gsm_services by islamcode16


									GSM Services                    Siemens

GSM Services

1      GSM Phase 1/2 Services        3
2      Applications                 13
3      GSM Phase 2+ Services        21

    Siemens    GSM Services

2             TM2100EU02TM_0001
GSM Services                                                      Siemens

1        GSM Phase 1/2 Services


                                            • ISDN-oriented
                                            • Mobile specific services
                                              & modifications

                    Teleservices    Bearer Services

                           GSM Phase 1/2

Fig. 1

    Siemens                                                                 GSM Services

    GSM Services Phase 1/2
    The GSM Services enable the users of a network to transmit or receive different
    types of information.
    The Mobile Station MS ME recognizes the desired service automatically or by user
    input and sends the appropriate service requests to the network.
    The services defined in GSM Phase 2 are similar to the ISDN (Integrated Services
    Digital Network) services. However, when compared with ISDN, GSM also contains
    mobile specific modifications and services.
    The GSM services are divided into three categories:
    l   Bearer Services BS
    l   Tele Services TS
    l   Supplementary Services SS

    Bearer Services BS
    GSM BS define the capabilities to transmit digital data (OSI Layer 1 – 3). Thus the
    information transmission between terminals at particular access points (user-network
    interface) is achieved. The application itself is not included in this definition.

    Tele Services TS
    GSM TS are defined "end to end". They offer the transmission of data (speech / data)
    and include the application itself (OSI Layer 1 – 7).

    TS and BS are so-called basic services. This means not that a user may
    automatically use these services after the completion of a subscriber contract. This
    only happens with essential services such as emergency service. Other services
    such as e.g. SMS or faxing must be additionally ordered.

    Supplementary Services SS
    Supplementary services are services which enhance or modify the existing BS or TS.
    Supplementary services may only be used in connection with a basic service.

4                                                                         TM2100EU02TM_0001
GSM Services                                                                     Siemens

             Tele Services TS:
             defines services "end-to-end"
             incl. application                     Bearer Services BS:
                                                   defines data transmission

                                  Bearer Services
                PLMN section                section outside PLMN

     TE                      Interworking                          Terminating    TE
               GSM network                     Transit network
    (MS)                     Function IWF                            network     (MS)

           Supplementary Services SS:
           enhance/modify TS / BS

Fig. 2

    Siemens                                                                 GSM Services

    GSM Phase 1/2 Bearer Services
    The Bearer Services (GSM Rec. 02.01, 02.02) enable data transmission between the
    respective terminal equipment interfaces. GSM Bearer Services offer asynchronous
    and synchronous data transport both circuit or packet switched. In GSM Phase 1 and
    2 data rates of 300 bit/s up to 9.6 kbit/s or 13 kbit/s for speech transmission are
    The Bearer Services 21 - 53 offer data transmission rates of 0.3 - 9.6 kbit/s. The
    subdivision into UDI (Unrestricted Digital Information) and 3.1 kHz is associated with
    the manner in which the services outside a PLMN are further transmitted and deter-
    mine the Interworking Function which must be activated for each service when the
    network is changed. UDI corresponds to the UDI services of ISDN and supplies a
    channel for unlimited transmission of digital information. The category 3.1 kHz is
    used to enable a transition in an analogue network (PSTN).
    Transparent services, with exception of the Interworking Function (enables to change
    the network) are not edited in the network elements. They are protected by Forward
    Error Correction FEC. The non-transparent mode activates an additional protection
    (Backward Error Correction BEC) via the radio interface.
    A change between speech and data is possible via the Bearer Services 61 and 81.
    Bearer Service 61 allows a multiple change between speech and data. In the case of
    Bearer Service 81, it is not permitted to change back to a voice service after
    changing to a data service.

6                                                                          TM2100EU02TM_0001
GSM Services                                                                                                    Siemens

         BS     Service        Structure       Bitrate     Mode   Transmission
         No.                                   [bit/s]
         21    line oriented   asynchronous        300     T/NT   UDI / 3.1 kHz
         22                                      1200      T/NT   UDI / 3.1 kHz
         23                                    1200/75     T/NT   UDI / 3.1 kHz
         24                                      2400      T/NT   UDI / 3.1 kHz     Bearer Services
         25                                      4800      T/NT   UDI / 3.1 kHz
         26                                      9600      T/NT   UDI / 3.1 kHz
         31    line oriented   synchronous       1200      T      UDI / 3.1 kHz
         32                                      2400      T/NT   UDI / 3.1 kHz
         33                                      4800      T/NT   UDI / 3.1 kHz
         34                                      9600      T/NT   UDI / 3.1 kHz
                                                           T/NT   UDI / 3.1 kHz
         41    PAD             asynchronous        300     T/NT   UDI
         42                                      1200      T/NT   UDI
         43                                    1200/75     T/NT   UDI
         44                                      2400      T/NT   UDI
         45                                      4800      T/NT   UDI
         46                                      9600      T/NT   UDI
         51    PAD             synchronous       2400      NT     UDI
         52                                      4800      NT     UDI
         53                                      9600      NT     UDI
         61    alternating                    13000/9600
               speech/data                                                        T/NT: Transparent / Non-Transparent
                                                                                  UDI: Unrestricted Digital Information
         81    speech                          1300/9600
                                                                                  PAD: Packet Assembler / Disassembler
               by data

