Presentation on theme: "Modes Mobile Station ( MS )"— Presentation transcript:
1 Modes Mobile Station ( MS ) MS Switched Offcan not receive incoming paging messages.can not make outgoing call.No dedicated channel is associated with it.MS Switched On And in Idle Modecan receive incoming paging messages.can make outgoing call.No dedicated channel is associated with it.MS in Dedicated ModeMS is in conversationA dedicated traffic channel TCH is associated with it.
2 Technical Terms Used w.r.t. MM(Mobility Management) IMSI International Mobile Subscriber IdentityMSISDN -Mobile Subscriber ISDN NumberTMSI Temporary Mobile Subscriber IdentityMSRN -Mobile Subscriber Roaming NumberIMEI - International Mobile Equipment IdentityLAI Local Area IdentityA Authentication AlgorithmA Ciphering AlgorithmA Kc(Ciphering Key) Generation Algorithm
3 MSISDN (Mobile subscriber ISDN Number) Technical Terms Used in GSMMSISDNMSISDN (Mobile subscriber ISDN Number)A number assigned to the mobile subscriberRegistered in Telephone DirectoryUsed by the calling party for dialingMSISDN is usedby the caller to set up a connection to this GSM mobile subscriber.by the MSC/GMSC to address the HLR when interrogating the visitor location of the GSM mobile subscriber.By the system to access the database of the GSM mobile subscriber in the HLR.Stored as semi permanent data in HLR
4 MSISDN format CC – Country Code NDC – National Destination Code CC NDC SN3 DIGITS2 DIGITS10 DIGITSCC – Country CodeNDC – National Destination Code- uniquely identifies the PLMN in a country-Max No of digits 15 as per ITU recommendation.
5 Technical Terms Used in GSM IMSI (International Mobile Subscriber Identity)A unique identity allocated to each MSISDN.Known only to the operatorTo ensure confidentiality to the subscriber.IMSI is usedBy VLR to address the HLR while updating the location of the GSM subscriber.To access the database of the GSM subscriber in the HLR, VLR and AuCStored aspermanent data in SIM,Semi permanent data HLR,Transient data in VLR.
6 IMSI MCC MNC MSIN MCC – Mobile Country Code 3 DIGITS2 DIGITS<= 10 DIGITSMCCMNCMSIN15 DIGITS OR LESSMCC – Mobile Country CodeTo Identify the home country of the PLMNMNC – Mobile Network CodeTo identify a GSM PLMN in a countryMSIN – Mobile Station Identification NumberUniquely identifies a subscriber within a home PLMN.2 DIGITS DIGITSHLRIDSN
7 Technical Terms Used in GSM TMSI (Temporary Mobile Subscriber Identity)Identity which guarantees the integrity of mobile subscriber on the radio interface.Uses only over the radio pathAssigned by VLR to each mobile subscriber entering the VLR areaStored in SIM of MS and in VLRTMSI is usedTo address the GSM subscriber in the BSSTo address the GSM subscriber data in the VLRConsists of Four Octets, coded using a full hexadecimal representation
8 LMSI (Local Mobile Subscriber Identification) Allocated by VLR and sent to HLRLMSI is the address at which GSM subscriber are stored in VLR databaseHLR includes it together with IMSI to speed up the search for subscriber data to in VLR.Comprises of 4 Octets.
9 MSRN (Mobile Subscriber Roaming Number) Required by GMSC to route an incoming call to a MS that is not currently under the gateway’s controlIt is a temporary number usedTo set up the voice connection from the originating MSC/GMSC to the VMSCTo address the GSM subscriber data in VLR.HLR knows the current MSC/VLR service area for a mobile subscriberHLR requests the current MSC/VLR to allocate a MSRN to the called subscriber and return to it.After receiving MSRN, HLR returns the same to GMSC, which can route the call to current MSC/VLR exchange.Format:--- MSRN=CC+NDC+SNCC=Country code.NDC=Network Destination Code.SN=Subscriber Number.
10 IMEI (International Mobile Equipment Identity Number) Identifies the mobile equipmentTACFACSNR6 CHAR2 CHARTAC – Type Approval CodeAllows approved types to be distinguishedfrom Non approval types.FAC – Final Assembly CodeIdentifies the place of manufactureSNR – Serial Number issued by manufacturer.
