umts cs system overview
TRANSCRIPT
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Table of Contents
PLMN Network Structure Addressing and Numbering plan GSM Network Evolution UMTS Network Evolution CORE Network Nodes 2G/3G Authentication Short Message Service Location Update Handover
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Cell
Location Area
MSC / VLR Area
Public Land Mobile Network (PLMN)
GSM Network Areas...
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Public Land Mobile Network (PLMN)
GSM Network Areas...
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MSC Service Area :پوشش داده مي شود MSCيك منطقه يا ناحية سرويس از شبكه را نشان مي دهد كه توسط يك
GSM Network Areas...
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Location Area ::كه در اين محدودهاست MSC/VLR Service Areaي از يك بخش
.اتفاق نمي افتد Location Update، عمليات موبايلمشترك با جابجايي1.
.پخش مي شود Location Areaدر آن براي يافتن مشترك Pagingپيام2.
GSM Network Areas...
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CGI : Cell Global ID
GSM Network Areas...
CellLocationيك Areaچندين به Cell هر .شود مي تقسيم Cell، پوشش با منطقة يك
.شود مي تعيين )(CGI سلول هويت شماره وسيلهب آن هويت كه است راديويي
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GSM /GPRS BSS
BTSBSC
NodeB
RNC
PCU
UTRAN
SCPSMS
SCE
PSTN/PLMN
Internet,Intranet
HLR/AuC
SGSN
CGBG
GGSN
GPRSbackbone
MGW
MGW
VMSC ServerGMSC Server
IP/ATM BackboneCS Domain
PS Domain
Iu-CS
Iu-PS
SS7
Other PLMN
MS
UE
UMTS R4 Core Network Structure
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MGW RNC
Small City
MGW RNC RNC
MGW RNC PSTN GW
RNCSmall City
Mini city
Small City
Only Signaling
signaling bearer
Large City
BICC
SCP SMS
SCEHLR
APP Server
MAP/CAP MAP/CAPMSC
ServerMSC
Server
Large‐scale Networking
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Functions of MSC Server
• Call control signaling processing
• Mobility Management
• VLR and SSP functions
• CDR Generation
• Control MGWs via H.248 protocol
• The inter‐working function of other MSC Server via BICC protocol
MGW
MSC Server
H.248
MSC Server
H.248
BICC
MGW
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RNC-O
HLR
MSC Server-O
MGW-O
RANAP
MAP
BICC
H.248AAL2
MGW-T
MSC Server-T
RNC-T
AMR/RTP
IPBackBone
RANAP
AAL2H.248
MAP
T1 T2 T3 T4
UE1 UE2
UE to UE Call in Soft Switch CN
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Functions of MGW
Terminates the signalling over the Mc interface from the MSC servers Terminates the bearer part of the signalling over the Iu interface and the Nb
interface Provide bearer terminations Complete media manipulation (e.g. transcoders, echo cancellers, or tone
senders ) Perform media conversion and framing protocol conversion
(G.711/G.729/AMR etc. )
MGW
MSC Server
H.248
MSC Server
H.248
BICC
MGW
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MSISDNMOBILE STATION ISDN NUMBER
CC NDC SN
National ( Significant ) Mobile Number
MSISDN: Mobile Station International ISDN number
CC: Country Code
NDC: National Destination Code
SN: Subscriber number
Examples: MSISDN = +98 920 XXXXXXX
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IMSI
MCC MNC MSIN
3 digits 2/3 digits
Not more than 15 digits
IMSI (International Mobile Subscriber Identity)
NMSI
MCC: Mobile Country Code MNC: Mobile Network Code MSIN: Mobile Subscriber Identification Number Examples: IMSI = 432 20 XXXXXXXXXX
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TMSI
• TMSI: Temporary Mobile Subscriber Identify
• Function: Taking the place of IMSI to be transferred in radio interface to ensure the security of subscriber’s information.
• Structure: consists of 4 octets, and the structure and coding can be chosen by agreement between operator and manufacturer in order to meet local needs.
• Type:– TMSI, used in CS domain, allocated by VLR;
– P‐TMSI, used in PS domain, allocated by SGSN;
• Notes: the TMSI has only local significance (i.e. within a VLR and the area controlled by a VLR, or within an SGSN and the area controlled by an SGSN).
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IMEI
TAC SNR SPARE
1 digits6 digits
IMEI (International Mobile Equipment Identity)
8 digits
• The IMEI is composed of the following elements (each element shall consist of decimal digits only):– Type Allocation Code (TAC). Its length is 8 digits;– Serial Number (SNR) is an individual serial number uniquely identifying
each equipment within each TAC. Its length is 6 digits;– Spare digit: this digit shall be zero, when transmitted by the MS
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MSRN
MSRN:Mobile Station Roaming Number • Function: to route calls to called MS/UE• Structure: the same as MSISDN• Notes:
– The MSRN must not be used for subscriber dialling. – The MSRN normally uses number segment different from that of MSISDN.
– MSRN is allocated by the VLR that the called MS is visiting.
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Network Equipment Number
CC NDC SN
MSC/VLR/HLR/SGSN/GGSN Number
• MSCs, GSNs and location registers are identified byinternational PSTN/ISDN numbers and/or Signalling PointCodes ("entity number", i.e., "HLR number", "VLR number","MSC number", "SGSN number" and "GGSN number") ineach PLMN.
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The LAI, used for paging, indicates to the MSC in which location area the UE isoperating. It is also used for location updating of mobile subscribers.The LAI contains the following:
LAI = MCC + MNC + LACMCC = Mobile Country Code Identical to IMSI MCCMNC = Mobile Network Code Identical to IMSI MNCLAC = Location Area CodeThe maximum length of LAC is 16 bits, enabling 65,536 different location areasto be defined in one PLMN.
RAIROUTING AREA IDENTITY
The Routing Area Identity is exactly the same as the Location Area Identity (LAI).RAI = MCC + MNC + LAC
LAILOCATION AREA IDENTITY
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1‐ The dialing information is received by PSTN e.g. via ISUP in the PLMN gatewayMSC 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 tothe HLR in order to obtain location‐specific routing information. The HLR knowsthe location routing label i.e. the MSC/VLR by the "location update" and relays thequery there.
3‐ The MSC/VLR makes a temporary directory number available and sends it backvia the HLR to the gateway MSC.
4‐ The gateway MSC converts this temporary directory number and sets up a circuitconnection (ISUP) to the visited MSC. The location area is specified in the MSC/VLR owing to the cross‐connection between temporary directory number and mobile subscriber.
5‐ The visited MSC now sends a "paging" to all BSCs situated in the location area.The BSC in which the subscriber is currently situated answers with a "paging
response".6‐ The MSC makes the connection to the called subscriber.
Mobile terminating call e.g. from PSTN
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PSTN GMSCHLR
MSC/VLR
1- MSISDN2- MSISDN
5- MSRN
3-IMSI
4-MSR
NMSISDN IMSI MSC Address
7-Paging 22
Classification of CS Procedures
• Mobility Management procedures:
– Location Updating – Detach – Authentication and ciphering
• Call control procedures
– Setup – Release
• Service related procedures
– CAMMEL service– Supplementary service
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