CCS Associated CCS Quasi associated CCS Non associated. TELECOM B SICS E1 a) 256 bytes per frame b) 8 bits Each TS in E1 Frame c) 0.125uS time taken by one frame d) Total 8000 frames in One SecondVoice Theorm a) Voice Frequency ~ 300 to 3300 Hz , bandwidth = 4000 Hz b) Nyquist theorm = Min 8000 sampling rate reqd ( 4000*2 ) c) One Sample = 8 bits ( Reprsntation of 256 Voice Levels , 2 pow 8 = 256) Erlang a) Unit of Traffic descibes total traffic volume in one hour b) Erlang = Busy time for ckts / Avl Time for me asurment , Ex : 20/60 = 3Er 15ckt - 8.1 Er 31ckt - 21.5 Er 3 E1 - 77 Er 10 E1 - 286 Er 20 - 592 30ckt - 20.3 Er 02 E1 - 48 Er 5 E1 - 136 15 E1 - 439 E r 30 - 901E1 Physical Interface a) 0th TS used for synchronization ( 0011011) b) Modes of Operation 1. Unframed - No TS at all 2. Framed - All 32 TS used for data 3.Multiframe - 0 TS for sync, rest 31 for data c) Bit '1' - 3V , Bit '0' - 0~0.3 V CAS ( Channel Associated Signalling ) a) Uses INBAND Signalling ( Voice frequencies ) b) Signaliing Associated in that E1 only - TS = 16 Line Sig. And TS=All Registered Signalling CAS Line Signalling a) Uses TS = 16 for indication of ck t. Status only ( I.e. FREE , SIEZ , FREE BY A/B , BUSY etc….) ABCD FwdABCD Bckwd STATUS10XX 10XX IDLE 00XX 10XX SIEZ 00XX 11XX SIEZ ACK 00XX 01XX ANS 00XX 11XX B PARTY REL 10XX 0/10XX A PARTY REL Ist Frame : TS-1 & TS-17 (4+4 bits) IInd Frame : TS-2 & TS-18 .... .... 15th Frame : TS-15 & TS-31 CAS Registered Signalling a) Uses voice TS for Registered Signalling . b) Types : DECADIC , DTMF , R2 Semi C , R2Fully C c) R2MF - R2 Multi Freq Fully Compled (Ack Reqd) d) MF - Combination of 2 Freq to represent one info CAS Registered Signalling Grp A Bwd Sig. Grp B Bwd Sig. 1 Send Next Dig. 2 Changed No. 2 Restart 3 Called Line Busy 3 Change over grp B 4 Congestion 4 CLI 5 Unallocated No. 5 Send Cat of A Party 6 Normal subs free 6 Switch to speech 7 Send last but 2 digits 8 Send last but 3 digits 9 Send last but 1 digit Grp 1 Fwd Sig. Grp II Fwd Sig. 1 Digit '1' 1 Ordinary Subs 2 Digit '2' 2 Priority Subs 3 Digit '3' 5 Operator 4 Digit '4' 6 STD Coin Box
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E1a) 256 bytes per frameb) 8 bits Each TS in E1 Framec) 0.125uS time taken by one framed) Total 8000 frames in One Second
Voice Theorma) Voice Frequency ~ 300 to 3300 Hz , bandwidth = 4000 Hzb) Nyquist theorm = Min 8000 sampling rate reqd ( 4000*2 )c) One Sample = 8 bits ( Reprsntation of 256 Voice Levels , 2 pow 8 =256)
Erlanga) Unit of Traffic descibes total traffic volume in one hour b) Erlang = Busy time for ckts / Avl Time for measurment , Ex : 20/60 = 3Er 15ckt - 8.1 Er 31ckt - 21.5 Er 3 E1 - 77 Er 10 E1 - 286 Er 20 - 59230ckt - 20.3 Er 02 E1 - 48 Er 5 E1 - 136 15 E1 - 439 Er 30 - 901
E1 Physical Interfacea) 0th TS used for synchronization ( 0011011)b) Modes of Operation
1. Unframed - No TS at all2. Framed - All 32 TS used for data3.Multiframe - 0 TS for sync, rest 31 for data
c) Bit '1' - 3V , Bit '0' - 0~0.3 V
CAS ( Channel Associated Signalling )a) Uses INBAND Signalling ( Voice frequencies )b) Signaliing Associated in that E1 only - TS = 16 Line Sig. And TS=All RegisteredSignalling
CAS Line Signallinga) Uses TS = 16 for indication of ck t. Status only ( I.e.FREE , SIEZ , FREE BY A/B , BUSY etc….)
