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Survey of 3G and LTE. Agenda. Introduction of Telecommunication Wireless Generation 1G / 2G/ 3G and 4G GSM Architecture Call Path Mobile to Mobile 3G Requirement LTE. Introduction of Telecommunication. What is Telecommunication ?.
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Agenda • Introduction of Telecommunication • Wireless Generation 1G / 2G/ 3G and 4G • GSM Architecture • Call Path Mobile to Mobile • 3G Requirement • LTE
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. • An MS Communicate with a BTS by transmitting and receiving radio waves, which consist of electromagnetic energy.
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.
Wireless Access Evolution & Background Subscribers • Broadband • Network Simplification • Cost of Ownership • New Services • Efficiency • More Data Services required • Voice Quality • Portability • Capacity • Data Service • Coverage • Mobility 2G 4G 3G 1G Voice Broadband
1st Generation Cellular System • Widespread introduction in early 1980s. • Analogue modulation. FM • Frequency division multiple access. FDMA • 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. GMSK • 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
BASIC GSM BLOCKS A subscriber BTS MSC/VLR Warid BSC BSC BTS B subscriber
THE GSM Mobile Station (MS) The Mobile station (MS) consists of the physical equipment used by a a PLMN subscriber to connect to the network. It Comprises • Mobile Equipment (ME) • Subscriber Identity Module (SIM) The SIM stores permanent and Temporary data about the mobile, the subscriber and the network, including • International Mobile subscriber Identity (IMSI) • MSISDN number of subscriber • Authentication key and Algorithms for authentication check.
The Base Station Subsystem (BSS) The Base Station Subsystem is the system of Base station equipments (BTS and BSC), which is viewed by the MSC through a single A-interface • The BSS Consist of : • One Base station Controller (BSC) • One or more Base Transceiver (BTS) • The Purpose of BTS is to : • Provide radio access to the mobile stations • Manage the radio access aspects of the system
Base Station Subsystem • BTS Contains : • Radio Transmitter/Receiver (TRX) • Signal processing and Control equipment • Antennas and Feeder cables • The BSC : • Allocates a channel for the duration of a call • Controls the power transmitted by the BTS or MS • Generates the handover to another cell when required.
Network Switching Subsystem (NSS) • Key Elements of NSS: • Mobile switching center (MSC) with: • Visitor Location Register (VLR) • Home Location Register (HLR) • Authentication center (AuC) • Equipment Identity Register (EIR) • Gateway MSC (GMSC)
The Mobile Switching Center (MSC) • The Mobile services switching center is an exchange which performs all the switching and signaling functions for mobile stations located in a geographical area designated as the MSC area. • Functions Of MSC: • Switching calls, controlling calls . • Interface with PSTN, ISDN • Mobility management over the radio network and other networks. • Billing information.
The Visitor Location Register (VLR) • Each MSC has a VLR but a VLR may serve many MSCs. • VLR Stores data temporarily for mobiles served by the MSC. • Information stored includes : • IMSI • MSISDN • MSRN • TMSI • LAI • Supplementary service parameters.
Home Location Register (HLR) • HLR stores details of all subscribers in the network, such as: • Subscription information • Location information : MS roaming number, VLR, MSC. • MS ISDN number. • Service restrictions. • Supplementary services. • Together with the AuC, HLR checks the validity and service profile of subscribers.
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMS Voicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
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 BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
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 BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
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 BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
Where is the B subscriber? • MSC interrogates in HLR.(HLR = Home Location Register) MSC Mobile Switching Centre
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
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 BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
HLR A subscriber BSC BTS BTS B subscriber VMSVoicemail MSC EIR PrePaid SMSC PSTNFixed Network OMO
Hosting MSC/VLR returns TEMPORARILY assigned visitor/roaming address for B-subscriber to HLR. MSC Mobile Switching Centre