Upload
nexusomid
View
230
Download
0
Embed Size (px)
Citation preview
7/25/2019 1- UMTS Network Structure.pdf
1/111
Table of Contents
PLMN Network Structureress ng an um er ng p an
GSM Network
Evolution
CORE Network Nodes2G/3G Authentication
Short Message ServiceLocation Update
an over
1
7/25/2019 1- UMTS Network Structure.pdf
2/111
2
7/25/2019 1- UMTS Network Structure.pdf
3/111
3
7/25/2019 1- UMTS Network Structure.pdf
4/111
GSM Network Areas...
MSC / VLR Area
Location Area
e
4
7/25/2019 1- UMTS Network Structure.pdf
5/111
GSM Network Areas...
u c an o e e wor
5
7/25/2019 1- UMTS Network Structure.pdf
6/111
GSM Network Areas...
MSC/VLR Service Area:
6
7/25/2019 1- UMTS Network Structure.pdf
7/111
...
:
MSC/VLR Service Area : . Location U date . . Paging Location Area .
7
7/25/2019 1- UMTS Network Structure.pdf
8/111
GSM Network Areas...Cell: Location Area Cell Cell.
)(CGI .
(BSIC) Cell .
CGI : Cell
Global
ID
BSIC : Basic Station Identity Code 8
7/25/2019 1- UMTS Network Structure.pdf
9/111
Addressing and Numbering plan
IMSI (International Mobile Station Identity) TMSI (Temporary Mobile Station Identity)
ersona en y um er
PUK (Personal Unblocking Key) PIN
KI (Individual Subscriber Authentication Key)
9
7/25/2019 1- UMTS Network Structure.pdf
10/111
INTERNATIONAL MOBILE SUBSCRIBER IDENTITY IMSI
The IMSI is a unique identifying code allocated to each subscriberallowin correct identification over the radio ath and throu h theWCDMA Systems PLMN network.
It is used for all identification signaling in the PLMN and all network
.The IMSI is stored in the UMTS Subscriber Identity Module (USIM), aswell as in the HLR and the VLR.
cons s s o ree eren par sIMSI = MCC + MNC + MSIN
MCC = Mobile Country Code= o e e wor o e
MSIN = Mobile Subscriber Identification Number
According to
the
WCDMA
specifications,
IMSI
can
have
a maximum
length
of
15
.
Examples: IMSI = 432 20 XXXXXXXXXX
10
7/25/2019 1- UMTS Network Structure.pdf
11/111
The MSISDN is a number that uniquely identifies a mobile telephone su scr pt on w t n t e Pu c Sw tc e Te ep ony Networ PSTN numbering plan.In WCDMA Systems the MSISDN is composed of :
MSISDN = CC + NDC + SNCC = Country Code
= a ona es na on o eSN = Subscriber Number
Examples: MSISDN = +98 920 XXXXXXX
11
7/25/2019 1- UMTS Network Structure.pdf
12/111
12
7/25/2019 1- UMTS Network Structure.pdf
13/111
The TMSI can be used to keep subscriber information confidentialon the air interface. It also increases paging capacity, as the lengthof the TMSI is shorter than the length of the IMSI.The TMSI is relevant on the local MSC/VLR level only and is changed
at certain events or time intervals. Each local operator can define his own TMSI structure.
within a Location Area (LA), for example, for paging. When a cellwithin a new Location Area (LA) is entered, the Location Area
update.
13
7/25/2019 1- UMTS Network Structure.pdf
14/111
LOCATION AREA IDENTITY (LAI)
e , use or pag ng, n ca es o e n w clocation area the UE is operating. It is also used for
location updating of mobile subscribers.The LAI contains the following:
LAI = MCC + MNC + LAC
MNC = Mobile Network Code Identical to IMSI MNCLAC = Location Area CodeThe maximum length of LAC is 16 bits, enabling 65,536different location areas to be defined in one PLMN.
ROUTING AREA IDENTITY RAIThe Routing Area Identity is exactly the same as theLocation Area Identity (LAI).
