650 likes | 842 Views
GSM Foundation Course. Prepared by Syed Amir Abbas. GSM Operator in Pakistan. CDMA One. 14%. GSM and Others. GSM. TDMA. 11%. 75%. Source: European Mobile Communications(EMC). Vendor’s Of Operators. Core (MSC/BSC) RAN (BTS)
E N D
GSM Foundation Course Prepared by Syed Amir Abbas
CDMA One 14% GSM and Others GSM TDMA 11% 75% Source: European Mobile Communications(EMC)
Vendor’s Of Operators Core (MSC/BSC) RAN (BTS) • Mobilink Alcatel/Huawei/Siemens/NokiaMotrola/Alcatel • UfoneHuawei/Nortel Huawei / Nortel • Telenore Siemens/Nokia Siemens / Nokia • WaridEricsson Ericsson / Huawei • Zong ZTE/Huawei Ericsson/ZTE/Alcatel
Subscriber Data Base • Mobilink 31,958,597 • Telenore 17,841,074 • Ufone 17,800,424 • Warid 15,114,678 • Zong 3,662,099 Information received from PTA site survey on May 2008 (www.pta.com)
What is Telecommunication ? • Telecommunication means to change information into electronic signals for remote transmission and switching. • Fast Deployment • Saving Transmission cost. • Easy and Fast Access.
Frequency “ The frequency of a radio wave is the number of times that the wave oscillates per second." • FM Radio : 100 MHz Approx. • Television : 300 MHz Approx. • Mobile Networks : 300 – 2000 MHz Approx.
Bandwidth • In electronic communication, bandwidth is the width of the range (or band) of frequencies that an electronic signal uses on a given transmission medium. • In this usage, bandwidth is expressed in terms of the difference between the highest-frequency signal component and the lowest-frequency signal component. • Bandwidth = Highest freq – Lowest Freq
A Channel is a frequency or set of frequency which can be allocated for the transmission and reception of information. Types Of Communication Channels. Channels
What is Multiple Access • Simultaneous private use of a transmission medium by multiple independent users is called Multiple Access. • Advantages Of Multiple Access • Increased capacity • Reduced capital requirement • Decreased per user expense
FDMA, TDMA & CDMA • FDMA (Frequency Division Multiple Access) • Each user on a different frequency • A channel is a frequency • TDMA (Time Division Multiple Access) • Each user on a different window period in time slot. • CDMA (Code Division Multiple Access) • Each user uses the same frequency all the time but mixed with different distinguished code patterns.
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).
2nd Generation Cellular System • 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.
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
Abis Interface Interface
GSM Network 'B' subscriber ANSWERS What happens NEXT? 'A' subscriber CALLS GSM Call Setup
AUC HLR A subscriber BSC • 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 BTS VMS MSC/VLR Warid EIR PrePaidNode SMSC INTERNET Telenore MSC w BSC PSTN Mobilink B subscriber
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 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.)
HLR A subscriber BSC BTS VMS Voicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
Checks A number. • To whom is A subscriber calling?(Checks B number) • Example : A subscriberhas prepaid number. MSC Mobile Switching Centre
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 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
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
Where is the B subscriber? • MSC interrogates in HLR.(HLR = Home Location Register) MSC Mobile Switching Centre
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber 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
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
Hosting MSC/VLR returns TEMPORARILY assigned visitor/roaming address for B-subscriber to HLR. MSC Mobile Switching Centre
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS
HLR A subscriber BSC BTS VMSVoicemail MSC EIR PrePaid SMSC IN INTERNET MSC BSC PSTNFixed Network PSTNInternational PABX B subscriber BTS