Fig. 3

    Siemens                                                                 GSM Services

    Tele Services TS
    The Tele Services (GSM Rec. 02.03) offer the complete range of communication
    services between users. The most important categories of TS are represented by
    voice services (TS11/12), Short Message Service (SMS: TS21-23), Teletext (TS51)
    and Fax transmission (TS61/62).
    l   TS11 sets up speech calls between a mobile subscriber (PLMN) and a fixed
        network subscriber (ISDN/PSTN) or (other) PLMN subscriber. There is a
        differentiation in the called party: Mobile Originating Call MOC means to be that
        the mobile subscriber has initiated the call, Mobile Terminating Call MTC means to
        be that the mobile subscriber is called.
    l   TS12 sets up speech calls between a mobile subscriber (PLMN) and one in an
        emergency service central office which is allocated to a respective location.
    l   TS21 & TS22: In the case of Short Message Services TS21 and TS22, it is
        possible to receive or transmit messages with a length up to 160 alphanumeric
    l   TS23: In the case of TS23, the Short Message Service Cell Broadcast (SMSCB), it
        is possible to receive messages of a length up to 93 alphanumeric characters from
        a Cell Broadcast Center. Classically described as "paging", messages on different
        topics concerning a particular area can be received (e.g. traffic; meteorological;
        stock information, etc.).
    Further Tele Services are provided as an option, but, due to a lack of demand,
    seldom implemented.

8                                                                         TM2100EU02TM_0001
GSM Services                                                                             Siemens


         Category                TS No.   Service

         Speech                   11      Telephony; MOC, MTC
                                  12      Emergency Call
         Short Message Service    21      Short Message MT, PP
                                  22      Short Message MO, PP
                                  23      Short Message Service Cell Broadcast
         Teletext transmission    51      Teletext
         Fax transmission         61      Alternating speech / fax (Group 3),
                                  62      T/NT
                                          Fax (Group 3) automatic, T/NT

                                                 T/NT: Transparent / Non-Transparent
                                                 UDI: Unrestricted Digital Information
                                                 PAD: Packet Assembler / Disassembler

Fig. 4

     Siemens                                                               GSM Services

     Supplementary Services
     Supplementary Services modify or extend a basic BS or a basic TS and can never be
     offered alone to a subscriber. A supplementary service must be offered together with
     a basic telecommunication service. The same supplementary service can be offered
     with a range of telecommunication services.
     The Supplementary Services are defined in the GSM Rec. 02.8x. An overview
     regarding general aspects of GSM Supplementary Services, including definitions and
     recommended regulations, is given by the GSM Rec. 02.04 (General on
     supplementary services).
     In the GSM Phase 1, only a small circuit of supplementary services concerning call
     forwarding, call transfer and call restriction has been specified. A more
     comprehensive range of supplementary services following ISDN was introduced in
     GSM Phase 2.
     The following groups of Supplementary Services will be offered:
     l   Number Identification Service
     l   Call Offering Services
     l   Call Completion Services
     l   Community of Interest Service
     l   Call Restriction Service
     l   Additional Information Transfer Service
     l   Multi Party Service
     l   Charging Service
     l   Simultaneous Use of Services

10                                                                        TM2100EU02TM_0001
GSM Services                                                                                         Siemens

     Category            Abbreviation   Service

     Number              CLIP           Calling Line Identification Presentation
     Identification      CLIR
                                        Calling Line Identification Restriction
                                        Connected Line identification Presentation
                         CoLR           Connected Line identification Restriction       Services
                         MCI            Malicious Call Identification
     Call Offering       CFU            Call Forwarding Unconditional
                         CFB            Call Forwarding on mobile subscriber Busy
                         CFNRy          Call Forwarding on No Reply
                         CFNRc          Call Forwarding on mobile subscriber Not
                         CT             Reachable
                                        Call Transfer
                                        Mobile Access Hunting
     Call Completion     HOLD           Call HOLD
                         CW             Call Waiting
                         CCBS           Completion of Call to Busy Subscriber
     Community           CUG            Closed User Group
     of Interest
     Call Restriction    BAOC           Barring of All Outgoing Calls
                         BOIC           Barring of Outgoing International Calls
                         BAIC           Barring of All Incoming Calls
                         BOIC-ex HC     BOIC except those to Home PLMN
                         BIC-Roam       Barring of Incoming Calls when
                                        Roaming outside the home PLMN
     Additional Infor-   UUS            User-to-User Signaling
     mation Transfer
     Multi Party         3PTY           Three Party Service
                         CONF           CONFerence calling
     Charging            AoC            Advice of Charge
                         FPH            FreePhone Service
                         REVC           REVerse Charging

