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General Packet Radio Service GPRS

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General Packet Radio Service GPRS Powered By Docstoc
					                   General Packet Radio Service
                             (GPRS)

                                                 Petteri Lappalainen
                                                     23.11.1998
                                                  IP Tech School
                                                Seminar Presentation
                                          Based on the material by
                               Tuomas Niemelä (-97), Hannu H. Kari (-98) and ETSI


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 1
                                         Wireless roadmap




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 2
                                                Contents
                 1. Introduction to GPRS             4. Special issues
                           •
                         What is GPRS ?                  •  SMS
                           •
                         GPRS characteristics            •  Charging
                           •
                         Applications                    •  O&M
                 2. GPRS architecture                    •  Supplementary services
                           •
                         Network elements                •  QoS
                 3. GPRS Operations                      •  Performance
                           •
                         Radio interface             5. GPRS business view
                         resource reservation             • What must be invested…
                           •
                         Security operations              • How to make money with
                           •
                         Connecting to GPRS                 GPRS
                           •
                         Data transfer                    • Users' benefits of GPRS
                           •
                         Mobility management              • Business model
                           •
                         Interworking with GSM       6. GPRS specifications
                         services


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 3
                              1. Introduction to GPRS

                 1.1. What is GPRS ?
                 1.2. GPRS access interfaces and reference points
                 1.3. How is GPRS seen by external networks and GPRS users
                 1.4. Air interface resources
                 1.5. GPRS characteristics
                 1.6. Applications




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 4
                                     1.1. What is GPRS ?
                 • Part of GSM phase 2+
                 • General Packet Radio Service
                           • General -> not restricted to GSM use (DECT ?, 3rd
                               generation systems ?)
                           •   Packet Radio -> enables packet mode communication
                               over air
                           •   Service, not System -> existing BSS (partially also NSS)
                               infrastructure is used
                 • Requires many new network elements into NSS
                 • Provides connections to external packet data networks
                   (Internet, X.25)
                 • Main benefits
                           • Resources are reserved only when needed and charged
                               accordingly
                           •   Connection setup times are reduced
                           •   Enables new service opportunities
NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 5
              1.2. GPRS access interfaces and
                      reference points
     R reference point                Um                          Gi reference point

                                                                                          PDNs or
    TE                    MT                    GPRS network 1                         other networks


               MS                                            Gp



                                                GPRS network 2




           • GPRS provides packet switched connections from MS
               to packet data networks (PDN)
           •   Different operator’s GPRS networks are connected
               through Gp interface

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 6
          1.3. How is GPRS seen by external
              networks and GPRS users?
               HOST
               155.222.33.55
                                                       GPRS
                                                       SUBNETWORK

                                                             SUBNETWORK
                                                             155.222.33.XXX

                                                  "Router"

                   SUBNETWORK                                                          SUBNETWORK
                   191.200.44.XXX                                                      131.44.15.XXX

                                                             Packet                        Corporate 2
                       Corporate 1                           Data
                                                             network
                                                             network
                                                                              Router
                                         Router
                                                             (Internet)



                                    Local                                        Local
                HOST                area                                         area        HOST
                191.200.44.21       network                                      network     131.44.15.3




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 7
                                             1.4. Air interface resources
An example of occupied TCH
capacity by CS traffic during
busy hour with n% blocking                                      14

                                                                12                                    Free
GPRS "steals" any TCH
capacity not used by CS                                                                               Capacity
                                                                10
traffic
                                                                    8
                                                              TCH
                                                                    6

                                                                    4
         14

         12                                                         2   Capacity occupied by CS traffic
         10

         8
                                                                    0
   TCH




         6

         4                                                              1:00 PM   1:15 PM   1:30 PM   1:45 PM
         2

         0
               3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00




          NOKIA TELECOMMUNICATIONS
              IP TECH SCHOOL seminar / 23.11.1998 / slide 8
                           1.5. GPRS characteristics
              GPRS uses packet switched resource allocation
                  • resources allocated only when data is to be
                      sent/received
              Flexible channel allocation
                  • one to eight time slots
                  • available resources shared by active users
                  • up and down link channels reserved separately
                  • GPRS and circuit switched GSM services can use
                      same time slots alternatively
              Traffic characteristics suitable for GPRS
                  • Intermittent, bursty data transmissions
                  • Frequent transmissions of small volumes of data
                  • Infrequent transmission of larger volumes of data