14
7/25/2019 1- UMTS Network Structure.pdf
15/111
INTERNATIONAL MOBILE EQUIPMENT IDENTITY (IMEI)The IMEI uniquely identifies User Equipment (UE) as a piece or assembly of equipment. Using the IMEI stolen or not type approved, mobiles causingsevere malfunctions can be barred. The IMEI consists of 15 digits.
e cons sts o t e o ow ng:
IMEI = TAC + FAC + SNR + spTAC= Type Approval CodeDetermined by a central WCDMA body, TAC identifies the type of equipment.
The FAC identifies the manufacturer of the equipmentSNR = Serial Number,
e s an n v ua ser a num er o s x g s w c un que y en es aequipment within each TAC and FAC.
sp = spare part for future use; this digit should always be zero whenit is transmitted by the UE.Example:IMEI= 357,087,008,609,717 (USSD= *#06#)
15
7/25/2019 1- UMTS Network Structure.pdf
16/111
7/25/2019 1- UMTS Network Structure.pdf
17/111
2G Mobile terminating call e.g. from PSTN
- e a ng n orma on s rece ve y e.g. v a n e ga ewayMSC The dialing information is converted in the gateway MSC.
2- A so-called "interrogation" is started as a response; i.e. a MAP message is sent to - .the location routing label i.e. the MSC/VLR by the "location update" and relays thequery there.
via the HLR to the gateway MSC.4- The gateway MSC converts this temporary directory number and sets up a circuit
VLR owing to the cross-connection between temporary directory number andmobile subscriber.5- The visited MSC now sends a " a in " to all BSCs situated in the location area.The BSC in which the subscriber is currently situated answers with a "pagingresponse".6- The MSC makes the connection to the called subscriber.
17
7/25/2019 1- UMTS Network Structure.pdf
18/111
MSISDN IMSIIMSI MSC AddressMSC Address
PSTNPSTN GMSCHLR
11-- MSISDNMSISDN--
55-- MSRNMSRN
3 3 --4 4 --M
S I
M S I
S R N S R N
MSC/VLR
77--PagingPaging 18
7/25/2019 1- UMTS Network Structure.pdf
19/111
GSM GPRS EDGE
19
7/25/2019 1- UMTS Network Structure.pdf
20/111
Basic GSM network
20
7/25/2019 1- UMTS Network Structure.pdf
21/111
GSM & Value Added Service21
7/25/2019 1- UMTS Network Structure.pdf
22/111
22
7/25/2019 1- UMTS Network Structure.pdf
23/111
HSCSD (High Speed Circuit Switched Data), 23
7/25/2019 1- UMTS Network Structure.pdf
24/111
SGSN (Serving GPRS Support Node)GGSN Gatewa GPRS Su ort Node
24
7/25/2019 1- UMTS Network Structure.pdf
25/111
Increasing speed with EDGE 25
7/25/2019 1- UMTS Network Structure.pdf
26/111
26
7/25/2019 1- UMTS Network Structure.pdf
27/111
Radio Access Network Core Network
CS Domain
External
e wor sEntities common
to the CS & PS Domain
UTRANUE
oma n
UMTS(Universal Mobile Telecommunications System) 27
7/25/2019 1- UMTS Network Structure.pdf
28/111
CDMA) Core network evolves from GSM onl to su ort GSM
GPRS and new WCDMA facilities 3GPP Release 99
s ra os 3GPP Release 4
3GPP Release 5
First IP Multimedia Services IMS w SIP & oS 3GPP Release 6
All IP network; contents of r6 still being defined
28
7/25/2019 1- UMTS Network Structure.pdf
29/111
e .
