Chapter One General Introduction of the HJD04 Switching

System

1.1 General Introduction of the System

1.1.1 Developments of the Switches

The SPC switch has been developing along with the telecommunication and computer technologies. The digital switching technology has gradually matured as the digitalization technology of telecommunication patterns develops. Computers are widely used in the switching controlling systems as the computer technology, especially the micro-processor technology, has achieved boosting development. Hence, it becomes possible to control the switching connection by means of computer stored programs.

With the development of the computer technology, the switching system control modes of SPC switches have been changing continuously. The modes can be divided into the centralized control mode, hierarchically-controlled mode, decentralized control mode and the hierarchically-distributed control modes.

1) Centralized Control Mode In 1960's, the development of the SPC switches was in the initial stage . The whole

switching system was controlled only by one processor because of high cost of computer systems. In order to reduce the cost, only one processor was used to control the whole system and all control functions of the switching system were undertaken by the central processor. This is called the centralized control mode.

Structural features of this mode led to poor reliability of the centralized SPC switches. The whole system may break down if the central processor has some problems. Moreover, as the capability of the processor is limited, it can't fulfill the processing demand of large switching capacity. This control mode is not used now in the modern large-scale switches.

2) Hierarchical Control Mode With the development of the microprocessors, it is possible to adopt the multi-processors in

one switching system. Most of the large-scale office switches now adopt this mode. Some simple and repetitive but highly-real-time operations are processed by the sub-processors so as to alleviate the burden of the central processor, and the requirement to the central processor can also be lowered.

The reliability of this mode is much higher than that of the centralized control mode, as its sub-processors are only in charge of parts of the function or subscribers. If a fault occurs, the

affected area is limited. The reliability of the central processor increases as it takes care of fewer functions and its complexity is reduced. But this mode doesn't completely change the pattern of one central processor controlling the whole system. So it still can not get rid of the defects of the centralized control mode.

3) Decentralized Control Mode To overcome the above-mentioned shortcomings that can not be solved, the Bell

Corporation developed decentralized switching system S1240. S1240 has no central processor. All the control functions are distributed in each part of the system and realized independently by many small processors. The system consists of many kinds of terminal modules, assistant control units and the digital switching network with the latter as the hub of the system. Processors within each module are independent from each other and the message communication is conducted through the digital switching network.

The full decentralization is realized through function decentralization, level decentralization and the space decentralization. The function decentralization means demarcating all services according to functions and each processor is in charge of one function. The level decentralization is that, among a group of processors, each one plays its role and the upper level hierarchically controls the lower level. The space decentralization means that each processor is in charge of a certain switching area, e.g. one processor serves a certain amount of subscribers.

In this way, the same type of terminal modules will not be affected if one of them breaks down. As functions are decentralized, any failure will only affect the volume of the service instead of the types of services the system offers. As to the space decentralization, breakdown of certain equipment only affects the area served by it and other areas will not be affected. So, the reliability of the whole system is improved.

However, this control mode has its own shortcomings. As the processors are added, the scale of communication between processors increases exponentially. This occupies much processing capacity of the processor, and complicates the software. Furthermore, some problems still remain to be solved, such as the performance evaluation of the distributed processing system, the perfection of the distributed data base technology and the realization of the parallel computing etc.

4) Hierarchical Distributed Architecture and the Control Mode To avoid the problems existing in the above-mentioned control modes, HJD04 switching

system developed the completely innovative hierarchically distributed structure and control mode. With this mode, the whole switching system is divided into several planes and processing layers. Each layer consists of many same-level processors. The control principle is that same-level processors coordinate with each other and the lower level obeys the upper level. The mode has some features of decentralization but avoids the problems of the latter as the same layer consists of limited constituents, and therefore, the coordination and message communication between them will not affect the efficiency of the processor. The control mode between the upper and lower levels is highly efficient, as it is similar to that of the centralized control mode. In this way, the control mode of HJD04 switching system incorporates the advantages of both the centralized and the

decentralized control mode. Moreover, we will see that in the future, this structural design of HJD04 switching system possesses wonderful compatibility and excellent function expansion ability when it is renovated and upgraded.

1.1.2 Structural Features of HJD04

The HJD04 digital switching system develops along with the development of the software and hardware of computers. Initial design of the system is not tradition-oriented but based on the computer system, which is the kernel of the switching system. It is deemed as a real-time computer-controlled system with the main task of realization of switching and other supplementary services.