Fig. 5

     Siemens    GSM Services

12             TM2100EU02TM_0001
GSM Services                           Siemens

2        Applications



Fig. 6

     Siemens                                                                 GSM Services

     Current Situation
     GSM is optimized like other 2G mobile communication standards for speech
     Speech transmission also play a dominating role in the services that may be taken
     up. There are many supplementary services for conversation connections that are
     specified in the GSM Recommendations and are for the most part compatible with
     the services offered by ISDN. Amongst these are, e.g. call forwarding, call barring,
     call waiting, automatic dial-back and conference calling.
     Mobile Equipment is therefore mainly developed for speech connections. In the GSM
     Rec. 02.06 the different types of Mobile Stations MS (MS = Mobile Equipment ME +
     Subscriber Identity Module SIM) and their possible transmission powers are defined.
     They are subdivided into:
     l   Appliances for permanent installation in vehicles (Car Phones)
     l   Portable equipment (for vehicles): Portables
     l   Handhelds / Mobile Phones
     The maximum transmission power amounts up to 20 W (old) or 8 W for car phones
     and up to 2 W for handhelds in GSM900 or up to 4 W for car phones and 1 W for
     Handhelds in GSM1800/1900. The output power is variable in 2 dB steps to a
     minimum of 5 / 2 mW (Power Control).
     Despite the fact that GSM is mainly optimized for speech transmission, the capability
     to transmit data was planned from the beginning. In addition to speech transmission,
     a lot of terminal equipment is capable of performing data services (e.g. SMS).
     For data transmission purposes, the possibility of connecting further suitable terminal
     equipment to the hand equipment is usually offered, via an adapter. Examples for
     this are fax equipment, laptops, organizers, digital cameras, GPS (Global Positioning
     System) receivers, etc.
     Independent equipment solutions are also beginning to encompass even more areas
     of use (e.g. mobile barcode readers with SMS).

14                                                                          TM2100EU02TM_0001
GSM Services                                                                   Siemens

                                              Current Applications:
                                               Terminal Devices
                Mobile equipment:
                • Car phones
                • Portables                             Transmission power:
                • Handhelds                             • 8 W / 4 W (GSM 900/1800)

     • Speech
     • Short messages (SMS)
     • Faxes
     • Data
     • Internet surfing
     • Organizer
     • Mobile banking
                                    Mobile accessories:
                                    • Fax devices
                                    • Laptops              • Barcode readers
                                    • Digital cameras      • GPS receivers
                                    • Headsets             • ....

Fig. 7

     Siemens                                                                     GSM Services

     Trend: Data transmission
     GSM was planned for both speech and data transmission. From central importance
     was and however, is speech transmission.
     In GSM the voice Tele Services (TS11/12) had to be implemented by every network
     operator right from the start. The data services, on the other hand, had to be
     implemented by all the network operators at a later time, e.g. fax service (TS61) from
     1994 onwards and SMS (TS21) from 1996 onwards. The decision regarding the
     implementation of further data services or the transport mechanism which were a
     prerequisite for this, was left to the individual network operators.
     The share of data transmission to the entire traffic via the radio interface (air time) of
     approx. 2 % shows that speech transmission, even in 2001, nine years after the
     introduction of GSM as the first 2G mobile communication standard, still holds a
     dominant position.
     The growth rate of the individual data services, particularly the SMS services, but
     also general data transmission as a part of the total number of connections, is al-
     ready showing a shift of focus from voice services to data services.
     In the future, data services will gain in importance. In the framework of an increasing
     mobility in the world of work (work outside the office, teleworking), the need for
     mobile transmission of data will increase. Examples for this are connection of fax
     equipment, of digital cameras and notebooks. In this context, the growing importance
     of the Internet should be emphasized. In addition, the transmission of smaller data
     packets using SMS is gaining in importance. Examples for this, besides personal
     short message paging offers (SMSCB), are telematics information, GPS location de-
     termination, inventory via mobile barcode readers and automatic information
     transmission from/to remote-controlled installations.