rc ec ure
a os
CN2G MS (voice only)
BSS
PSTNAbisA
E PSTN
SS7BTS
BSC MSCVLR
GMSCCDGs
H2G+ MS (voice & data)
Gb
HLR AuC GcGr
Gn Gi
RNS
IubATM
IuPS
IPSGSN GGSN
3G UE (voice & data)
Node B
RNC
BSS Base Station SystemBTS Base Transceiver StationBSC Base Station Controller
RNS Radio Network SystemRNC Radio Network Controller
CN Core Network MSC Mobile service Switching ControllerVLR Visitor Location RegisterHLR Home Location RegisterAuC Authentication ServerGMSC Gateway MSC
SGSN Serving GPRS Support NodeGGSN Gateway GPRS Support Node
UMTS Universal Mobile Telecommunication System
29
7/25/2019 1- UMTS Network Structure.pdf
30/111
e . rc ec ure o w c ng
CN2G MS (voice only)
BSS
PSTNAbis A NcMc
CSMGW
CSMGWNb
PSTNMc
SS7BTS
BSC MSC ServerVLR
GMSC serverCDGbGs
H2G+ MS (voice & data)
IP/ATMHLR AuC GcGr
Gn Gi
RNS
Iub IuPS
ATM
SGSN GGSN
BSS Base Station S stem CN Core Network SGSN Servin GPRS Su ort Node
Node B
RNC
3G UE (voice & data)
BTS Base Transceiver StationBSC Base Station Controller
RNS Radio Network SystemRNC Radio Network Controller
MSC Mobile service Switching ControllerVLR Visitor Location RegisterHLR Home Location RegisterAuC Authentication ServerGMSC Gateway MSC
GGSN Gateway GPRS Support Node
30
7/25/2019 1- UMTS Network Structure.pdf
31/111
UMTS Release 99 Core Network
CN (Core Network)RAN
circuit switched (CS) domain
MSC/VLR GMSC PSTN/GERAN ISDN
network elementHLREIR ACCSE
UTRAN GGSNSGSNPDN
IP-
packet switched (PS) domain WAPCGBG
BillingCentre
Inter-PLMN
Network 31
7/25/2019 1- UMTS Network Structure.pdf
32/111
32
7/25/2019 1- UMTS Network Structure.pdf
33/111
3G R99 Networking
33
7/25/2019 1- UMTS Network Structure.pdf
34/111
Difference between 3G R4 and 3G R99
34
7/25/2019 1- UMTS Network Structure.pdf
35/111
Huawei mobile softswitch solution
GGSN: Gatewa GPRS Su ort NodeHLR: Home Location RegisterMGW: Media GatewayMSC server: Mobile Switching Center ServerCN: Core NetworkCS: Circuit Switched domainSGSN: Serving GPRS Support NodePS: Packet Switched domainPSTN: Public Switched Tele hone NetworkUTRAN: UMTS Terrestrial Radio Access NetworkBSS: Base Station SubsystemVoBB:Voice over broadband.
UMTS CN Release 4
35
UMTS CN R l 4 CS D i
7/25/2019 1- UMTS Network Structure.pdf
36/111
UMTS CN Release 4 CS DomainApplications and Services
CAPCAP
Call ControlLevelHLR
PS DomainPS Domain
Call Control Mobility Management MGW Control VLR functionality
MSCServer
GMSCServer
Nc (e.g. BICC)
compared to R`99
compared to R`99
CDRs (HLRInterrogation)
Bearer LevelGERAN
Mc (H.248/MEGACO)Mc (H.248/MEGACOA
Iu
PSTN/ISDN
CSMGW
CSMGWUTRAN
Nb (e.g. ATM, IP)Iu
A
MEGACO: Media Gateway Control protocol
MGW: Bearer Control Transmission Resource Management Data Format Conversion TranscodingCDR: Call Data Records
. MGW: Media Gateway
36
7/25/2019 1- UMTS Network Structure.pdf
37/111
Separation of planes ( MSC Server System )
MSC Server System separates call control & signaling and traffic in twoseparate network elements:
MSC Server
Control &
MSC
MSC Server System
Speech & DataMGW
TraditionalMobile Switch
Signalling
Speech & Data
37
7/25/2019 1- UMTS Network Structure.pdf
38/111
38
7/25/2019 1- UMTS Network Structure.pdf
39/111
The MSC Server System saves transmission costs by local
, .
39
7/25/2019 1- UMTS Network Structure.pdf
40/111
The benefits with a layered architecture are many:
Reduced traffic load in the backbone network throu hremote switching with the M MGw close to the localtraffic. As much as 70% of the total traffic could be local
which could be routed within the M MGw instead of entering the backbone network; therefore, significantsavings in transmission can be achieved.