Beak-through has been achieved in the HJD04 switching system regarding the system architecture and switching network because of its complete innovative design. With the newly designed hierarchically distributed architecture and control mode, and the unique " fully-interconnected distributed duplicated T-type switching network ", the HJD04 switching system has powerful processing capacities even equipped with less expensive low-rate processors. The computer-centered designing offers the HJD04 switching system with the natural adaptability to develop the IN service, ISDN function and SS7 signaling systems etc.

Wide application to PSTN and private networks enables the HJD04 switching system to achieve great improvement in terms of functions and performance. A series of products, including HJD04C, HJD04D, HJD04E, HJD04RM, 04-DLE and 04-RSU etc., have been successfully developed. In addition, series of built-in optical/ electric interfaces are offered to fulfill various kinds of subscriber demands and to enhance functions of the system.Major performance indexes of the HJD04 switching system are listed hereunder:* Max. Capacity of the system: HJDo4D---Subscriber lines: 100K; tandem trunks: 40K; HJD04E-- Subscriber lines: 500K; tandem trunks: 250K;* Processing capacity: >3 million BHCA (HJD04D) >18 million BHCA (HJD04E)* Providing powerful SS7 (both the 24-bit and the 14-bit are compatible );* Providing Centrex ;* Providing the ISDN function with min. and max. integration capability ;* Possessing the SSP function of IN;* Providing V5.x interface;* Providing internal optical transmission interface;* Supporting the access of remote wire-line and wireless subscribers (RSU, DLE, WLL-04);* Supporting the centralized maintenance, centralized monitoring and centralized charging of the whole network;* Possessing high reliability and maintainability;* Processing good upward/downward compatibility and the expanding services will safeguard the user’s investment ;

* Providing profound and efficient technology and product support as well as service means;* Possessing flexible system structure which is accessible to new technologies’* Satisfying the prevailing and future demands of communication network.

1.1.3 Application Scope

The HJD04 switching system is designed in accordance with the technology standard of China’s communication network. It meets the demands of China’s digital & analogue hybrid network and digital network and the demands of China’s network management. The system structure is adaptable to the development of ISDN.

Th eHJD04 digital SPC switching system consists of 32 modules of which 31 modules can be used for telephone exchange except one that serves as the I/O module. When the whole system is established, flexible composition of the network can be realized in the mode of cumulative modules.

The HJD04E digital SPC switching system has 64 modules. The system can be based on the module connection to form flexible networks. Due to the adoption of the large-capacity star-shape optical fiber directly-connected switching network （256KX256K ）， each switching module can support 8192 subscriber ports, 4096 trunk ports and 4096 2B+D ports. It has 4096-N channel time slots, among which N is the office module number (including the Module 0).

BHCA ：Larger than 300K/hour (When there are 31 modules, the system BHCA is greater than 9 million / hour).

1) Traffic Volume and the Number of Frames for A single Module HJD04D Switch： (1). The traffic volume under the normal load is no less than 867e; (2). Maximum: 1TCF and 3 SCF; one TCF has 512 lines and one SCF has 1024 lines. HJD04E Switch：

(1) The normal load is not smaller than 3450erl;(2) One control frame at maximum and seven subscriber frames are configured.

2) Pure Trunk Modules HJD04D Switch ： (1). Adopting SS7: 0.65e/L (one TCF); digital trunk: 1440 lines; (2). Adopting SS1: 0.65e/L (one TCF); digital trunk 1200 lines; 128 sets of MF registers at maximum; (3). Adopting SS1: 0.65e/L (one TCF); digital trunks + analog trunks 1328 lines , among which 1200 lines at maximum are digital trunks and 128 lines at maximum are analogue trunks with 128 sets of MF registers. HJD04E Switch ：

(1) Adopting the SS7: ：0.95erl/L(1 control frame) ， 4096 digital trunk lines; being able

to have two STM-1 optical trunk interfaces;(2) Adopting SS1: digital trunks 900 lines; more than 128 sets of MFR .

3) Trunk / Subscriber Mixed Modules HJD04D switch ：

The configuration of the trunk/subscriber module is one TCF at most and three SCFs. The configuration table comes as Table 1.1.1.