16                                                                             TM2100EU02TM_0001
GSM Services                                                                                      Siemens

                                        Trend in GSM:
                                        speech ® data

              speech:                                                  Traffic volume of
                                                                        data services
         "normal connection"                                                 (total):
            emergency call                        Implementation            1-2%
            Implementation                                            Implementation
             obligatory after                                      depending on operator
               start phase                           SMS:
                                                 short message,
                                                 remote control,
                                Implementation                             e-mail,
                                                 barcode reader,
                                   obligatory                          file transfer,
                                                                        video tele-
                                     fax                                   phony,
                 1992                1994              1996               1998             2000

Fig. 8

     Siemens                                                                      GSM Services

     Current Demands to GSM
     The current demands made for GSM are manifold. Amongst the requirements are:
     l   a quick transfer of a large data volumes
     l   mobile computer connection/ Internet access
     l   user friendliness
     l   improved speech quality
     l   world-wide availability
     l   world-wide offer of Home PLMN services
     l   the creation of specific services for special user groups / tools for flexible service

     Many of these requirements are taken into account by the Annual Releases of GSM
     Phase 2+.

18                                                                              TM2100EU02TM_0001
GSM Services                                                     Siemens

           Demands on

                          • Quick transfer of large
                             data volumes
                             (E-Mail, Internet, File transfer,
                          • Improved speech quality
                          • User friendliness
                          • Worldwide availability
                          • Worldwide HPLMN service
           Solutions:     • Specific services
           Phase 2+

Fig. 9

     Siemens    GSM Services

20             TM2100EU02TM_0001
GSM Services                                          Siemens

3         GSM Phase 2+ Services

                         Demands on
                    mobile communications?

                             Phase 2+

                                              Phase 2+

                               GSM Phase 2+

Fig. 10

     Siemens                                                                    GSM Services

     GSM Phase 2+ Solutions
     For many of these requirements that are made on mobile communications now and
     in the near future, solutions are being developed in the GSM Phase 2+. New specific
     data and voice services, more efficient and user friendly mobile stations, the
     introduction of IN Services for the entire GSM, the possibility of the flexible creation of
     features for particular user groups and many other features are introduced in the
     Annual Releases of GSM Phase 2+ and are constantly being further optimized.

22                                                                             TM2100EU02TM_0001
GSM Services                                                                              Siemens

                               satellite     multi-                         SOR
                               roaming band / mode                        Support of
                                e.g. ICO                                Optimal Routing
                     EFR             Multiple Subscriber            UUS
                Enhanced                    Profile               User-User
                 Full Rate         ASCI                           Signalling
                               Advanced Speech
             GPRS                  Call Items       CAMEL
                                               Customized Application
          General Packet
           Radio Service    HSCSD               for Mobile network
                         High Speed Circuit       Enhanced Logic
                           Switched Data      EDGE
                                       Enhanced Data rates
                                      for the GSM Evolution

                                          Phase 2+

Fig. 11

     Siemens                                                                 GSM Services

     Data Transmission
     One of the problems of data transmission using GSM is posed by the current
     comparatively user unfriendly usage of data services in the terminals (e.g. SMS) or
     the complicated connection of terminal equipment via adapter.
     Terminal equipment in which different functions are integrated, as well as displays
     optimized for each individual data transmission form provide an answer to this.
     A decisive problem is posed by the comparatively low data transmission rates of
     GSM Phase 1 and 2. Data transmission rates of 0.3 -9.6 kbit/s compared to 64 kbit/s
     using ISDN are considerably too low.
     To increase the data transmission rates, new bearer services are being developed in
     GSM Phase 2+ which will adapt the data transmission rates to the ISDN transmission
     rates in various usage areas or even be considerably above them.
     l   High Speed Circuit Switched Data HSCSD
     l   General Packet Radio Service GPRS
     l   Enhanced Data rates for the GSM Evolution EDGE

24                                                                         TM2100EU02TM_0001
GSM Services                                                                                                                    Siemens

                                 GSM / ISDN: Data Transmission Rates                                            EDGE

     max. data rate [kbit/s]

                                          ISDN               GSM             GSM             GSM               GSM
                                                            Phase 1/2                       Phase 2+
                                 ISDN: Integrated Services Digital Network    HSCSD: High Speed Circuit Switched Data
                                 GPRS: General Packet Radio Service           EDGE: Enhanced Data rates for the GSM Evolution

Fig. 12

     Siemens                                                                    GSM Services

