GSM Architecture
Numbering and Routing
GSM Services
GSM Network ArchitectureGSM Network Architecture
Engr. Mian Shahzad IqbalLecturerDepartment of TelecommunicationEngineering
IntroductionIntroductionGlobal System for Mobile Communication (GSM)Global System for Mobile Communication (GSM)
Anybody Anybody –– 500 million users (may 2001)500 million users (may 2001)Anywhere Anywhere –– 168 countries (may 2001)168 countries (may 2001)Any media Any media –– voice, messaging, data, multimediavoice, messaging, data, multimedia
Source: Hillebrand, 1
GSM ArchitectureGSM Architecture
OMC
Home Location Register
AuC
Equipment ID
Network Management Center
BTS
BTS
BTS
ME
ME
ME
Subscriber Identity Module
Subscriber Identity Module
Subscriber Identity Module
Base station controller
PSTN
Mobile switching center
Data communication network
BTS = Base Transceiver Station
AuC = Authentication Center
OMC = Operation and Maintenance Center
PSTN = Public Switched Telephone Network
ME = Mobile Equipment
Source: Stallings, 313
Source: Mehrotra, 27
Visitor Location Register
GSM ArchitectureGSM Architecture
F1 F2 F1' F2'Frequency
12345678
45 MHz
BS Transmission Band : 935 – 960 MHZ
MS Transmission Band : 890 – 915 MHZ
Year IntroducedYear Introduced 19901990
Access methodAccess method TDMATDMA
Channel BandwidthChannel Bandwidth 200 kHz200 kHz
Number of duplex Number of duplex channelschannels
125125
Users per channelUsers per channel 88
Speech coding bit Speech coding bit raterate
13 kbps13 kbps
Data coding bit rateData coding bit rate 12 kbps12 kbps
Frame sizeFrame size 4.6 ms4.6 ms
SIM (Subscriber Identity Module)SIM (Subscriber Identity Module)
Billions of Calls
Millions of Subscribers
Thousand of Different Types of Telephones
Hundreds of Countries
Dozens of Manufacturers….
And only one Card: The SIM
Source: Hillebrand, 369
http://ucables.com/products/simcards/
•Administrative data
•Security data
•Subscriber data
•Roaming data
•PLMN (Public Land Mobile Network
Subscriber Identity Module Subscriber Identity Module (SIM)(SIM)
Subscriber Identity ModuleSubscriber Identity ModuleContainsContains
phone number (MSISDN)phone number (MSISDN)international mobile subscriber identity (IMSI)international mobile subscriber identity (IMSI)status of SIMstatus of SIMservice codeservice codeauthentication keyauthentication keyPIN (personal identification code)PIN (personal identification code)PUK (personal unlock code)PUK (personal unlock code)
SIM CardsSIM Cards
SIM cards are embedded with a SIM cards are embedded with a microprocessormicroprocessor
Stores customer identity information and is Stores customer identity information and is made to fit inside the cellular phonemade to fit inside the cellular phone
Memory capacityMemory capacity1K, 3K, 8K, 16K,32K,64K1K, 3K, 8K, 16K,32K,64K
+G S M
Global GSM MobilityCardThe Smart Card to use
SIM Card
+
BatteryHandset
Mobile Station
=
battery
f153454
2Wjmhfodkgdjipj
Mobile StationMobile Station
G S M
Global GSM MobilityCardThe Smart Card to use +
SIM-Card
Subscriber knowsCalled party number = MS-ISDN-PIN
Contains:- IMSI
Handset
= Calling line0609225831
SIMSIM--CardCard and GSM Mobile and GSM Mobile EquipmentEquipment
25 mm
15 mm
Microchip with storeduser information
Credit Card Size
Permanent data:- Unique mobile subscriber identitythrough IMSI number,
- Authentication parameter Ki,- Authentication algorithm A3,- Generating encryption key Kcalgorithm A8.
Removable data:- Temporary Mobile Subscriber Number,- Location Area Identification.