Table 1.1.1 Trunk / Subscriber Mixed Module Configuration Table Max.

equipment

Frame

configuration

Subscriber

lines

(0.18erl/L)

Max. DTR

sets

Trunk

ports

(0.65erl/L)

Max.

Analo

gue

trunks

Max.

Digital

trunks

Max.

MFR sets

SS7 1 TCF +1

SCF

1024+512 32 1440 1440

1 TCF+2

SCF

2048+512 64 1380 1380

1 TCF +3

SCF

3072+512 96 540 540

SS1 1 TCF +1

SCF

1024+512 32 1200 128 1200 128

1 TCF +2

SCF

2048+512 64 1140 120 1140 128

1 TCF +3

SCF

3072+512 96 420 128 420 64

4) The Capacity of the HJD04 Switch in Various Applications (1). Capacity of large or medium switch: 512 to 100k subscriber lines or 60 – 40,000 trunk lines; (2). Terminal office of small economical capacity: 512 to 3584 subscriber lines (3). Access unit of remote subscribers: 16 to 1024 subscriber lines (4) large-capacity tandem office ：30 K to 250 K trunk lines (5) large-capacity and multi-module terminal and tandem office with module area distribution

1.2 System Architecture of the HJD04 Digital SPC Switch

1.2.1 Overall Architecture of the System

The HJD04 Switching system adopts the innovative hierarchically distributed architecture and control mode. The whole system is divided into five planes and four processing levels (See Figure 1.2.1):

The five planes (levels) come as follows:(1) Service Console Plane

This level is the operation plane for subscribers. It consists of maintenance, charging, measurement, operator seats and service consoles of the business hall. The local service consoles of the system form a completely open terminal system by connecting Ethernet and support the remote centralized network management and maintenance function.(2) Input/ Output Plane

This level is the man-machine communication plane. It consists of input/output communication processors and input/output processors that are parasitic on the modules.(3) Switching Processing Plane

This level is the voice, data and video service switching plane. It consists of the switching network and various modules.(4) Function Processing Plane

This level is the telephony support plane. It is subordinate to the corresponding module and consists of the processors which implement different functions.(5) Co-processing Plane

This level is the telephony support plane. It consists of the co-processors which serve the corresponding functional processors.

The bottom level consists of various circuit interfaces such as the interface of analogue subscriber lines, the interface of digital subscriber lines, the interface of analogue trunk and the interface of digital trunk etc.

The relationship among the levels is that the lower level is subordinate to the upper level and each level plays the relevant function. The elements in the same plane are different in function but equal in status, which fully embodies the concept of distribution. The basic element of the system is the module. No matter what kind of modules they are, they become members of the system to strengthen the system and the capacity as long as they can satisfy the communication procedure and interface regulations. At present, there are input/output modules, switching modules, the SS7 module and remote modules etc.

1

2

2

4

5

I/O3

3

4

6

9

10

7

5 11

12

8

1

3

Notes: 1. Open terminal system 2. network element management plane 3. I/O processing and communication 4. input and output plane 5. input and output processor 6. switch processing plane 7. switching network 8. module processor

9. functional processing plane10. functional processor11. co-processing plane12. co-processor

Figure 1.2.1 Hierarchical Architecture of the HJD04 Digital SPC Switching System

The kernel of the system is the switching network. The HJD04 switching system adopts a completely innovative control mode: fully Inter-connected distributed duplicate T-type switching system. (See figure 1.2.2) The structure of this network is that each module has a 20-core ribbon cable which is connected with all the modules (including the module of the ribbon cable ). Hence, the switching networks that are located in modules integrate into a whole network and form a switching plane. In order to ensure the reliability of the system, the switching network adopts dual-plane designing so that when one plane breaks down, the other one can go on working. The two planes can work by turns in the active/ standby mode.

The input/output level of the switching network (NT1, concentrator/expander) provides each module with 4096 64Kb/s ports, and the mid-unit connection level of the switching network (NT3, switching level) provides each module with 2 X 1024 time slots (TS) (dual-plane).The multi-party communication component which is between the switching level of the switching network and the expander makes it more convenient for the system to fulfill the function of conferences and other service functions.