11 All the cells in a Location area are served by single VLR. Location area consist of one or more than one cell which may be served by one or more BSC s.All the cells in a Location area are served by single VLR.
12 Location Area SS 7 HLR BSC LA 1 BSC VLR 1 LA 2 BSC LA 3 BSC BTS BTS MSC1LA 1BTSBSCBTSVLR 1LA 2SS 7BTSHLRBSCMSC2BTSLA 3BTSBSCVLR 2Location Area
13 Location AreaEach location area in a GSM PLMN is identified by a Location Area Identity ( LAI ).LAI = MCC + MNC + LACMCC - Mobile Country Code.MNC - Mobile Network Code.LAC - Location Area Code .MCCMNCLAC3 digits2 digits2 octets maxLAI( 16 bits )Maximum length of LAC is 16 bits.Thus there can be maximum of 65,536 Location Areas defined in one GSM PLMN.Stored as semi permanent data in VLRStored in SIM of MS
14 Subscriber Data at MSC/HLR Data related to identification and numbering ( IMSI, MSISDN).Data related to MS Subscription type.Authentication and Ciphering Data.MS VLR number
15 Subscriber Data at MSC/VLR Data related to identification and numbering ( IMSI, MSISDN,MSRN and TMSI ).Data related to MS subscription type.Authentication and Ciphering Data.MS status data, Location AreaHand-over data,
16 Authentication is used to check the validity of a mobile subscriber. At MSAt N/WKiKiRAND( 128 bits )A3A3SRESSRES( 32 bits )=?AUTHENTICATION
17 Ki ( 128 bits) : Identification Key - Purpose : Ki is used to calculate SRES and Kc.- Ki is stored in SIM and HLR.- Ki is never transmitted over signaling network.RAND ( 128 bits ):Random Number- Purpose : RAND is used to calculate SRES and Kc.Kc ( 64 bits ) : Ciphering Key- Purpose : Kc is used to encrypt data over radio interface.SRES ( 32 bits) :Signed Response
19 Ciphering is used to encrypt data on radio interface. RANDKiKc generation is done at the time of Authentication.A8Frame No. (22 bits )Kc ( 64 bits)A5Ciphering StreamCiphered BitsXORInformation Bits ( 114 bits )CIPHERING
20 LOCATION UPDATE SCENARIO - I Request For ServiceOld MSC/ VLRNew MSC/ VLRHLR /AUCMSBSSChannel Request1RACHSDCCH Assignment2AGCHLocation Update Request ( TMSI , LAI 0 )3SDCCHRequest IMSI( TMSI )4Send IMSI
21 LOCATION UPDATE SCENARIO - II Authentication and Ciphering New MSC/ VLROld MSC/ VLRHLR/ AUCMSBSS5Get Authentication Parameters( IMSI )Authentication ParametersAuthenticate MS ( RAND )( RAND,Kc,SRES )SDCCH6Authentication Response ( SRES )SDCCHCipher Radio Channel7( Kc )Cipher Up Link ChannelSDCCH
22 LOCATION UPDATE SCENARIO - III Authentication and Ciphering New MSC/ VLROld MSC/ VLRHLR/ AUCMSBSSUp Link Ciphered8SDCCHBSS Ciphers Down link Channel .9Ciphering Complete
24 LOCATION UPDATE SCENARIO - V Update HLR/VLR & TMSI Reallocation New MSC/ VLROld MSC/ VLRHLR/ AUCMSBSSLocation Updated Complete14SDCCH15Clear Signaling ConnectionClear Complete16Release Radio Signaling ChannelSDCCH
25 SETUP PHASE - CALL SETUP - CALL RELEASE Mobile To Land Call Set-up ScenarioSETUP PHASE- REQUEST FOR SERVICE ( CHANNEL ) BY MS- AUTHENTICATION- CIPHERING- EQUIPMENT VALIDATION ( EIR CHECK )- VALIDATION AT VLR- CALL SETUP- HAND OVERs- CALL RELEASE
26 Service Request (TMSI,LAI) MOBILE TO LAND CALL - IRequest For ServiceMSC/VLRBSSMSChannel Request1RACHSDCCH Assignment2AGCHService Request (TMSI,LAI)3SDCCHAuthenticationCipheringEquipment validation
