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Textbook
《Telecommunication Switching Systems and Networks》《现代电信交换与网络-英文版》
Author: Thiagarajan Viswanathan出版:电子工业出版社,2009.1
About the languages
Writing: EnglishSpeaking: English + Chinese
About the Grade
Final examination: 50%Attendance and Homework: 50%
About the contents
This class mainly focuses on the concepts and principles of different switching techniques. Chapters covered in this class:
Chapter 1, Chapter 2, Chapter 3, Chapter 4, Chapter 6, Chapter 9, Chapter 10, Chapter 12
Charpter1 Introduction
School of Information Science and Engineering, Shandong UniversityAssociate Prof., Deqiang Wang
Outline
Evolution of TelecommunicationsSimple Telephone CommunicationBasics of a Switching SystemSwitching Systems
TerminologySubscriberSourceDestinationSignalingPoint-to-point linkFully connected networksSwitching system, switching office, exchange
Control functionsStep-by-stepCrossbar systemsStored program control (SPC)Space division switchingTime division switchingTrunkSubscriber line
TerminologySimplex communicationHalf-duplex communicationFull-duplex communicationSidetoneInlets/OutletsSwitching NetworkFolded network
Nonblocking NetworkBlocking NetworkBlocking ProbabilityBusy time trafficErlangTransit exchangeNonfolded networkSubscriber loop signalingInterexchange signalingIntraexchange or register signaling
TerminologyTerminology
Direct controlCommon controlManual switchingLocal battery exchangeCentral battery exchangeUrban networksMetropolitan networks
Rural networks Long distance/toll networksWide area networks
1.1 Evolution of Telecommunications
Telegraphy, 1837, Great BritainTelephony, 1876, BellPoint-to-point connection
The number of subscribers supported : 2
1.1 Evolution of Telecommunications
Full connected network
Number of subscribers: NNumber of links:N(N-1)/2Cost Efficiency: low(expensive)
1.1 Evolution of Telecommunications
Subscriber interconnection using a switching system
Switching System
S1 S2 SN-1 SN
Number of subscribers: N
Number of links:N
Cost Efficiency: high(cheap)
1.1 Evolution of Telecommunications
Classification of switching systemsSwitching system
manual automatic
Electromechanical Electronic
Step-by-step Crossbar
Space division switching Time division switching
Digital Analog
1.1 Evolution of Telecommunications
Telecommunication network structure
SS1
SS3 SS4
SS2
Subscriber lines
Trunks
Trunks
1.1 Evolution of Telecommunications
Communication systemsElectrical communication system
Wired or WirelessOptical communication system
Wired or Wireless
Links between network nodesTrunksSubscriber linesEach link deploys some kind of communication technology
1.1 Evolution of Telecommunications
Service Specific NetworksTelegraph networksTelex networksTelephone networksData networks
1.2 Simple Telephone Communication
Simplex telephone circuit
Microphone Earphone
V
L
1.2 Simple Telephone Communication
Duplex telephone circuit
Earphone
Earphone
Microphone
MicrophoneV
L
1.2 Simple Telephone Communication
Telephone circuit with sidetone coupling
Subscriber Exchange
1.3 Basics of Switching System
Elements of switching systemSwitching network subsystem(交换网络子系统)Signaling subsystem(信令子系统)Control subsystem(控制子系统)Accessary circuits(辅助电路)
SwitchingNetwork
TrunkInterface
SubscriberLine
InterfaceServiceCircuit
Interface
TrunkInterface
SubscriberLine
InterfaceServiceCircuit
Interface
SubscriberAnd
ServiceLine
ScanningAnd
Distributor
TrunkCircuit
ScanningAnd
DistributorUnits
Control
Operator Console
JUNCTORs
1.3 Basics of Switching System
Model of a Switching networkSwitching network is a component of the switching systemElements of a switching network
Function: Establish a electrical path between a given inlet/outlet pair
SwitchingMatrix/Network
NInlets
MOutlets
Symmetric network:N=M
1.3 Basics of Switching System
Inlets/outlets connections
Four types of connection:Local call(本局呼叫), outgoing call(出局呼叫), Incoming call(入局呼叫),Transit call(转接呼叫)
SwitchingMatrix/Network
IncomingTrunks
OutgoingTrunks
SubscriberInlets
SubscriberOutlets
1.3 Basics of Switching System
Folded network(折叠网络)
All the inlets/outlets are connected to the subscriber lines (For Local Exchange)
SwitchingMatrix/Network
NSubscriber
Lines
1.3 Basics of Switching System
Nonfolded network(无折叠网络)
All the inlets/outlets are connected to Incoming Trunks/Outgoing Trunks(For Transit Exchange)
SwitchingMatrix/Network
NIncomingTrunks
NOutgoingTrunks
1.3 Basics of Switching System
Nonblocking network(无阻塞网络)As long as a called subscriber is free, a calling subscriber will always be able to establish a connection to the called subscriber.
Blocking network(有阻塞网络)The number of simultaneous switching paths is less than the maximum number of simultaneous conversations.Blocking probability: the probability a user may get blocked.
1.3 Basics of Switching System
Control SubsystemDistinguish the relationship between inlets/outlets and subscribers/trunksInterpret the signaling information receivedSense the end of information transferEstablish / release connections
1.3 Basics of Switching System
SignalingFunction: help exchanges to establish connections between subscribers correctly.Category
Subscriber loop signalingInterexchange signalingIntraexchange or register signaling
1.4 Switching Systems
Manual switching system
1.4 Switching Systems
Step-by-step & Crossbar
1.4 Switching Systems
SPC exchange 程控交换机
SPC: Stored program control (存储程序控制)
1.4 Switching Systems
ATM Switch
1.4 Switching Systems
Optical Switch
1.4 Switching Systems
Router
Assignment
Ex. 6Ex. 13