, supporting approximately 20 thousand mobile subscribers. Except the absence of the ASIGF board, the rest of the VPM structure is the same as that of MPM, & their functions are generally the same. Unlike MPM module , the single T network of VPM module does not control the connection of the speech channels. Instead it only performs the connection of the internal control, & the communication signaling, VPM mainly carries out the functions related to VLR, providing the actual storage & management in such temporary resources as TMSI, MSRN etc. It also controls the communication with other network entities eg, VLR, HLR, VPM itself can manage NO.7 signaling handling.

BSS: base subsystem MSC: mobile switching centerMSM: message switching module SNM: switching network moduleMPM: mobile peripheral module VPM: visitor peripheral modulePSM: peripheral switching module (cable) HLR: homing location registerAUC: authorization center

Figure: ZXG10 mobile communication system structure diagram

TCP /IP

Charging center NMC

SNM MSM

OMC-S

PSM MPM VPM

HLR/AUC NO. 7 SIGNALING NETWORK

PSTN ISDN PSPDN PLMN

OMC-R

BTS D1800 BTS G900

BSC

X.25TCP/IP

BSS

TCP/IP

PACKET HANDLING MODULE (PHM)

With PSM as its platform, the physical architecture of PHM employs X.25 protocol to support two call types, namely Case A & Case B.Case A: B channel packet data are handled by COMM & MP in PHM.Case B: The switching network transmits B channel packet data to AU (access unit) at PSPDN side for handling.

INTERNET ACCESS MODULE (IAM)

IAM is developed on the ZXJ10 platform, consisting of the call signaling handling module, the MODEMPOOL module & the protocol handling module with the purpose of increasing relevant IP services for ZXJ10. The present services focus on the internet access, IP telephone/fax: & the provision of remote network access for the subscribers. Via the common lines, ISDN lines & other private lines, the remote subscribers can get access to the networks. Furthermore, IAM also provides such services as network subscriber account management, subscriber authorization & access authorization control, ensuring the subscribers network access validity. The access capability can be of n*30 lines. The extension capability can be smoothly achieved by over 20,000 lines

Figure: Internet access diagram

Telecommunication operators can add internet services effectively & smoothly. This plays the part of the “data bypass” objectively & consequently reduces the pressure caused by internet on modern telecommunication networks.Additionally IAM can be employed to establish not only the large capacity internet access point so as to make construction of the service groups very flexible, but also the enterprises INTRANET. Or it can build the VPN network for clients. Meanwhile as the IP telephone/fax network gateway. IAM can provide internet telephone/fax services for the end-users, for eg. IPPHONE, IPFAX, internet incoming/outgoing call, analog access & postal box services.

Internet FBI

PRI/FR

E1/DDN

PSTN

M

ZXJ10 IAM

ROUTER

WWWSERVER

DNS SERVER

AAA SERVER

INTERNET

OAM

PC terminal