SlideShare une entreprise Scribd logo
1  sur  135
Télécharger pour lire hors ligne
Tinniam.V.Ganesh
                        http://gigadom.wordpress.com




03/22/12   Tinniam V Ganesh                            1
Agenda
      •    Network Architecture, Network Elements
      •    Typical 2G Architecture
      •    PLMN, CS, PS, AN,CN
      •    MSC, HLR, VLR
      •    GMSC, AuC, EIR
      •    2.5 G Architecture
      •    SGSN, GGSN
      •    Recap
      •    SMS Architecture
      •    SMS Network Elements
      •    3G Network Architecture
      •    Frequency reuse
      •    Handoff
      •    Bluetooth stack
      •    WiFI
      •    Recap
      •    Quiz 3



03/22/12                                  Tinniam V Ganesh   2
Evolution of Technology




03/22/12           Tinniam V Ganesh   3
Typical 2G Architecture




03/22/12           Tinniam V Ganesh   4
Signaling in Core Network
      Based on SS7
      • ISUP and specific Application Parts
      GSM MAP and ANSI-41 services
      • Mobility, call-handling, O&M
      • Authentication, supplementary services
      • SMS, …
      Location registers for mobility management
      • HLR: home location register has permanent data
      • VLR: visitor location register keeps local copy for roamer




03/22/12                                   Tinniam V Ganesh          5
GSM 2G Architecture




03/22/12         Tinniam V Ganesh   6
Wireless definitions

      PLMN
      A Public Land Mobile Network (PLMN) is established and operated by an administration or
             Recognized Private Operating Agency (RPOA)

      The PLMN infrastructure is logically divided into
      5.    Core Network (CN)
      6.    Access Network (AN)

      Access Network (AN)
      9.    BSS in 2G systems (BTS, BSC)
      10.   RNS in 3G systems (NodeB, RNC)

      The Core Network (CN) is divided into
      13.   Circuit Switched domain
      14.   Packet Switched domain




03/22/12                                    Tinniam V Ganesh                                    7
PLMN
      Circuit Switched (CS) domain
      Access Network – BTS, BSC
      Core Network - MSC, VLR, HLR, GMSC, SMSC

      Packet Switched (PS) domain
      Access Network – BTS, BSC
      Core network - SGSN, GGSN




03/22/12                              Tinniam V Ganesh   8
GSM Architecture

      Access Network
      2.    BTS
      3.    BSC

      Core Network
      6.    MSC
      7.    HLR
      8.    VLR
      9.    AuC
      10.   EIR
      11.   SMSC
      12.   GMSC




03/22/12                   Tinniam V Ganesh   9
GSM- Access Network
      Mobile Station : The mobile communicates over the air interface with a base
         transceiver station (BTS) .
      The handset has 2 parts namely the mobile equipment and the subscriber
         identity module (SIM)
      The SIM contains the user specific information, subscriber authentication
         information and some service info.
      BTS : The BTS contains the radio transceivers that provide the radio interface to
         mobile stations. One or more BTS are connected to the Base Station
         Controller.

      BSC The BSC provides a number of functions related to
      • Radio resource (RR) management
      • Mobility management (MM) for subscribers in coverage areas

      Together the BTS and BSCs are known as the Base Station System (BSS)




03/22/12                               Tinniam V Ganesh                                   10
Mobile Switching Center (MSC)
      •    Mobile services switching center (MSC) —The MSC performs the telephony switching
           functions of the system. It controls calls to and from other telephone and data systems.
      •
      •    The Mobile-services Switching Centre (MSC) constitutes the interface between the radio
           system and the fixed networks.

      •    The MSC performs all necessary functions in order to handle the circuit switched
           services to and from the mobile stations.

      •    The Mobile-services Switching Centre is an exchange which performs all the switching
           and signalling functions for mobile stations located in a geographical area designated as
           the MSC area.
      •    Does radio resource management
      •    Does switching, routing of calls
      •    Is involved in charging




03/22/12                                     Tinniam V Ganesh                                          11
Home Location Register (HLR)
      •    Home location register (HLR) —The HLR is a database used for storage and
           management of subscriptions. The HLR is considered the most important database,

      HLR stores the following information
      • the subscription information
      • some location information enabling the charging and routing of calls towards the MSC
         where the MS is registered (e.g. the MS Roaming Number, the VLR Number, the MSC
         Number, the Local MS Identity)
      • the International Mobile Station Identity (IMSI);
      • one or more Mobile Station International ISDN number(s) (MSISDN);
      The data base contains other information such as
      • teleservices and bearer services subscription information
      • service restrictions (e.g. roaming limitation)
      • a list of all the group IDs a service subscriber is entitled to use to establish voice group
         or broadcast calls
      •    supplementary services; the HLR contains the parameters attached to these services;




03/22/12                                     Tinniam V Ganesh                                          12
Visitor Location Register (VLR)
      •    Visitor location register (VLR) —The VLR is a database that contains temporary
           information about subscribers that is needed by the MSC in order to service visiting
           subscribers.
      •    The VLR is always integrated with the MSC.
      •    When a mobile station roams into a new MSC area, the VLR connected to that MSC will
           request data about the mobile station from the HLR.
      •    Later, if the mobile station makes a call, the VLR will have the information needed for
           call setup without having to interrogate the HLR each time.

      •    The VLR stores the following information
            -   the   International Mobile Subscriber Identity (IMSI);
            -   the   Mobile Station International ISDN number (MSISDN);
            -   the   Mobile Station Roaming Number (MSRN),
            -   the   Temporary Mobile Station Identity (TMSI), if applicable;




03/22/12                                        Tinniam V Ganesh                                     13
Authentication Center (AuC)
      •    Authentication center (AUC) —A unit called the AUC provides authentication and
           encryption parameters that verify the user's identity and ensure the confidentiality of
           each call. The AUC protects network operators from different types of fraud found in
           today's cellular world.
      •    The Authentication Centre (AuC) is an entity which stores data for each mobile
           subscriber to allow the International Mobile Subscriber Identity (IMSI) to be
           authenticated and to allow communication over the radio path between the mobile
           station and the network to be ciphered.
      •    The Authentication Centre (AuC) is associated with an HLR, and stores an identity key
           for each mobile subscriber registered with the associated HLR. This key is used to
           generate:
             – data which are used to authenticate the International Mobile Subscriber Identity
                (IMSI);
             – a key used to cipher communication over the radio path between the mobile station
                and the network




03/22/12                                    Tinniam V Ganesh                                         14
Equipment Identification Register (EIR)
      •    Equipment identity register (EIR) —The EIR is a database that contains information
           about the identity of mobile equipment that prevents calls from stolen, unauthorized, or
           defective mobile stations. The AUC and EIR are implemented as stand-alone nodes or as
           a combined AUC/EIR node.
      •    The Equipment Identity Register (EIR) in the GSM system is the logical entity which is
           responsible for storing in the network the International Mobile Equipment Identities
           (IMEIs), used in the GSM system.




03/22/12                                    Tinniam V Ganesh                                          15
Gateway MSC (GMSC)
      •    If a network delivering a call to the PLMN cannot interrogate the HLR, the call is routed
           to an MSC. This MSC will interrogate the appropriate HLR and then route the call to the
           MSC where the mobile station is located. The MSC which performs the routing function
           to the actual location of the MS is called the Gateway MSC (GMSC).




03/22/12                                     Tinniam V Ganesh                                          16
03/22/12   Tinniam V Ganesh   17
2.5G Architectural details




03/22/12            Tinniam V Ganesh    18
General Packet Radio Service (GPRS)

      Core Network
      •     Serving GPRS Support Node (SGSN)
      •     Gateway GPRS Support Node (GGSN)




03/22/12                              Tinniam V Ganesh   19
Serving GPRS Support Node (SGSN)
  A Serving GPRS Support Node (SGSN) is responsible for
   the delivery of data packets from and to the mobile stations within its geographical
     service area.
   packet routing and transfer,
   mobility management (attach/detach and location management),
   logical link management, and
   authentication
   charging functions.

  The location register of the SGSN stores location information
   current cell, current VLR
   user profiles (e.g., IMSI, address(es) used in the packet data network) of all GPRS users
     registered with this SGSN.




03/22/12                                   Tinniam V Ganesh                                     20
Gateway GPRS Support Node (GGSN)

      GGSN
      • The GGSN is responsible for the interworking between the GPRS network and external
         packet switched networks,
      • The GGSN ‘hides’ the GPRS infrastructure from the external network.
      • The GGSN converts the GPRS packets coming from the SGSN into the appropriate
         packet data protocol (PDP) format 




03/22/12                                 Tinniam V Ganesh                                    21
GSM Evolution for Data Access




03/22/12              Tinniam V Ganesh     22
03/22/12   Tinniam V Ganesh   23
SMS Architecture


                                          SMS-GMSC /
                                          SMS-IWMSC                         MSC/SGSN                    MS
                SC             1.                                  3.                          5.
                           <        >                          <        >                  <        >
                                                       ↑                               ↑

                                              2.                              4.*
                                                    <




                                                                                     <
                                                   HLR                              VLR


           SC – Service Centre
           SMS-IWMSC – SMS Interworking MSC
           SMS-GMSC – Gateway MSC for SMS




03/22/12                                            Tinniam V Ganesh                                         24
SMS Network Elements
      •    Service Centre (SC): function responsible for the relaying and store‑and‑forwarding of a
           short message between an SME and an MS
      •    Gateway MSC For Short Message Service (SMS‑ GMSC): function of an
           MSC capable of receiving a short message from an SC, interrogating an HLR
           for routing information and SMS info, and delivering the short message to
           the VMSC or the SGSN of the recipient MS
      •    Interworking MSC For Short Message Service (SMS‑ IWMSC): function of
           an MSC capable of receiving a short message from within the PLMN and
           submitting it to the recipient SC




03/22/12                                     Tinniam V Ganesh                                         25
SMS Services

      Short Message Mobile Terminated

      SM MT denotes the capability of the GSM/UMTS system to transfer a short message
         submitted from the SC to one MS, and to provide information about the delivery of the
         short message either by a delivery report or a failure report

      Short Message Mobile Originated

      SM MO denotes the capability of the GSM/UMTS system to transfer a short message
      submitted by the MS to one SME via an SC, and to provide information about the delivery of
      the short message either by a delivery report or a failure




03/22/12                                   Tinniam V Ganesh                                        26
3G Rel 99 Architecture




03/22/12          Tinniam V Ganesh   27
3G Architecture
      Access Network
      Universal Terrestial Radio Access Network
      Radio Network Systems (RNS) or UTRAN
      4.    Node B
      5.    Radio Network Controller RNC

      Core Network
      •     MSC Server (UMTS)
      •     HLR
      •     VLR
      •     GMSC
      •     SMSC




03/22/12                                   Tinniam V Ganesh   28
GSM Signaling Protocol Architecture




03/22/12               Tinniam V Ganesh          29
Wireless Mobility Data

           Technology             Data capability
           GSM                    9.6/14.4 kbps
           CDMA                   9.6/14.4 kbps
           GPRS                   128 Kbps
           EDGE                   384Kbps
           WCDMA                  144 kbps vehicular
                                  384 outdoors
                                  2 Mbps indoors
           CDMA2000               144 kbps vehicular
                                  384 outdoors
                                  2 Mbps indoors




03/22/12
                               Tinniam V Ganesh        30
Wireless Technologies




03/22/12          Tinniam V Ganesh   31
Optimizing Frequency reuse




03/22/12             Tinniam V Ganesh   32
Access Network

      •    The network is divided into a number of cells or geographic coverage areas
      •    Within each cell is a base station which contains the radio transmission and
           reception equipments
      •    The coverage area of the base station depends in factors like transmit power
           of station, the height of the base station the topology of the area.
      •    Specific radio frequencies are allocated within each cell
      •    The frequencies are reused in other cells that are sufficiently far away to
           avoid interference




03/22/12                                Tinniam V Ganesh                                  33
Problem due to limited spectrum

      Spectrum allocation at 800 Mhz – 25 Mhz
      1G AMPS systems – 30 Khz/channel
      Capacity = 25 Mhz/30Khz = 833 channels
      Hence 833 simultaneous users (hardly enough)




03/22/12                             Tinniam V Ganesh   34
Frequency re-use

      Assume 832 channels available
      Divide into 4 sets = 832/4 = 208 channels per cell
      For N cells in the system total capacity = 208N (instead of 832)




03/22/12                                Tinniam V Ganesh                 35
Frequency reuse




03/22/12       Tinniam V Ganesh   36
Cell boundaries
      •    Want to cover area without gaps or overlaps:
           squares, triangles, hexagons
      •    Want to have signal strength as large as possible for all points within the cell
      •    hexagon is closest to a circle
      •    This is an idealized representation, in the real world, cell boundaries are ill-defined.




03/22/12                                      Tinniam V Ganesh                                        37
Limitations of Frequency reuse

      This is limited by
      S/I
      S – Signal strength in db
      I – Co channel interference in db




03/22/12                                  Tinniam V Ganesh   38
Methods of increasing capacity
              Cells are split to add channels




03/22/12                Tinniam V Ganesh        39
Method to increase capacity-sectoring




03/22/12                  Tinniam V Ganesh         40
Methods for increasing capacity-
                   Umbrella cells




03/22/12               Tinniam V Ganesh       41
03/22/12   Tinniam V Ganesh   42
Bluetooth
      •     Bluetooth is the name given to a new technology using short-range radio links,
           intended to replace the cable(s) connecting portable and/or fixed electronic devices. It is
           envisaged that it will allow for the replacement of the many propriety cables that
           connect one device to another with one universal radio link. Its key features are
           robustness, low complexity, low power and low cost. Designed to operate in noisy
           frequency environments, the Bluetooth radio uses a fast acknowledgement and
           frequency hopping scheme to make the link robust. Bluetooth radio modules operate in
           the unlicensed ISM band at 2.4GHz, and avoid interference from other signals by
           hopping to a new frequency after transmitting or receiving a packet. Compared with
           other systems in the same frequency band, the Bluetooth radio hops faster and uses
           shorter packets. 




03/22/12                                      Tinniam V Ganesh                                           43
Bluetooth stack




03/22/12       Tinniam V Ganesh   44
Bluetooth stack
      •    The Radio layer defines the requirements for a Bluetooth transceiver operating in the
           2.4 GHz ISM band.
      •    The Baseband layer describes the specification of the Bluetooth Link Controller (LC)
           which carries out the baseband protocols and other low-level link routines.
      •    The Link Manager Protocol (LMP) is used by the Link Managers (on either side) for
           link set-up and control.
      •    The Host Controller Interface (HCI) provides a command interface to the Baseband
           Link Controller and Link Manager, and access to hardware status and control registers.
      •    Logical Link Control and Adaptation Protocol (L2CAP) supports higher level protocol
           multiplexing, packet segmentation and reassembly, and the conveying of quality of
           service information.
      •     The RFCOMM protocol provides emulation of serial ports over the L2CAP protocol.
           The protocol is based on the ETSI standard TS 07.10.

      •    The Service Discovery Protocol (SDP) provides a means for applications to discover
           which services are provided by or available through a Bluetooth device. It also allows
           applications to determine the characteristics of those available services.