The 1024 TSs of each module in the switching network are not all used for voice switching. The former 32 time slots are used for communication between modules. When the system modules are less than 32, the number of TS used for communication is equal to the number of the modules. Each module can only send the message from the TS which has the same sequence number of this module but can receive messages from the other 31 time slots.

The transmission rate of the reconnection cable of the switching network is 32.678Mb/s, and the reconnection relationship of the switching units among the modules is shown as Figure 1.2.3:

PCM96

PCM127

Figure 1.2.2 HJD04 Fully-distributed Duplicate-T Switching Network

Multi-partyCommunication

Parts NT2

Duplicated 2# Module

Duplicated n# Module

.复制 n 模块

Duplicated Voice-memory.

1024×8

Concentrator

NT1

S.S

NT2

1024×8

T-type NetworkNT3

1# module Voice Memory

1024×8

1024×8

1024×8

102

4×8

1024×8

1024×8

PCM0 S

P

S

P

PCM31

S

P

S

P.Expander

NT1

PCM0

S

P.

PCM31

S

P

PCM96

S

P

串

PCM127

S

P

20-core flat ribbon cable connected to other modules

Com

e from the 1st M

oduleC

ome from

the 2nd Module

Notes: M-- Module

Figure 1.2.3 Inter-module Switching Unit Multiplexing Relationship

The structure of HJD04E is that each module has an optical fiber with four interfaces , which is connected with the system switching unit (DSU). Through the DSU back-board printed wire, it is multiplexed with all the modules (including the module of the ribbon cable ). Hence, the switching networks that are located in modules integrate into a whole network and form a switching plane. The HJD04E optical-connected duplicate-T switching network includes Planes A and B. In order to ensure the reliability of the system, the switching network adopts dual-plane designing so that when one plane breaks down, the other one can go on working. The two planes can work by turns in the active/ standby mode. It provides 4096 TS for each module. The maximum system capacity is 256Kx256K.

The input/output level of the switching network (NT1, concentrator/expander) provides each module with 8196 64Kb/s ports, and the mid-unit connection level of the switching network (DSU, switching level) provides each module with 4096 time slots (TS) (dual-plane).The HJD04E provides the multi-party communication component independently and makes it more convenient for the system to fulfill the function of conferences and other service functions.

…

…. M 1

DSU

M 2

DSU

M i

DSU

M 31

DSU

1 2 i 31

…

…

The multiplexing relationship of the inter-module switching unit is shown as figure 1.2.4.Plane A optical fiber

Module 0#Module 1#

cableModule 2#Module 3#

Module 4#Module 5#

Module 30#Module 31#

光纤Module 0#Module 1#

Module 2#Module 3#

Module 4#Module 5#

Module 30#Module 31#

Figure 1.2.4 Digital Switching Network Unit (DSU) Connection Diagram (32 modules)The internal part of the system switching unit is based on the duplicated

T-type architecture. The T connector is composed of the voice memory and control memory.

DSU0A

DSU1A

DSU2A

DSU15A

DSU0B

DSU1B

DSU2B

DSU15B

Plane B

High-speed bus

High-speed bus(back-board printed wire)

1.2.2 Hardware System Architecture

1) Basic Composition of the System HJD04C(D) ：

The structure of the HJD04 switching system is modularized. The max. amount of modules is 32, among which the switching modules are numbered from 1 to 31 and Module No.0 is the I/O module. The communication and data exchange between different modules are carried out through the duplicated T-type switching network of the system. The maintenance console (MC) and billing console or charging console (CC) of the system are connected with the system through Module No. 0. The subscriber measurement console or measurement desk (MD) can connect with any of the other modules. See Figure 1.2.5.

Figure 1.2.5 Basic Composition of the HJD04 Switch

HJD04E ：The system architecture is modularized with the area decentralization among the modules. The

maximum modules in the system can reach 64. Modules from No. 1 to No. 63 are the switching modules. Each module can realize the inter-module communication and data exchange through the system duplicate T-type switching network. The maintenance console, the measurement console and the billing console are connected with the system modules through the LAN. The services consoles can be integrated into one as is shown in Figure 1.2.6.

1

1# Switching Module

I# Switching Module

M# Switching Module

32# Switching Module

0# I/O Module

MC ; CC

。。。。。。 。。。。。。

SS7 Module

MC of SS7 MD

Notes: switching room: SR

M: module

CC; charging console or billing console

MC maintenance console

MD: measurement desk or measurement console

Figure 1.2.6 HJD04E System Composition

2) Module Architecture and Composition The HJD04C/D switch is composed of three basic modules, i.e. input and output module No.