     High Speed Circuit Switched Data HSCSD
     HSCSD is an enhancement for the classical GSM circuit switched data transmission.
     1. New Coding Scheme: Introducing a new coding scheme, which allows to
        transmit 14.4 kbit/s in one physical channel, the data rate was increased 50%.
        The enhancement is possible using reduced redundancy for data transmission
        over Um. This is only possible if the radio interface quality is sufficient good. If the
        quality of transmission decreases, i.e. the error rate increases, the data rate is
        automatically reduced from 14.4 kbit/s to the classical 9.6 kbit/s.
     2. Channel Combining: It is possible to combine several physical channel to one
        user to enhance the data rate. Theoretically, all 8 physical channel of one carrier
        can be combined to one user. Thus, HSCSD increases the maximum theoretical
        data rate to 115.2 kbit/s. In praxis, HSCSD is restricted by the maximum data
        rate, which can be switched through in the GSM NSS, i.e. 64 kbit/s. Therefor, in
        praxis only a maximum of four physical channel with 14.4 kbit/s are combined to
        one user. This enables a maximum data rate of 57.6 kbit/s.
     For implementation of HSCSD no new network elements have to be integrated in a
     GSM-PLMN. The protocol architecture also remains unchanged. Changes are
     confined to certain existing components (software modifications).
     HSCSD is described in the GSM Rec. 02.34.

26                                                                             TM2100EU02TM_0001
GSM Services                                                                                    Siemens

                          High Speed Circuit Switched Data

                         ®                                                                 ••••
                    14.4 kbit/s
                    14.4 kbit/s
     mission                  28.8 kbit/s
                                              57.6 kbit/s
                Circuit                      for continuous                  moving pictures,
               Switched                         data flow                    video telephone

               only point-to-point          no new network
                                                                     SW modifications

                    Disadvantage:                           smaller HW
                 not resource efficient                     modifications

Fig. 13

     Siemens                                                                  GSM Services

     General Packet Radio Service GPRS
     GPRS introduces a total new transmission principle into the GSM PLMNs.
     1. Packet Switched data transmission: For the first time, packet switched data
        transmission is possible in GSM. A direct access to Packet Data Networks PDNs
        (e.g. Internet, Intranet, X.25) is created. The packet data transmission allows to
        turn from time dependent charging to volume dependent charging (advantage for
        the user) and to optimize the usage of radio resources (advantage for the
        network operator).
     2. New Coding Schemes: Four new Coding Schemes CS are introduced for the
        data transmission on Um. CS-1 offers transmission rates of 9.05 kbit/s, CS-2 of
        13.4 kbit/s, CS-3 of 15.6 kbit/s and CS-4 of 21.4 kbit/s per physical channel. The
        redundancy is reduced from CS-1 to CS-4. This allows optimized reaction on the
        current actual quality of the radio interface, i.e. CS-4 is automatically chosen, if
        the radio interface is nearly perfect, CS-1 if the quality is comparable low.
     3. Channel Combining: Theoretically, it is possible to combine up to 8 physical
        channel of one carrier to one user. Different to HSCSD, there are no restrictions
        from NSS side. A total new NSS architecture allows to transmit high data rates
        well beyond 100 kbit/s. Thus, theoretically up to 171.2 kbit/s can be transmitted.
     The introduction of GPRS means to be significant modifications and enhancements
     of the total GSM PLMN. A new parallel Core Network for packet data transmission
     with new network elements has to be introduced. The BSS has to be enhanced by
     new functions. A new protocol architecture has to be implemented.
     As a packet oriented service, GPRS leads to a wide range of applications with a high
     volume but bursty traffic. GPRS is suitable for Internet applications (e.g. Internet
     surfing), E-mail, telematics, telemetry and fleet management. GPRS also creates the
     possibility for broadcast data transmission ("point to multipoint”). Using GPRS, a
     large number of applications are possible for mobile subscribers, which, up until now,
     could only be used in fixed PDNs. GPRS means to combine the mobile and IP world.
     GPRS is a prerequisite for the UMTS introduction.
     The definition of GPRS was done in two steps in the GSM Phase 2+ Annual Re-
     leases '97 and '99. The effects of GPRS are pronounced in many GSM
     Recommendations. A main description is given in Rec. 02.60 and 03.60.