03/22/12                                     Tinniam V Ganesh                                       45
Bluetooth stack vs OSI




03/22/12           Tinniam V Ganesh   46
Bluetooth Features




03/22/12        Tinniam V Ganesh   47
Blue tooth target devices




03/22/12             Tinniam V Ganesh   48
03/22/12   Tinniam V Ganesh   49
Why WiFi ?
      1.   Setup Cost – Reduced cabling required
      2.   Flexibility – Quick and easy to setup in temporary or permanent space
      3.   Scalable – Can be expanded with growth
      4.   Freedom – You can work from any location that you can get a signal
      5.   Lower total cost of ownership – Because of affordability and low install cost
      6.   Mobile Users – Can access the Corporate network from any public hotspot using VPN




03/22/12                                   Tinniam V Ganesh                                    50
802.11b


      •    Been around the longest, well-supported, stable, and cost effective, but runs
           in the 2.4 GHz range that makes it prone to interference from other devices
           (microwave ovens, cordless phones, etc) and also has security disadvantages
      •    Has 11 channels, with 3 non-overlapping, and supports
      •    rates from 1 to 11 Mbps, but realistically about 4-5 Mbps
      •    Uses direct-sequence spread-spectrum technology




03/22/12                                 Tinniam V Ganesh                                  51
802.11g
      •    Extension of 802.11b, with the same disadvantages (security and
           interference)
      •    Has a shorter range than 802.11b
      •    Is backwards compatible with 802.11b so it allows or a smooth transition
           from 11b to 11g
      •    Flexible because multiple channels can be combined for faster throughput,
           but limited to one access point
      •    Runs at 54 Mbps, but realistically about 20-25 Mbps and about 14 Mbps
           when b associated
      •    Uses frequency division multiplexing technology




03/22/12                                Tinniam V Ganesh                               52
802.11a
      Completely different from 11b and 11g.

      3. Flexible because multiple channels can be combined for faster throughput and more
         access points can be collocated
      4. Shorter range than 11b and 11g
      5. Runs in the 5 GHz range, so less interference from other devices
      6. Has 12 channels, 8 non-overlapping, and supports rates from 6 to 54 Mbps, but
         realistically about 27 Mbps max
      7. Uses frequency division multiplexing technology




03/22/12                                  Tinniam V Ganesh                                   53
Security in WiFi

      Data Security/Encryption
      • Third Party solution - Fortress
      • Wi-Fi Protected Access (WPA)
      • Wired Equivalent Privacy (WEP)-Shared key

      Access
       WPA/WEP
       MAC Authentication – MAC address control

      Attack – Denial of Service
      • Client Protection
      • Antivirus/Firewall




03/22/12                                Tinniam V Ganesh   54
03/22/12   Tinniam V Ganesh   55
Questions ?




03/22/12    Tinniam V Ganesh   56
Quiz 3
      1. The Core Network (CN) consists of CS domain and PS domain
                    a. True         b. False
      2. The Access Network in 2G does not include
            a.      BSC b. BTS c. MSC d. RNC
      3. The 2G CS domain does not include
             a. MSC b. HLR c. AuC d. SGSN
      4.Which is not true of the HLR
               a. It is a Database b. It stores IMSI, features and services c. It is involved routing of
             calls from PSTN d. Does switching and routing
      5. Which is not true of EIR
           a. Stores IMEI          b. Used to determine if equipment is stolen c. Is a database
           d. Does radio resource management
      6. A GMSC
          a. Will query HLR for call from PSTN b. Does switching and routing c. Connected to
             PSTN d. All of the above
      7. Which is true SGSN
          a. Does packet routing & transfer b. Does mobility management c. Does charging d. all
             of the above




03/22/12                                       Tinniam V Ganesh                                            57
Quiz 3
      1. Which is not true of the speeds
          a. GSM – 64 Kbps b. GPRS – 115 kbps c. EDGE - 384 Kbps d. 3 G – 2 Mbps
      2. A SC in a SMS network is used for storing and forwarding SMS messages
          a. True            b. False
      3. The Access Network of a 3G Architecture consists of
          a. MSC, HLR, VLR        b. RNC, Node B c. SGSN, GGSN d. AUC, EIR
      4. Assume spectrum is 30 Mhz and channel bandwidth is 30 Khz then number of users is
          a. 833        b. 1000 c. 500              d. Cannot say
      5. Which is not true of Bluetooth
          a. Uses 2.4 GHz        b. Uses TDMA with TDD       c. Range 1 Km d. Gross Data rate
              of 1 km.
      6. L2CAP is not used for
          a. QoS            b. Segmentation          c.Reassembly       d. Link serup and tear
              down
      7. Security in WiFi networks uses
                   a. WPA          b. WEP        c. MAC Authentication       d. All of the above
      9. MSCs use packet switching technology
          a. True                     b. False




03/22/12                                   Tinniam V Ganesh                                        58
Call flows and Advanced wireless concepts




03/22/12                Tinniam V Ganesh               59
Agenda – Session 4
      Call flows and Advanced wireless concepts

      •    GSM Air interface
      •    GSM air interface channels
      •    Location Updating Sequence Flows
      •    Mobile origination to PSTN
      •    PSTN origination to Mobile
      •    GPRS call flow
      •    SMS call Flow
      •    Recap
      •    Inter BSC Handoff scenario
      •    UMTS
      •    Softswitch
      •    IMS Architecture
      •    3.5 G
      •    Mobile data explosion
      •    The evolution of LTE
      •    Recap
      •    Quiz 4



03/22/12                                      Tinniam V Ganesh   60
Basic Network Architecture



           BTS
                         BSC




                                                  HLR
                                        MSC
             BTS



                   BTS




03/22/12                       Tinniam V Ganesh         61
Air Interface Access techniques

      Radio spectrum is a finite resource
      The radio access method is either Frequency division duplex (FDD) or Time Division Duplex
          (TDD). The protocol method is TDMA, FDMA or CDMA
      Frequency Division Duplex (FDD) : Two separate radio channels are used for
          communicating to the base station
      • One radio channel for , f1, for downlink
      • One radio channel, f2, for uplink




                               f1 - downlink


                                                                   FDD

                            f2 - uplink



03/22/12                                  Tinniam V Ganesh                                        62
TDD

      •    Time Division Duplex (TDD)
      •    One radio channel for communicating to base station. Duplexing is done on
           time




03/22/12                               Tinniam V Ganesh                                63
Mobile radio propagation effects
      •    Signal strength
            – Must be strong enough between base station and mobile unit to maintain
               signal quality at the receiver
            – Must not be so strong as to create too much co-channel interference with
               channels in another cell using the same frequency band
      •    Fading
            – Signal propagation effects may disrupt the signal and cause errors




03/22/12                               Tinniam V Ganesh                                  64
GSM Architecture
      The interface between the BTS and BSC is known as the A-bis interface
      MSC One or more BSCs are connected to MSC. The MSC is a switch the node that controls
         call setup, call routing and many of the functions provided by the standard
         telecommunication switch
      VLR is a database that contains subscriber related information for the duration that a
         subscriber is in the coverage area of an MSC. The MSC and VLR are in the same
         platform,

      The interface between the BSC and MSC is known as A-interface
      This is a SS7 based interface using the SCCP. Above this is the BSS Application Part
          (BSSAP) which is the protocol for communicating between the BSC and the MSC.
      Since the MSC communicated with the BSC and the MS the BSSAP is divided into two parts
          the BSSMAP (BSS Management Application Part) and the Direct Transfer Application
          Part (DTAP)
      BSSMAP are messages to BSS
      DTAP messages are passed transparently thro the BSS to the NS`




03/22/12                                 Tinniam V Ganesh                                      65
GSM Protocol stack




03/22/12        Tinniam V Ganesh   66
GSM Architecture

      HLR The Home Location register contains subscriber data such has the details
          the subscriber has subscribed to . Associated with the HLR ios the
          authentication center (AuC). This is the network element that contains the
          subscriber specific authentication data such as the secret key
      For a given subscriber using a random number generated by the AuC and
          passed to the SIM via the HLR., MSC and ME.
      The SIM performs the calculation using the Ki and the authentication algorithm.
      If the result os the calculation by the SIM matches that in AuC then the
          subscriner has been authenticated




03/22/12                              Tinniam V Ganesh                                  67
GMSC

      When a call from a PSTN it arrives at a type of MSC known as the GMSC.
      The GMSC queries the HLR to determine the location of the subscriber
      The response from the HLR indicates to the GMSC when the subscriber may be
         found
      The call is forwarded by the GMSC to the MSC serving the subscriber




03/22/12                             Tinniam V Ganesh                              68
The GSM Air interface

      GSM uses TDMA with Frequency Division duples (FDD)
      GSM has been deployed in 900 Mhz, 1800 Mhz, 1900 Mhz
      In GSM a given band is divided into 200 Khz carries or RF channels in both uplink and
          downlink directions
      For eg. In standard 900 Mhz band the first uplink is 890.2 Mhz and the last uplink is 914.8
          allowing a total of 124 carriers
      914.8 Mhz – 890.2 Mhz = 24.6 Mhz/200 Khz = 123+ 1 carriers or channels
      Each RF carrier is divided into 8 time slots .
      The 8 time slots are used to carry user traffic and also control traffic




03/22/12                                   Tinniam V Ganesh                                         69
Types of Air Interface channels

      There   are 3 types of channels
      2.       Broadcast channels
      3.       Control channels
      4.       Traffic channels

      Broadcast Channels
      Frequency correction channel (FCCH) used for frequency correction of the MS
      Synchronization channel (SCH) – Broadcast by BTS and is used for mobile station for frame
            synchronization
      Broadcast Control Channel (BCCH) – Broadcast general information

      Common Control Channel (CCCH)
      Paging channel – used for paging of the mobiles
      Random Access Channel (RACH) – Only used in uplink. It is used to allocate to MS a Stand
             alone dedicated Control Channel (SDCCH) or directly to a Traffic Channel (TCH)
      Access Grant Channel (AGCH) – used in the downlink in responswe to a access request
             received on the RACH




03/22/12                                  Tinniam V Ganesh                                        70
Air interface channels
      •    Notification Channel – used to notify MS
      •    Standalone dedicated control channel (SDCCH) – Used towards MS when it is
           not used for TCH. Used for SMS. Call establishment signaling prior to
           allocation of TCH
      •    Slow Associated Control Channel (SACCH) – Power Control messages from
           BTS to MS are sent on this channel. In the uplink the MS sends
           measurement reports to the BTS
      •    Fast Associated Control Channel (FACCH) – Used to transmit non voice
           information to and from the MS




03/22/12                               Tinniam V Ganesh                                71
Air interface channel structure

      Certain time slots in a given RF carrier are allocated to control channel whereas
         the remaining are for traffic channels. For eg. Time slot 0 us for BCCH
         /CCCH . It may also carry 4 SDCCH




                BCCH/CCCH/
                             TCH   TCH   TCH      TCH       TCH   TCH   TCH
                  SDCCH




03/22/12                                 Tinniam V Ganesh                                 72
How does the cellular network know the
                mobile’s position?
      The cell phone keeps the cellular operator informed about your location.




03/22/12                               Tinniam V Ganesh                          73
Location Area
      Location Area (LA)
      • A GSM network is divided into cells. A group of cells is considered a location
         area. A mobile phone in motion keeps the network informed about changes
         in the location area. If the mobile moves from a cell in one location area to a
         cell in another location area, the mobile phone should perform a location
         area update to inform the network about the exact location of the mobile
         phone.
      Home Location Register (HLR)
      • The HLR maintains a database for the mobile subscribers. At any point of
         time, the HLR knows the address of the MSC VLR that control the current
         location area of the mobile. The HLR is informed about a location area
         update only if the location area change has resulted in a change of the MSC
         VLR.
      Mobile Switching Center - Visitor Location Register (MSC VLR)
      • The MSC VLR is responsible to switching voice calls and it also keeps track of
         the exact location area where the mobile user is present. Note that a typical
         MSC VLR will service several location areas.




03/22/12                               Tinniam V Ganesh                                    74
Location Update
      1.   When the MS is switched on it must camp on a suitable cell. This involves scanning
           the air interface to select a cell with a suitably strong signal and decoding the
           informationbroadcast by the BTS on the BCCH
      2.   The MS makes a channel request on the RACH with a cause as Location Updating
      3.   The BSS allocates an SDCCH for the MS to use. It instructs the MS to move to the
           SDCCH by sending an immediate assignment message on the AGCH
      4.   The MS then moves the SDCCH and send the location updating message. This
           contains the location area identity and the mobile identity. The mobile identity is
           either the International Mobile Subscriber Identity (IMSI) or the Temporary Mobile
           Subscriber Identity (TMSI).
      5.   This is sent through the BSS to the NSC
      6.   On receipt of the IMSI the NSC.VLR attempt to authenticate the subscriber.
      7.   If the MSC does not have authentication information then it request the HLR using
           the MAP operation Send Authetication Info.
      8.   The HLR AuC sends the MAP Return Result with up to five authentication vectors




03/22/12                                 Tinniam V Ganesh                                        75
Location Update
      Known as triplets. Each triplet contains a random number (RAND) and a signed response
           (SRES)
      2.   The MSC sends an Authentication request to the MS. This contains the RAND.
      3.   The MS performs the same calculations as were performed by the HLR/AuC and
           send the Authentication response containing the SRES parameter.
      4.   The MSC/VLR check rto make sure that the SRES from the MS matches the SRES
           from HLR/AuC
      5.   If a match is made then the MS is authenticated
      6.   At this point the MSC/VLR use te MAP Operation Update Location to inform the HLR
           of the subscriber location.
      7.   The HLR immediately sends a Cancel Location message to the VLR to remove anty
           previous location
      8.   VLR deletes any previous data
      9.   HLR uses a MAP operation to Insert Subscriber data to VLR
      10.  VLR acknowledges receipt of information
      11.  HLR sends a return result of the MAP Update Location




03/22/12                                 Tinniam V Ganesh                                     76
Location Update

      1.   On receipt of the return result the MSC sends a DTAP message Location
           Updating Accept to the MS




03/22/12                             Tinniam V Ganesh                              77
Location Update Sequence flow
                                                                                                                           Previous

                                       BSS                         MSC/VLR                    HLR/AuC                       MSC/VLR
               Channel Request




           Immediate Channel Assignment



           Location Updating Request
                                           Location Updating Request

                                                                       Send Authentication Info


                                                                        Send Authentication Info RR

                                 Authentication Request


                               Authentication Response


                                                                        Update Location

                                                                                                      Cancel Location


                                                                                                      Cancel Location RR




03/22/12                                              Tinniam V Ganesh                                                                78
Location Update Sequence flow
                                                                                                        Previous

                                     BSS                         MSC/VLR                      HLR/AuC    MSC/VLR

                                                                     Insert Subscriber data


                                                                     Insert Subscriber data RR


                                                                     Update Location RR

                             Location Update Accept


                                           Clear Command



                                           Clear Complete




           Channel release




03/22/12                                              Tinniam V Ganesh                                             79
Mobile Originated Call to PSTN
      Request Access
      • The MS sends a Channel Request (CHAN_REQ) message on the RACH. 
         The BSS responds with a radio resource assignment (IMM_ASS_CMD) on the AGCH. 
         The MS sends a Service Request (CM_SERV_REQ) message to the BSS on the SDCCH.

      Authentication
      • Before the network will provide any services to the MS, the network will require the MS
         to authenticate itself. The BSS sends an Authentication Request (AUTH_REQ) message
         to the MS. The RAND serves as the "challenge" for authentication.
      • The MS calculates the proper SRES based on the RAND that was given and sends the
         SRES to the BSS in an Authentication Response (AUTH_RESP) message.
      • The BSS verifies the SRES. If the SRES is correct then the MS is authenticated and
         allowed access to the network. The BSS will send a Service Accept (CM_SERV_ACC)
         message letting the MS know that the service request was received and processed.
      • Once authenticated, the BSS orders the MS to switch to cipher mode with the
         CIPH_MOD_CMD message.