µ SIM-Card
G S M
Global GSM MobilityCardThe Smart Card to use
The The SIMSIM--CardCard FunctionsFunctions
NatureInternational Mobile Subscriber Identity
Conformity with E212
Mobile Station -Integrated Services Digital Network Nb
Similar to ISDN, Conformity with E164/E213
Nb. digits 3 2 max 10 1 to 3 2 to 4 total max 15
*This code does not identify a geographical areabut an operator
MS - ISDN
Format MCC MNC MSINH1 H2 x x x ......... x x x CC NDC SN
M1 M2 x x x x x x x x
MeaningMobile
CountryCode
MobileNetwork
Code
Mobile SubscriberIdent. Nb
H1 H2 = Identity of HLR within the home PLMN
CountryCode
(wheresubscription
has been made)
NationalDestination
Code *
Mobile Subscriber(national definition)
M1 M2 = nbr of logical HLR
IMSI
National Significant Mobile NumberIdentify a PLMNworldwide
Identify the subscriberof a PLMN
SubscriberSubscriber IdentificationIdentification
Revision level (Phase 1, 2, 2+)
RF power
Encryption algorithm (A5/1,A5/2)
Frequency (900/1800/1900)
Short message
Classmark
Class GSM900
GSM1800
GSM1900
Power classes
1
2
3
4
5
8 W*
5 W
2 W**
0.8 W
1 W**
0.25 W
4 W
1 W**
0.25 W
4 W
* Typical value for car mounted** Typical value for handheld
MS MS ClassmarkClassmark
MS (Mobile Station)
ME (Mobile Equipment)
ADVANTAGES OF GSM
DigitalDigital Global
Open Interfaes Secure
Noise Robust
NETWORK ARCHITECTURE
MS
Mobile StationBSS
Base Station Subsystem
OMS
Operations & Maintenance Subsystem
NSS Network Switching Subsystem
BSS (Base Station Subsystem)
BSS Connectivity
NSS (Network Switching Subsystem)
OMS (Operations & Maintenance Subsystem)
The Network In Reality
GSM Network ElementsGSM Network Elements
HandsetHandsetBTS: BTS: Base Transceiver StationBase Transceiver Station
MSC: MSC: Mobile Switching CenterMobile Switching Center
BSC: BSC: Base Station ControllerBase Station Controller
HLR/VLR:HLR/VLR: Home Location Register/Visiting Home Location Register/Visiting Location RegisterLocation RegisterSIM Card: SIM Card: Subscriber Identity Module CardSubscriber Identity Module Card
Service Centers: Service Centers: USSD, SMS, ...USSD, SMS, ...
Base Transceiver Station (BTS)Base Transceiver Station (BTS)/ Base Station/ Base Station
Responsible for communication to and from Responsible for communication to and from MHsMHs via air interfacevia air interface
MS communicates with the mobile system using a MS communicates with the mobile system using a radio channel to a BTSradio channel to a BTS
BTS comprises radio transmission and BTS comprises radio transmission and reception devicesreception devices
Including the antennae and signaling processing Including the antennae and signaling processing specific to the radio interfacespecific to the radio interface
BTS separates the speech and control BTS separates the speech and control signaling associated with a MS and sends signaling associated with a MS and sends them to the BSC on separate channelsthem to the BSC on separate channels
Mobile services SwitchingMobile services SwitchingCenter (MSC)Center (MSC)
Responsible for all switching functions Responsible for all switching functions related to call processingrelated to call processing
Coordinate the setting up of calls to and from Coordinate the setting up of calls to and from GSM usersGSM users
MSC is the interface between GSM MSC is the interface between GSM network & PSTN (Public Switched network & PSTN (Public Switched Telephone Network)Telephone Network)
Gateway MSC (G-MSC)
• The MSC with an interface to other networks is called GMSC.
• Network operator may equip all there MSCs with gateway function or only few.
• MSC that don’t have gateway function has to route call from GMSC.
• GMSC has some additional tasks like call from outer network enters in GMSC which queries HLR then forwarded the call to MSC where the called party is located.