28                                                                          TM2100EU02TM_0001
GSM Services                                                                                               Siemens

                         General Packet Radio Service

                                                                                  Packet Switched
                                                  1 - 8 channels
    CS-1   9.05 kbit/s

                                                up to > 100 kbit/s
                                                                                       billing according
    CS-2      13.4 kbit/s                         (theoret. 171.2 kbit/s)
                                                                                        to data volume

    CS-3        15.6 kbit/s                    point-to-multipoint
                                                                              internet, telemetry,
    CS-4            21.4 kbit/s                                                fleet management,
                                                                            e-mail, traffic telemetry,..
  channel different redundancy depending on     Modifications in
                   air interface quality
  coding                                       Network & Protocol
                          Advantage:              architecture                  protocol architecture
                     • resource efficient                                          modifications
                     • direct IP access
                     • prerequisite for UMTS

Fig. 14

     Siemens                                                                   GSM Services

     Enhanced Data rates for the GSM Evolution EDGE
     EDGE has to be regarded as a booster for GPRS or HSCSD.
     1. New Modulation Principle: EDGE introduces a new, sophisticated modulation
        principle into GSM. It is called 8 Phase Shift Keying (8PSK). Compared with the
        classical GSM modulation principle, the so-called Gaussian Minimum Shift
        Keying (GMSK), a 3 times higher data rate is possible.
     EDGE can used to enhance the data rates of GPRS and HSCSD. In combination
     with GPRS (so-called E-GPRS) data rates up to 69.2 kbit/s (gross rate) can be
     achieved. Combining up to 8 physical channel to one user, this means to be a
     maximum theoretically data rate of 553.6 kbit/s.
     Exceeding clearly the 384 kbit/s, which have been requested for 3G wide range
     applications, EDGE (better: E-GPRS) has been accepted as 3G transmission
     It is used to enhance GSM (and also D-AMPS) networks toward 3G requirements.
     This is useful for all network operators, which lack of licenses for UMTS.
     Furthermore, a fast roll-out is possible to support high data rates also in rural areas,
     where UMTS cannot be implemented in a first step.

30                                                                            TM2100EU02TM_0001
GSM Services                                                                                           Siemens

               EDGE: Enhanced Data rates for the GSM Evolution
    bundling                 1               2             3                 4                     8

  data rate/TS
    [kbit/s]            up to 69.2                                                   ••••

       rate                   up to 138.4 kbit/s

                                             up to 207.6 kbit/s

                                                        up to 553.6 kbit/s

                            GSM           GSM
                          (HSCSD)        (EDGE)        EDGE:
      Modulation           GMSK           8PSK         • Booster for GPRS (&HSCSD)
                                                       • High-level modulation (813 instead of 270 kbit/s)
     Carrier width         200 kHz       200 kHz
                                                       • Use of "classical" GSM channel structure
   Modulation rate 270.8 kbit/s         813 kbit/s      (FDMA/TDMA: 200 kHz; 8 TS with 4.615 ms each)
                                                       • max. 8 x 69.2 kbit/s = 553.6 kbit/s Þ
          bit rate/TS     14.4 kbit/s   69.2 kbit/s      meets 3G requirements (Zone 3: rural)
          Max. rate       115 kbit/s    553.6 kbit/s

Fig. 15

     Siemens                                                              GSM Services

     Enhanced Speech Transmission
     A better quality of speech transmission which uses the same (gross) transmission as
     the classical Full Rate FR speech codec is offered in GSM Phase 2+ by the
     Enhanced Full Rate EFR speech codec.
     An expansion of the existing GSM voice services has been introduced using the term
     Advanced Speech Call Items ASCI in GSM Phase 2+. This is for special user
     groups, particularly for the usage of railway GSM systems (GSM-R). The ASCI
     services contain group and broadcast services with a fast call setup and control of
     The following specifications are summarized using the term ASCI:
     l   Voice Broadcast Service VBS (Rec. 02.69)
     l   Voice Group Call Service VGCS (Rec. 02.68)
     l   enhanced Multi-Level Precedence and Pre-Emption eMLPP (Rec. 02.67)

32                                                                       TM2100EU02TM_0001
GSM Services                                                                Siemens

          Speech Transmission
              in Phase 2+
          Enhanced Full Rate EFR       Advanced Speech Call Items
             improved speech codec
                   (13 kbit/s)       • Voice Broadcast Service VBS
                                     • Voice Group Call Service VGCS
                                     • enhanced Multi-Level Precedence
                                       and Pre-Emption eMLPP
                                         ® For Closed User Groups (GSM-R)
                                         ® Group and broadcast services
                                         ® Quick call set-up
                                         ® Priority control

Fig. 16

     Siemens                                                                    GSM Services

     Voice Broadcast Service VBS
     Closed user groups (e.g. GSM-R) need to be able to transmit information quickly
     from one subscriber to a number of other subscribers.
     VBS enables subscribers to multiply a message to a number of other subscribers
     ("listeners"). For this message transmission only the initial Mobile Station (originating
     MS) interacts with the PLMN, whilst the receiving MSs passively receive the
     messages. The initiating MS transmits to the network the identity of the group of sub-
     scribers to which the message has to be sent. A call notification, which is not con-
     firmed by the “listening” MSs, as well as the message, are sent out to all cells in
     which the group members are located.
     VBS can be initiated not only by a MS, but also by the fixed network. Mobile stations,
     which belong to a particular group and are located in a previously defined
     geographical area and/or in a closely defined group of dedicated network stations
     may be ad-dressed.
     The setup time for the VBS should be extremely short, as these messages, amongst
     other purposes, are intended for warnings of situations regarding safety.