03/22/12                                   Tinniam V Ganesh                                       80
Mobile Originated Call to PSTN
      Initial Call Setup
      • The MS will immediately switch to cipher mode and send a Cipher Mode Complete
          (CIPH_MOD_COM) message.
      • The MS then sends a Call Setup (SETUP) message to the BSS. The message includes the
          address information (MSISDN) of the called party.
      • The BSS assigns a TCH to the MS by sending an Assignment Command (ASS_CMD)
          message. This message includes which Transceiver (TRX) and which Time Slot (TS) to
          use.
      • The BSS does not actually assign a TCH to the MS until the MSC sends a Call
          Proceeding (CALL_PROC) message to the BSS indicating that the IAM has been sent.
      • The MS immediately switches to the assigned TCH. The MS sends an Assignment
          Complete (ASS_COM) message back to the BTS on the FACCH.




03/22/12                                 Tinniam V Ganesh                                      81
Mobile Originated Call to PSTN
      Call Setup
      • The MSC sends an Initial Address Message (IAM) to the GMSC. The IAM contains the
          MSISDN of the called party as the MS dialed it.
      • The MSC will also send a Call Proceeding (CALL_PROC) message down to the BSS and
          this is when the BSS would assign a TCH to the MS, as described in step 10 above.
      •  Based on the dialed number, the GMSC decides where to route the IAM within the
          PSTN.
      • The PSTN will continue to route the IAM until it reaches the correct Switching Center
          and the call routing is complete. The PSTN will then establish the call circuit and send
          an Address Complete Message (ACM) back to the GMSC.
      • The GMSC then forwards the ACM back to the responsible MSC indicating that the call
          circuit has been established




03/22/12                                    Tinniam V Ganesh                                         82
Mobile Originated Call to PSTN
    Call Establishment
    • Once the MSC receives the ACM, it sends an ALERT message to the MS
       indicating that the call is going through. The BSS sends the ALERT message
       on the FACCH. Once the MS receives the ALERT, it will generate the ringing
       sound in the earpiece. The BSS sends an alerting message the subscriber will
       hear the line ringing.
    • Once the called party answers the phone, the PSTN will send an Answer
       message to the MSC. The MSC forwards this to the MS in a Connection
       (CON) message.
    • Once the MS receives the CON message, it switches over to voice and begins
       the call. All voice traffic occurs on the assigned TCH.




03/22/12                              Tinniam V Ganesh                                83
Mobile Originated Call to PSTN
      Call Termination
      • When either the caller or the called party hangs up, the call will be disconnected. Either
          party can initiate the disconnect. In this example, the MS initiates the disconnect. The
          MS sends a Disconnect (DISC) message to the BTS on the FACCH.
      • The BSS forwards the DISC to the MSC. Once the MSC receives the DISC message, it
          sends a Release (REL) message through the GMSC to the PSTN as well as down through
          the BSS to the MS.
      • The MS responds by sending a Release Complete (REL_COM) message to the BSS on the
          FACCH. The BSS forwards the REL_COM message up to the MSC. Once the MSC
          receives the REL_COM message the call is considered ended from the call control
          perspective.
      • Although the call has ended, the BSS still has a TCH allocated to the MS. The MSC
          sends a Channel Release (CHAN_REL) message to the BSS. The BSS forwards the
          CHAN_REL message to the MS.
      • The MS responds with a DISC (LAPDm) message and returns to an idle mode. The BSS
          reallocates the channel for other call or releases the TRX. 




03/22/12                                   Tinniam V Ganesh                                          84
Mobile Originated Call to PSTN
                                                                                        PSTN
                                       BSS                                    MSC/VLR
             CM Service Request
             Service request MO call                  Complete Layer 3


                           Authentication Request


                           Authentication Response


                                                      Cipher Mode Command

           Ciphering Mode Command


           Ciphering Mode Complete
                                                       Cipher Mode Complete



                Setup


                                                       Call Proceeding


                                                       Assignment Request



           Assignment Command


           Assignment Complete


                                                     Assignment Complete



03/22/12                                                  Tinniam V Ganesh                     85
Mobile Originated Call to PSTN

                                                                      PSTN
                BSS                                 MSC/VLR



                                                          IAM


                                                                ACM


                      Alerting


                                                              ANM



                      ANM


                      Connect Acknowledge




03/22/12                         Tinniam V Ganesh                            86
PSTN to Mobile call flow
      Mobile Terminated Call
      • Route Establishment to find the MSC/VLR
      • The calling party dials the MSISDN for the mobile subscriber. The PSTN identifies the
         network (PLMN) that the dialed MSISDN belongs to and will locate a GMSC for that
         network. The PSTN sends an Initial Address message to the GMSC.
      • The GMSC forwards the MSISDN to the HLR and requests routing information for it.
         The HLR looks up the MSISDN and determines the IMSI and the SS7 address for the
         MSC/VLR that is servicing the MS.
      • The HLR then contacts the servicing MSC/VLR and asks it to assign a Mobile Station
         Routing Number (MSRN) to the call.
      • The MSC/VLR allocates the MSRN and forwards it to the HLR.
         Note: It is important to remember that the MSC/VLR assigns a MSRN to the call not to
         the MS itself.
      • The HLR forwards the MSRN as well as routing information for the servicing MSC/VLR
         to the GMSC.
      • The GMSC sends an Initial Addressing message to the servicing MSC/VLR and uses the
         MSRN to route the call to the MSC/VLR. Once the servicing MSC/VLR receives the call,
         the MSRN can be released and may be made available for reassignment.




03/22/12                                  Tinniam V Ganesh                                      87
PSTN to Mobile call flow
      Paging the Mobile Station
      • The MSC/VLR then orders all of its BSCs and BTSs to page the MS. Since the
          MSC/VLR does not know exactly which BSC and BTS the MS is monitoring, the page
          will be sent out across the entire Location Area.
      Initial Setup
      • The MS receives the Page Request (PAG_REQ) on the PCH. The MS recognizes that the
          page is intended for it, based on a TMSI or an IMSI.
      • The MS sends a Channel Request (CHAN_REQ) message on the RACH.
      • The BSS responds on the AGCH by sending an Immediate Assignment (IMM ASS)
          message which assigns an SDCCH to the MS. At this point, the network does not know
          that the MS is the one that it is paging, it only knows that this MS wants access to the
          network
      • The MS immediately switches to the assigned SDCCH and sends a Paging
          Response (PAG_RES) message on the SDCCH. This lets the network know that the MS
          is responding to its page.




03/22/12                                    Tinniam V Ganesh                                         88
PSTN to Mobile call flow
      Authentication
      • Before the network will provide any services to the MS, the network will
         require the MS to authenticate itself. The BSS sends an Authentication
         Request (AUTH_REQ) message to the MS. The RAND serves as the "challenge"
         for authentication.
      • The MS calculates the proper SRES based on the RAND that was given and
         sends the SRES to the BSS in anAuthentication Response (AUTH_RESP)
         message.
      • The BSS verifies the SRES. If the SRES is correct then the MS is
         authenticated and allowed access to the network.
      •  Once the MSC/VLR has authenticated the MS, it will order the BSS and MS
         to switch to cipher mode using the CIPH_MOD_CMD message. Once the MS
         in encryption mode, the VLR will normally assign a new TMSI to the MS.




03/22/12                            Tinniam V Ganesh                                89
PSTN to Mobile call flow
      Establishing a Channel
      • Once the MS is authenticated and in encryption mode, The MSC sends a Setup Message
          to the BSS, the BSS forwards the SETUP message to the MS on the assigned
          SDCCH.the assigned SDCCH. The SETUP message may include the Calling Line
          Identification Presentation (CLIP), which is essentially caller ID.
      •  The MS responds by sending a Call Confirmed (CALL_CON) message; which indicates
          that the MS is able to establish the requested connection. The BSS relays the message
          up to the MSC.
      Call Setup
      • The BSS then sends an Assignment Command (ASS_CMD) message to the MS on the
          assigned SDCCH. The ASS_CMD message assigns a Traffic Channel (TCH) to the MS.
      • The MS immediately switches to the TCH and responds with an Assignment
          Complete (ASS_COM) message on the FACCH. The MS begins ringing once it has
          established the TCH. 
          Remember that all signaling that occurs on the traffic channel actually occurs on a
          FACCH, which is a time slot that is stolen from the TCH and used for signaling. 
           The MS sends an ALERT message to the MSC on the FACCH. The BSS forwards the
           ALERT message through the PSTN to the calling party and the caller hears the line
           ringing.




03/22/12                                    Tinniam V Ganesh                                      90
PSTN to Mobile call flow
      Call Establishment
      • Once the user answers the call (by pressing the send button), the MS will send
          a Connect CON message to the MSC. The Connect message is forwarded back to the
          caller's switch to activate the call.
      • The MSC sends a Connect Acknowledge CON_ACK message to the MS and the call is
          established.
      •  
      Call Disconnect
      • Disconnect happens the same way as for any other call. In this example, the calling
          party initiates the disconnect.
      • When the calling party hangs up, the calling party's switch initiates a Release (REL)
          message. The message is forwarded to the serving MSC, which is then forwarded to the
          BSS.
      • The BSS will send a Disconnect (DISC) message to the MS on the FACCH.




03/22/12                                  Tinniam V Ganesh                                       91
PSTN to Mobile call flow
      •    The MS confirms release of the call by sending a Release (REL) message on the FACCH,
           which is forwarded to the MSC.
      •    The MSC sends e Release Complete (REL_COM) message through the BSS to the MS. As
           far as call control (CC) is concerned, the connection has been terminated.
      •    The MS still has a TCH assigned to it, so the BSS sends a Channel Release (CHAN_REL)
           message to the MS. This releases the radio resource on the Air Interface.
      •    The MS responds be sending a final Disconnect message and returns to idle.




03/22/12                                   Tinniam V Ganesh                                       92
PSTN to Mobile call flow
                             BSS                 MSC/VLR                       HLR                      GMSC         PSTN

                                                                                                               IAM

                                                                                    Send Routing Info (SRI)


                                                     Provide Routing Number (PRN)


                                                                 IAM (MSRN)


                                   Paging

           Paging Request


            Channel Request


           Immediate Assignment



           Paging Response

                               Paging Response


                               Cipher mode command


           Ciphering mode command


           Ciphering mode response




03/22/12                                                     Tinniam V Ganesh                                               93
PSTN to Mobile call flow
                          BSS                      MSC/VLR               HLR    GMSC         PSTN

                                 Cipher mode complete


                             Setup



                             Call confirmed


                             Assignment request



           Assignment command




           Assignment complete


            Alerting


                                                                ACM

                                                                                  ACM

               Connect


                                                               ANM

                                                                                       ANM


                                 Connect Acknowledge




03/22/12                                                     Tinniam V Ganesh                       94
PSTN to Mobile Call Flow




03/22/12           Tinniam V Ganesh   95
SMS-MO
      1. The mobile station transfers the short message to the MSC.

           2. The MSC queries the VLR to verify that the message transfer does not
           violate the supplementary services invoked or the restrictions imposed on the
           subscriber.

           3. The MSC sends the short message to the SMSC using
           the forwardShortMessage operation.

           4. The SMSC delivers the short message to the SMC.

           5. The SMSC acknowledges the successful outcome of
           the forwardShortMessage operation to the MSC.

           6. The MSC returns the outcome of the short message operation to the
           mobile station.




03/22/12                                Tinniam V Ganesh                                   96
SMS-MO




                                             SGSN
                    SMS-IWMSC
           SC                                MSC    MS
                x



                                              VLR




03/22/12                        Tinniam V Ganesh         97
SMS-MO




03/22/12    Tinniam V Ganesh   98
SMS-MT
      1.The Short message is transferred from SC to SMS-GMSC
      2.SMS-GMSC queries the HLR(SRI) and receives the routing information for the mobile
           subscriber (SRI-ACK).
      3. The SMS-GMSC sends the short message to the MSC using the forwardShortMessage
           operation(FSM).
      4. The MSC retrieves the subscriber information from the VLR. This operation may include
           an authentication procedure.
      5. The MSC transfers the short message to the mobile station.`
      6. The MSC returns the outcome of the forwardShortMessage operation to the SMS-
           GMSC(FSM-ACK).
      7. If requested by the SMC, the SMSC returns a status report indicating delivery of the
           short message.




03/22/12                                  Tinniam V Ganesh                                       99
SMS-MT




                                              SGSN
                    SMSC-GMSC                        MS
           SC                                 MSC
                x



                          HLR                  VLR




03/22/12                        Tinniam V Ganesh          100
SMS-MT




03/22/12   Tinniam V Ganesh   101
Handover

      A handover (aka handoff) is the process by which a call in progress is transferred from one
         radio channel in the same cell or different cell.
      A handover can occur
      Within a cell
      Between cells of the same BTS
      Between cells of diffferent BTS of same BSC
      Between cells of different BSC
      Between cells of different MSCs




03/22/12                                    Tinniam V Ganesh                                        102
Inter BSC handover

      Inter BSC handover
      • The BSC must involve the MSC
      • One the serving BSC determines that a handover should take place it sends a message
          handover required too the NSC
      • The message contains information about the desired target cell and the the current cell
      • The MSC analyzes the information and identifies the target BSC associated with the
          target cell
      • It then sends a Handover Request to rthe target BSC




03/22/12                                   Tinniam V Ganesh                                       103
Inter BSC handover
                           Serving                                                Target
                                                     MSC/VLR
                            BSS                                                    BSS

           Measurement Report



            Measurement Report

                                  Handover Request

                                                           Handover Request


                                                           Handover Request Ack


                                 Handover Command


             Handover Command
                                                                                       Handover Access

              MS tunes to new                              Handover Detect
              channel                                                                  Handover Complete

                                                           Handover Complete

                                  Clear Command


                                                                                     Measurement Report
                                  Clear Complete

                                                                                     Measurement Report


                                                                                     Measurement Report




03/22/12                                             Tinniam V Ganesh                                      104
Hand-off scenario




03/22/12        Tinniam V Ganesh   105
Handoff/handover

      •    Handoff (also known as handover) is the ability of the subscriber to maintain
           a call while moving within a network
      •    Handoff is used in AMPS, IS-136 and IS-95. In GSM it is called handover
      •    Handover means that subscriber is transitioned from one radio channel and/
           or time slot) to another.
      •    Depending on the two cells in question the handover can be between two
           sectors on the same station between two BSCs between 2 MSCs or even
           between networks



             Base station A
                                                                     Base station B




             Base station A
                                                                     Base station B




03/22/12                                Tinniam V Ganesh                                   106
GPRS call flow
      Attach
      •      The terminal initiates a attach process
      •      The SGSN authenticates the GPRS mobile by sending a RAND value (a random
             value).
      •      The SIM applies secret GSM algorithms on the RAND and the secret key Ki to obtain
             the session key Kc and SRES.
      •      The computed SRES value is passed to the SGSN.
      •      SGSN authenticates the response
      •      SGSN accepts the attach request
      Activate PDP context
      9.     The terminal does a PDP Activate PDP context
      10.    SGSN does a DNS Query to the DNS server to find the address of the GGSN (Global
             GPRS Support Node)
      11.    The DNS server sends the IP Address of the GGSN
      12.    The SGSN sends a Create PDP Activate context to the GGSN
      13.    The GGSN does a RADIUS authenticate to RADIUS server
      14.    The RADIUS does a authenticate response




03/22/12                                  Tinniam V Ganesh                                       107
GPRS call flow

      1.   GGSN request for dynamic IP address
      2.   The DHCP sends back a IP address
      3.   The GGSN sends a Create PDP Context Response
      4.   SGSN sends a PDP Context Accept




03/22/12                              Tinniam V Ganesh    108
GPRS call flow
                                                                                                        Radius          DHCP
                                SGSN                 DNS Server                GGSN
                                                                                                        server          server