Base Station Controller (BSC)Base Station Controller (BSC)
Monitor and Control several base stationsMonitor and Control several base stationsFrequency administration, control of Frequency administration, control of BTSsBTSs, , exchange functionsexchange functions
Responsible for all the radio interface Responsible for all the radio interface managementmanagement
Channel allocation and release, handover Channel allocation and release, handover managementmanagement
BSC is the interface between MSC and BSC is the interface between MSC and BTSBTS
BSC is connected on one side to several BSC is connected on one side to several BTSsBTSs and on the other side to the MSCand on the other side to the MSC
Home Location Register (HLR)Home Location Register (HLR)
A database in charge of the management A database in charge of the management of mobile subscribersof mobile subscribersContains information of network Contains information of network subscriberssubscribers
Information on Information on teleservicesteleservices and bearer and bearer services subscription, service restrictions, and services subscription, service restrictions, and supplementary servicessupplementary servicesThe data stored in HLR is of a semi The data stored in HLR is of a semi permanent nature and does not usually permanent nature and does not usually change from call to callchange from call to call
Visitor Location Register (VLR)Visitor Location Register (VLR)
Contains the relevant data of all Contains the relevant data of all MSsMSscurrently located in a serving MSCcurrently located in a serving MSC
The permanent data is the same as data in The permanent data is the same as data in the HLRthe HLRThe temporary data includesThe temporary data includes
Temporary Subscriber Identity (TMSI)Temporary Subscriber Identity (TMSI)Location Area Identity (LAI) of an MSLocation Area Identity (LAI) of an MS
VLR allocates mobile subscriber roaming VLR allocates mobile subscriber roaming numbers (MSRNs) for the incoming call numbers (MSRNs) for the incoming call setupsetup
The relation between MSC and VLR
• Sum of MSC areas determine the geographical area of any PLMN.
• Each MSC has its own VLR so PLMN can also be described as the sum of all VLR areas.
• VLR can serve several MSC but one MSC always use only one VLR.
Equipment identity register (EIR)
• The separation of subscriber identity from the identifier of MS also bears a potential pitfall for GSM subscribers.
• It is possible to operate any GSM MS with any valid GSM SIM. An opportunity exists for black market and stolen equipment. •To combat this problem EIR is introduced to identify and track such equipment.
EIR (cont) • Each GSM phone has a unique identifier IMEI which
can not be altered. • Like HLR and VLR, the EIR is also a data base
which maintain three lists.
EIR (cont)
• The processes of mobile equipment fallen dramatically due to great success of GSM consequently the theft rate reduced. So several GSM operators have decided not to install the EIR.
• If the EIR is installed there is no specification when the EIR should be interrogated. The EIR may be interrogated any time during call setup or during location update.
Transcoding rate and adaptation unit. (TRAU)
• One of the most interesting features of GSM is TRAU. Its function is the compress and decompress the speech between TRAU and MS. Possible location are as below.
Geographical Network StructureGeographical Network Structure
Location UnitsLocation UnitsCellCellLocation Area (LA)Location Area (LA)MSC/VLR Service Area MSC/VLR Service Area PLMN (Public Land Mobile Network) Service PLMN (Public Land Mobile Network) Service AreaAreaGSM Service AreaGSM Service Area
Cell PlanningCell Planning
Location Information Location Information ----GSM Service Area HierarchyGSM Service Area Hierarchy
The area The area in which a in which a subscribesubscriber can r can access access the the network.network.
cell
Location Area
MSC/VLR
PLMN Service Area(one per operator)
GSM Service Area
Numbering & RoutingNumbering & Routing
NumberingNumbering
Mobile Subscriber ISDN Number (MSISDN)Mobile Subscriber ISDN Number (MSISDN)Mapping to Mobile Station Roaming Number Mapping to Mobile Station Roaming Number (MSRN) by HLR(MSRN) by HLR
International Mobile Subscriber Identify (IMSI)International Mobile Subscriber Identify (IMSI)Stored in SIM/HLRStored in SIM/HLR
Temporary Mobile Subscriber Identity (TMSI)Temporary Mobile Subscriber Identity (TMSI)Assigned by VLR, Stored in VLRAssigned by VLR, Stored in VLR
International Mobile Equipment Identity (IMEI)International Mobile Equipment Identity (IMEI)Unique ID to handset, used by air interfaceUnique ID to handset, used by air interface