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 9
                                           1.6. Applications

                     •     Standard data network protocol based
                              • IP based applications
                                  – WWW, FTP, Telnet, ...
                                  – Any conventional TCP/IP based applications
                              • X.25 based applications
                                  – Packet Assembly/Disassembly (PAD) type approach
                     •     GPRS specific protocol based
                              • Point-to-point applications
                                  – Toll road system, UIC train control system
                              • Point-to-multipoint applications
                                  – Weather info, road traffic info, news, fleet management
                     •     SMS delivery (GPRS as a bearer for SMS)



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 10
                                   2. GPRS architecture

            2.1. Interfaces, reference points and network elements
            2.2. Functional view on GPRS
            2.3. Subscription of GPRS service
            2.4. New network elements
                2.4.1. GGSN
                2.4.2. SGSN
                2.4.3. Other elements
                2.4.4. GPRS backbones
            2.5. GPRS Mobile classes
            2.6. MS multislot capabilities




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 11
       2.1. Interfaces, reference points and
                  network elements
                                                  SMS-GMSC
                                                  SMS-IWMSC                 SM-SC

                                        MAP-H                    MAP-C
                                                            Gd
                                   MSC/VLR                            HLR
                                                           MAP-D
                                                      Gs                    Gc
                                      A
                                                 Gb           Gr                 Gi
          TE             MT               BSS         SGSN            GGSN             PDN   TE
                                                                 Gn
                  R              Um               Gp                  MAP-F
                                                                                 EIR
                                                      GGSN

                                                  Other PLMN

                 Signalling Interface
                 Signalling and Data Transfer Interface

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 12
                    2.2. Functional view on GPRS
                                         BTS      BSC                                             Packet
                         Um                                                                       network
                                                                                                   PSTN
          R/S


                                                                       MSC
                                                                                                                     SMS-GMSC
                                                  Gb                                                HLR/AuC
                                                                               Gs            Gr                     Gd
                                                            Gr    Gd
                      Serving GPRS                                                   Packet                 Corporate 1
                      Support Node                               Gs                  SS7
                                                                                     network
                      (SGSN)              Gn                                         Network                        Server
                                                                                                   EIR
                   Border                                 GPRS
                   Gateway (BG)    Intra-PLMN             INFRASTRUCTURE                MAP-F
  Packet
Inter-PLMN                         backbone
  network
Backbone                           network                                                           Router
                                                                                                                Local
network          Gp                (IP based)            Gateway GPRS     Firewall                              area
                                                         Support Node                Data
                                                                                      Packet
                  Firewall Point-To-                                                                            network
                                                         (GGSN)                      network
                                                                                      network
                           Multipoint               Gn                               (Internet)
                           Service                                           Gi.IP
                                                                                                            Corporate 2
                           Center                                                                                   Server
                           (PTM SC)                                     Gi.X.25
                                                                        Data
                                                                         Packet
                                                           Firewall
                                                                        network
                                                                         network
                                                                        (X.25)
                                                                                                     Router
                                                                                                                Local
                                                                                                                area
                                                                                                                network

NOKIA TELECOMMUNICATIONS
 IP TECH SCHOOL seminar / 23.11.1998 / slide 13
         Assignment of functions to general
                logical architecture
                 Function                           MS   BSS   SGSN   GGSN   HLR
                 Network Access Control:
                 Registration                                                 X
                 Authentication and Authorisation   X           X             X
                 Admission Control                  X     X     X
                 Message Screening                                     X
                 Packet Terminal Adaptation         X
                 Charging Data Collection                       X      X

                 Packet Routeing & Transfer:
                 Relay                              X     X     X      X
                 Routeing                           X     X     X      X
                 Address Translation and Mapping    X           X      X
                 Encapsulation                      X           X      X
                 Tunnelling                                     X      X
                 Compression                        X           X
                 Ciphering                          X           X             X