               Attach request

            Authenticate request
            (RAND)


             Authenticate response
             (SRES)

               Attach accept

               Attach complete


               Activate PDP Context
               APN                 DNS Query (APN)

                                   DNS Response (GGSN IP)


                                               Create PDP Context

                                                                                       RADIUS Authenticate Request


                                                                                       RADIUS Authenticate Response

                                                                                                DHCP Address request

                                                                                                DHCP Address response
                                              Create PDP Context
                                              Response



           Activate PDP Context Accept




03/22/12                                                            Tinniam V Ganesh                                             109
03/22/12   Tinniam V Ganesh   110
Universal Mobile Telecommunication Service (UMTS)

      UMTS represents an evolution of GSM to support 3G capabilities
      The air interface is known as UTRAN
      UMTS uses Wideband CDMA (WCDMA)
      The air interface consists of
      5.   Node B
      6.   RNC
      Core Network
      8.   MSC Server
      9.   Media Gateway
      10. HLR
      11. VLR
      12. GMSC




03/22/12                          Tinniam V Ganesh                     111
                                                                       111
UTRAN

      UMTS Terrestrial Radio Access Network (UTRAN)
      The UTRAN consists of the Radio Network Controller (RNC) and Node B which is the base
         station
      The RNC is analogous to the GSM BSC
      The Base station is equivalent to the Node B




03/22/12                                  Tinniam V Ganesh                                    112
Wireless Network (Release 4)
                                                    PSTN                                      Gi                 Gp
                          PSTN PSTN



                                    CS-        Mc
                                                    GMSC                                    GGSN
                                    MGW             server

                                                               C
                                                                                Gc

                                                     Nc            HLR            AuC
                         PSTN
                                                                             H                     Gn
                                          Nb
                                                                                  Gr
                                                           D         EIR
                                                                                                                                           MSC Server –Mobile Switching Center Server
                                G                              F                Gf
                 VLR                      VLR                                                                                              CS-MGW – Core System Media Gateway
                                E              B                       Gs
                     B                                                                        SGSN                                         GMSC Server– Gateway Mobile Switching Center
           MSC server       Nc
                                          MSC server                                                                                       Server
                Mc
                                           Mc
                                                                                                                                           GGSN – Gateway GPRS Support Node
                                                                                                                                CN
                                                                                                                                           SGSN – Serving GPRS Support Node
           CS-MGW               CS-MGW
                          Nb                                                                                                               VLR – Visitor Location Register
                                           A
                                                      Gb                                                                                   HLR – Home Location Register
                                                                                     IuCS                     IuPS
                                                                                                                                           EIR – Equipment Identification Register
                           BSS                                                                                        RNS
                                                                                                                          Iur              AuC – Authentication Center
                                               BSC                                                      RNC                          RNC   BSC – Base Station Controller
                                           Abis                                                         Iub                                BTS – Base Transceiver System
                                    BTS              BTS                                  Node B                 Node B                    RNC – Radio Network Controller
                                                                                       cell
                                                                                                                                           RNC – Radio Network Controller
                           Um                                                             Uu                                               PSTN – Public Switched Telephone Network


                                                                                     ME

                                                                   SIM-ME i/f        or       Cu


                                                                            SIM           USIM

                                                                                                   MS



                                                                                                                            113
03/22/12                                                                                                      Tinniam V Ganesh                                                            113
3G Rel 4 Architecture - Softswicth




03/22/12                Tinniam V Ganesh        114
UMTS Network Architecture


           Node B
                                RNC




                                                           HLR
                                              Softswitch
              Node B



                       Node B




03/22/12                              Tinniam V Ganesh           115
Softswitch
      •    Softswitch denotes a component in a new architecture designed for migrating
           from a voice centric world to a data centric world.
      •    Separates signaling from the bearer traffic allowing for greater flexibility and
           efficiency
      •    Represents a move from the monolithic traditional circuit switches to a more
           distributed, open architecture and provides for greater degree of flexibility




03/22/12                                  Tinniam V Ganesh                                    116
Softswitch vs Legacy Switch



                              Signaling                                                 Signaling
                                  &                                             SS7         &                SS7

                               Control                                                   Control
                                                                                                         Application
                                                                                                          Servers

                                                                                            Packet
                                Time
             T      Line         Slot        Line        T
             D   Interfaces     Inter-    Interfaces     D
                                                                          TDM                                          TDM
             M
                               change
                                                         M
                                                                           or      Media              Media             or
                                                                           IP     Gateway            Gateway            IP



           – Monolithic                                               – Disaggregated
             (Control + Bearer Integrated)                              (Control separated from Bearer)
           – Proprietary Interfaces                                   – Open Interfaces
           – Inefficient Resource Utilization                         – Most Efficient Resource Utilization
           – Limited Scalability                                      – High Scalability
           – Higher Operating Costs                                   – Lower Capital / Operating Costs
           – Long Feature Development Intervals                       – Rapid Feature Development / 3rd Party




03/22/12                                               Tinniam V Ganesh                                                      117
IMS Architecture
          IMS is a framework of network nodes that use SIP signaling and an all IP core.
          Access agnostic. The network can be accessed by Fixed lines, mobiles, PDA etc
          Promises rich services like voice, data, video conferencing, real time gaming etc
          Uses the GPRS network
           Uses DIAMETER for AAA and database access
          Allows for Fixed Mobile Convergence




03/22/12                                     Tinniam V Ganesh                                  118
IMS Network




03/22/12     Tinniam V Ganesh   119
Market conditions
          Mobile data is growing at an
           exponential speed
          Mobile data in US & Europe expected to
           grow at a CAGR of 55% & 42%
           respectively
          Mobile data revenues expected to grow
           at a rate of 18%
          Mobile broadband connections will
           reach 1 billion by 2012 segmented
           between 3G & 4G technologies

      Highlights
      • Annual IP traffic will exceed ½ a
         zettabyte in 4 years by 2012 (10 21)
      • Internet video (Youtube, DVD sharing
         ,IPTV) account for 30% of IP traffic
      • Video communication and dynamic
         video will increase the burden on the
         network
      • Global IP traffic will double every two
         years to 2010 and beyond


03/22/12                                   Tinniam V Ganesh   120
The explosion of mobile data

      In the last 2 years
      • 1 billion new mobile subscriptions added
      • 2 billion wireless devices sold

      Device range from Mobile phones, Smartphones, Netbooks, PDAs, Wireless dongles and
         Tablets

      •    Currently there are 3.5 billion subscribers worldwide
      •    3G accounts for 350 million with 30 million added every quarter
      •    LTE forecast to reach 32.6 million by 2013




03/22/12                                    Tinniam V Ganesh                               121
The rise and rise of data




03/22/12          Tinniam V Ganesh     122
Growth in data traffic




03/22/12          Tinniam V Ganesh   123
3.5 G
      High Speed Downlink Packet Data Access (HSDPA)
      Enhanced modulation scheme over WCDMA with throughput of 14.4 Mbps
      Uses 16 QAM in addition QPSK

      High Speed Uplink Packet Data Access (HSUPA)
      Enables uplink of 1.4 Mbps upto 5.76 Mbps




                                      WCDMA           HSDPA     HSUPA
           GSM           GPRS
                                       Rel 99          Rel 5     Rel 6




                         EDGE




03/22/12                                Tinniam V Ganesh                   124
Elements of the LTE System

      LTE encompasses the evolution of
      • Radio access through E-UTRAN (eNodeB)
      • Non-radio aspects under the term System Architecture Evolution (SAE)

      Entire system composed of LTE & SAE is called Evolved Packet System (EPS)

      At a high level a LTE network is composed of
      • Access network comprised of E-UTRAN
      • Core Network called Evolved Packet Core (EPC)




03/22/12                                 Tinniam V Ganesh                         125
LTE Network Elements

           UE – User Equipment used to connect to the EPS (Evolved Packet System). This is an
           LTE capable UE

           The LTE network is comprised of a) Access Network b) Core Network

           Access network
            ENB (eNodeB) – The evolved RAN consists of single node, the eNodeB that interfaces
           with UE. The eNodeB hosts the PHY,MAC, RLC & RRC layers. It handles radio
           resource management & scheduling.

           Core Network (Evolved Packet Core-EPC)
            MME (Mobility Management Entity) – Performs paging, chooses the SGW during
           UE attach

            S-GW (Serving Gateway) – routes & and forwards user data packets

            P-GW (Packet Gateway) – provides connectivity between the UE and the external
           packet networks.




03/22/12                                   Tinniam V Ganesh                                      126
LTE Network Elements




03/22/12        Tinniam V Ganesh   127
LTE Technologies
          LTE uses OFDM (Orthogonal Frequency Division Multiplexing) for lower latency and
           better spectral efficiency

          Uses MIMO (Mulitple In Multiple Out) LTE uses several transmit & receive paths
           reducing interference with increase in spectral efficiency and throughput.

          Flatter architecture – Fewer Network elements in the LTE Evolved Packet Core(EPC).
           This results in lower latency because of lesser number of hops as compared to 3G.
           Absence of RNC like Network Element(NE).




03/22/12                                    Tinniam V Ganesh                                    128
2.5G GPRS Network Elements




03/22/12           Tinniam V Ganesh     129
The evolution of mobile technology

                Year       Standards             Technological evolution
           1.   1999       3GPP Rel 99           GSM, GPRS, EDGE, UMTS based
                                                 (2G, 2.5G, 2.75G, 3G)

           2.   2001       3GPP Rel 4            Minor upgrades to UMTS, radio
                                                 interface
           3.   2002       3GPP Rel 5            HSDPA , IMS architecture (3.5G)

           4.   2005       3GPP Rel 6            Higher speeds

           5.   2007       3GPP Rel 7            HSPA+,PoC, Voice & Video over
                                                 VOIP
           6.   2008       3GPP Rel 8            EPS (E-UTRAN/LTE) (3.99G/4G)

           7.   2009       3GPP Rel 9            Enhancement to EPS

           8.   2010       3GPP Rel 10           LTE- Advanced (4G)




03/22/12                      Tinniam V Ganesh                                     130
03/22/12   Tinniam V Ganesh   131
Questions ?




03/22/12    Tinniam V Ganesh   132
Quiz 4
    1. A call from a PSTN to wireless network comes first to the
         a. MSC                b. GMSC                     c. HLR                   d. VLR
    2. The GMSC determines where to route the call by
          a. Checking its VLR          b. Querying the HLR c. It knows where the mobile is d. none
        of the above
    4. GSM has been deployed in
         a. 800 Mhz                b. 1800 Mhz              c. 1900 Mhz               d. 2.4 Ghz
    5. Which is not an Air Interface channel
              a. Broadcast channel               b. Control channel        c. Traffic channel    d. All
        of the above
    7. SDCCH is used for
           a. SMS         b. For call establishment signaling c. both a & b d. None of the abover
    6. How does a mobile inform its whereabouts
          a. It is stored in HLR b. By doing a Location Update c. HLR is informed of location
        changes d. Both b & c
    7. While doing Location Update, authentication is done at AuC & Mobile
         a. True        b. False
    8. For Authentication MSC sends the mobile
         a. RAND           b. SRES         c. Ki      d. All of the above
    9. MS sends a channel request on
         a. RACH            b. AGCH               c. SDCCH             d. TCH

03/22/12                                     Tinniam V Ganesh                                             133
Quiz 4

      1. Which of the following is true in a PSTN to mobile call
              a. GMSC sends MSISDN to HLR b. HLR determines MSC/VLR from MSISDN c.
          MSC/VLR sends a MSRN
               d. all of the above
      4. UMTS uses
               1. TDMA with FDD            2. CDMA          3. WCDMA        4. FDMA with FDD
      12. Softswitch separates bearer from control
                  a. True         b. False
      13. Which is not true for softswitch
             a. Uses time slot interchange b. uses media gateway c. does packet switching d.
          none of the above
      14. Which of the following is true for IMS
           a. Uses SIP signaling b. Uses an IP Core c. Uses DIAMETER d. all of the above
      15. LTE is made of the following
            a. BTS, BSC, MSC             b. Node B, RNC, Softswitch   c. Node B, RNC, SGSN,
          GGSN         d. eNodeB, MME, SGW, GGW




03/22/12                                 Tinniam V Ganesh                                      134
Good luck & thank
           You !!!



           Tinniam V Ganesh
           tvganesh.85@gmail.com
           Read my blogs: http://gigadom.wordpress.com/
                          http://savvydom.wordpress.com/




03/22/12          Tinniam V Ganesh                         135

Contenu connexe

Tendances (20)

Gsm signaling
Gsm signalingGsm signaling
Gsm signaling
 
Tutorial cellular mobile communication
Tutorial cellular mobile communicationTutorial cellular mobile communication
Tutorial cellular mobile communication
 
Gsm system and radio frequency
Gsm system and radio frequency Gsm system and radio frequency
Gsm system and radio frequency
 
Coral gsm cdma gateway
Coral gsm cdma gatewayCoral gsm cdma gateway
Coral gsm cdma gateway
 
Call flow in gsm
Call flow in gsmCall flow in gsm
Call flow in gsm
 
GSM Network - Distributed Service Model
GSM Network - Distributed Service ModelGSM Network - Distributed Service Model
GSM Network - Distributed Service Model
 
Cellular communication
Cellular communicationCellular communication
Cellular communication
 
Digital cellular networks GSM
Digital cellular networks GSMDigital cellular networks GSM
Digital cellular networks GSM
 
GSM
GSMGSM
GSM
 
Gsm
GsmGsm
Gsm
 
Gsm
GsmGsm
Gsm
 
Gsm Originating Call Flow
Gsm Originating Call FlowGsm Originating Call Flow
Gsm Originating Call Flow
 
Gsm air interface
Gsm air interface Gsm air interface
Gsm air interface
 
Gsm signaling protocol
Gsm signaling protocolGsm signaling protocol
Gsm signaling protocol
 
Gsm network
Gsm networkGsm network
Gsm network
 
GSM, Cell Planning & Frequency Reuse
GSM, Cell Planning & Frequency ReuseGSM, Cell Planning & Frequency Reuse
GSM, Cell Planning & Frequency Reuse
 
Gsm
GsmGsm
Gsm
 
Call flows
Call flowsCall flows
Call flows
 
Full gsm overview (modified)
Full gsm overview  (modified)Full gsm overview  (modified)
Full gsm overview (modified)
 
Ch5 gsm network protocols
Ch5 gsm network protocolsCh5 gsm network protocols
Ch5 gsm network protocols
 

Similaire à Wireless technologies - Part 2

GSM Archiitrcture - Ufone PPT
GSM Archiitrcture - Ufone PPTGSM Archiitrcture - Ufone PPT
GSM Archiitrcture - Ufone PPTWaqas Ahmed Nawaz
 
Global system for mobile communication
Global system for mobile communicationGlobal system for mobile communication
Global system for mobile communicationbhartis3
 
Global system for mobile communication(GSM)
Global system for mobile communication(GSM)Global system for mobile communication(GSM)
Global system for mobile communication(GSM)Jay Nagar
 
Wireless Cellular Communication_Mudule2_Dr.Shivashankar.pdf
Wireless Cellular Communication_Mudule2_Dr.Shivashankar.pdfWireless Cellular Communication_Mudule2_Dr.Shivashankar.pdf
Wireless Cellular Communication_Mudule2_Dr.Shivashankar.pdfDr. Shivashankar
 
Gsm architecture
Gsm architectureGsm architecture
Gsm architecturesaqlain11
 
Gsm review note by zemaryali
Gsm review note by zemaryaliGsm review note by zemaryali
Gsm review note by zemaryaliZaryal Social
 