IDID--NumbersNumbersMSISDN = CC + NDC + SNMSISDN = CC + NDC + SN
MSISDN: Mobile Station ISDN NumberMSISDN: Mobile Station ISDN NumberCCCC Country CodeCountry CodeNDCNDC National Destination CodeNational Destination CodeSNSN Subscriber NumberSubscriber Number
IMSI = MCC + MNC + MSINIMSI = MCC + MNC + MSINIMSIIMSI International Mobile Subscriber IdentityInternational Mobile Subscriber IdentityMCCMCC Mobile Country CodeMobile Country CodeMNCMNC Mobile Network CodeMobile Network CodeMSINMSIN Mobile Station Identification NumberMobile Station Identification Number
IDID--Numbers (cont.)Numbers (cont.)IMEI = TAC + FAC + SNR + spareIMEI = TAC + FAC + SNR + spare
IMEIIMEI Internal Mobile Equipment IdentityInternal Mobile Equipment IdentityTACTAC Type Approval Code, determined by a Type Approval Code, determined by a central central GSM/PCS bodyGSM/PCS bodyFACFAC Final Assembly Code, identifies the Final Assembly Code, identifies the
manufacturermanufacturerSNRSNR Serial Number, uniquely identifies all Serial Number, uniquely identifies all
equipment within each TAC and FACequipment within each TAC and FACIMEISV = TAC + FAC + SNR + SVNIMEISV = TAC + FAC + SNR + SVN
IMEISVIMEISV International Mobile Equipment Identity International Mobile Equipment Identity and and Software Version NumberSoftware Version NumberSVNSVN Software Version NumberSoftware Version Number
IDID--Numbers (cont.)Numbers (cont.)MSRN = CC + NDC + SNMSRN = CC + NDC + SN
MSRNMSRN Mobile Station Roaming NumberMobile Station Roaming NumberCCCC Country CodeCountry CodeNDCNDC National Destination CodeNational Destination CodeSNSN Subscriber Number. In this case, the Subscriber Number. In this case, the address to address to the serving MSCthe serving MSC
LAI = MCC + MNC + LACLAI = MCC + MNC + LACMCCMCC Mobile Country CodeMobile Country CodeMNCMNC Mobile Network CodeMobile Network CodeLACLAC Location Area CodeLocation Area Code
IDID--Numbers (cont.)Numbers (cont.)CGI = MCC + MNC + LAC + CICGI = MCC + MNC + LAC + CI
CGICGI Cell Global IdentityCell Global IdentityCICI Cell IdentityCell Identity
BSIC = NCC + BCCBSIC = NCC + BCCBSICBSIC Base Station Identity CodeBase Station Identity CodeNCCNCC Network Color Code (3bits)Network Color Code (3bits)BCCBCC Base Station Color Code (3bits)Base Station Color Code (3bits)
LN = CC + NCD + LSPLN = CC + NCD + LSPLNLN Location NumberLocation NumberCCCC Country CodeCountry CodeNCDNCD National Destination CodeNational Destination CodeLSPLSP Locally Significant PartLocally Significant Part
ID ID --Numbers (cont.)Numbers (cont.)LN = CC + NCD + LSPLN = CC + NCD + LSP
LNLN Location NumberLocation NumberCCCC Country CodeCountry CodeNCDNCD National Destination CodeNational Destination CodeLSPLSP Locally Significant PartLocally Significant Part
RSZI = CC + NDC + ZCRSZI = CC + NDC + ZCRSZIRSZI Regional Subscription Zone IdentityRegional Subscription Zone IdentityCCCC Country CodeCountry CodeNDCNDC National Destination CodeNational Destination CodeZCZC length of the Zone code (2 octets)length of the Zone code (2 octets)
RoutingRouting
Information resident in MS & SIMInformation resident in MS & SIMIMSI, TMSI, IMEI, and misc. informationIMSI, TMSI, IMEI, and misc. information
Routing Information used by NetworkRouting Information used by NetworkMSISDN, MSRNMSISDN, MSRN
GSM Services and FeaturesGSM Services and Features
1.1. Tele ServicesTele Services
2.2. Bearer Services or Data Bearer Services or Data ServicesServices
3.3. Supplementary ServicesSupplementary Services
Hello
1
Speaking
Speaking
1
Originatedcall
Terminatedcall
Hello
TeleservicesTeleservices
1 1 -- TelephonyTelephony
G S M
Global GSM MobilityCardThe Smart Card to use
Do not require a SIM-Cardwhile "112" is invoked
Emergency112
TeleservicesTeleservices
2 2 -- Emergency CallEmergency Call
GSM Network
message B
message B
message B
message B
message A
message A
message A
message A
InformationProvider B
InformationProvider A
TeleservicesTeleservices
3 3 -- Short Message Short Message CellCell BroadcastBroadcast
SMS-MO/ PPRadioPLMN
SMS-MT/ PP
RadioPLMN
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TeleservicesTeleservices
4 4 -- Short Message ServiceShort Message Service
SMS-SC
Alternate Speech and Fax:
Automaticfax:
TeleservicesTeleservices
5 5 -- FaxFax
Teleservicesvoice
TeleservicesFax G3, SMS
Cable thatbears data
Embodiedbearer
treatments forradio transmission
Data / Faxkit adaptation
TeleservicesTeleservices
6 6 -- User's Data Call FeaturesUser's Data Call Features
Voicemessage
server
Please leavea message
after the tone
GSM network
1
Busy
Voice mailbox
Forwardto voicemail box
Warming up...