0 , Switching Module and SS7 Module . (1) Architecture and Composition of the Switching module

A. Composition of the Switching Module The HJD04C/D system can be configured with 31switchign modules at most. Each module is

composed of the control shelf and the subscriber shelf. Each control shelf can support 3 subscriber shelves. Each subscriber shelf contains 1024 subscribers, as is shown in Figure 1.2.7.

M3 M4

M1

MC CC MD

M2

M7

M63

SR B

SR A(Main SR)

M6

Toll fiber

M5

DSU

SR C

toll光纤

HUB local光纤SS7 MC

Figure 1.2.7 Composition of the Switching Module

Descriptions:MP —main processor ; serving as MP-04E in the HJD04E system AXM —auxiliary memory and serving as AXM-E in HJD04DPLUS/E system DSN —digital switching network ; HJD04C/D includes NT1 、 NT2 and NT3; HJD04E

includes NT1E ，NTP and DSU.ADNT—time sequence circuit board DTP —digital trunk processorDTMP—dual tone processor MFP — multi-frequency processor CP — communication processor ; not used in HJD04DPLUS/E system OTP —outer-line testing processor SSP —subscriber/analogue trunk processor ISP —position processor IOIF—2B+D expanded interface TCP — SS7 interface processor , not used in the HJD04DPLUS/E systemDSP —ISDN interface processor LT —ISDN digital subscriber interface boardOTNI— optical auto-healing loop interface board (155M)OTI — optical interface board (34M)LOTI—low-rate optical interface boardAPH —HDSL interface boardAPB — pair gain interface boardSLIC—subscriber line integrated circuit board

In each module, the module processor (MP) is linked to different functional processors by the bus. The key components such as MP, CP, DSN etc. are dually-configured and the other functional components are working in the function-sharing mode, which guarantees the module’s security and reliability.

B. Hardware Structure of Switching ModulesThe switching module is formed by the trunk control frame and subscriber control frame.

The structure of the subscriber control frame is showed as Figure 1.2.8. It has 6 layers. Layer 1 is used for the ringing current and power supply; Layers 2-5 are those for SLICs and contain 1024 subscribers in all; Layer 6 is one for the subscriber signaling processor and network.

The structure of the trunk control frame is showed as Figure 1.2.9. It has 6 layers: Layer 1 is used for the power supply; Layers 2 and 3 can be used for subscribers ; Layer 3 can also serve as the trunk layer; Layer 4 is one for trunks; Layer 5 is used for control; Layer 6 is used for the network time sequence .。

Figure 1.2.8 Subscriber Frame ( Shelf) Architecture

Figure 1.2.9 HJD04C/D Control Frame ( Shelf) Architecture

(2) I/O Module Structure and CompositionThe I/O module is numbered 0 and located in the control frame of the switching modules

(Figure 1.2.10). Each module 0 consists of two boards IOCP and IOP. The system supports more than two 0# modules, i.e. more than two sets of charging consoles (CC) and measurement desks (MD). In the HJD04E system, the functions of IOP and IOCP are performed by AXM-E in each module.

Figure 1.2.10 HJD04C/D Input/ Output Module Composition

(3). Structure and Composition of the SS7 ModuleThe SS7 module, as an independent module of the system, is composed of one HJD04

standard frame. The single-frame SS7 module is able to support 64 links and can be connected to 3 SS7 modular frames, The SS7 module system can support 256 links. Among the module frames, one is the main module frame and others are the sub-module frames. The main processor of the main module frame expands its bus through the board STBL and operates the processors of the sub-module frames.

A. Composition of the SS7 Module a) Composition of the Main Module

The composition of the main module is shown as Figure 1.2.11.

IOP IOCP

MCCC

Address Line

2B+D 2B+D

Business Hall

Business Hall

I/O Module

1 6

Control Line

Data Line

PCM link to DSN in the system

………

to the sub_frame STBL

Figure 1.2.11 Composition of the SS7 Main Module

b) Composition of the Sub-module Frame The composition of the sub-module frame is shown in Figure 1.2.12.

