Introduction to Telecommunication Network An exchange of standard code information between devices...

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Anin A

Afif A

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Gary A

Dhika AB

April AB

Mulya AB

Rizka B

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Mirel AB

Hani AB

Airita AB

Yusuf AB


Signaling

Course Number : TTH2A3

CLO : 1

Week : 4 (end of CLO #1)


Call Establishment

Two types of signaling:

• CAS (Channel Associated Signaling)

• CCS (Common Channel Signaling)

Seizure(off-hook)

Ringing

tone

Ringing

current

Backward clear (on-hook)

Dial tone

Address digit(B-number)

Answer(off-hook)

Forward clear

(on-hook)

- Identification of calling subscriber

- Allocation of storage

address digits and

- Connection of common

equipment

- Disconnection of

dialtone

- Digit analysis and

search of B sub

- Switch path set

- Disconnection of

equipment

EXCHANGE

C O N V E R S A T I O N

Supervision

111012

BA

12

3

4

6

7a 7b

8

5

9

Cal

l set

up

C

all s

etu

p

Clear down Clear down


What is Signaling?

• An exchange of standard code information between devices in the network

• Functionalities: – Call setup

– Supervision

– Clear down

A(calling party)

B(called party)

release

signal

release signal

A(calling party)

c) clear down

Telecom

Network

release signal

release

signal

B(called party)

b) conversation

Telecom

Network

speech

speech

speech

A(calling party)

B(called party)

setup

signal

setup signal

a) call setup

Telecom

Network

setup signal

setup

signal

speech path

signaling path

node (exchange)


Signaling Classification (1/4)

1. Based on transmission channel – CAS (Channel Associated Signaling), signaling = information

– CCS (Common Channel Signaling), one channel for all signaling

2. Based on functionalities – Line signaling

– Register signaling

• decadic pulse

• MFC

– Non compelled

– Compelled

» Full MFC

» Semi MFC

on-hook off-hook

dial " 3"

IDT

dial " 1"

t (ms)

Vab



3. Based on delivery method

– End to end

– Link by link

– Enblock

– Overlap

4. Based on direction to establish a call

– Forward

– Backward



5. Based on current characteristic

– Direct Current

– Alternating Current • Number of frequency used (single and multi frequency)

• Frequency used compared to bandwidth (in-band and out of-band)

– Analog

– Digital

6. Based on direction to establish a call

– Forward

– Backward



7. Based on network segment

– Subscriber segment • Z interface (analog)

• Digital Subscriber System (DSS) #1 (digital)

– Inter-Exchange segment

8. Based on geographical

– Regional

– International


Illustration

Local

Exchange

MDF

Secondary

Cable

Distribution

Point

NTE

Telephone

Demarcation

Point

Primary

Cable

Street

Cabinet

Dro

p

wire

Telecom

Network

subscriber

signaling

Inter-exchange signaling

subscriber signaling

Subscriber lines

(Access Network)

Network signaling

(inter-exchange signaling)

Subscriber

signaling

Subscriber

signaling


Line and Register Signaling

• Line signal is for supervisory: – monitor: idle, blocking, etc.

– control: clear forward, force release, seizure, etc.

• Register signal carries information about phone number (source/calling and destination/called), source class, destination status (idle/busy): – Decadic pulses

– MFC (Multi Frequency Code) contains 2 to 6 frequency for each code

on-hook off-hook

dial " 3"

IDT

dial " 1"

t (ms)

Vab


CAS and CCS

• CAS: every information channel equally associated with signaling channel. The channel physically could be the same or different (separated in time or frequency)

• CCS: several information channels use common channel for signaling. Usually physically separated. Example of CCS is SS7 (Signaling System Number 7)

1

2

n

Exchange BExchange A

signaling channelvoice/data channel

signaling channelvoice/data channel

n voice/data channel

1

2

nExchange A Exchange B

m

m << n1

m signaling channel


Signaling System 7

History

• Signaling System 1 to 5 use in-band signaling (CAS)

• CCITT developed a digital signaling standard called Signaling System 6

• SS6 was based on Packet-Switched, proprietary data network

• SS6 uses 2.4 kbps data links to send packets of data to distant switches to request service

• SS7 began deployment in 1983, was initially used for inter office network, but now it is deployed in local central offices

• Provides a global standard for call setup, routing, control and database access

CCSS7 CCSS7

N7 N7

CCIS7 CCIS7


Signaling System 7

Elements

SP (Signaling Point)

• STP (Signaling Transfer Point)

• SCP (Signaling Control Point)

• SSP (Service Switching Point)

• SEP (Signaling End Point)

SL (Signaling Link)

• A Link

• B Link

• C Link

• D Link

• E Link


Signalling Point (SP)

• SP is any node in the network that can process signaling message

• SEP (Signaling End Point) or simply SP is a SP that can only process signaling message dedicated to it

• On the contrary, STP (Signaling Transfer Point) can transfer signaling message to other SP

• Example: 1. Local Exchange / Central Office (Switching Center)

2. Operation and Maintenance Center (OMC)

3. Service Control Point (SCP)

4. Signaling Transfer Point (STP)


Signaling Link between SP and STP

• Signaling Link (SL) – Transmission media to transfer signaling message between two SP

• Link Set – Bundle of SL that connect two SP directly

• Link Group – Several SL within Link Set that has similar characteristic

link group

link set signalling link

link group

SP STP


Signaling Route

• Originating Point, SP that originally sends a signaling message

• Destination Point, SP that the signaling message is intended to receive

• Signaling Route, is the path designated to deliver the signaling message

• Signaling Route consists of STP and SL, which reside between Originating Point (OP) and Destination Point (DP)


Signaling Mode

Based on the link used to deliver information and signaling, signaling mode is distinguished into:

1. Associated

2. Non Associated

Quasi Associated, predefined route

Fully Non Associated, free route (not applicable due to incapability to reconstruct message)

SP SP

Associated

Signaling

Speech

SP SP

STP STP

SP SP

STP

STP

STP

STP


Information Plane & Control Plane

• In SS7, signalling message provides call management (call setup, supervision, termination) and network management

• Signalling message are sent as short message block (packet) using message switching between SP and STP

• There will be two network plane: – Information plane (deliver information using circuit switch)

– Control plane (deliver signaling using message switch)


Control Plane

STP

User

STP

STP STP

User

SP

SP

CONTROL PLANE

SP = Signalling Point STP = Signalling Transfer Point

SP

SP

SP

SP

SP

SS7


Information Plane

User User

LE

LE

INFORMATION PLANE

LE = Local Exchange TC = Transit Center

TC

TC


End of CLO #1 See you on next class

Introduction to Telecommunication Network An exchange of standard code information between devices...

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