                 Mobility Management:               X           X      X      X

                 Logical Link Management:
                 Logical Link Establishment         X           X
                 Logical Link Maintenance           X           X
                 Logical Link Release               X           X

                 Radio Resource Management:
                 Um Management                      X     X
                 Cell Selection                     X     X
                 Um-Tranx                           X     X
                 Path Management                          X     X


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 14
                     2.3. Subscription of GPRS
                            service (1/2)
            Subscription storage: HLR
            Supports Multiple Subscriber Profile (MSP)
            Mobile identification: IMSI
            One or several PDP addresses per user
               • Each subscribed configuration contains
                              • PDP type          (e.g., IP, X.25)
                              • PDP address (static, e.g. 128.200.192.64)
                              • Subscribed QoS (level 1…4)
                              • Dynamic address allowed
                              • VPLMN address allowed
                              • GGSN address
                              • Screening information (optional)


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 15
                     2.3. Subscription of GPRS
                            service (2/2)
            Subscription is copied from HLR to SGSN during GPRS
             Attach
            Part of PDP context is copied to relevant GGSNs when a
             PDP address is activated
            Possible PDP address allocation alternatives
                • Static address allocated from HPLMN
                • Dynamic address allocated from HPLMN
                • Dynamic address allocated from VPLMN
            HPLMN operator specifies which alternatives are possible




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 16
        2.4.1. Gateway GPRS Support Node

            GGSN
            • Typically located at one of the MSC sites
            • One (or few) per operator
            • Main functions
                • Interface to external data networks
                • Resembles to a data network router
                • Forwards end user data to right SGSN
                • Routes mobile originated packets to right destination
                • Filters end user traffic
                • Collects charging information for data network usage
                • Data packets are not sent to MS unless the user has
                   activated the PDP address


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 17
          2.4.2. Serving GPRS Support Node
            SGSN
            • Functionally connected with BSC, physically can be at
              MSC or BSC site
            • One for few BSCs or one (or few) per every BSC
            • One SGSN can support BSCs of several MSC sites
            • Main functions
               • Authenticates GPRS mobiles
               • Handles mobile’s registration in GPRS network
               • Handles mobile’s mobility management
               • Relays MO and MT data traffic
                    • TCP/IP header compression, V.42bis data
                              compression, error control MS- SGSN (ARQ)
                     •     Collect charging information of air interface usage

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 18
                                       2.4.3. Other elements
BG (Border Gateway)
• (Not defined within GPRS)
• Routes packets from SGSN/GGSN of one operator to a SGSN/GGSN of an
  other operator
• Provides protection against intruders from external networks
DNS (Domain Name Server)
• Translates addresses from ggsn1.oper1.fi -format to 123.45.67.89 format
  (i.e. as used in Internet)
Charging Gateway
• Collects charging information from SGSNs and GGSNs
PTM-SC (Point to Multipoint -Service Center)
• PTM Multicast (PTM-M): Downlink broadcast; no subscription; no ciphering
• PTM Group call (PTM-G): Closed or open groups; Down/up -link; ciphered
• Geographical area limitation

    NOKIA TELECOMMUNICATIONS
    IP TECH SCHOOL seminar / 23.11.1998 / slide 19
                               2.4.4. GPRS backbones

            Enables communication between GPRS Support Nodes
            Based on private IP network
                 • IPv6 is the ultimate protocol
                 • IPV4 can be used as an intermediate solution
            Intra-PLMN backbone
                 • Connects GPRS Support Nodes of one operator
                 • Operator decides the network architecture
                              • LAN, point-to-point links, ATM, ISDN, ...
            Inter-PLMN backbone
                • Connects GPRS operators via BGs
                • Provides international GPRS roaming
                • Operators decide the backbone in the roaming agreement