CELLULAR COMMUNICATION SYSTEM
CELLULAR COMMUNICATION SYSTEMCELLULAR COMMUNICATION SYSTEM
CELLULAR COMMUNICATION SYSTEMSuryani Ilias
 
Day 02 gsm-network_architecture
Day 02 gsm-network_architectureDay 02 gsm-network_architecture
Day 02 gsm-network_architecturehaider04
 
System Introduction
System IntroductionSystem Introduction
System IntroductionSokunth Che
 
E4-E5_CM_01_BASICS OF MOBILE.ppt
E4-E5_CM_01_BASICS OF MOBILE.pptE4-E5_CM_01_BASICS OF MOBILE.ppt
E4-E5_CM_01_BASICS OF MOBILE.pptAGMEBI
 
presentation on gsm architecture and fixed assignment
presentation on gsm architecture and fixed assignmentpresentation on gsm architecture and fixed assignment
presentation on gsm architecture and fixed assignmentFabiha Ain
 
GSM TECHNOLOGIES-ARCHITECTURE.pptx
GSM TECHNOLOGIES-ARCHITECTURE.pptxGSM TECHNOLOGIES-ARCHITECTURE.pptx
GSM TECHNOLOGIES-ARCHITECTURE.pptxANIKETKUMARSHARMA3
 
GSM.pptx-MorelaHTENG.pptx
GSM.pptx-MorelaHTENG.pptxGSM.pptx-MorelaHTENG.pptx
GSM.pptx-MorelaHTENG.pptxPoojaG86
 

Similaire à Wireless technologies - Part 2 (20)

GSM Archiitrcture - Ufone PPT
GSM Archiitrcture - Ufone PPTGSM Archiitrcture - Ufone PPT
GSM Archiitrcture - Ufone PPT
 
Global system for mobile communication
Global system for mobile communicationGlobal system for mobile communication
Global system for mobile communication
 
Introduction to GSM
Introduction to GSMIntroduction to GSM
Introduction to GSM
 
Global system for mobile communication(GSM)
Global system for mobile communication(GSM)Global system for mobile communication(GSM)
Global system for mobile communication(GSM)
 
Wireless Cellular Communication_Mudule2_Dr.Shivashankar.pdf
Wireless Cellular Communication_Mudule2_Dr.Shivashankar.pdfWireless Cellular Communication_Mudule2_Dr.Shivashankar.pdf
Wireless Cellular Communication_Mudule2_Dr.Shivashankar.pdf
 
Gsm architecture
Gsm architectureGsm architecture
Gsm architecture
 
Gsm architecture
Gsm architectureGsm architecture
Gsm architecture
 
Gsm review note by zemaryali
Gsm review note by zemaryaliGsm review note by zemaryali
Gsm review note by zemaryali
 
CELLULAR COMMUNICATION SYSTEM
CELLULAR COMMUNICATION SYSTEMCELLULAR COMMUNICATION SYSTEM
CELLULAR COMMUNICATION SYSTEM
 
Day 02 gsm-network_architecture
Day 02 gsm-network_architectureDay 02 gsm-network_architecture
Day 02 gsm-network_architecture
 
System Introduction
System IntroductionSystem Introduction
System Introduction
 
E4-E5_CM_01_BASICS OF MOBILE.ppt
E4-E5_CM_01_BASICS OF MOBILE.pptE4-E5_CM_01_BASICS OF MOBILE.ppt
E4-E5_CM_01_BASICS OF MOBILE.ppt
 
presentation on gsm architecture and fixed assignment
presentation on gsm architecture and fixed assignmentpresentation on gsm architecture and fixed assignment
presentation on gsm architecture and fixed assignment
 
Gsm architecture
Gsm architectureGsm architecture
Gsm architecture
 
GSM_SANAT_Ppt
GSM_SANAT_PptGSM_SANAT_Ppt
GSM_SANAT_Ppt
 
Gsm
GsmGsm
Gsm
 
Gsm architecture
Gsm architectureGsm architecture
Gsm architecture
 
GSM TECHNOLOGIES-ARCHITECTURE.pptx
GSM TECHNOLOGIES-ARCHITECTURE.pptxGSM TECHNOLOGIES-ARCHITECTURE.pptx
GSM TECHNOLOGIES-ARCHITECTURE.pptx
 
GSM.pptx-MorelaHTENG.pptx
GSM.pptx-MorelaHTENG.pptxGSM.pptx-MorelaHTENG.pptx
GSM.pptx-MorelaHTENG.pptx
 
report
reportreport
report
 

Plus de Tinniam V Ganesh (TV)

Plus de Tinniam V Ganesh (TV) (9)

Internet of Things - TEDx talk
Internet of Things - TEDx talkInternet of Things - TEDx talk
Internet of Things - TEDx talk
 
Long Term Evolution (LTE) -
Long Term Evolution (LTE) -Long Term Evolution (LTE) -
Long Term Evolution (LTE) -
 
Design principles of scalable, distributed systems
Design principles of scalable, distributed systemsDesign principles of scalable, distributed systems
Design principles of scalable, distributed systems
 
Cloud Computing
Cloud ComputingCloud Computing
Cloud Computing
 
Intelligent networks, camel_services_and_applications_v1
Intelligent networks, camel_services_and_applications_v1Intelligent networks, camel_services_and_applications_v1
Intelligent networks, camel_services_and_applications_v1
 
Wireless technologies - Part 1
Wireless technologies - Part 1Wireless technologies - Part 1
Wireless technologies - Part 1
 
Seven habits of highly effective people
Seven habits of highly effective peopleSeven habits of highly effective people
Seven habits of highly effective people
 
Signaling system 7 (ss7)
Signaling system 7 (ss7)Signaling system 7 (ss7)
Signaling system 7 (ss7)
 
Technology trends that will shape our future
Technology trends that will shape our futureTechnology trends that will shape our future
Technology trends that will shape our future
 

Dernier

UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7DianaGray10
 
AI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity WebinarAI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity WebinarPrecisely
 
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfJamie (Taka) Wang
 
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...Aggregage
 
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfIaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfDaniel Santiago Silva Capera
 
IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019
IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019
IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019IES VE
 
Designing A Time bound resource download URL
Designing A Time bound resource download URLDesigning A Time bound resource download URL
Designing A Time bound resource download URLRuncy Oommen
 
Building AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxBuilding AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxUdaiappa Ramachandran
 
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDEADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDELiveplex
 
Machine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdfMachine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdfAijun Zhang
 
Basic Building Blocks of Internet of Things.
Basic Building Blocks of Internet of Things.Basic Building Blocks of Internet of Things.
Basic Building Blocks of Internet of Things.YounusS2
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintMahmoud Rabie
 
UiPath Solutions Management Preview - Northern CA Chapter - March 22.pdf
UiPath Solutions Management Preview - Northern CA Chapter - March 22.pdfUiPath Solutions Management Preview - Northern CA Chapter - March 22.pdf
UiPath Solutions Management Preview - Northern CA Chapter - March 22.pdfDianaGray10
 
Igniting Next Level Productivity with AI-Infused Data Integration Workflows
Igniting Next Level Productivity with AI-Infused Data Integration WorkflowsIgniting Next Level Productivity with AI-Infused Data Integration Workflows
Igniting Next Level Productivity with AI-Infused Data Integration WorkflowsSafe Software
 
Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Brian Pichman
 
COMPUTER 10 Lesson 8 - Building a Website
COMPUTER 10 Lesson 8 - Building a WebsiteCOMPUTER 10 Lesson 8 - Building a Website
COMPUTER 10 Lesson 8 - Building a Websitedgelyza
 
VoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBXVoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBXTarek Kalaji
 
20230202 - Introduction to tis-py
20230202 - Introduction to tis-py20230202 - Introduction to tis-py
20230202 - Introduction to tis-pyJamie (Taka) Wang
 
Bird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystemBird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystemAsko Soukka
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6DianaGray10
 

Dernier (20)

UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7
 
AI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity WebinarAI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity Webinar
 
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
 
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
 
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfIaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
 
IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019
IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019
IESVE Software for Florida Code Compliance Using ASHRAE 90.1-2019
 
Designing A Time bound resource download URL
Designing A Time bound resource download URLDesigning A Time bound resource download URL
Designing A Time bound resource download URL
 
Building AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxBuilding AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptx
 
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDEADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
 
Machine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdfMachine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdf
 
Basic Building Blocks of Internet of Things.
Basic Building Blocks of Internet of Things.Basic Building Blocks of Internet of Things.
Basic Building Blocks of Internet of Things.
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership Blueprint
 
UiPath Solutions Management Preview - Northern CA Chapter - March 22.pdf
UiPath Solutions Management Preview - Northern CA Chapter - March 22.pdfUiPath Solutions Management Preview - Northern CA Chapter - March 22.pdf
UiPath Solutions Management Preview - Northern CA Chapter - March 22.pdf
 
Igniting Next Level Productivity with AI-Infused Data Integration Workflows
Igniting Next Level Productivity with AI-Infused Data Integration WorkflowsIgniting Next Level Productivity with AI-Infused Data Integration Workflows
Igniting Next Level Productivity with AI-Infused Data Integration Workflows
 
Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )
 
COMPUTER 10 Lesson 8 - Building a Website
COMPUTER 10 Lesson 8 - Building a WebsiteCOMPUTER 10 Lesson 8 - Building a Website
COMPUTER 10 Lesson 8 - Building a Website
 
VoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBXVoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBX
 
20230202 - Introduction to tis-py
20230202 - Introduction to tis-py20230202 - Introduction to tis-py
20230202 - Introduction to tis-py
 
Bird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystemBird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystem
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6
 

