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Thread: UMTS Services and Service Aspects

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    Default UMTS Services and Service Aspects

    <i>Introduction: </i>
    </font>Services are
    communication capabilities that are made available to the users by the
    Home Environment (HE) and the Serving Network(SN). The services are
    divided into four main classes:
    </font><blockquote>
    <ol><li>Bearer Services
    </li><li>Teleservices
    </li><li>Supplementary Services
    </li><li>Service Capabilities
    </li></font></ol>
    </blockquote>
    Lets discuss each of them below

    </font><i>Bearer Services: </i>
    </font>Bearer services in UMTS
    are negotiable (unlike GSM where they are not) and can be used flexibly
    by applications. Bearer services provide the capability for information
    transfer between access points and only lower layer functions. PS (see
    [4]) and CS (see [3]) domains provide a specific set of bearer
    capabilities. </font>Bearer services are
    charachterised by a set of end-to-end charachteristics with
    requirements on QoS. QoS (or Quality of Service) is the quality of the
    service that has been requested. The service charachteristics includes
    things like traffic type, supported bit rates and the quality of
    information. These parameters are negotiated when a connection is being
    established. If the network is unable to provide the required QoS, it
    will re-negotiate the QoS depending on what is available. After the
    connection has been established, if there is a need then these
    parameters can be re-negotiated again. The following are the brief
    description of the bearer services.
    </font><blockquote>
    <i>Information transfer: </i>
    </font><i>Connection oriented / connectionless services</i>
    </font>Both Connection oriented and connectionless services shall be supported.

    </font><i>Traffic type:</i>
    </font>It is required that the bearer service provides one of the following:
    </font><ul><li>guaranteed/constant bit rate,
    </li><li>non-guaranteed/dynamically variable bit rate, and
    </li><li>real time dynamically variable bit rate with a minimum guaranteed bit rate..
    </li></font></ul>
    Real time and non real time applications shall be supported.
    </font><ul><li>Real time video, audio and speech shall be supported. This implies the:
    </li><li>ability to provide a real time stream of guaranteed bit rate, end to end delay and delay variation.
    </li><li>ability to provide a real time conversational service of guaranteed bit rate, end to end delay and delay variation.
    </li><li>Non real time interactive and file transfer service shall be supported. This implies the:
    </li><li>ability to support message transport with differentiation as regards QoS between different users.
    </li><li>Multimedia applications shall be supported. This implies the:
    </li><li>ability to support several user flows to/from one user having different traffic types (e.g. real time, non real time)
    </li></font></ul>

    <i>Traffic characteristics</i>
    </font>It shall be possible for
    an application to specify its traffic requirements to the network by
    requesting a bearer service with one of the following configurations </font><ol><li>Point-to-Point
    <ul><li>Uni-Directional
    </li><li>Bi-Directional
    </li><li>Symmetric
    </li><li>Asymmetric
    </li></ul>
    </li><li>Uni-Directional Point-to-Multipoint
    <ul><li>Multicast
    </li><li>Broadcast
    </li></ul>
    </li></font></ol>

    <i>Information Quality</i>
    </font>Information quality characterises the bit integrity and delay requirements of the applications.

    </font><i>Maximum transfer delay</i>
    </font>Transfer delay is the
    time between the request to transfer the information at one access
    point to its delivery at the other access point. </font><i>Delay variation</i>
    </font>The delay variation of the information received information over the bearer has to be controlled to support real-time services.
    </font><i>Bit error ratio </i>
    </font>The ratio between incorrect and total transferred information bits.
    </font><i>Data rate</i>
    </font>The data rate is the amount of data transferred between the two access points in a given period of time.

    </font><i>Supported bit rates</i>
    </font>It shall be possible for
    one application to specify its traffic requirements to the network by
    requesting a bearer service with any of the specified traffic type,
    traffic characteristics, maximum transfer delay, delay variation, bit
    error ratios &amp; data rates. It shall be possible for the network to
    satisfy these requirements without wasting resources on the radio and
    network interfaces due to granularity limitations in bit rates. It
    shall be possible for one mobile termination to have several active
    bearer services simultaneously, each of which could be connection
    oriented or connectionless. The only limiting factor for satisfying
    application requirements shall be the cumulative bit rate per mobile
    termination at a given instant (i.e. when summing the bit rates of one
    mobile termination’s simultaneous connection oriented and
    connectionless traffic, irrespective of the traffic being real time or
    non real time) in each radio environment:
    </font><ul><li>At least 144 kbits/s in satellite radio environment.
    </li><li>At least 144 kbits/s in rural outdoor radio environment.
    </li><li>At least 384 kbits/s in urban/suburban outdoor radio environments.
    </li><li>Greater than 2 Mbits/s in urban/suburban outdoor radio environments.
    </li><li>At least 2048 kbits/s in indoor/low range outdoor radio environment.
    </li><li>Greater than 2 Mbits/s in indoor/low range outdoor radio environment.
    </li></font></ul>

    </blockquote>


    <i>Teleservices</i>
    </font>Teleservices provide the
    full capabilities for communications by means of terminal equipment,
    network functions and possibly functions provided by dedicated centres.
    Basically it is a service that provides complete end-to-end capability
    for communication between mobile users according to standards.
    Teleservices contain both single media and miultimedia services. Some
    of the teleservices are listed below
    </font><ul><li>Speech/Telephony
    </li><li>Emergency Calls
    </li><li>Short Message Service - Point to Point (SMS-PP)
    </li><li>Short Message Service - Cell Broadcast (SMS-CB)
    </li><li>Internet Access
    </li></font></ul>
    Teleservices utilises the bearer
    services provided by lower layers. The Bearer Services and the
    Teleservices are not coupled to each other so as to aid independent
    development and changes to one may not necessarily mean changes to
    other.
    </font><i>Supplementary Services (SS)</i>
    </font>A supplementary service
    modifies or supplements a basic telecommunication service.
    Consequently, it cannot be offered to a user as a stand alone service.
    A stand alone service can be either Bearer Service or Teleservice but
    cannot be Supplementary service. It shall be offered together or in
    association with a basic telecommunication service. The same
    supplementary service may be applicable to a number of basic
    telecommunication services. Also, one basic telecommunication service
    may use several SS simultaneously.
    </font>The following is list of some of the supplementary services (see [5] for more details)
    </font><ul><li>Call Forwarding
    </li><li>Call Deflection
    </li><li>Call Waiting
    </li><li>Call Hold
    </li><li>Call Restriction and Call barring
    </li><li>Number Identification
    </li></font></ul>

    <i>Service Capabilities</i>
    </font>Services Capability
    Features are open, technology independent building blocks accessible
    via a standardised application interface. This interface shall be
    applicable for a number of different business and applications domains
    (including besides the telecommunication network operators also service
    provider, third party service providers acting as HE-VASPs, etc.). All
    of these businesses have different requirements, ranging from simple
    telephony and call routing, virtual private networks, fully interactive
    multimedia to using UE based applications. Since the API is
    standardised but not the services, Mobile operators can utilise the API
    to build unique value-added services. </font><br>

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