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 20
                               2.5. GPRS mobile types
    Class A:
        • Simultaneous GPRS and conventional GSM operation
        • Supports simultaneous circuit switched and GPRS data transfer
    Class B:
        • Can be attached to both GPRS and conventional GSM services
          simultaneously
        • Can listen circuit switched and GPRS pages (via GPRS)
        • Supports either circuit switched calls or GPRS data transfer but
          not simultaneous communication
    Class C:
        • Alternatively attached in GPRS or conventional GSM
        • No simultaneous operation
        • ‘GPRS only’ mobiles also possible (e.g. for telemetric
          applications)
NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 21
                2.6. GPRS multislot capabilities

                               MS RX                   0    1       2      3           4        5       6           7           0           1
                                                       5    6   7              0           1 2          3       4               5           6
         1-slot                MS TX
                               Monitor


                               MS RX                   0    1       2     3        4        5       6           7           0           1

          2-slot               MS TX                  5     6   7         0            1 2          3       4               5           6

                               Monitor


                                 MS RX                 0    1       2    3         4        5       6       7           0           1
        3-8 -slot                MS TX                 5    6   7         0        1            2   3       4           5           6

                                 Monitor

                                                 3 slots:               4th slot:                       5th slot:



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 22
                                      3. GPRS operations

            3.1 Security: Basic security rules
                 • Authentication, key management, ciphering
            3.2 GPRS attach
            3.3 Data transmission
                 • MO, MT, MO+MT
            3.4 Mobility management
            3.5 Interworking with GSM services




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 23
           3.1. Security: Based on GSM phase 2

     Authentication
         • SGSN uses same principle as MSC/VLR:
                       •     Get triplet, send RAND to MS, wait for SRES from MS, use Kc
              •
           MS can’t authenticate the network
     Key management in MS
         • Kc generated same way from RAND using Ki as in GSM
     Ciphering
         • Ciphering algorithm is optimized for GPRS traffic (‘GPRS - A5’)
         • Ciphering is done between MS and SGSN
     User confidentiality
         • IMSI is only used if a temporary identity is not available
         • Temporary identity (TLLI) is exchanged over ciphered link

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 24
                                          3.2. GPRS Attach

            GPRS Attach function is similar to IMSI attach
                • Authenticate the mobile
                • Generate the ciphering key
                • Enable the ciphering
                • Allocate temporary identity (TLLI)
                • Copy subscriber profile from HLR to SGSN
            After GPRS attach
                • The location of the mobile is tracked
                • Communication between MS and SGSN is secured
                • Charging information is collected
                • SGSN knows what the subscriber is allowed to do
                • HLR knows the location of the MS in accuracy of SGSN

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 25
          3.3. Data transfer: Basic rules (1/4)

            • SGSN:
               • Does not interpret user data, except
                              • SGSN may perform TCP/IP header compression
                     •
                 Does not interpret source or destination addresses
                     •
                 Sends all packets to specified GGSN that handles
                 the PDP context
            • GGSN:
               • Performs optional filtering
               • Decides where and how to route the packet



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 26
                                 3.3. Data transfer (2/4)

            Mobile originated (left when MS in HPLMN, right when in
             VPLMN, no filtering/screening)
                          BTS         BSC                                                 BSC    BTS




                                        SGSN             Packet
                                                        Inter-PLMN                    SGSN
                                                   BG    network
                                                        backbone               BG
                                                        network

             HPLMN               Intra-PLMN                                              Intra-PLMN    VPLMN
                                 backbone                                                backbone
                                 network                                                 network
                                 (IP based)                                              (IP based)

                                                 GGSN                          GGSN
                                                         Data
                                                          Packet
                                                         network
                                                          network
                                                         (Internet)
                                                                         Corporate
                                                                                Server




                                                                      Router
                                                                               Local
                                                                               area
                                                                               network
NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 27
                                  3.3. Data transfer (3/4)

            Mobile terminated (left when MS in HPLMN, right when in
             VPLMN, with/without filtering/screening)
                            BTS        BSC                                                BSC    BTS




                                         SGSN           Packet
                                                        Inter-PLMN                    SGSN
                                                   BG    network
                                                        backbone               BG
                                                        network

              HPLMN               Intra-PLMN                                             Intra-PLMN    VPLMN
                                  backbone                                               backbone
                                  network                                                network
                                  (IP based)                                             (IP based)