Wireless technologies - Part 2

  • 1. Tinniam.V.Ganesh http://gigadom.wordpress.com 03/22/12 Tinniam V Ganesh 1
  • 2. Agenda • Network Architecture, Network Elements • Typical 2G Architecture • PLMN, CS, PS, AN,CN • MSC, HLR, VLR • GMSC, AuC, EIR • 2.5 G Architecture • SGSN, GGSN • Recap • SMS Architecture • SMS Network Elements • 3G Network Architecture • Frequency reuse • Handoff • Bluetooth stack • WiFI • Recap • Quiz 3 03/22/12 Tinniam V Ganesh 2
  • 3. Evolution of Technology 03/22/12 Tinniam V Ganesh 3
  • 4. Typical 2G Architecture 03/22/12 Tinniam V Ganesh 4
  • 5. Signaling in Core Network Based on SS7 • ISUP and specific Application Parts GSM MAP and ANSI-41 services • Mobility, call-handling, O&M • Authentication, supplementary services • SMS, … Location registers for mobility management • HLR: home location register has permanent data • VLR: visitor location register keeps local copy for roamer 03/22/12 Tinniam V Ganesh 5
  • 6. GSM 2G Architecture 03/22/12 Tinniam V Ganesh 6
  • 7. Wireless definitions PLMN A Public Land Mobile Network (PLMN) is established and operated by an administration or Recognized Private Operating Agency (RPOA) The PLMN infrastructure is logically divided into 5. Core Network (CN) 6. Access Network (AN) Access Network (AN) 9. BSS in 2G systems (BTS, BSC) 10. RNS in 3G systems (NodeB, RNC) The Core Network (CN) is divided into 13. Circuit Switched domain 14. Packet Switched domain 03/22/12 Tinniam V Ganesh 7
  • 8. PLMN Circuit Switched (CS) domain Access Network – BTS, BSC Core Network - MSC, VLR, HLR, GMSC, SMSC Packet Switched (PS) domain Access Network – BTS, BSC Core network - SGSN, GGSN 03/22/12 Tinniam V Ganesh 8
  • 9. GSM Architecture Access Network 2. BTS 3. BSC Core Network 6. MSC 7. HLR 8. VLR 9. AuC 10. EIR 11. SMSC 12. GMSC 03/22/12 Tinniam V Ganesh 9
  • 10. GSM- Access Network Mobile Station : The mobile communicates over the air interface with a base transceiver station (BTS) . The handset has 2 parts namely the mobile equipment and the subscriber identity module (SIM) The SIM contains the user specific information, subscriber authentication information and some service info. BTS : The BTS contains the radio transceivers that provide the radio interface to mobile stations. One or more BTS are connected to the Base Station Controller. BSC The BSC provides a number of functions related to • Radio resource (RR) management • Mobility management (MM) for subscribers in coverage areas Together the BTS and BSCs are known as the Base Station System (BSS) 03/22/12 Tinniam V Ganesh 10
  • 11. Mobile Switching Center (MSC) • Mobile services switching center (MSC) —The MSC performs the telephony switching functions of the system. It controls calls to and from other telephone and data systems. • • The Mobile-services Switching Centre (MSC) constitutes the interface between the radio system and the fixed networks. • The MSC performs all necessary functions in order to handle the circuit switched services to and from the mobile stations. • The Mobile-services Switching Centre is an exchange which performs all the switching and signalling functions for mobile stations located in a geographical area designated as the MSC area. • Does radio resource management • Does switching, routing of calls • Is involved in charging 03/22/12 Tinniam V Ganesh 11
  • 12. Home Location Register (HLR) • Home location register (HLR) —The HLR is a database used for storage and management of subscriptions. The HLR is considered the most important database, HLR stores the following information • the subscription information • some location information enabling the charging and routing of calls towards the MSC where the MS is registered (e.g. the MS Roaming Number, the VLR Number, the MSC Number, the Local MS Identity) • the International Mobile Station Identity (IMSI); • one or more Mobile Station International ISDN number(s) (MSISDN); The data base contains other information such as • teleservices and bearer services subscription information • service restrictions (e.g. roaming limitation) • a list of all the group IDs a service subscriber is entitled to use to establish voice group or broadcast calls • supplementary services; the HLR contains the parameters attached to these services; 03/22/12 Tinniam V Ganesh 12
  • 13. Visitor Location Register (VLR) • Visitor location register (VLR) —The VLR is a database that contains temporary information about subscribers that is needed by the MSC in order to service visiting subscribers. • The VLR is always integrated with the MSC. • When a mobile station roams into a new MSC area, the VLR connected to that MSC will request data about the mobile station from the HLR. • Later, if the mobile station makes a call, the VLR will have the information needed for call setup without having to interrogate the HLR each time. • The VLR stores the following information - the International Mobile Subscriber Identity (IMSI); - the Mobile Station International ISDN number (MSISDN); - the Mobile Station Roaming Number (MSRN), - the Temporary Mobile Station Identity (TMSI), if applicable; 03/22/12 Tinniam V Ganesh 13
  • 14. Authentication Center (AuC) • Authentication center (AUC) —A unit called the AUC provides authentication and encryption parameters that verify the user's identity and ensure the confidentiality of each call. The AUC protects network operators from different types of fraud found in today's cellular world. • The Authentication Centre (AuC) is an entity which stores data for each mobile subscriber to allow the International Mobile Subscriber Identity (IMSI) to be authenticated and to allow communication over the radio path between the mobile station and the network to be ciphered. • The Authentication Centre (AuC) is associated with an HLR, and stores an identity key for each mobile subscriber registered with the associated HLR. This key is used to generate: – data which are used to authenticate the International Mobile Subscriber Identity (IMSI); – a key used to cipher communication over the radio path between the mobile station and the network 03/22/12 Tinniam V Ganesh 14
  • 15. Equipment Identification Register (EIR) • Equipment identity register (EIR) —The EIR is a database that contains information about the identity of mobile equipment that prevents calls from stolen, unauthorized, or defective mobile stations. The AUC and EIR are implemented as stand-alone nodes or as a combined AUC/EIR node. • The Equipment Identity Register (EIR) in the GSM system is the logical entity which is responsible for storing in the network the International Mobile Equipment Identities (IMEIs), used in the GSM system. 03/22/12 Tinniam V Ganesh 15
  • 16. Gateway MSC (GMSC) • If a network delivering a call to the PLMN cannot interrogate the HLR, the call is routed to an MSC. This MSC will interrogate the appropriate HLR and then route the call to the MSC where the mobile station is located. The MSC which performs the routing function to the actual location of the MS is called the Gateway MSC (GMSC). 03/22/12 Tinniam V Ganesh 16
  • 17. 03/22/12 Tinniam V Ganesh 17
  • 18. 2.5G Architectural details 03/22/12 Tinniam V Ganesh 18
  • 19. General Packet Radio Service (GPRS) Core Network • Serving GPRS Support Node (SGSN) • Gateway GPRS Support Node (GGSN) 03/22/12 Tinniam V Ganesh 19
  • 20. Serving GPRS Support Node (SGSN) A Serving GPRS Support Node (SGSN) is responsible for  the delivery of data packets from and to the mobile stations within its geographical service area.  packet routing and transfer,  mobility management (attach/detach and location management),  logical link management, and  authentication  charging functions. The location register of the SGSN stores location information  current cell, current VLR  user profiles (e.g., IMSI, address(es) used in the packet data network) of all GPRS users registered with this SGSN. 03/22/12 Tinniam V Ganesh 20
  • 21. Gateway GPRS Support Node (GGSN) GGSN • The GGSN is responsible for the interworking between the GPRS network and external packet switched networks, • The GGSN ‘hides’ the GPRS infrastructure from the external network. • The GGSN converts the GPRS packets coming from the SGSN into the appropriate packet data protocol (PDP) format  03/22/12 Tinniam V Ganesh 21
  • 22. GSM Evolution for Data Access 03/22/12 Tinniam V Ganesh 22
  • 23. 03/22/12 Tinniam V Ganesh 23
  • 24. SMS Architecture SMS-GMSC / SMS-IWMSC MSC/SGSN MS SC 1. 3. 5. < > < > < > ↑ ↑ 2. 4.* < < HLR VLR SC – Service Centre SMS-IWMSC – SMS Interworking MSC SMS-GMSC – Gateway MSC for SMS 03/22/12 Tinniam V Ganesh 24
  • 25. SMS Network Elements • Service Centre (SC): function responsible for the relaying and store‑and‑forwarding of a short message between an SME and an MS • Gateway MSC For Short Message Service (SMS‑ GMSC): function of an MSC capable of receiving a short message from an SC, interrogating an HLR for routing information and SMS info, and delivering the short message to the VMSC or the SGSN of the recipient MS • Interworking MSC For Short Message Service (SMS‑ IWMSC): function of an MSC capable of receiving a short message from within the PLMN and submitting it to the recipient SC 03/22/12 Tinniam V Ganesh 25
  • 26. SMS Services Short Message Mobile Terminated SM MT denotes the capability of the GSM/UMTS system to transfer a short message submitted from the SC to one MS, and to provide information about the delivery of the short message either by a delivery report or a failure report Short Message Mobile Originated SM MO denotes the capability of the GSM/UMTS system to transfer a short message submitted by the MS to one SME via an SC, and to provide information about the delivery of the short message either by a delivery report or a failure 03/22/12 Tinniam V Ganesh 26
  • 27. 3G Rel 99 Architecture 03/22/12 Tinniam V Ganesh 27
  • 28. 3G Architecture Access Network Universal Terrestial Radio Access Network Radio Network Systems (RNS) or UTRAN 4. Node B 5. Radio Network Controller RNC Core Network • MSC Server (UMTS) • HLR • VLR • GMSC • SMSC 03/22/12 Tinniam V Ganesh 28
  • 29. GSM Signaling Protocol Architecture 03/22/12 Tinniam V Ganesh 29
  • 30. Wireless Mobility Data Technology Data capability GSM 9.6/14.4 kbps CDMA 9.6/14.4 kbps GPRS 128 Kbps EDGE 384Kbps WCDMA 144 kbps vehicular 384 outdoors 2 Mbps indoors CDMA2000 144 kbps vehicular 384 outdoors 2 Mbps indoors 03/22/12 Tinniam V Ganesh 30
  • 31. Wireless Technologies 03/22/12 Tinniam V Ganesh 31
  • 32. Optimizing Frequency reuse 03/22/12 Tinniam V Ganesh 32
  • 33. Access Network • The network is divided into a number of cells or geographic coverage areas • Within each cell is a base station which contains the radio transmission and reception equipments • The coverage area of the base station depends in factors like transmit power of station, the height of the base station the topology of the area. • Specific radio frequencies are allocated within each cell • The frequencies are reused in other cells that are sufficiently far away to avoid interference 03/22/12 Tinniam V Ganesh 33
  • 34. Problem due to limited spectrum Spectrum allocation at 800 Mhz – 25 Mhz 1G AMPS systems – 30 Khz/channel Capacity = 25 Mhz/30Khz = 833 channels Hence 833 simultaneous users (hardly enough) 03/22/12 Tinniam V Ganesh 34
  • 35. Frequency re-use Assume 832 channels available Divide into 4 sets = 832/4 = 208 channels per cell For N cells in the system total capacity = 208N (instead of 832) 03/22/12 Tinniam V Ganesh 35
  • 36. Frequency reuse 03/22/12 Tinniam V Ganesh 36
  • 37. Cell boundaries • Want to cover area without gaps or overlaps: squares, triangles, hexagons • Want to have signal strength as large as possible for all points within the cell • hexagon is closest to a circle • This is an idealized representation, in the real world, cell boundaries are ill-defined. 03/22/12 Tinniam V Ganesh 37
  • 38. Limitations of Frequency reuse This is limited by S/I S – Signal strength in db I – Co channel interference in db 03/22/12 Tinniam V Ganesh 38
  • 39. Methods of increasing capacity Cells are split to add channels 03/22/12 Tinniam V Ganesh 39
  • 40. Method to increase capacity-sectoring 03/22/12 Tinniam V Ganesh 40
  • 41. Methods for increasing capacity- Umbrella cells 03/22/12 Tinniam V Ganesh 41
  • 42. 03/22/12 Tinniam V Ganesh 42
  • 43. Bluetooth •  Bluetooth is the name given to a new technology using short-range radio links, intended to replace the cable(s) connecting portable and/or fixed electronic devices. It is envisaged that it will allow for the replacement of the many propriety cables that connect one device to another with one universal radio link. Its key features are robustness, low complexity, low power and low cost. Designed to operate in noisy frequency environments, the Bluetooth radio uses a fast acknowledgement and frequency hopping scheme to make the link robust. Bluetooth radio modules operate in the unlicensed ISM band at 2.4GHz, and avoid interference from other signals by hopping to a new frequency after transmitting or receiving a packet. Compared with other systems in the same frequency band, the Bluetooth radio hops faster and uses shorter packets.  03/22/12 Tinniam V Ganesh 43
  • 44. Bluetooth stack 03/22/12 Tinniam V Ganesh 44
  • 45. Bluetooth stack • The Radio layer defines the requirements for a Bluetooth transceiver operating in the 2.4 GHz ISM band. • The Baseband layer describes the specification of the Bluetooth Link Controller (LC) which carries out the baseband protocols and other low-level link routines. • The Link Manager Protocol (LMP) is used by the Link Managers (on either side) for link set-up and control. • The Host Controller Interface (HCI) provides a command interface to the Baseband Link Controller and Link Manager, and access to hardware status and control registers. • Logical Link Control and Adaptation Protocol (L2CAP) supports higher level protocol multiplexing, packet segmentation and reassembly, and the conveying of quality of service information. • The RFCOMM protocol provides emulation of serial ports over the L2CAP protocol. The protocol is based on the ETSI standard TS 07.10. • The Service Discovery Protocol (SDP) provides a means for applications to discover which services are provided by or available through a Bluetooth device. It also allows applications to determine the characteristics of those available services. 03/22/12 Tinniam V Ganesh 45
  • 46. Bluetooth stack vs OSI 03/22/12 Tinniam V Ganesh 46
  • 47. Bluetooth Features 03/22/12 Tinniam V Ganesh 47
  • 48. Blue tooth target devices 03/22/12 Tinniam V Ganesh 48
  • 49. 03/22/12 Tinniam V Ganesh 49
  • 50. Why WiFi ? 1. Setup Cost – Reduced cabling required 2. Flexibility – Quick and easy to setup in temporary or permanent space 3. Scalable – Can be expanded with growth 4. Freedom – You can work from any location that you can get a signal 5. Lower total cost of ownership – Because of affordability and low install cost 6. Mobile Users – Can access the Corporate network from any public hotspot using VPN 03/22/12 Tinniam V Ganesh 50
  • 51. 802.11b • Been around the longest, well-supported, stable, and cost effective, but runs in the 2.4 GHz range that makes it prone to interference from other devices (microwave ovens, cordless phones, etc) and also has security disadvantages • Has 11 channels, with 3 non-overlapping, and supports • rates from 1 to 11 Mbps, but realistically about 4-5 Mbps • Uses direct-sequence spread-spectrum technology 03/22/12 Tinniam V Ganesh 51
  • 52. 802.11g • Extension of 802.11b, with the same disadvantages (security and interference) • Has a shorter range than 802.11b • Is backwards compatible with 802.11b so it allows or a smooth transition from 11b to 11g • Flexible because multiple channels can be combined for faster throughput, but limited to one access point • Runs at 54 Mbps, but realistically about 20-25 Mbps and about 14 Mbps when b associated • Uses frequency division multiplexing technology 03/22/12 Tinniam V Ganesh 52
  • 53. 802.11a Completely different from 11b and 11g. 3. Flexible because multiple channels can be combined for faster throughput and more access points can be collocated 4. Shorter range than 11b and 11g 5. Runs in the 5 GHz range, so less interference from other devices 6. Has 12 channels, 8 non-overlapping, and supports rates from 6 to 54 Mbps, but realistically about 27 Mbps max 7. Uses frequency division multiplexing technology 03/22/12 Tinniam V Ganesh 53
  • 54. Security in WiFi Data Security/Encryption • Third Party solution - Fortress • Wi-Fi Protected Access (WPA) • Wired Equivalent Privacy (WEP)-Shared key Access  WPA/WEP  MAC Authentication – MAC address control Attack – Denial of Service • Client Protection • Antivirus/Firewall 03/22/12 Tinniam V Ganesh 54
  • 55. 03/22/12 Tinniam V Ganesh 55
  • 56. Questions ? 03/22/12 Tinniam V Ganesh 56
  • 57. Quiz 3 1. The Core Network (CN) consists of CS domain and PS domain a. True b. False 2. The Access Network in 2G does not include a. BSC b. BTS c. MSC d. RNC 3. The 2G CS domain does not include a. MSC b. HLR c. AuC d. SGSN 4.Which is not true of the HLR a. It is a Database b. It stores IMSI, features and services c. It is involved routing of calls from PSTN d. Does switching and routing 5. Which is not true of EIR a. Stores IMEI b. Used to determine if equipment is stolen c. Is a database d. Does radio resource management 6. A GMSC a. Will query HLR for call from PSTN b. Does switching and routing c. Connected to PSTN d. All of the above 7. Which is true SGSN a. Does packet routing & transfer b. Does mobility management c. Does charging d. all of the above 03/22/12 Tinniam V Ganesh 57