     Voice Group Call Service VGCS
     VGCS enables voice group call for Closed User Groups with special call qualities. A
     group call channel is created which enables the fixed network and mobile stations to
     create a group call channel on which the group members may listen or also transmit.
     After the person who has initiated the call has transmitted his message, he/she
     leaves the channel and changes over to the "listener" mode. Now every subscriber
     may apply for channel allocation, i.e. the "right to broadcast" and use this until he/she
     changes back into "listener mode". A VGCS group call is ended by the initiator.
     The addressed groups are the same for VGCS and VBS.

     enhanced Multi-Level Precedence and Pre-Emption eMLPP
     A control of priorities of the ASCI services is possible using eMLPP. Five priorities'
     classes for subscribers are existing (0 - 4: 0 highest, 4 lowest priority) and two priori-
     ties' classes (A, B) for internal network processes (e.g. to configure group calls and
     The maximum priority that is applied to a subscriber is negotiated with the service
     provider and stored on the SIM card.

34                                                                             TM2100EU02TM_0001
GSM Services                                                                                                Siemens

                                  Advanced Speech Call Items

    Voice Broadcast Service VBS
    • 1 "speaker“ (MS or fixed network), many listeners
    • Message for particular groups / particular cells
    • Only “speaker" interacts with network
    • Notification (instead of paging) & message in def. cells
    • "Listener" passive (confirmation message possible)         enhanced Multi-Level
                                                                 Precedence & Pre-Emption
                                                                 • Priority control for VBS, VGCS
                                                                 • Priority classes:
                                                                   5 (subscriber) + 2 (network-internal
                                                                 • Priority allocation: service provider / SIM

   Voice Group Call Service VGCS
   • Speech group call: 1 group call channel
   • 1 "speaker", many listeners; group as with VBS
   • Changing speaker (call initiator ® listener mode)
   • "Transmission rights" in speech pauses
   • Ended by initiator / VAD

Fig. 17

     Siemens                                                                 GSM Services

     CAMEL: Customized Applications for Mobile network Enhanced Logic
     The support of IN (Intelligent Network) services in GSM is introduced with CAMEL
     (GSM Rec. 02.78, 03.78, 09.78).
     Previous IN solutions for GSM were of a proprietary nature and could therefore only
     be used by subscribers in the home PLMN (HPLMN). CAMEL allows the global use
     of IN services. CAMEL services can also be deployed for international roaming in all
     CAMEL-supporting GSM networks. Operator-specific services can be introduced with
     These kinds of services were introduced in 3 phases (Annual Rel. '96, '98 and '99) in
     Services such as call screening services, call supervision services and number
     translation services were defined in CAMEL Phase 1.
     CAMEL Phase 2 specifies additional services such as online charging, transfer of
     subscriber location information and downloading of HPLMN-specific charging
     CAMEL Phase 3 implements the interworking of GSM Mobility Management and
     GSM features, thereby allowing so-called location-based services. The ability to
     control calls with more than 2 parties is also supported.
     CAMEL Phase 3 is a large component of the new UMTS VHE concept and is
     consequently a major step on the evolutionary path from GSM to UMTS.
     Network modifications are required for the introduction of CAMEL. A so-called
     CAMEL Service Environment (CSE – modification of the network) and a CAMEL
     Application Part (CAP – extension of the protocol architecture) will be introduced.

36                                                                         TM2100EU02TM_0001
GSM Services                                                                                       Siemens

                                Customized Application
                           for Mobile network Enhanced Logic
                                                              allows             usage also with
             ETSI definition
                                                         operator-specific       International
             of IN services                                  services              Roaming

      Implementation in steps:
          Step 1: Release ‘96
          Support of some service definitions
          e.g. "Call Screening Services", "Call Supervision Services",            exchange of
          "Number Translation Services"                                       subscriber information
                      Step 2: Release ‘97                                       HPLMN « VPLMN
                      other features: download HPLMN-charging
                      information, on-line charging, internal pre-paid,
                      Specialized Resource Functions SRF (add.
                      service info, tones, announcements,..), local info,
                      ...                                                      implementation of
                                    Step 3: Release ‘99                      IN functional elements
                                    • Co-operation with GSM mobility
                                    • Multiparty calls
                                    • Support of UMTS - VHE concept

Fig. 18

     Siemens                                                                     GSM Services