ABCD Fwd ABCD Bckwd STATUS
10XX 10XX IDLE
00XX 10XX SIEZ
00XX 11XX SIEZ ACK
00XX 01XX ANS
00XX 11XX B PARTY REL
10XX 0/10XX A PARTY REL
Ist Frame : TS-1 & TS-17 (4+4 bits)
IInd Frame : TS-2 & TS-18
....
....15th Frame : TS-15 & TS-31
CAS Registered Signallinga) Uses voice TS for Registered Signalling .b) Types : DECADIC , DTMF , R2 Semi C , R2FullyCc) R2MF - R2 Multi Freq Fully Compled (Ack Reqd)
d) MF - Combination of 2 Freq to represent one info
CAS Registered Signalling
Grp A Bwd Sig. Grp B Bwd Sig.
1 Send Next Dig. 2 Changed No.
2 Restart 3 Called Line Busy
3 Change over grp B 4 Congestion
4 CLI 5 Unallocated No.
5 Send Cat of A Party 6 Normal subs free
6 Switch to speech
7 Send last but 2 digits8 Send last but 3 digits
9 Send last but 1 digitGrp 1 Fwd Sig. Grp II Fwd Sig.
Layer-3 :b. Signalling Route Management - Traffic / Sharing / Overloading Routingc. Signalling Link Management - Control / Monitor / Status of Linkse Signalling Traffic Management - Change over/ Back in case of Faile. Alignment - SIO , SIN , SIE , SIOSf. Message Distribution - Distributing the MSG to ISUP , SCCPg. Message Discrimination - Mine or Other DPC / NW
Service Indicator 0 - SNM ( Signalling NW Management Message )1 - MTN ( Mtc Regular Msg )2 - MTNs ( Mtc Special Message )3 - SCCP ( Carry Non-Voice Traffic Ex: SMS )4 - TUP5 - ISUP ( Voice related traffic )6 - Data User Part ( Call & ckt Related )7 - Data User part ( Facility Regn & Cancellation )
Layer-3 TimersT1 Delay to avoid message mis-sequencing on changeover .5 to 1.2 sec.T2 Wait for changeover Ack .7 to 2. 0 secT3 Delay to avoid message mis-sequencing on changeback .5 to 1.2 sec.T4 Wait for changeback Ack (1st attempt) 5 to 1.2 sec.T5 Wait for changeback Ack (2nd attempt) 5 to 1.2 sec.