                                                 GGSN                          GGSN
                                                         Data
                                                          Packet
                                                         network
                                                          network
                                                         (Internet)
                                                                         Corporate
                                                                                Server




                                                                      Router
                                                                               Local
                                                                               area
                                                                               network
NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 28
                                 3.3. Data transfer (4/4)

            Mobile originated and terminated (left MSs in same
             PLMN, right MSs in different PLMN)
                        BTS        BSC                                                    BSC    BTS




                                     SGSN                Packet
                                                        Inter-PLMN                    SGSN
                                                   BG    network
                                                        backbone               BG
                                                        network

           HPLMN               Intra-PLMN                                                Intra-PLMN    VPLMN
                               backbone                                                  backbone
                               network                                                   network
                               (IP based)                                                (IP based)
                    SGSN
                                                 GGSN                          GGSN
                                                         Data
                                                          Packet
                                                         network
                                                          network
                                                         (Internet)
                                                                         Corporate
                        BTS                                                     Server
                                   BSC



                                                                      Router
                                                                               Local
                                                                               area
                                                                               network

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 29
                      3.4. Mobility management (1/3)
            Instead of Location Area, GPRS uses Routing Areas to
              group cells. RA is a subset of LA.

            • IDLE:
                • MS is not known by the network (SGSN)
            • STANDBY:
                • MS’s location is known in accuracy of Routing Area
                • MS can utilize DRX (to save battery)
                • MS must inform its location after every Routing
                           Area change (no need to inform if MS changes
                           from one cell to another within same Routing Area)
                     •     Before the network can perform MT data transfer
                           MS must be paged within the Routing Area
                     •     MS may initiate MO data transfer at any time

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 30
                      3.4. Mobility management (2/3)

            • READY:
               • MS’s location is known in accuracy of cell
               • MS must inform its location after every cell change
               • MS can initiate MO data transfer at any time
               • SGSN does not need to page the MS before MT
                           data transfer
                     •     MS listens continuously GPRS PCCCH channel
                              • DRX in READY state is optional




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 31
                      3.4. Mobility management (3/3)

            Mobility management messages:
               • Cell update (implicit, with any message)
                              • When MS changes the cell within a Routing Area in
                                   READY state
                     •     Routing Area update
                              • When MS changes the cell between two Routing
                                   Areas in READY or STANDBY state
                              •    Two types of Routing Area Updates (from MS’s point
                                   of view only one type)
                                      – Intra-SGSN Routing Area Update
                                      – Inter-SGSN Routing Area Update
                     •     Periodic Routing Area updates are applicable



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 32
      3.5. Interworking with GSM services (1/3)
            • GPRS can interwork with GSM services through Gs-
              interface
            • If no Gs interface exists:
                 • Type of the location update procedure is indicated
                    by the network in the response message to MS
            • Effects on different MS classes if Gs does not exist:
                 • A-class mobiles must use conventional GSM
                    services via normal GSM channels
                 • B-class mobiles won’t get simultaneous support
                    from the network. Depending on MS design
                              • MS can try listen both paging channels
                                   simultaneously by themselves
                              •    MS does IMSI detach and use only GPRS service
                     •     No effect on C-class mobiles as simultaneous
                           services are not supported

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 33
       3.5. Interworking with GSM services (2/3)

        Combined GPRS and IMSI attach
           • To save radio resources
           • MS indicates its request for combined attach
           • MS sends combined GPRS and IMSI attach to SGSN
           • SGSN may authenticate the MS
           • SGSN informs MSC/VLR about the new MS
        Combined Location and Routing Area update
           • To save radio resources
           • MS indicates its request for combined update
           • This is done when both Location Area and Routing Area
             changes at the same time
           • Combined Location and Routing Area update is not done if
             MS has CS connection

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 34
        3.5. Interworking with GSM services (3/3)