40
7/25/2019 1- UMTS Network Structure.pdf
41/111
CORE NETWORK NODES
3GMSC
RNCCore NetworkRadio Access
HLR
AuC Service Information
3GSGSN GGSN
3GMSC
Supplementary Services Location Updating
3G
Locating the Subscriber
database, which containsinformation about the
RNCForeign Network
,service information.
Authentication information
3GSGSN
GGSN
s a so store n t e .
41
HLR& A C
7/25/2019 1- UMTS Network Structure.pdf
42/111
HLR & AuC
CS Domain Subscriber Registration Storing/Managementsubscriber profiles
Deliver rofiles to VLR/SGSN Storing secret Keys
GMSCVLR Storing Location Information
(VLR / SGSN) MTC: Deliver Routinginformation to GMSC / GGSN
Associated with AuC
: Security Algorithm
Generating Security Parameter(GSM: Triples; UMTS: Quintets)
Deliver Parameter to VLR / SGSN (via HLR)
HLR AuC
Associated with HLR
Gr Gc
GGSNSGSN
PS Domain
BS: Bearer ServiceTS: Tele ServiceSS: Supplementary Service
Subscriber data (Examples): Semi permanent Data: MSISDN, IMSI, Services
(BS, TS, SS), QoS Profile, CSI, Service Restrictions,..
QoS: Quality of ServiceIMSI: International Mobile Subscriber IdentityMSISDN: Mobile Station ISDN NumberMSRN: Mobile Station Roaming Number
,MS Non Reachable flag, MSRN, SMS flags ,..
42
7/25/2019 1- UMTS Network Structure.pdf
43/111
43
7/25/2019 1- UMTS Network Structure.pdf
44/111
BSG: Broadband Signaling GatewayCCU: Call Control UnitDBMS: Database Management System
DRU: Data Routin Unit
Logical structure of the HLR9820 DSU: Data Service UnitNMS: Network Management SystemPGW: Provisioning Gateway OMU: O eration and Maintenance Unit
44
7/25/2019 1- UMTS Network Structure.pdf
45/111
The AuC is responsible to store the secret Keys of the subscribers and thesecurity algorithm, which are necessary for the generation of the GSM andUMTS security parameters. On request o t e VLR respective y t e SGSN t eAuC generates the security parameters. They are delivered via HLR to VLR /
SGSN to enable Authentication, Ciphering and Integrity Check.The AuC is always associated with an HLR (communication via a proprietaryinterface).
45
7/25/2019 1- UMTS Network Structure.pdf
46/111
46
7/25/2019 1- UMTS Network Structure.pdf
47/111
Interfaces of 3G-SGSN
(HPLMN)
RNC
3G SGSN3G SGSNGr
HLR & AUCGp3G Core Network
VPLMN
Gf
GdGa SMSCCG
47
7/25/2019 1- UMTS Network Structure.pdf
48/111
Logical structure of the SGSN9810
48
7/25/2019 1- UMTS Network Structure.pdf
49/111
49
7/25/2019 1- UMTS Network Structure.pdf
50/111
50
7/25/2019 1- UMTS Network Structure.pdf
51/111
Huawei mobile MSC Server solution
The MSOFTX3000 provided by Huawei serves as an MSC server
51
7/25/2019 1- UMTS Network Structure.pdf
52/111
52
7/25/2019 1- UMTS Network Structure.pdf
53/111
53
7/25/2019 1- UMTS Network Structure.pdf
54/111
VMSC Networking & GMSC Networking
54
7/25/2019 1- UMTS Network Structure.pdf
55/111
TMSC Networking
55
7/25/2019 1- UMTS Network Structure.pdf
56/111
GMSC/VMSC/TMSC Combined Networking56
7/25/2019 1- UMTS Network Structure.pdf
57/111
MSC Pool Networking
57
MainVLR
Visitor Location Register VLR
7/25/2019 1- UMTS Network Structure.pdf
58/111
VLRtasks:
storing Subscriber profilesFor all UEs in MSC Area
Mobility Management storing Location Information controlling
Security Features*
VLR as MSCs Data Base : Subscriber Profile,
e.g. IMSI, MSISDN, Services (TS, BS, SS),..