You have3 voices
messages...
Retrieving the voicemessages
TeleservicesTeleservices
7 7 -- VoiceVoice MessagingMessaging
Bearer ServicesBearer Services
Limited to 1,2 and 3 OSI layerLimited to 1,2 and 3 OSI layer
Packet Switched ProtocolsPacket Switched Protocols
Data Rates from 300bps to 9.6kbpsData Rates from 300bps to 9.6kbps
Calling line0609225831
Cnted line0609173957
Calling Line Identification
presentation (CLIP)
restriction (CLIR)
Connected Line Identification
presentation (CoLP)
restriction (CoLR)
Calling Name Presentation(CNAP)
Calling PartyCoLPCLIR
Called PartyCLIP CoLR
SupplementarySupplementary ServicesServices
1 1 -- Line IdentificationLine Identification
unconditional (CFU)
on busy (CFB)
on no reply (CFNRy)
on not reachable (CFNRc)1 2
SupplementarySupplementary ServicesServices
2 2 -- Call Call TransferTransfer andand Call Call ForwardingForwarding
1 2
HOLD
1 2
WAIT
1
2
Multi Party:1
2
Max = 5 persons
Waiting / Hold:
SupplementarySupplementary ServicesServices3 3 -- WaitingWaiting / / HoldHold andand Multi Multi PartyParty
Outgoing (BAOC)
Outgoing international (BOIC)
Outgoing international except home PLMN country (BOIC-exHC)
Incoming (BAIC)
Incoming when roaming outside(BIC-Roam)
SupplementarySupplementary ServicesServices
4 4 -- Call Call BarringBarring
2
Speaking
1
1
HELLO
Unable to placea call.
Reinitiatethe call
SPEAKING
BUSY...
Speaking
Call isestablished
1
This call in state
Idle
Ring ! Ring !
NEW!
SupplementarySupplementary ServicesServices5 5 -- Call Call CompletionCompletion (CCBS)(CCBS)
information on progressof the cost of the call
Completion of callneed charging
Insert aSIM credit Card
Advice of Charge Information (AoCI)
Advice of Charge Charging (AoCC)
SupplementarySupplementary ServicesServices
6 6 -- AdviceAdvice of Chargeof Charge
The aim of the CAMEL (Customized Application for Mobile network Enhanced Logic) is to provide GSM network operators with the ability to create specific services in their home network, and export these services to their subscribers when roaming outside the home network.CAMEL introduces the ability to provide location dependent IN type ofservices to mobiles subscribers.
Intelligent Network ServicesIntelligent Network Services
IN IN andand CAMELCAMELMain IN Services:Personal NumberVirtual Private Network (VPN) Sponsored Cell & Call Prepaid CallingLocation InquiryGeo Zone
IN Services: IN Services: VirtualVirtual PrivatePrivateNetworkNetwork
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Corporate Numbering Plan
Lower rate for on-net calls
Closed User Group
Wireline Access
Speed DialingLocation & Timedependant routing
Location & Timedependant screening
50 c/min
25 c/min
25 c/min
25 c/min
924 63256
IN Services: IN Services: PrepaidPrepaid CallingCalling
Account statusenquiry andnotification
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Your accountbalance is $ 24.50
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Last call costs $ 0.50New balance is$ 24.50
Flexible features for easyservice packaging
Multiple Tariff Plans
Tariffs using fixed charge, CC, NC, distance, time & day, roaming charges...
Possible language selection by subscriber
Bulk account loading for easy provisioning
Multiple recharging options
Copyright © 1996 Northern Telecom
RANK1ONE5542 1139 1464 228 99494
6/91 6/99VALID DATES
SCOOBY DOO
PromotionalInformations:
call #15
IN Services: Location IN Services: Location InquiryInquiryC
opyright © 1996 N
orthern Telecom
Possible customization of announcement directly by the advertiser
Today’s special atThe Anchor is Maine lobster soup
Be the first ten caller and get a free cocktail !
The closest restaurants are:
The Wind Jammeron 132 Flinton StreetSea foodPhone 55 1968 press 1 to connect
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Cell dependent information
Direct connection to advertisers
The closest restaurants are: The Tower, Tower Hill, Phone 56 4589, Press 1 to connectThe AnchorSt Catherine DockPhonce 56 2548Press 2 to connect
Q & A ?Q & A ?