            Paging CS services via GPRS network
            • MSC/VLR gets MT call or SMS
            • In VLR, presence of SGSN address tells that the MS is
              in GPRS attached state
            • MSC/VLR sends the paging request to SGSN address
              (not to BSC)
            • SGSN checks the location of MS (identified by IMSI)
            • SGSN pages the MS via GPRS channels indicating “CS
              page” status
            • MS replies to the page using normal GSM channels



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 35
                                           4. Special issues

                 4.1. SMS
                 4.2. Charging
                 4.3. O&M
                 4.4. Supplementary services
                 4.5. Quality of Service
                 4.6. Performance




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 36
              4.1 Special issues: SMS support

            MO and MT SMSs can be carried via GPRS network
            HLR stores and returns two SS7 addresses to GMSC:
                • SGSN address
                • MSC/VLR address
            Primary route:
                • Via SGSN, if available
            Secondary route:
                • Via MSC/VLR, if available and primary failed




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 37
                          4.2 Special issues:
                       GPRS charging of PTP (1/2)
            SGSN gathers charging:
               • usage of radio resources (packets, bits)
               • usage of packet data protocols (time)
               • usage of general GPRS resources
                              • e.g. signaling messages, GPRS backbone
            GGSN gathers charging :
               • based on destination/source of data packets
               • usage of external data networks (packets, bits)
               • usage of general GPRS resources
            Operator selects what information is used for billing




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 38
                         4.2 Special issues:
                      GPRS charging of PTM (2/2)
            SGSN gathers usage of:
               • usage of radio resources
                              • amount of data
                              • geographical areas
                              • number of repetition
                     •
                 usage of general GPRS resources
            PTM Service Center gathers charging :
               • usage of general GPRS resource
               • usage of PTM-G groups




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 39
                           4.3 Special issues:
                       Operation and management
            GSM related parts can be handled with Q3
            GPRS backbone network is based on IP network
              • IP network uses Simple Network Management
                 Protocol (SNMP)
                                   GPRS/GSM OMC


                                   BTS
                                             BSC


                                                                     Inter-operator's GPRS
                                                                     backbone management



                                                                              Packet
                                                                          Inter-operator
                                                 SGSN                      network
                                                                          backbone
                                                                          network

                                         GPRS
                                         backbone       IP
                                         network        ROUTER
                                         (IP based)
                                                                                             Operator B's GPRS
                                                                                             backbone management
                                                        GGSN
                                                                              Data
                                                                               Packet
                                                                              network
                                                                               network
                                                                              (Internet)
                       Operator A's GPRS                       Data network
                       backbone management                     management




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 40
                               4.4 Special issues:
                             Supplementary services
            Most of the conventional GSM supplementary services
             are not applicable for GPRS
               • E.g., Call forwarding when busy, Calling line
                  identification, Call waiting
            Some supplementary services may be applicable
               • Advice of charge (can be difficult to realize)
               • Closed user group (can be implemented as part of
                  external data network)
            GPRS has its own supplementary services
               • Barring of GPRS Interworking Profile(s)



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 41
                                   4.5 Quality of Service

                 • Precedence class (1,2,3)
                 • Delay class (1-4)
                 • Reliability class
                 • Peak throughput class; and
                 • Mean throughput class.




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 42
                                   4.5.1 Reliability Class

                 • Data reliability is defined in terms of the residual error
                     rates for the following cases (see GSM 02.60):
                 • Probability of data loss
                 • Probability of data delivered out of sequence
                 • Probability of duplicate data delivery
                 • Probability of corrupted data




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 43
                           4.5.2 Throughput classes
                         Peak Throughput Class                   Peak Throughput in octets per second
                                   1             Up to 1 000 (8 kbit/s).
                                   2             Up to 2 000 (16 kbit/s).
                                   3             Up to 4 000 (32 kbit/s).
                                   4             Up to 8 000 (64 kbit/s).
                                   5             Up to 16 000 (128 kbit/s).
                                   6             Up to 32 000 (256 kbit/s).
                                   7             Up to 64 000 (512 kbit/s).
                                   8             Up to 128 000 (1 024 kbit/s).
                                   9             Up to 256 000 (2 048 kbit/s).