Temporary Subscriber Datae.g. LMSI, TMSI, MSRN,
Security Parameter, Location Information, IMSI attach/detach,..
MSC* e.g. Authentication, Authorization,
Cipher & Integrity Start
D Location Updates (Subscriber Profiles VLR) Security Parameter (via HLR VLR) Interrogation (MSRN via HLR to GMSC)
Location Updates (Subscriber Profiles VLR) Security Parameter (via HLR VLR) Interrogation (MSRN via HLR to GMSC) HLR AuC
TS: Tele ServicesBS: Bearer ServicesSS: Supplementary Services
IMSI: International Mobile Subscriber IdentityLMSI: Local Mobile Subscriber IdentityTMSI: Temporary Mobile Subscriber Identity
MSRN: Mobile Station Roaming Number
58
7/25/2019 1- UMTS Network Structure.pdf
59/111
59
SMSGMSC & SMSIWMSC
7/25/2019 1- UMTS Network Structure.pdf
60/111
CSExternal
VLRDomain
or some es gnateMSCs can act as
SMSGMSC/IWMSC(Network operator
SMSGMSC
epen en
Short MessageService Center
SMS Gateway MSC
SMSIWMSCSMS Interworking MSC
Gd
SGSNDomain
60
7/25/2019 1- UMTS Network Structure.pdf
61/111
61
7/25/2019 1- UMTS Network Structure.pdf
62/111
Location Registration (Circuit and Packet Switched)
IMSI Attach/Detach (Circuit Switched)
Routin Area U date Packet Switched Cell Attach/Detach (Packet Switched)
Location Info Retrieval (Circuit and Packet Switched)
Paging (Circuit Switched)
Paging (Packet Switched)
Authentication Procedure (Circuit/Packet Switched)
Ciphering Procedure (Circuit/Packet Switched)
en y ec ng rcu ac e w c e
UE Hardware (IMEI) Checking (Circuit/Packet Switched)
62
7/25/2019 1- UMTS Network Structure.pdf
63/111
Functions of 2G/3G Authentication
The network and an MS can perform validity verification on each other.
63
MGW
SIEMENS SIEMENS
7/25/2019 1- UMTS Network Structure.pdf
64/111
NodeB
Confidentiality
Service Protection
64
Authentication
7/25/2019 1- UMTS Network Structure.pdf
65/111
Authentication
The rand is relayed to the mobile station. This generates the SRES withthe help of the parameter Ki stored on the SIM card and A3 (SRES =A3(ki, .the SRES of the triple. If both SRES are the same, the authentication issuccessful. If they are different, the SIM card is rejected, An authentications per orme w en an n a es a serv ce reques , suc as a ca ,location update, and activation of a supplementary service. and onlyemergency calls are possible depending on the project.Ciphering
For the ciphering, the rand is also used in the MS. The key kc is generated=
and A8.The ciphering is thereupon carried out with the algorithm 5 stored in the
.The key kc contained in the triple is meanwhile relayed to the BSS. Thealgorithm A5 is also available here, so that the ciphering can be carried out
ere as we .
65
2G Authentication
7/25/2019 1- UMTS Network Structure.pdf
66/111
SRES =Signed Response66
2G Ciphering
7/25/2019 1- UMTS Network Structure.pdf
67/111
67
7/25/2019 1- UMTS Network Structure.pdf
68/111
Relation Between the 2G Authentication Parameters68
2G User Confidentiality (privacy):
7/25/2019 1- UMTS Network Structure.pdf
69/111
Methods for ensurin user confidentialit are used both in the mobile station and inthe network. The mobile station secures itself against misuse by asking for a four digitPersonal Identification Number (PIN) when the MS is switched on. The PIN code is
. correct, the MS is unlocked and ready for use.On the network side, sensitive signaling information (IMEI, IMSI, directory numbers,
.
process between
MS
and
BTS
is
initiated.