To the mian-frame STBL

……

Figure 1.2.12 Composition of the Sub-module Frame

Descriptions: STBL— signal transit board on the left

AXMMPA MPB

STBL

DTP1

CSSP7

MTCP0

MTCP1

CSSP0

DTP0

STBL

DTP0

DTP1

CSSP7

CSSP0

MTCP1

MTCP0

MTCP— message communication processor CSSP—signaling processor DTP —signaling link processor

B. Architecture of the SS7 Module The No.7 main and standby modules are all of single-block structure, the only difference is

that in the standby modules no boards MPA, MPB and AXM configured. See Figure 1.2.13.

Figure 1.2.13 Architecture of the SS7 Module

1.2.3 Architecture of the Software System

The software of HJD04 switching system is designed in accordance with the overall designing requirement and based on the characteristics of the hierarchically distributed architecture . It adopts the top-to-bottom designing method and the concept of structural programming designing .

1) Division of the Software Functions In designing the software, the overall functions are considered first. The software is classified into many levels in accordance with their functions and in the virtual-machine principle. The overall functions are first divided into functional groups, which are sub-divided into function sub-groups, and then the functional sub-groups are further divided into functional blocks. The principle of FMM (Finite Message Machine) is adopted to enhance the modularization of the program so as to make it more convenient for the designers to work. Therefore, the software system of the HJD04 switching system is a layered modularized structure.

The software system of HJD04 switching system is divided into five functional groups: operating system, telephony support, call processing, maintenance and management. The software structure which is based on the essence of virtual-machine is shown as Figure 1.2.14:

S D D C C C C C C C C M M M A MT T T S S S S S S S S T T P X PB P P S S S S S S S S C C B M AL 1 0 P P P P P P P P P P 7 6 5 4 3 2 1 0 1 0

Figure 1.2.14 Layered Modular Software Architecture

(1) Operating System The operating system of HJD04 switching system varies with the different types of control

units. Software of various service console groups is based on PC while the operating system of DOS or WINDOWS is used. The MC 68K monitoring program is used by various sub-processors. The specific operating system, which is developed by using MC68K as the core , is used by the module processors. The specific operating system is in charge of operation management, facility management, data base management and communication. 。(2) Telephone Support

The software of telephone support is composed of the software of many sub-processors. Its main task is to convert the physical signal to the logical signal or vice versa, so as to enable it to become the electric signal that can drive the circuit to work. For example, the software of SSP (subscriber signaling processor) identifies the status of subscriber terminals and the electric signal

The Centralized Management/Maintenance

Local Management/Maintenance

Call Process

Maintenance Support

Telephony Support

The Operation System

Management Support

Terminal Circuit Switching Network

Peripheral Device

of telephone number as the logical signal of the on hook/off hook of the subscriber, or drives the circuit according to the commands that are released by the module processor, e.g. ringing etc.Call processing The call processing of the HJD04 switching system can be divided into the call control and call service. The call control can be divided into routine call control and performance call control. The routine call control includes the subscriber call processing, trunk call processing, seat call processing, etc. The performance call control mainly refers to the performance realization of various new services. The call service is used to support the call control and to complete the translation of the office prefix and the number analysis, etc.

(4) Maintenance The purpose of maintenance is to safeguard the switching system in good working status. The maintenance includes routine testing and diagnosis & analysis of failure. Maintenance function can be realized by the maintenance management console and maintenance supporting module of the module processor. (5) Management The management mainly refers to the operating management of the switching office. It includes subscriber management, trunk route management, signaling management, charging management and traffic statistics etc. The subscriber management, trunk route management and traffic statistics of the HJD04 switching system are fulfilled by the maintenance console and the management supporting module of the module processor. SS7 management and charging management are provided by dedicated operating consoles.

2) Software Function Distribution The HJD04 switching system adopts hierarchically distributed architecture and software

functional modules are assigned to different control units with hardware configuration. The control unit can be a PC, module processor, various sub-processors and co-processors. Different control units are equipped with different software module combination and fulfill different system functions; or the same control units are equipped with different software module combinations and fulfill different system functions; or the same control units are equipped with the same software module combination and fulfill the same system functions. Within one control unit, only limited software module combinations can be loaded. It is not necessary and not possible to load the whole software module combinations. But the operating system is configured in each control unit.