                         Mean Throughput Class                      Mean Throughput in octets per hour
                                   1             Best effort.
                                   2             100 (~0.22 bit/s).
                                   3             200 (~0.44 bit/s).
                                   4             500 (~1.11 bit/s).
                                   5             1 000 (~2.2 bit/s).
                                   6             2 000 (~4.4 bit/s).
                                   7             5 000 (~11.1 bit/s).
                                   8             10 000 (~22 bit/s).
                                   9             20 000 (~44 bit/s).
                                  10             50 000 (~111 bit/s).
                                  11             100 000 (~0.22 kbit/s).
                                  12             200 000 (~0.44 kbit/s).
                                  13             500 000 (~1.11 kbit/s).
                                  14             1 000 000 (~2.2 kbit/s).
                                  15             2 000 000 (~4.4 kbit/s).
                                  16             5 000 000 (~11.1 kbit/s).
                                  17             10 000 000 (~22 kbit/s).
                                  18             20 000 000 (~44 kbit/s).
                                  19             50 000 000 (~111 kbit/s).

NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 44
                                     4.6 Performance 1/3
                     Example

    • SGSN that handles 2 Mbps up and downlink traffic
             – Average packet size 500 octets (4000 bits)
             – => Each packet must be processed totally every 1 milliseconds
                • IP stack in backbone
                • possible UDP (de)fragmentation, IP checksums
                • GTP header processing, finding the right context
                • possible paging of the MS
                • compression in SNDCP level, possible segmentation
                • LLC CRC, LLC acknowledges, LLC timers
                • handle GPRS ciphering/deciphering
                • BSSGP protocol
                • Frame relay protocol


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 45
                                     4.6 Performance 2/3
                          Example continued

                • Background tasks
                         – Ensuring the QoS for every mobile
                            • Scheduling pending packets to time horizon
                            • Rescheduling everything after MS has changed the cell
                     – Handling charging data collection
                     – Performance monitoring
                     – Handle SGSN operating system, task switching, etc.
                     – Handle diagnostics of the network element
                • If SGSN handles 65 Mbps, instead of 2 Mbps?
                     – => SGSN has just about 30 micro seconds to do all
                       above



NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 46
                                     4.6 Performance 3/3
                          Solution to the example

              • Each network element has limited capacity (x
                packets/second)
              • If operator needs more capacity (e.g. 50x)
                        – use 50 parallel boxes
                        – for example,
                            • every GGSN boxes are really independent of each other
                            • each SGSN handles its own area (list of cells)
              • Capacity grows linearly but complexity in each box
                remains the same
              • Reliability? Configuration?


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 47
                              5. GPRS Business View


    5.1. What must be invested to get GPRS up and running?
    5.2. How to launch GPRS with minimised incremental cost
    5.3. How to make money with GPRS?
    5.4. Users' benefits of GPRS
    5.5. Business model




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 48
          5.1 What must be invested to get GPRS
                    up and running?

                 • Updates on existing network elements
                          – BTS, BSC, MSC/HLR, O&M, billing system, network
                            planning
                 • New network elements
                          – Totally new network for GPRS backbone, based on IP
                          – New packet network nodes
                          – A lot of Internet "stuff" (routers, DNS servers, firewalls, …)
                 • Totally new skills needed
                          – "Internet way" of thinking
                 • New mobiles and new type of users
                 • New type of business thinking


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 49
         5.2 How to launch GPRS with minimised
                     incremental cost

                 • A single SGSN/GGSN combined functional unit
                 • BTSs support basic GPRS services with software
                   update only, BSCs need HW upgrade to add connection
                   to SGSN
                 • Use existing paging and control channels for GPRS
                 • Limit the number of radio channels available for GPRS
                 • Gs interface can be deleted => no MSC developments




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 50
                    5.3. How to make money with
                               GPRS?
                 • New users
                          – More subsribers
                 • New services
                          – New ways to get money from users
                          – New intances to pay instead of the users (e.g. advertisers)
                 • New applications
                          – New ways to get money from users
                 • More data traffic
                          – More data traffic
                          – Small payments per packet, but huge number of packets




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 51
                      5.4. Users' benefits of GPRS

                 • GPRS Selling arguments:
                          – Higher capacity Internet access
                                   • Up to 171,2 kbps in theory, 40 kbps in practice
                          – Quicker access to Internet
                                   • No set up time, Iternet access all the time available
                          – Lower cost
                                   • Flat rate or volume based billing
                          – Or no cost
                                   • via anonymous access (somebody else pays the bill)




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 52
                                     5.5. Business model
                                                             1/2

                 • If the users are paying little (or nothing), how does this
                     make profit to the operator?