The subscriber is identified by means of a temporarily allocated Temporary Mobile
u scr er ent ty e ore t e encrypt on process s starte . e s allocated by the network after a successful first time location update, and is reallocated (renewed) after every successful authentication verification. When the mobile station is switched off, the current TMSI is stored in the SIM and is available when the MS is switched on again.
69
7/25/2019 1- UMTS Network Structure.pdf
70/111
70
7/25/2019 1- UMTS Network Structure.pdf
71/111
71
7/25/2019 1- UMTS Network Structure.pdf
72/111
72
7/25/2019 1- UMTS Network Structure.pdf
73/111
73
7/25/2019 1- UMTS Network Structure.pdf
74/111
74
EIR:Equipment Identity Register
7/25/2019 1- UMTS Network Structure.pdf
75/111
Storing IMEIs(counterpart: ME)
on White / Gray / Black List Performing IMEI Check
on VLR / SGSN request
optional network
function
MSC /CS Domain
VLR
F
EIR
Gf
SGSNInternational Mobile stationEquipment Identity (IMEI)
PS Domain
75
7/25/2019 1- UMTS Network Structure.pdf
76/111
76
7/25/2019 1- UMTS Network Structure.pdf
77/111
77
7/25/2019 1- UMTS Network Structure.pdf
78/111
78
7/25/2019 1- UMTS Network Structure.pdf
79/111
79
7/25/2019 1- UMTS Network Structure.pdf
80/111
80
7/25/2019 1- UMTS Network Structure.pdf
81/111
81
7/25/2019 1- UMTS Network Structure.pdf
82/111
82
7/25/2019 1- UMTS Network Structure.pdf
83/111
83
7/25/2019 1- UMTS Network Structure.pdf
84/111
84
7/25/2019 1- UMTS Network Structure.pdf
85/111
85
7/25/2019 1- UMTS Network Structure.pdf
86/111
86
7/25/2019 1- UMTS Network Structure.pdf
87/111
87
7/25/2019 1- UMTS Network Structure.pdf
88/111
88
7/25/2019 1- UMTS Network Structure.pdf
89/111
89
7/25/2019 1- UMTS Network Structure.pdf
90/111
90
7/25/2019 1- UMTS Network Structure.pdf
91/111
91
7/25/2019 1- UMTS Network Structure.pdf
92/111
92
u en ca on arame ers
Authentication Quintuple
7/25/2019 1- UMTS Network Structure.pdf
93/111
Authentication QuintupleRANDThe RAND is a random number provided by the network for a UE. The UE uses theRAND to generate the authentication response RES or RES+RES_EXT, IK, and CK. TheRAND has 16 bytes.AUTNThe AUTN is sent to a UE for authenticating the network. The AUTN has 16 bytes.XRESThe XRES is the authentication response expected from the UE. If the RES or
RES+RES_EXT generated by the UE is the same as the XRES, the authentication is. .
CKThe CK is the UMTS cipher key in a UMTS network. The CK has 16 bytes.
The IK is the integrity key in a UMTS network. The IK has 16 bytes.
93
Authentication Parameters Stored on a USIM Card
IMSI
7/25/2019 1- UMTS Network Structure.pdf
94/111
IMSIKIu en ca on an encryp on a gor ms , , , , , , , , an or c
SQNMS
IMSIKI
CKSN
* * AMFOP or OPcSQN
94
Relation Between the 3G Authentication Parameters
7/25/2019 1- UMTS Network Structure.pdf
95/111
95
EIR:Equipment Identity Register
7/25/2019 1- UMTS Network Structure.pdf
96/111
Storing IMEIs(counterpart: ME)
on White / Gray / Black List Performing IMEI Check
on VLR / SGSN request optional network functionMSC /
CS Domain
VLR
F
EIR
Gf
SGSNInternational Mobile stationEquipment Identity (IMEI)
PS Domain
96
Equipment Identity Register EIR
7/25/2019 1- UMTS Network Structure.pdf
97/111
Equipment Identity Register EIR
prophylaxis. Stolen or non valid Mobile Equipment ME can be blocked from furtherusage.The E ui ment Identit Re ister EIR is the lo ical entit which is res onsible forstoring in the network the International Mobile Equipment Identities IMEIs (TS23.002). An IMEI clearly identifies a unique Mobile Equipment ME and containsinformation about the place of manufacture, device type and the serial number of theequipment.