     SIM Toolkit
     The SIM (Subscriber Identity Module) Toolkit application was introduced in the GSM
     Standard in the Releases ‘96/’97 and integrated in GSM Standard (Rec. 11.11,
     The SIM Toolkit is an expression of the desire to enable a service differentiation in
     the networks, without having to offer different Mobile Equipment variants. Using the
     SIM Toolkit, there is no need to buy always new a new MS if a new service is created
     or if a service is updated. The SIM Toolkit applications are completely logically
     separated from the GSM functions of the SIM and supplement the functionality of
     mobile equipment.
     Using SIM Toolkits it is, for instance, possible to:
     l   download data via SMS from the network, directly onto the SIM (Data Download),
         making new data, commands or applications that are different from the extant SIM
         Toolkit applications possible
     l   deliver complete SMS from the SIM to the ME for transmission
     l   implement "Call Control" by using the SIM, i.e. check digit sequences of the sub-
         scriber before execution, modify if necessary or prevent the execution
     l   local information about cell identity, call status, etc. shall be implemented into the
         SIM applications to modify the applications if the status is changed
     In the near future SIM Toolkit applications will consist of e.g.:
     l   mobile banking via GSM
     l   booking flights
     l   information services
     Because these applications involve specific commercial and safety questions special
     safety mechanisms are used for the SIM Toolkit and/or the opposite side of
     transmission (Rec. 02.48, 03.48).

38                                                                              TM2100EU02TM_0001
GSM Services                                                                           Siemens

             SIM Toolkit


                       Subscriber Identity Module

                                                     SIM Toolkit
                                    • Supplements ME functions without HW modifications
                                    • Data download (SMS)
                                    • Call control (digit sequence)
                                    • Info on cell identity, call status Þ
                                      application modifications for status change possible
          ME                        • Applications: home banking, booking flights,
    Mobile Equipment                   info services,...
                                    • Special security mechanisms

Fig. 19

     Siemens                                                                    GSM Services

     Mobile station application Execution Environment MExE
     MExE shall support a operator specific applications to the network and the mobile
     stations, as well as a simplified access to the Internet. The possibility of installing
     user-friendly interfaces by downloading software is included.
     Two techniques may be employed within the framework of MExE:
     l   WAP (Wireless Application Protocol architecture), which was developed by WAP
         Forum Ltd. WAP is intended to allow the development of applications as industry
         standard (e.g. Internet surfing) via a wireless communication network, independent
         from the access technology. The WAP was optimized for small equipment (mobile
         phones); it is based on the Internet client server architecture.
     l   JAVA, will find application due to its universal usage, the independence from a
         platform, as well as the built-in capability of being able to recognize networks. This
         universality is achieved at the cost of a decrease of PC performance and is
         therefore restricted to the high-end applications, such as PDAs (Personal Digital
         Assistants) or laptops.

40                                                                             TM2100EU02TM_0001
GSM Services                                                                Siemens

                            Mobile station application
                             Execution Environment

                                    simplified implementation
                                      of operator-dependent

                        user friendly interfaces       SW download
                          (internet surfing /
                            mobile phones)

          Wireless                                                   JAVA
     Application Protocol

Fig. 20

     Siemens                                                                   GSM Services

     Support of Optimal Routing SOR (Rec. 02.79)
     SOR enables the routing of incoming calls directly to the mobile subscriber, i.e. to
     his/her current location even in a foreign network (VPLMN), instead of taking the long
     route via the home network (HPLMN). Only signaling is exchanged between VPLMN
     and HPLMN.

     User-to-User Signaling UUS (Rec. 02.87)
     User-to-User Signaling enables a combination of SMS (Short Message Service) and
     telephone services. Simple short messages e.g. telephone numbers, addresses etc.
     may be transmitted while a call is in progress to the other call partner.

     Multiple Subscriber Profile MSP (Rec. 02.97)
     MSP is intended to offer the possibility of separate identities for one subscriber. Up to
     four different identities per subscriber will be possible and may be stored on one SIM
     card. Thus the user may multiply his personal identity, e.g. into private and business,
     for incoming calls that require a different treatment (e.g. alarm, supplementary
     services, etc.).

42                                                                           TM2100EU02TM_0001
GSM Services                                                                    Siemens

    Other Phase 2+ Features
              SOR                                                User to User
            Support of
          Optimal Routing

    • Direct connection
    • No detour via HPLMN                          private
    • VPLMN Û HPLMN: only signaling
                                                                Subscriber Profile

                                      • Max. 4 different
                                        subscriber identities              work
                                      • 1 SIM

Fig. 21

     Siemens    GSM Services

44             TM2100EU02TM_0001

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