27 Equipment ValidationA process by which a specific ME can be identified to prevent the use of stolen, unauthorized or malfunctioning equipment in the network.Each equipment is uniquely identified by an International Mobile Equipment Identity (IMEI) code.IMEI is incorporated into ME by the manufacturerIMEI Consists of three componentsType approval code (TAC)Final Assembly Code (FAC)Serial Number (SNR)IMEI is stored in EIR
29 MOBILE TO LAND CALL - II Call Setup MSC/VLRBSSMSCall Setup Request5SDCCHCall Proceeding6SDCCHAssign Trunk and radioAssign TCH7SDCCHRadio Assignment CompleteSDCCHTrunk and Radio Assignment Complete
30 MOBILE TO LAND CALL - III Call SetupMSC/VLRGMSCBSSHLRPSTNMSNetwork Setup ( Dialed Digits )8Network AlertingAlerting9FACCHConnectStart Billing10ConnectFACCHConnect Acknowledge11FACCH
31 MOBILE TO LAND CALL - IV Call Release MSC/VLRGMSCBSSHLRPSTNMSDisconnect12Network ReleaseRelease13FACCHRelease Complete14FACCHClear Command15Channel ReleaseFACCHRelease Complete
32 Land To Mobile Call Set-up Scenario Phases of Land To Mobile Call( Mobile Terminating - MT Call )Routing AnalysisPagingAuthenticationCipheringCall-SetupCall Release
33 Fixed to Mobile Call Routing VLRPSTNMSCHLRBSSMSRNMSISDNIMSI/TMSIIMSI/TMSIMSISDNMSISDNMSRNIMSI/TMSI
34 Fixed to Mobile Call Routing VLRPSTNMSCHLRBSS(VISITED)(HOME)MSRNMSISDNMSISDNMSRNMSRNIMSI/TMSIMSISDNIMSI/TMSIMSRNIMSI/TMSI
35 Routing Analysis LAND TO MOBILE CALL - I HLR MSC/VLR GMSC PSTN Incoming Call1( MSISDN )Get Route2Get Route( MSISDN )3( IMSI )Routing Information4( MSRN )Routing Information( MSRN )Incoming Call5( MSRN )
36 Paging LAND TO MOBILE CALL - II BSS MS MSC (TMSI) PCH ( RACH ) Perform PagePage(TMSI)6PCHChannel Request7( RACH )8Access Granted( AGCH )Paging Response( TMSI, LAI )9SDCCHPage Response
37 LAND TO MOBILE CALL - III Call Set-upBSSMSCMSCall Set Up10SDCCHCall Set Up Confirm11SDCCHAssign Trunk & Radio ChannelAssign Radio Channel12SDCCHRadio Channel AssignedTrunk and Radio Channel Assignment CompleteSDCCH
38 LAND TO MOBILE CALL - IV Call Setup MSC/VLRGMSCBSSHLRPSTNMSMobile Alerting13FACCHNetwork AlertingConnect ( off-hook )14FACCHConnectConnect Acknowledge15
39 LAND TO MOBILE CALL - V Call Release MSC/VLRGMSCBSSHLRPSTNMSNetwork ReleaseDisconnect16FACCHRelease17Release CompleteFACCHRelease Complete18FACCHClear Command19Clear ChannelClear CompleteFACCH
40 Mobile To Mobile Call Set-up Scenario Phases of Mobile To Mobile CallRequest for service.AuthenticationMobile OriginatingCipheringCall-SetupCall ReleaseRouting AnalysisPagingMobile TerminatingAuthenticationCipheringCall-SetupCall-Release
41 CHANNELS USED IN GSM PHYSICAL CHANNELS LOGICAL CHANNELS Traffic channelsControl channels
42 CONTROL CHANNELS BROADCAST CONTROL CHANNEL COMMON CONTROL CHANNEL DEDICATED CONTROL CHANNEL
43 BROADCAST CONTROL CHL BCCH---BroadCast CHannel FCCH---Frequency Correction CHannelSCH------Synchronisation CHannel
44 COMMON CONTROL CHL PCH-----Paging CHannel RACH---Random Access CHannel AGCH---Access Grant CHannel
45 DEDICATED CONTROL CHL SDCCH---Standalone Dedicated Control CH SACCH---Slow Associated Control CHFACCH---Fast Associated Control CH