  • 58. Quiz 3 1. Which is not true of the speeds a. GSM – 64 Kbps b. GPRS – 115 kbps c. EDGE - 384 Kbps d. 3 G – 2 Mbps 2. A SC in a SMS network is used for storing and forwarding SMS messages a. True b. False 3. The Access Network of a 3G Architecture consists of a. MSC, HLR, VLR b. RNC, Node B c. SGSN, GGSN d. AUC, EIR 4. Assume spectrum is 30 Mhz and channel bandwidth is 30 Khz then number of users is a. 833 b. 1000 c. 500 d. Cannot say 5. Which is not true of Bluetooth a. Uses 2.4 GHz b. Uses TDMA with TDD c. Range 1 Km d. Gross Data rate of 1 km. 6. L2CAP is not used for a. QoS b. Segmentation c.Reassembly d. Link serup and tear down 7. Security in WiFi networks uses a. WPA b. WEP c. MAC Authentication d. All of the above 9. MSCs use packet switching technology a. True b. False 03/22/12 Tinniam V Ganesh 58
  • 59. Call flows and Advanced wireless concepts 03/22/12 Tinniam V Ganesh 59
  • 60. Agenda – Session 4 Call flows and Advanced wireless concepts • GSM Air interface • GSM air interface channels • Location Updating Sequence Flows • Mobile origination to PSTN • PSTN origination to Mobile • GPRS call flow • SMS call Flow • Recap • Inter BSC Handoff scenario • UMTS • Softswitch • IMS Architecture • 3.5 G • Mobile data explosion • The evolution of LTE • Recap • Quiz 4 03/22/12 Tinniam V Ganesh 60
  • 61. Basic Network Architecture BTS BSC HLR MSC BTS BTS 03/22/12 Tinniam V Ganesh 61
  • 62. Air Interface Access techniques Radio spectrum is a finite resource The radio access method is either Frequency division duplex (FDD) or Time Division Duplex (TDD). The protocol method is TDMA, FDMA or CDMA Frequency Division Duplex (FDD) : Two separate radio channels are used for communicating to the base station • One radio channel for , f1, for downlink • One radio channel, f2, for uplink f1 - downlink FDD f2 - uplink 03/22/12 Tinniam V Ganesh 62
  • 63. TDD • Time Division Duplex (TDD) • One radio channel for communicating to base station. Duplexing is done on time 03/22/12 Tinniam V Ganesh 63
  • 64. Mobile radio propagation effects • Signal strength – Must be strong enough between base station and mobile unit to maintain signal quality at the receiver – Must not be so strong as to create too much co-channel interference with channels in another cell using the same frequency band • Fading – Signal propagation effects may disrupt the signal and cause errors 03/22/12 Tinniam V Ganesh 64
  • 65. GSM Architecture The interface between the BTS and BSC is known as the A-bis interface MSC One or more BSCs are connected to MSC. The MSC is a switch the node that controls call setup, call routing and many of the functions provided by the standard telecommunication switch VLR is a database that contains subscriber related information for the duration that a subscriber is in the coverage area of an MSC. The MSC and VLR are in the same platform, The interface between the BSC and MSC is known as A-interface This is a SS7 based interface using the SCCP. Above this is the BSS Application Part (BSSAP) which is the protocol for communicating between the BSC and the MSC. Since the MSC communicated with the BSC and the MS the BSSAP is divided into two parts the BSSMAP (BSS Management Application Part) and the Direct Transfer Application Part (DTAP) BSSMAP are messages to BSS DTAP messages are passed transparently thro the BSS to the NS` 03/22/12 Tinniam V Ganesh 65
  • 66. GSM Protocol stack 03/22/12 Tinniam V Ganesh 66
  • 67. GSM Architecture HLR The Home Location register contains subscriber data such has the details the subscriber has subscribed to . Associated with the HLR ios the authentication center (AuC). This is the network element that contains the subscriber specific authentication data such as the secret key For a given subscriber using a random number generated by the AuC and passed to the SIM via the HLR., MSC and ME. The SIM performs the calculation using the Ki and the authentication algorithm. If the result os the calculation by the SIM matches that in AuC then the subscriner has been authenticated 03/22/12 Tinniam V Ganesh 67
  • 68. GMSC When a call from a PSTN it arrives at a type of MSC known as the GMSC. The GMSC queries the HLR to determine the location of the subscriber The response from the HLR indicates to the GMSC when the subscriber may be found The call is forwarded by the GMSC to the MSC serving the subscriber 03/22/12 Tinniam V Ganesh 68
  • 69. The GSM Air interface GSM uses TDMA with Frequency Division duples (FDD) GSM has been deployed in 900 Mhz, 1800 Mhz, 1900 Mhz In GSM a given band is divided into 200 Khz carries or RF channels in both uplink and downlink directions For eg. In standard 900 Mhz band the first uplink is 890.2 Mhz and the last uplink is 914.8 allowing a total of 124 carriers 914.8 Mhz – 890.2 Mhz = 24.6 Mhz/200 Khz = 123+ 1 carriers or channels Each RF carrier is divided into 8 time slots . The 8 time slots are used to carry user traffic and also control traffic 03/22/12 Tinniam V Ganesh 69
  • 70. Types of Air Interface channels There are 3 types of channels 2. Broadcast channels 3. Control channels 4. Traffic channels Broadcast Channels Frequency correction channel (FCCH) used for frequency correction of the MS Synchronization channel (SCH) – Broadcast by BTS and is used for mobile station for frame synchronization Broadcast Control Channel (BCCH) – Broadcast general information Common Control Channel (CCCH) Paging channel – used for paging of the mobiles Random Access Channel (RACH) – Only used in uplink. It is used to allocate to MS a Stand alone dedicated Control Channel (SDCCH) or directly to a Traffic Channel (TCH) Access Grant Channel (AGCH) – used in the downlink in responswe to a access request received on the RACH 03/22/12 Tinniam V Ganesh 70
  • 71. Air interface channels • Notification Channel – used to notify MS • Standalone dedicated control channel (SDCCH) – Used towards MS when it is not used for TCH. Used for SMS. Call establishment signaling prior to allocation of TCH • Slow Associated Control Channel (SACCH) – Power Control messages from BTS to MS are sent on this channel. In the uplink the MS sends measurement reports to the BTS • Fast Associated Control Channel (FACCH) – Used to transmit non voice information to and from the MS 03/22/12 Tinniam V Ganesh 71
  • 72. Air interface channel structure Certain time slots in a given RF carrier are allocated to control channel whereas the remaining are for traffic channels. For eg. Time slot 0 us for BCCH /CCCH . It may also carry 4 SDCCH BCCH/CCCH/ TCH TCH TCH TCH TCH TCH TCH SDCCH 03/22/12 Tinniam V Ganesh 72
  • 73. How does the cellular network know the mobile’s position? The cell phone keeps the cellular operator informed about your location. 03/22/12 Tinniam V Ganesh 73
  • 74. Location Area Location Area (LA) • A GSM network is divided into cells. A group of cells is considered a location area. A mobile phone in motion keeps the network informed about changes in the location area. If the mobile moves from a cell in one location area to a cell in another location area, the mobile phone should perform a location area update to inform the network about the exact location of the mobile phone. Home Location Register (HLR) • The HLR maintains a database for the mobile subscribers. At any point of time, the HLR knows the address of the MSC VLR that control the current location area of the mobile. The HLR is informed about a location area update only if the location area change has resulted in a change of the MSC VLR. Mobile Switching Center - Visitor Location Register (MSC VLR) • The MSC VLR is responsible to switching voice calls and it also keeps track of the exact location area where the mobile user is present. Note that a typical MSC VLR will service several location areas. 03/22/12 Tinniam V Ganesh 74
  • 75. Location Update 1. When the MS is switched on it must camp on a suitable cell. This involves scanning the air interface to select a cell with a suitably strong signal and decoding the informationbroadcast by the BTS on the BCCH 2. The MS makes a channel request on the RACH with a cause as Location Updating 3. The BSS allocates an SDCCH for the MS to use. It instructs the MS to move to the SDCCH by sending an immediate assignment message on the AGCH 4. The MS then moves the SDCCH and send the location updating message. This contains the location area identity and the mobile identity. The mobile identity is either the International Mobile Subscriber Identity (IMSI) or the Temporary Mobile Subscriber Identity (TMSI). 5. This is sent through the BSS to the NSC 6. On receipt of the IMSI the NSC.VLR attempt to authenticate the subscriber. 7. If the MSC does not have authentication information then it request the HLR using the MAP operation Send Authetication Info. 8. The HLR AuC sends the MAP Return Result with up to five authentication vectors 03/22/12 Tinniam V Ganesh 75
  • 76. Location Update Known as triplets. Each triplet contains a random number (RAND) and a signed response (SRES) 2. The MSC sends an Authentication request to the MS. This contains the RAND. 3. The MS performs the same calculations as were performed by the HLR/AuC and send the Authentication response containing the SRES parameter. 4. The MSC/VLR check rto make sure that the SRES from the MS matches the SRES from HLR/AuC 5. If a match is made then the MS is authenticated 6. At this point the MSC/VLR use te MAP Operation Update Location to inform the HLR of the subscriber location. 7. The HLR immediately sends a Cancel Location message to the VLR to remove anty previous location 8. VLR deletes any previous data 9. HLR uses a MAP operation to Insert Subscriber data to VLR 10. VLR acknowledges receipt of information 11. HLR sends a return result of the MAP Update Location 03/22/12 Tinniam V Ganesh 76
  • 77. Location Update 1. On receipt of the return result the MSC sends a DTAP message Location Updating Accept to the MS 03/22/12 Tinniam V Ganesh 77
  • 78. Location Update Sequence flow Previous BSS MSC/VLR HLR/AuC MSC/VLR Channel Request Immediate Channel Assignment Location Updating Request Location Updating Request Send Authentication Info Send Authentication Info RR Authentication Request Authentication Response Update Location Cancel Location Cancel Location RR 03/22/12 Tinniam V Ganesh 78
  • 79. Location Update Sequence flow Previous BSS MSC/VLR HLR/AuC MSC/VLR Insert Subscriber data Insert Subscriber data RR Update Location RR Location Update Accept Clear Command Clear Complete Channel release 03/22/12 Tinniam V Ganesh 79
  • 80. Mobile Originated Call to PSTN Request Access • The MS sends a Channel Request (CHAN_REQ) message on the RACH.  The BSS responds with a radio resource assignment (IMM_ASS_CMD) on the AGCH.  The MS sends a Service Request (CM_SERV_REQ) message to the BSS on the SDCCH. Authentication • Before the network will provide any services to the MS, the network will require the MS to authenticate itself. The BSS sends an Authentication Request (AUTH_REQ) message to the MS. The RAND serves as the "challenge" for authentication. • The MS calculates the proper SRES based on the RAND that was given and sends the SRES to the BSS in an Authentication Response (AUTH_RESP) message. • The BSS verifies the SRES. If the SRES is correct then the MS is authenticated and allowed access to the network. The BSS will send a Service Accept (CM_SERV_ACC) message letting the MS know that the service request was received and processed. • Once authenticated, the BSS orders the MS to switch to cipher mode with the CIPH_MOD_CMD message. 03/22/12 Tinniam V Ganesh 80
  • 81. Mobile Originated Call to PSTN Initial Call Setup • The MS will immediately switch to cipher mode and send a Cipher Mode Complete (CIPH_MOD_COM) message. • The MS then sends a Call Setup (SETUP) message to the BSS. The message includes the address information (MSISDN) of the called party. • The BSS assigns a TCH to the MS by sending an Assignment Command (ASS_CMD) message. This message includes which Transceiver (TRX) and which Time Slot (TS) to use. • The BSS does not actually assign a TCH to the MS until the MSC sends a Call Proceeding (CALL_PROC) message to the BSS indicating that the IAM has been sent. • The MS immediately switches to the assigned TCH. The MS sends an Assignment Complete (ASS_COM) message back to the BTS on the FACCH. 03/22/12 Tinniam V Ganesh 81
  • 82. Mobile Originated Call to PSTN Call Setup • The MSC sends an Initial Address Message (IAM) to the GMSC. The IAM contains the MSISDN of the called party as the MS dialed it. • The MSC will also send a Call Proceeding (CALL_PROC) message down to the BSS and this is when the BSS would assign a TCH to the MS, as described in step 10 above. •  Based on the dialed number, the GMSC decides where to route the IAM within the PSTN. • The PSTN will continue to route the IAM until it reaches the correct Switching Center and the call routing is complete. The PSTN will then establish the call circuit and send an Address Complete Message (ACM) back to the GMSC. • The GMSC then forwards the ACM back to the responsible MSC indicating that the call circuit has been established 03/22/12 Tinniam V Ganesh 82
  • 83. Mobile Originated Call to PSTN Call Establishment • Once the MSC receives the ACM, it sends an ALERT message to the MS indicating that the call is going through. The BSS sends the ALERT message on the FACCH. Once the MS receives the ALERT, it will generate the ringing sound in the earpiece. The BSS sends an alerting message the subscriber will hear the line ringing. • Once the called party answers the phone, the PSTN will send an Answer message to the MSC. The MSC forwards this to the MS in a Connection (CON) message. • Once the MS receives the CON message, it switches over to voice and begins the call. All voice traffic occurs on the assigned TCH. 03/22/12 Tinniam V Ganesh 83
  • 84. Mobile Originated Call to PSTN Call Termination • When either the caller or the called party hangs up, the call will be disconnected. Either party can initiate the disconnect. In this example, the MS initiates the disconnect. The MS sends a Disconnect (DISC) message to the BTS on the FACCH. • The BSS forwards the DISC to the MSC. Once the MSC receives the DISC message, it sends a Release (REL) message through the GMSC to the PSTN as well as down through the BSS to the MS. • The MS responds by sending a Release Complete (REL_COM) message to the BSS on the FACCH. The BSS forwards the REL_COM message up to the MSC. Once the MSC receives the REL_COM message the call is considered ended from the call control perspective. • Although the call has ended, the BSS still has a TCH allocated to the MS. The MSC sends a Channel Release (CHAN_REL) message to the BSS. The BSS forwards the CHAN_REL message to the MS. • The MS responds with a DISC (LAPDm) message and returns to an idle mode. The BSS reallocates the channel for other call or releases the TRX.  03/22/12 Tinniam V Ganesh 84
  • 85. Mobile Originated Call to PSTN PSTN BSS MSC/VLR CM Service Request Service request MO call Complete Layer 3 Authentication Request Authentication Response Cipher Mode Command Ciphering Mode Command Ciphering Mode Complete Cipher Mode Complete Setup Call Proceeding Assignment Request Assignment Command Assignment Complete Assignment Complete 03/22/12 Tinniam V Ganesh 85
  • 86. Mobile Originated Call to PSTN PSTN BSS MSC/VLR IAM ACM Alerting ANM ANM Connect Acknowledge 03/22/12 Tinniam V Ganesh 86
  • 87. PSTN to Mobile call flow Mobile Terminated Call • Route Establishment to find the MSC/VLR • The calling party dials the MSISDN for the mobile subscriber. The PSTN identifies the network (PLMN) that the dialed MSISDN belongs to and will locate a GMSC for that network. The PSTN sends an Initial Address message to the GMSC. • The GMSC forwards the MSISDN to the HLR and requests routing information for it. The HLR looks up the MSISDN and determines the IMSI and the SS7 address for the MSC/VLR that is servicing the MS. • The HLR then contacts the servicing MSC/VLR and asks it to assign a Mobile Station Routing Number (MSRN) to the call. • The MSC/VLR allocates the MSRN and forwards it to the HLR. Note: It is important to remember that the MSC/VLR assigns a MSRN to the call not to the MS itself. • The HLR forwards the MSRN as well as routing information for the servicing MSC/VLR to the GMSC. • The GMSC sends an Initial Addressing message to the servicing MSC/VLR and uses the MSRN to route the call to the MSC/VLR. Once the servicing MSC/VLR receives the call, the MSRN can be released and may be made available for reassignment. 03/22/12 Tinniam V Ganesh 87
  • 88. PSTN to Mobile call flow Paging the Mobile Station • The MSC/VLR then orders all of its BSCs and BTSs to page the MS. Since the MSC/VLR does not know exactly which BSC and BTS the MS is monitoring, the page will be sent out across the entire Location Area. Initial Setup • The MS receives the Page Request (PAG_REQ) on the PCH. The MS recognizes that the page is intended for it, based on a TMSI or an IMSI. • The MS sends a Channel Request (CHAN_REQ) message on the RACH. • The BSS responds on the AGCH by sending an Immediate Assignment (IMM ASS) message which assigns an SDCCH to the MS. At this point, the network does not know that the MS is the one that it is paging, it only knows that this MS wants access to the network • The MS immediately switches to the assigned SDCCH and sends a Paging Response (PAG_RES) message on the SDCCH. This lets the network know that the MS is responding to its page. 03/22/12 Tinniam V Ganesh 88