3) Software Programming Language The following three languages are mainly used in the HJD-04 system software programming :---- BC object-oriented program designing language ;---- standard C advanced programming language;---- ASM 68K assembly programming language. (1) BC Object-oriented Program Designing language

The object-oriented program designing is one of the most advanced technology in the world. Programs based on it are characterized by high modularization, high possibility of reuse and high

maintainability. It can be programmed by many people at the same time and is convenient for communication. As for BC, it supports the object-oriented program designing. So the centralized network management software and local service console software are all written in this language.(2) Standard C Advanced Programming Language The standard C language is quite descriptive and the generated codes are of high efficiency. The target code is completely secluded from the programming environment and can be loaded into the targeted control unit for operation. So the switching software and many telephony supporting software are written in this language.

(3) ASM68K Assembly Programming Language The assembly programming language can fully reflect the style of programming and

personality of programmed objects, and its code creation is of the highest efficiency. This language is often adopted when the processor is required to be less time-consuming, and is used in places where it is tough to describe the soft and hard interface with the advanced language. Therefore, the low-level of the switching software and part of the telephone supporting software are written in this language.

1.3 Brief Introduction to the HJD04 Operation Maintenance System

The HJD04 operation and the maintenance system has the English operation systems based on the local area network technology, Client/Server architecture, the object-oriented programming, WINDOWS of Chinese/English version, data base technology, VISUAL technology and C++ language. The HJD04 operation and maintenance system provides not only the maintenance functions such as controlling, testing and maintenance, ( which keep the HJD04 digital switching system running normally and reliably), but also provides various managing functions such as call traffic statistics, charging data management, routine service management, etc. The system is designed to offer rich functions, convenient operation interface, easy-and-quick operation modes, and secure-and-reliable operation. Moreover, it is featured by configuration flexibility, plenty of interfaces , and excellent openness and expandability.

1.3.1 HJD04 Composition of the HJD04 Operation Maintenance System

The HJD04 switching system adopts a new hierarchical distribution structure and control mode; the whole system is composed of 5 planes, in which, the I/O plane and service console plane are oriented toward the maintenance and management. The perfect combination of the two planes serve as the man-machine communication bridge to conduct the operation and maintenance management functions of the HJD04 switching system.

1) Composition of the HJD04 Operation Maintenance System

The functions of the HJD04 operation maintenance system are performed by the relative hardware and software. Their locations and logical connection are showed in Figure 1.2.1.

The switching processing plane supports the operation maintenance function, in addition to the service processing function.

The I/O plane includes all the sub-processors linked to service consoles, such as IOCP, IOP, MTCP and CP etc. Its function is to transfer the information between service consoles and the system.

The service console plane includes the maintenance management system, charging processing system, outer line testing system and SS7 management system, etc. It provides functions of managing programs and data and operation control ( which are needed for the normal operation of the management and the switching system) and assisting the user to control the system and perform the daily management and the routine tests. It is the important means to safeguard and upgrade the communication service quality of the switching system. Moreover, in order to meet the requirements of the telecommunication management network, all the service consoles can support the centralized maintenance and network management system.

2) Descriptions of the Service Console Plane Functions (1). Operation Maintenance Management SystemIts functions are to control the operation of the switch and manage the routine services. In

terms of the function and the faced objects, the functions can be divided into the following sets:I. Module control:Initiating and loading the system, upgrading the software, loading the new data and setting

the system’s running status.II. Service operation:Providing service functions to maintain the equipment and manage the routine services.

III. Designated Connection:Performing different temporary connections.

IV. Equipment control:Managing components, registers and trunk circuits.

V. Setting operation:Carrying out different settings.

VI. Internal line testing:Performing the internal tests of the subscriber circuit, switching network, register and

trunk circuits. VII. Network management:

Dynamically managing and controlling the subscriber calling and route selection, performing circuit management functions such as circuit blocking or reserving. VIII. Data management:

Managing and dumping system’s running data. IX. Alarming information:

Real-timely processing the alarming messages, displaying, storing and printing the different types of these messages.

X. Statistics of alarming:Carrying out the sorting and printing of the different types of alarming messages.

XI. Daily maintenance: Supporting daily service management, including direct modifying the subscriber data, numbering,

number-deleting and number-changing.