The Mobile
Equipment
ME
is
classified
as
"white
listed",
"grey
listed",
"black
listed"
orit may be unknown as specified in TS 22.016 and TS 29.002.
The EIR performs IMEI Checks on VLR respectively SGSN request to check whetherthe ME is stolen or non valid.The EIR is connected to:
The SGSN via Gf interface The VLR via F interface
97
7/25/2019 1- UMTS Network Structure.pdf
98/111
Short Message Services
98
SIEMENS SIEMENS SIEMENS SIEMENS
1
2
MSC VLR
5
7/25/2019 1- UMTS Network Structure.pdf
99/111
5
SIEMENS SIEMENS
InterworkingMSC
MSC function(MAPMSC) usually
5
n egra e n eSMSCenter itself
mobile origination
PBX
45Delivery report
SMSCenter
99
7/25/2019 1- UMTS Network Structure.pdf
100/111
1BMSISDN+SMS2Interrogate HLR(BMSISDN+SMSC)
(SMMT) Short message mobile termination
3MSCID+BIMSI4IMSI+SMS+SMSC5,6 Checking IMSI
ag ng8SMS to MS
100
7/25/2019 1- UMTS Network Structure.pdf
101/111
Location Update
101
7/25/2019 1- UMTS Network Structure.pdf
102/111
LA-1 Location update isperformed when there
LA-2 .
No locationupdate
Location update
102
In practice, there are three types of location updates:1 L i R i i P O
7/25/2019 1- UMTS Network Structure.pdf
103/111
1. Location Re istration Power On2. Generic3. Periodic
Location registration : takes place when a mobile station is turned on. This is also known as IMSI Attach
because as soon as the mobile station is switched on, it informs the Visitor Location.
successful registration, the network sends the mobile station two numbers that arestored in the SIM(Subscriber Identity Module)card of the mobile station.
Generic: Every time the mobile receives data through the control channels, it reads the LAI
and compares it with the LAI stored in its SIM card. A Generic location update isperformed if they are different. The mobile starts a location Update process by
Periodic: Periodic Location Update is carried out when the network does not receive any
location update request from the mobile in a specified time.
103
7/25/2019 1- UMTS Network Structure.pdf
104/111
104
7/25/2019 1- UMTS Network Structure.pdf
105/111
Handover/Relocation
105
Handover
Handover is the means of maintaining a call when a user moves
7/25/2019 1- UMTS Network Structure.pdf
106/111
.
The call must be switched to an alternative cell to provide service,automatically and without loss of service.
Handover is a complex process requiring synchronisation of eventsbetween the mobile station and the network.
In particular, there is the need to route the call to the new cell before
handover can be effected whilst maintaining the old connection until
Handover is a time critical process requiring action to be taken beforethe existing radio link degrades to such an extent that the call is lost.
106
Handover
7/25/2019 1- UMTS Network Structure.pdf
107/111
107
7/25/2019 1- UMTS Network Structure.pdf
108/111
BTS BTS
108
7/25/2019 1- UMTS Network Structure.pdf
109/111
BSC/RNC
BSC/ BSC/
RNCRNC
BTSBTSNodeBNodeB
BTSBTSNodeBNodeB
109
Inter BSC/RNC Intra MSC Handover
7/25/2019 1- UMTS Network Structure.pdf
110/111
MSCMSCVLR
BSCBSC
BBTTSS
BSCBSC
BBTTSS
BBTT
BBTTSS
BBTTSS
SS
BBTT
BBTTSS
BB
BBTTSS
SS
110
Inter BSC/RNC Inter MSC Handover
BSCBSC
7/25/2019 1- UMTS Network Structure.pdf
111/111
MSC1MSC1VLRBB
TTSS
BBTTSS
BBTT
MSC2MSC2 VLR
SS
BBTT
SS
BSCBSCBBTTSS
BBTTSS
BBTT
BBTTSS
SSBBTTSS
111