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GSM TOWARDS LTE NETWORKS. Lecture # 2. CELLULAR GENERATIONS. First Generation Wireless : Analog Second Generation Wireless (2G): Digital Second Generation Wireless + (2G+): More Data Third Generation Wireless (3G): Universal Global Wireless Voice and Data System Worldwide Effort Toward 3G
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GSM TOWARDS LTE NETWORKS Lecture # 2
CELLULAR GENERATIONS • First Generation Wireless : Analog • Second Generation Wireless (2G): Digital • Second Generation Wireless + (2G+): More Data • Third Generation Wireless (3G): • Universal Global Wireless Voice and Data System • Worldwide Effort Toward 3G • International Standard Underway: IMT-2000
1st GENERATION CELLULAR SYSTEM Widespread introduction in early 1980s. Analogue modulation. Frequency division multiple access. Voice traffic only. No inter-network roaming possible. Insecure air interface. Examples : AMPS (Advance mobile Phone System, American based,800MHz) TACS (Total Access Communications System, UK based,900MHz) C-450 (German standard, 450MHz) JTACS (Japanese Total Access Communications System,900MHz). 3
2nd GENERATION OF CELLULAR NETWORKS Widespread introduction in 1990s. Use digital modulation. Variety of multiple access strategies. More efficient use of radio spectrum. International roaming capability. Secure air interface. Compatibility with ISDN. 4
GSM ARCHITECTURE OVERVIEW A GSM system is made up of three subsystems: The mobile station (MS) The Base station subsystem (BSS) The Network and switching subsystem (NSS) The interfaces defined between each of these sub systems include: “A” interface between NSS and BSS “Abis” interface between BSC and BTS (Within the BSS) “Um” air interface between the BSS and the MS 5
GSM ARCHITECTURE OVERVIEW • Main components of GSM • The mobile station (MS) • BSS Base Station Subsystem (BTS+BSC) • MSS Mobile Station Subsystem (MSC/HLR, ..) MSC BTS BSC
Abis Interface Interface 7
MS (Mobile Station) MS BTS BSS (Base Station System) BSC PSTN, ISDN... MSC (Network Switching Subsystem) NSS Voicemail Server EIR VLR HLR AuC SM-SC OMC OMC OMM (Operations & Maintenance Management) GSM interfaces NMC X.25 links GSM NETWORK / DEPARTMENT OVERVIEW / 2G NETWORK RF department RAN department Transmission department NSS department
SS Switching Systems GSM system Signaling transmission Call connections and signaling transmission AUC HLR VLR EIR Other Networks NMC and OMC MSC GMSC BSS BSC Base Station Systems BTS MS GSMOverview 00/9
GSM Network 'B' subscriber ANSWERS What happens NEXT? 'A' subscriber CALLS GSM Call Setup 10
MS Mobile Station = phone + SIM card BTS Base Transceiver Station BSC Base Station Controller HLR Home Location Register MSC Mobile services Switching Centre VLR Visitor Location Register AUC Authentication Centre Stand-alone or integrated in HLR EIR Equipment Identity Register For blacklisting stolen and unwanted equipment SMSC Short Message Service ”Support” Centre VMS Voice Messaging System PrePaid Node Hosting prepaid service system IN Intelligent Network services PSTN Public Switched Telephone Network PABX Private Automatic Branch Exchange AUC HLR A subscriber BSC BTS VMS MSC/VLR Warid EIR PrePaidNode SMSC INTERNET Telenore MSC w BSC PSTN Mobilink B subscriber 11
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 12 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 13 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 14 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 15 BTS
BSCBase Station Controller A subscriber BTS = Base Transceiver Station • The call request reaches the BSC from the BTS and is forwarded to MSC. • After call is established, the BSC will perform decoding of the call (in typical config.) 16
HLR A subscriber BSC BTS VMS Voicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 17 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 18 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 19 BTS
Checks A number. To whom is A subscriber calling?(Checks B number) Example : A subscriberhas prepaid number. MSC Mobile Switching Centre 20
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 21 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 22 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 23 BTS
Does the A subscriber have money left on his/her account? When the call is established and on-going the subscriber’s account is decremented accordingly. PrePaid Node 24
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 25 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 26 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 27 BTS
Where is the B subscriber? MSC interrogates in HLR.(HLR = Home Location Register) MSC Mobile Switching Centre 28
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 29 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 30 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 31 BTS
HLR says ’I am the home of the B subscriber and I know where he/she is right now’ (i.e. which VLR) Tells this VLR ’Give me a visitor address for this subscriber’ (Roaming Number) HLR Home Location Register 32
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 33 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 34 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 35 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 36 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 37 BTS
Hosting MSC/VLR returns TEMPORARILY assigned visitor/roaming address for B-subscriber to HLR. MSC Mobile Switching Centre 38
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 39 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 40 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 41 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 42 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 43 BTS
’Thanks for the visitor address!’ ’I will send this address to the MSC that requested for it.’ HLR Home Location Register 44
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 45 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 46 BTS
HLR MSC A subscriber BSC BTS VMSVoicemail EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 47 BTS
’Thank you, HLR!’ Speech connection path will set up now towards the MSC/VLR where the B subscriber is presently located. MSC Mobile Switching Centre 48
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 49 BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 50 BTS