  • 89. PSTN to Mobile call flow Authentication • Before the network will provide any services to the MS, the network will require the MS to authenticate itself. The BSS sends an Authentication Request (AUTH_REQ) message to the MS. The RAND serves as the "challenge" for authentication. • The MS calculates the proper SRES based on the RAND that was given and sends the SRES to the BSS in anAuthentication Response (AUTH_RESP) message. • The BSS verifies the SRES. If the SRES is correct then the MS is authenticated and allowed access to the network. •  Once the MSC/VLR has authenticated the MS, it will order the BSS and MS to switch to cipher mode using the CIPH_MOD_CMD message. Once the MS in encryption mode, the VLR will normally assign a new TMSI to the MS. 03/22/12 Tinniam V Ganesh 89
  • 90. PSTN to Mobile call flow Establishing a Channel • Once the MS is authenticated and in encryption mode, The MSC sends a Setup Message to the BSS, the BSS forwards the SETUP message to the MS on the assigned SDCCH.the assigned SDCCH. The SETUP message may include the Calling Line Identification Presentation (CLIP), which is essentially caller ID. •  The MS responds by sending a Call Confirmed (CALL_CON) message; which indicates that the MS is able to establish the requested connection. The BSS relays the message up to the MSC. Call Setup • The BSS then sends an Assignment Command (ASS_CMD) message to the MS on the assigned SDCCH. The ASS_CMD message assigns a Traffic Channel (TCH) to the MS. • The MS immediately switches to the TCH and responds with an Assignment Complete (ASS_COM) message on the FACCH. The MS begins ringing once it has established the TCH.  Remember that all signaling that occurs on the traffic channel actually occurs on a FACCH, which is a time slot that is stolen from the TCH and used for signaling.  The MS sends an ALERT message to the MSC on the FACCH. The BSS forwards the ALERT message through the PSTN to the calling party and the caller hears the line ringing. 03/22/12 Tinniam V Ganesh 90
  • 91. PSTN to Mobile call flow Call Establishment • Once the user answers the call (by pressing the send button), the MS will send a Connect CON message to the MSC. The Connect message is forwarded back to the caller's switch to activate the call. • The MSC sends a Connect Acknowledge CON_ACK message to the MS and the call is established. •   Call Disconnect • Disconnect happens the same way as for any other call. In this example, the calling party initiates the disconnect. • When the calling party hangs up, the calling party's switch initiates a Release (REL) message. The message is forwarded to the serving MSC, which is then forwarded to the BSS. • The BSS will send a Disconnect (DISC) message to the MS on the FACCH. 03/22/12 Tinniam V Ganesh 91
  • 92. PSTN to Mobile call flow • The MS confirms release of the call by sending a Release (REL) message on the FACCH, which is forwarded to the MSC. • The MSC sends e Release Complete (REL_COM) message through the BSS to the MS. As far as call control (CC) is concerned, the connection has been terminated. • The MS still has a TCH assigned to it, so the BSS sends a Channel Release (CHAN_REL) message to the MS. This releases the radio resource on the Air Interface. • The MS responds be sending a final Disconnect message and returns to idle. 03/22/12 Tinniam V Ganesh 92
  • 93. PSTN to Mobile call flow BSS MSC/VLR HLR GMSC PSTN IAM Send Routing Info (SRI) Provide Routing Number (PRN) IAM (MSRN) Paging Paging Request Channel Request Immediate Assignment Paging Response Paging Response Cipher mode command Ciphering mode command Ciphering mode response 03/22/12 Tinniam V Ganesh 93
  • 94. PSTN to Mobile call flow BSS MSC/VLR HLR GMSC PSTN Cipher mode complete Setup Call confirmed Assignment request Assignment command Assignment complete Alerting ACM ACM Connect ANM ANM Connect Acknowledge 03/22/12 Tinniam V Ganesh 94
  • 95. PSTN to Mobile Call Flow 03/22/12 Tinniam V Ganesh 95
  • 96. SMS-MO 1. The mobile station transfers the short message to the MSC. 2. The MSC queries the VLR to verify that the message transfer does not violate the supplementary services invoked or the restrictions imposed on the subscriber. 3. The MSC sends the short message to the SMSC using the forwardShortMessage operation. 4. The SMSC delivers the short message to the SMC. 5. The SMSC acknowledges the successful outcome of the forwardShortMessage operation to the MSC. 6. The MSC returns the outcome of the short message operation to the mobile station. 03/22/12 Tinniam V Ganesh 96
  • 97. SMS-MO SGSN SMS-IWMSC SC MSC MS x VLR 03/22/12 Tinniam V Ganesh 97
  • 98. SMS-MO 03/22/12 Tinniam V Ganesh 98
  • 99. SMS-MT 1.The Short message is transferred from SC to SMS-GMSC 2.SMS-GMSC queries the HLR(SRI) and receives the routing information for the mobile subscriber (SRI-ACK). 3. The SMS-GMSC sends the short message to the MSC using the forwardShortMessage operation(FSM). 4. The MSC retrieves the subscriber information from the VLR. This operation may include an authentication procedure. 5. The MSC transfers the short message to the mobile station.` 6. The MSC returns the outcome of the forwardShortMessage operation to the SMS- GMSC(FSM-ACK). 7. If requested by the SMC, the SMSC returns a status report indicating delivery of the short message. 03/22/12 Tinniam V Ganesh 99
  • 100. SMS-MT SGSN SMSC-GMSC MS SC MSC x HLR VLR 03/22/12 Tinniam V Ganesh 100
  • 101. SMS-MT 03/22/12 Tinniam V Ganesh 101
  • 102. Handover A handover (aka handoff) is the process by which a call in progress is transferred from one radio channel in the same cell or different cell. A handover can occur Within a cell Between cells of the same BTS Between cells of diffferent BTS of same BSC Between cells of different BSC Between cells of different MSCs 03/22/12 Tinniam V Ganesh 102
  • 103. Inter BSC handover Inter BSC handover • The BSC must involve the MSC • One the serving BSC determines that a handover should take place it sends a message handover required too the NSC • The message contains information about the desired target cell and the the current cell • The MSC analyzes the information and identifies the target BSC associated with the target cell • It then sends a Handover Request to rthe target BSC 03/22/12 Tinniam V Ganesh 103
  • 104. Inter BSC handover Serving Target MSC/VLR BSS BSS Measurement Report Measurement Report Handover Request Handover Request Handover Request Ack Handover Command Handover Command Handover Access MS tunes to new Handover Detect channel Handover Complete Handover Complete Clear Command Measurement Report Clear Complete Measurement Report Measurement Report 03/22/12 Tinniam V Ganesh 104
  • 105. Hand-off scenario 03/22/12 Tinniam V Ganesh 105
  • 106. Handoff/handover • Handoff (also known as handover) is the ability of the subscriber to maintain a call while moving within a network • Handoff is used in AMPS, IS-136 and IS-95. In GSM it is called handover • Handover means that subscriber is transitioned from one radio channel and/ or time slot) to another. • Depending on the two cells in question the handover can be between two sectors on the same station between two BSCs between 2 MSCs or even between networks Base station A Base station B Base station A Base station B 03/22/12 Tinniam V Ganesh 106
  • 107. GPRS call flow Attach • The terminal initiates a attach process • The SGSN authenticates the GPRS mobile by sending a RAND value (a random value). • The SIM applies secret GSM algorithms on the RAND and the secret key Ki to obtain the session key Kc and SRES. • The computed SRES value is passed to the SGSN. • SGSN authenticates the response • SGSN accepts the attach request Activate PDP context 9. The terminal does a PDP Activate PDP context 10. SGSN does a DNS Query to the DNS server to find the address of the GGSN (Global GPRS Support Node) 11. The DNS server sends the IP Address of the GGSN 12. The SGSN sends a Create PDP Activate context to the GGSN 13. The GGSN does a RADIUS authenticate to RADIUS server 14. The RADIUS does a authenticate response 03/22/12 Tinniam V Ganesh 107
  • 108. GPRS call flow 1. GGSN request for dynamic IP address 2. The DHCP sends back a IP address 3. The GGSN sends a Create PDP Context Response 4. SGSN sends a PDP Context Accept 03/22/12 Tinniam V Ganesh 108
  • 109. GPRS call flow Radius DHCP SGSN DNS Server GGSN server server Attach request Authenticate request (RAND) Authenticate response (SRES) Attach accept Attach complete Activate PDP Context APN DNS Query (APN) DNS Response (GGSN IP) Create PDP Context RADIUS Authenticate Request RADIUS Authenticate Response DHCP Address request DHCP Address response Create PDP Context Response Activate PDP Context Accept 03/22/12 Tinniam V Ganesh 109
  • 110. 03/22/12 Tinniam V Ganesh 110
  • 111. Universal Mobile Telecommunication Service (UMTS) UMTS represents an evolution of GSM to support 3G capabilities The air interface is known as UTRAN UMTS uses Wideband CDMA (WCDMA) The air interface consists of 5. Node B 6. RNC Core Network 8. MSC Server 9. Media Gateway 10. HLR 11. VLR 12. GMSC 03/22/12 Tinniam V Ganesh 111 111
  • 112. UTRAN UMTS Terrestrial Radio Access Network (UTRAN) The UTRAN consists of the Radio Network Controller (RNC) and Node B which is the base station The RNC is analogous to the GSM BSC The Base station is equivalent to the Node B 03/22/12 Tinniam V Ganesh 112
  • 113. Wireless Network (Release 4) PSTN Gi Gp PSTN PSTN CS- Mc GMSC GGSN MGW server C Gc Nc HLR AuC PSTN H Gn Nb Gr D EIR MSC Server –Mobile Switching Center Server G F Gf VLR VLR CS-MGW – Core System Media Gateway E B Gs B SGSN GMSC Server– Gateway Mobile Switching Center MSC server Nc MSC server Server Mc Mc GGSN – Gateway GPRS Support Node CN SGSN – Serving GPRS Support Node CS-MGW CS-MGW Nb VLR – Visitor Location Register A Gb HLR – Home Location Register IuCS IuPS EIR – Equipment Identification Register BSS RNS Iur AuC – Authentication Center BSC RNC RNC BSC – Base Station Controller Abis Iub BTS – Base Transceiver System BTS BTS Node B Node B RNC – Radio Network Controller cell RNC – Radio Network Controller Um Uu PSTN – Public Switched Telephone Network ME SIM-ME i/f or Cu SIM USIM MS 113 03/22/12 Tinniam V Ganesh 113
  • 114. 3G Rel 4 Architecture - Softswicth 03/22/12 Tinniam V Ganesh 114
  • 115. UMTS Network Architecture Node B RNC HLR Softswitch Node B Node B 03/22/12 Tinniam V Ganesh 115
  • 116. Softswitch • Softswitch denotes a component in a new architecture designed for migrating from a voice centric world to a data centric world. • Separates signaling from the bearer traffic allowing for greater flexibility and efficiency • Represents a move from the monolithic traditional circuit switches to a more distributed, open architecture and provides for greater degree of flexibility 03/22/12 Tinniam V Ganesh 116
  • 117. Softswitch vs Legacy Switch Signaling Signaling & SS7 & SS7 Control Control Application Servers Packet Time T Line Slot Line T D Interfaces Inter- Interfaces D TDM TDM M change M or Media Media or IP Gateway Gateway IP – Monolithic – Disaggregated (Control + Bearer Integrated) (Control separated from Bearer) – Proprietary Interfaces – Open Interfaces – Inefficient Resource Utilization – Most Efficient Resource Utilization – Limited Scalability – High Scalability – Higher Operating Costs – Lower Capital / Operating Costs – Long Feature Development Intervals – Rapid Feature Development / 3rd Party 03/22/12 Tinniam V Ganesh 117
  • 118. IMS Architecture  IMS is a framework of network nodes that use SIP signaling and an all IP core.  Access agnostic. The network can be accessed by Fixed lines, mobiles, PDA etc  Promises rich services like voice, data, video conferencing, real time gaming etc  Uses the GPRS network  Uses DIAMETER for AAA and database access  Allows for Fixed Mobile Convergence 03/22/12 Tinniam V Ganesh 118
  • 119. IMS Network 03/22/12 Tinniam V Ganesh 119
  • 120. Market conditions  Mobile data is growing at an exponential speed  Mobile data in US & Europe expected to grow at a CAGR of 55% & 42% respectively  Mobile data revenues expected to grow at a rate of 18%  Mobile broadband connections will reach 1 billion by 2012 segmented between 3G & 4G technologies Highlights • Annual IP traffic will exceed ½ a zettabyte in 4 years by 2012 (10 21) • Internet video (Youtube, DVD sharing ,IPTV) account for 30% of IP traffic • Video communication and dynamic video will increase the burden on the network • Global IP traffic will double every two years to 2010 and beyond 03/22/12 Tinniam V Ganesh 120
  • 121. The explosion of mobile data In the last 2 years • 1 billion new mobile subscriptions added • 2 billion wireless devices sold Device range from Mobile phones, Smartphones, Netbooks, PDAs, Wireless dongles and Tablets • Currently there are 3.5 billion subscribers worldwide • 3G accounts for 350 million with 30 million added every quarter • LTE forecast to reach 32.6 million by 2013 03/22/12 Tinniam V Ganesh 121
  • 122. The rise and rise of data 03/22/12 Tinniam V Ganesh 122
  • 123. Growth in data traffic 03/22/12 Tinniam V Ganesh 123
  • 124. 3.5 G High Speed Downlink Packet Data Access (HSDPA) Enhanced modulation scheme over WCDMA with throughput of 14.4 Mbps Uses 16 QAM in addition QPSK High Speed Uplink Packet Data Access (HSUPA) Enables uplink of 1.4 Mbps upto 5.76 Mbps WCDMA HSDPA HSUPA GSM GPRS Rel 99 Rel 5 Rel 6 EDGE 03/22/12 Tinniam V Ganesh 124
  • 125. Elements of the LTE System LTE encompasses the evolution of • Radio access through E-UTRAN (eNodeB) • Non-radio aspects under the term System Architecture Evolution (SAE) Entire system composed of LTE & SAE is called Evolved Packet System (EPS) At a high level a LTE network is composed of • Access network comprised of E-UTRAN • Core Network called Evolved Packet Core (EPC) 03/22/12 Tinniam V Ganesh 125
  • 126. LTE Network Elements UE – User Equipment used to connect to the EPS (Evolved Packet System). This is an LTE capable UE The LTE network is comprised of a) Access Network b) Core Network Access network ENB (eNodeB) – The evolved RAN consists of single node, the eNodeB that interfaces with UE. The eNodeB hosts the PHY,MAC, RLC & RRC layers. It handles radio resource management & scheduling. Core Network (Evolved Packet Core-EPC)  MME (Mobility Management Entity) – Performs paging, chooses the SGW during UE attach  S-GW (Serving Gateway) – routes & and forwards user data packets  P-GW (Packet Gateway) – provides connectivity between the UE and the external packet networks. 03/22/12 Tinniam V Ganesh 126
  • 127. LTE Network Elements 03/22/12 Tinniam V Ganesh 127
  • 128. LTE Technologies  LTE uses OFDM (Orthogonal Frequency Division Multiplexing) for lower latency and better spectral efficiency  Uses MIMO (Mulitple In Multiple Out) LTE uses several transmit & receive paths reducing interference with increase in spectral efficiency and throughput.  Flatter architecture – Fewer Network elements in the LTE Evolved Packet Core(EPC). This results in lower latency because of lesser number of hops as compared to 3G. Absence of RNC like Network Element(NE). 03/22/12 Tinniam V Ganesh 128
  • 129. 2.5G GPRS Network Elements 03/22/12 Tinniam V Ganesh 129
  • 130. The evolution of mobile technology Year Standards Technological evolution 1. 1999 3GPP Rel 99 GSM, GPRS, EDGE, UMTS based (2G, 2.5G, 2.75G, 3G) 2. 2001 3GPP Rel 4 Minor upgrades to UMTS, radio interface 3. 2002 3GPP Rel 5 HSDPA , IMS architecture (3.5G) 4. 2005 3GPP Rel 6 Higher speeds 5. 2007 3GPP Rel 7 HSPA+,PoC, Voice & Video over VOIP 6. 2008 3GPP Rel 8 EPS (E-UTRAN/LTE) (3.99G/4G) 7. 2009 3GPP Rel 9 Enhancement to EPS 8. 2010 3GPP Rel 10 LTE- Advanced (4G) 03/22/12 Tinniam V Ganesh 130
  • 131. 03/22/12 Tinniam V Ganesh 131
  • 132. Questions ? 03/22/12 Tinniam V Ganesh 132
  • 133. Quiz 4 1. A call from a PSTN to wireless network comes first to the a. MSC b. GMSC c. HLR d. VLR 2. The GMSC determines where to route the call by a. Checking its VLR b. Querying the HLR c. It knows where the mobile is d. none of the above 4. GSM has been deployed in a. 800 Mhz b. 1800 Mhz c. 1900 Mhz d. 2.4 Ghz 5. Which is not an Air Interface channel a. Broadcast channel b. Control channel c. Traffic channel d. All of the above 7. SDCCH is used for a. SMS b. For call establishment signaling c. both a & b d. None of the abover 6. How does a mobile inform its whereabouts a. It is stored in HLR b. By doing a Location Update c. HLR is informed of location changes d. Both b & c 7. While doing Location Update, authentication is done at AuC & Mobile a. True b. False 8. For Authentication MSC sends the mobile a. RAND b. SRES c. Ki d. All of the above 9. MS sends a channel request on a. RACH b. AGCH c. SDCCH d. TCH 03/22/12 Tinniam V Ganesh 133
  • 134. Quiz 4 1. Which of the following is true in a PSTN to mobile call a. GMSC sends MSISDN to HLR b. HLR determines MSC/VLR from MSISDN c. MSC/VLR sends a MSRN d. all of the above 4. UMTS uses 1. TDMA with FDD 2. CDMA 3. WCDMA 4. FDMA with FDD 12. Softswitch separates bearer from control a. True b. False 13. Which is not true for softswitch a. Uses time slot interchange b. uses media gateway c. does packet switching d. none of the above 14. Which of the following is true for IMS a. Uses SIP signaling b. Uses an IP Core c. Uses DIAMETER d. all of the above 15. LTE is made of the following a. BTS, BSC, MSC b. Node B, RNC, Softswitch c. Node B, RNC, SGSN, GGSN d. eNodeB, MME, SGW, GGW 03/22/12 Tinniam V Ganesh 134
  • 135. Good luck & thank You !!! Tinniam V Ganesh tvganesh.85@gmail.com Read my blogs: http://gigadom.wordpress.com/ http://savvydom.wordpress.com/ 03/22/12 Tinniam V Ganesh 135