                          – Not the high cost per time but the large number of packets
                          – Somebody else may pay the bill (e.g. anonymous access)


        Example business model
                   # sub-                    QoS level Monthly Cost/kB Volume/ Monthly Total annual Total data
                   scribers                              fee (FIM) FIM     day (FIM) cost/subs cost (MFIM) volume (GB)
    Business users    100000                 High               50    0,02     1000        650         780       36500
    "Normal" users  1000000                  Normal             25    0,01        20        31         372        7300
    Web surfers     1000000                  Best effort        50       0       250        50         600       91250
    Computers         100000                 High               50     0,1        20       110         132         730
    Total           2200000                                                                           1884      135780




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 53
                              5.5. Business model 2/2

                    Volume calculations
                            Average data         per day       372    GB/d
                            volume               per hour     15,5    GB/h
                                                 per sec        4,3   MB/s
                                                 per sec      34,3    Mbps

                            Peak hour data       per year   43800     GB/a
                            volume               per day       120    GB/d
                                                 per hour        30   GB/h   all data in 4 busy hours
                                                 per sec        8,3   MB/s
                                                 per sec      66,7    Mbps

                            Number of time                   6667 TSs        average 10 kbps/TS
                            slots needed
                                                 Carrier      833 Carriers




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 54
                            6. GPRS Standardization

                GPRS Phase 1: Release 97
                 • Basic set of GPRS functionality
                 • Optional features
                GPRS Phase 2: GPRS for UMTS
                 • Certain issues defined in stage 1 documents are not
                   included in the first release of the GPRS standard
                 • New requirements have been pointed out for UMTS

                   Standard was approved March/June 1998




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 55
                                    6.1 List of participants

               The following companies and organizations have been
                participating in GPRS work in last 3 years

               Some of the manufacturers, operators and others
                participating GPRS standardization:
                  • Alcatel, BT, CNET, CSELT, Detemobil, Eplus,
                     Ericsson, France Telecom, IBM, Inmarsat, Lucent,
                     Mannesmann, Motorola, NEC, Nokia, Nortel/Matra,
                     Omnipoint, OPI, Philips, SFR, Siemens, Telecom
                     Finland, Telia, UIC, Vodafone
               EU sponsored project team PT8OV to expedite GPRS
                standardization
               Support of PT12


NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 56
                              6.2 GPRS Specifications
                  GPRS document structure

                  Doc.      Title

                  01.60     Requirements Specification of GPRS

                  Stage 1
                  02.60   General GPRS Overview
                  10.60   GPRS standarsisation status and overview

                  Stage 2
                  03.60     General System Description and Newtwork Architecture
                  03.64     Radio Architecture Description
                  03.61     Point to Multipoint – Multicast (very draft)
                  03.62     Point to Multipoint – Group Call (non existing)

                  New Stage 3
                  04.60   Radio stage 3: RLC/MAC Radio Protocol
                  04.61   PTM-M Services (not existing yet)
                  04.62   PTM-G Services (not existing yet)
                  04.64   LLC
                  04.65   SNDCP
                  07.60   User Interworking
                  08.18   BSSGP: The Gb Interface
                  08.16   Gb Network Service
                  08.14   Gb Layer 1
                  09.16   Gs Layer 2
                  09.18   Gs Layer 3
                  09.60   GPRS Tunnelling Protocol (GTP): Gn & Gp Interface
                  09.61   External Interworking Networks




NOKIA TELECOMMUNICATIONS
IP TECH SCHOOL seminar / 23.11.1998 / slide 57

				
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