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Fathur AB

Anin A

Afif A

Hari A

Gary A

Dhika AB

April AB

Mulya AB

Rizka B

Dion AB

Siska AB

Mirel AB

Hani AB

Airita AB

Yusuf AB

Pilsung AB

Taegyun A

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Signaling System #7 Process and Structure

Course Number : TTH2A3

CLO : 2

Week : 5

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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

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Signaling System 7

Elements

SP (Signaling Point)

• STP (Signaling Transfer Point)

• SCP (Service Control Point)

• SSP (Service Switching Point)

• SEP (Signaling End Point)

SL (Signaling Link)

• A Link

• B Link

• C Link

• D Link

• E Link

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Network Design Consideration

1. STP capacity – Number of signaling links

– Signalling message transfer time

– Transmission capacity (bit rate)

2. Network performance – Number of SP allowed

– Signaling delay

3. Availability & Reliability

– Availability: 1-level is worse (limited route)

– Reliability: 1-level is worse (limited route)

– Network Performance: 1-level is better (shorter delay)

link group

link set signalling link

link group

SP STP

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One Level Structure

• Every SP is connected to at least 2 STP

• All STP are connected in full mesh

STP STP STP STP

STP

SP

SP

SP SP SP SP

STP

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Two Level Structure

• Every SP is connected to at least two lower level STP

• Every lower level STP is connected to at least two higher level STP

• All higher level STP are connected in full mesh

STP

STP STP STP

STP STP STP

STP STP STP

Lower level

Higher level

SP SP SP SP SP SP

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Signaling: Case Study AT&T

Link Connects Function

A (Access) SP STP Access from LE/CO to Network Signaling

B (Bridge) STP STP (same level) Connects 2 STPs in the same level

C (Cross) STP STP (pair) Alternate route when B fail

D STP STP (different level) Connects 2 STPs in different level

E SP STP Direct route

F SP SP Direct route

STP

STP

STP

STP

STP

STP

SP

SP

SP

STP

STP

A

A

E

E

C C

B

B

B

C

D

B

D

D

D

A

A

A

A

F

SP Signalling Point (=Switching Office)

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Service Primitives

• request: issued by a service user to invoke a service element

• indication: issued by a service provider to advise that a service element has been invoked by the service user

• response: issued by the service user to complete a particular service element which invoked previously

• confirmation: issued by a service provider to complete a service element

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Signaling Point Code

• Every SP has a unique identifier (ID), Signaling Point Code

• Sender’s ID Originating Point Code

• Receiver’s ID Destination Point Code

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SS7 Architecture

1. Signaling Data Link defines the physical, electrical and functional characteristics and the means to access it

2. Signaling Link defines the functions and procedures for and relating to the transfer of signaling messages over one individual signaling data link

3. Signaling Network defines those transport functions and procedures that are common to and independent of the operation of individual signaling links

4. User Part

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Multiplexing

• TDMA (Time Division Multiple Access)

– GSM, GPRS, SS7

• FDMA (Frequency Division Multiple Access)

– GSM, GPRS, WiFi

• CDMA (Code Division Multiple Access)

– Bluetooth, WiFi

• SDMA (Space Division Multiple Access)

• PDMA (Power Division Multiple Access)

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See you on next class