(2) Charging Processing SystemIt is used to perform online charging processing and charging service management.I. Online charging function:Supporting online real-time charging, including the local-call multiple time counting, rural,

local and toll charging, and the Centrex prompt charging etc.II. Maintenance function:Supporting the operation of adding, deleting, inquiring and modifying call rate tables, and

charging formula; supporting the inter-office charging, immediate inquiring and back-up operation of the call tickets.

III. Bill settling and processing function: Settling the call bills daily and monthly; generating and printing out daily bills.; adding, deleting,

inquiring, modifying the subscriber & office data and fixed fees.

(3) Outer Line Testing SystemI. Fault Registering Function:Performing the subscriber fault complaint and registration.II. Outer Line Testing Function:Supporting such tests as outer line short/open circuits, loop resistance, inter-line resistance

and capacitance, insulation to the ground and to the power supply .III. Function of Reserving (Booking or Pre-arranging)) Automatic Testing of the Outer

Lines:Automatically testing the external lines of a certain subscriber or some subscribers at the set

time.IV. Subscriber File Management Function:Supporting the generation, adding, deleting, modifying and inquiring of the subscriber files.V. Alarm-receiving Function:Receiving and registering the permanent-glow alarming of the subscriber.

(4) SS7 Operation Maintenance SystemI. Maintenance console management:Loading programs and data into MTP and daily maintaining the MTP components.II. Data management:Adding, deleting, inquiring and modifying the data of MTP.III. Monitoring Function:Serving as a SS7monitoring device and maintaining and observing the messages.

(5) Network Management Supporting Function:I. Alarming and upward-transferring the reports:

The service consoles transfer the operation reports and different alarming information to the centralized maintenance and network management system.

II. Analyzing and processing the network management commands: The service consoles accept the commands of the network management system, analyze and

process them, and report the results real-timely to the upper-level network management system.

3) I/O System(1). General IntroductionThe I/O system is an indispensable part of the switching system. It serves as the main-

machine communication tie and bridge. In a normal digital switching system, the I/O system should be able to transfer the message of the man-machine communication in a flexible, fast and accurate way. An I/O system covers the following aspects:

I. Structure of the system control ;II. Data/information throughput;III. Information protection system;IV. Setting up the upward and downward path ;V. I/O directions;

VI. System communication modes. The hierarchical distribution control structure of the HJD04 switching system allows its

I/O system to be configured in a distributed way and to provided the redundant configuration. The I/O system can be parasitic on any of the physical modules but relatively independently controlled. In logic and controlling relations, I/O system is positioned between the service consoles and models, forming a relatively independent system.

The I/O information can be transferred upward and downward. The upward information goes from the service modules to the service consoles and the downward information is from the service consoles to the service modules. For the comparatively big and high-density information, a dedicated channel is used to guarantee the fast and accurate transmission; for some important information, multiple redundant configurations are adopted to safeguard the transmission. HJD04 switching system uses three communication modes: point-to-point, point-to- multiple-point and broadcasting modes, which are selected in different environments. The I/O system uses these communication modes, which can be used separately or in combination. (2) System Composition

The HJD04 I/O system, also named 0# module, mainly consists of processors IOP and IOCP. But in terms of the I/O functions, it also includes the components OTP, MTCP and CP etc. See Figure 1.3.1: 。

Figure 1.3.1 Input/ Output System and The Service Console Connection Diagram

1.3.2 A New Generation of Operation and Maintenance System

The functions of the new-generation HJD04 operation and maintenance system are also performed by the related hardware and the software. Its location and logic connection diagram are shown in Figure 1.2.1 (HJD04 digital SPC switching system hierarchical distributed diagram).

The switch processing plane supports the operation and maintenance functions in addition to the service functions.

The input/ output plane is mainly composed of a new generation of processors AXME and etc. The functions are to send messages between the service consoles and the system.

The service console adopts the C/S architecture and its functions cover the operation and maintenance management, billing management, outer-line measurement (testing), SS7 management and traffic processing. It provides all the programs, data management and operation control which are needed by the normal operation of the management and maintenance system. It helps perform the switch system control, routine maintenance and routine testing. It plays an important role in the

I/O Plane : IOP/ICP etc.

Service Console Plane : MC, CC etc.

LAN

Other Servers

Service Terminal

normal operation of the system and in improving the TNM and provides relatively perfect support for the centralized maintenance and NM system.