Protocol Class : Class -0 : Basic Connectionless ( Non Critical,TCAP )Class -1 : Sequenced Connectionless (Critical, TCAP )Class -2 : Basic Connection Oriented (BSSAP )
Class -3 : Flow Control Connection Oriented(BSSAP )Class -4 : Flow Control + Err Recovery
Calling / Called party :1. Address Indicator :
a. Routing Indicator : GT based or ( DPC + SSN )b. GTT Indicator : No GT or GT - 1 or 2 or 3 or 4c. SSN Indicator : Present / Not Presentd. Point Code Indicator : Present / Not Present
2. Address : a. Point Codeb. SSN
c. GT - 1 :i. Nature of Address Ind : Subscriber Number / National Sig. No. / International No.ii. Odd / Even Indicator ( Spr) iii. Address Information ( 919839212499 )
d. GT - 2 :i. Translation Type ii. Address Information ( 919839212499 )
e. GT - 3 :i. Translation Type ii. Encoing Scheme - Unknown / BCD Odd / BCD Eveniv. Address Information iii Numbering Plan - ISDN / Telephony / Data / Telex / Land Mobile / Mobile
e. GT - 4 :i. Translation Type ii. Encoing Scheme - Unknown / BCD Odd / BCD Eveniii. Numbering Plan iv. Nature of Address Indicator v. Address Information ( Contains Address for Example : 919839212499 )
User Data :1. Length Indicator 2. User Data Ex: TCAP etc
Connection Oriented
- Only used in BSSAP where heavy data transfer is required for ex. Between MSC/VLR to BSC to BTS
GTT> Method of hiding the SS7 point code and sub-system number from the originator of a message
a) GT Consists of – Translation type (TT) – Numbering plan (NP) – Nature of address (NA) – Global title digits (GTDIG)
b) GT Benefits – Central administration of routing information makes it easier to restructure the network – It is possible to set up alternative routing schemes and load sharing – More compact and dyanmic routing tables – The function is required for the introduction of certain new services (such as call completion to busy subscriber, CCBS and 800 free phone)
a) The result of a global title translation can be: – the point code for a signaling destination – a subsystem service group ( this is used in the intelligent network to guarantee a fail-safe service control point (SCP). Two SCPs can be combined to form a subsystem service group that is accessed frothe relevant service switching point (SSP) via globa l title translation. )
– a translator service group ( this consists of up to four signaling points, each of which can perform the necessary translation ) – a further translation in the same network node
1. Transaction Part : ( Deals with SCCP Message ) a. TCAP Message Type : BEGIN / UNI / END / CONTINUE / ABORTb. Length Indicatior of Transaction Tag ( Max 2048 , SCCP takes Care of Segmenting / Breaking )c. Transaction Info ( Not Valid for UNI )
i. Origination Transaction Id ( Mandatory for BEGIN , CONTINUE )- Length Indicator & Value
i. Destination Transaction Id ( Mandatory for END , ABORT , CONTINUE )- Length Indicator & Value
i. P_Abort Cause ( Mandatory for TC_P_Abort Request )- Reason for Abort
2. Dialog Part :a. Dialog Indicator Tagb. Length Indicatior of Dialog Tagc. Dialog Information - Depend on USER For Ex : MAP , INAP
3. Message Component Part : ( Deals with USERs such as MAP , INAP ...) a. Component Indicator Tagb. Length Indicatior of Component Tagc.Component Type : ( Invoke / Return Result Last / Return Result Not Last / Return Error / Reject )d. Component lengthe. Component User Information by MAP , INAP , CAMEL , OMAP , SSAP Etc..........
Functions of TCAP are to control:· The transaction between both endpoints in the network· The communication to the users of TCAP.
b) Key Network Features of GPRSPacket switchingSpectrum efficiencyInternet awareSupports tdma and gsm
c) Limitations of GPRSLimited cell capacity for all usersSpeeds much lower in realitySupport of gprs mobile terminate by terminals is not ensuredSuboptimal modulationTransit delaysNo store and forward
d) SGSN - Serving GPRS Support Nodehandles session management, mobility management, billing and traffic measurementsbit level encryption of data which is to be sent over the air interface.Put GPRS data received from the BSC in IP format for sending to the GGSN and vice-versa.Provide GPRS routing to BSC’s
d) GGSN - GPRS Gateway Support NodeThe GGSN is the gateway in and out of the GPRS system.It routes packets from an external network ( "the Internet" ) to the SGSN which is currently serving the MS,and routes packets from the SGSNs to which it is connected to the external network. Th is concept is called tunnelling.
d) Similar TechniquesEnhanced Data rates for GSM Evolution (EDGE)Universal Mobile Telephone System (UMTS)
Intelligent Network ( IN )Requirement / Advantages
Rapid deployment of Vendor / SSP Free Services which are centrally administered
SSPCCF - Call Control Functions ( Takes Care of all call related processing in Switch )SSF - Service Switching functions ( Provides IN Triggering and IN Accessibility )SRF - Specialized resource function ( Provides interactioon bw Call processing SW
in SSP)
SCPSCF - Service Control Functions ( Executes IN service logic and interfaces witrh
SSP via SSF )SDF - Service data function ( Maintains all customer and nw data )SMP - Service Management Point ( Administration and Operation of IN )