22.1053GPPRelease 17Services and service capabilitiesTS
6.1 Definition of teleservices
Teleservices provide the full capabilities for communications by means of terminal equipment, network functions and possibly functions provided by dedicated centres.
6.2 Description of teleservices
The basic reference for the description of teleservices is the ITU-T Recommendation F.700 . It provides a generic, network independent, description of multimedia services. The methodology used covers both single media and multimedia services, the single media services being a particular type of multimedia services. Multimedia services are classified into categories with similar functional characteristics. The six categories are multimedia conference services, multimedia conversational services, multimedia distribution services, multimedia retrieval services, multimedia messaging services and multimedia collection services.
The rest of clause 6 describes the teleservices and options that shall be provided.
A teleservice can be viewed as set of upper layer capabilities utilising the lower layer capabilities described by the set of attributes in clause 5.
Multimedia teleservices support the transfer (and in some case retrieval, messaging, distribution) of several types of information (service components). For this reason, there are service attributes (relating to all the components of a teleservice) and service component attributes (relating to only one service component).
6.3 Support of teleservices
The realisation of teleservices requires the association of terminal and network capabilities. In the terminals and in the network, both upper layer capabilities and lower layer capabilities are necessary. The term upper layer capabilities is used because it relates to the OSI upper layers. Decoupling between upper layers and lower layers (transfer) is required. Even if this de-coupling may impact radio interface optimisation, it is nevertheless the only way of designing a system that is not outdated;
– Each time the information rate associated with an already supported teleservice is decreased by more efficient source coding techniques.
– Each time a new service is introduced that requires transfer capabilities not used by currently available teleservices.
Taking the example of two application that exchange information through a teleservice, the upper layer capabilities can be located in various places;
– In the two terminals if the two applications are connected to a PLMN.
Figure 2: PLMN teleservice
In the terminal of the application connected to a PLMN and in the upper layer interworking unit that is at the border of the PLMN and the target network if one application is connected to a PLMN and the other one is connected to another type of system. The upper layer interworking unit makes the adaptation between the PLMN and the target network at a service level.
Figure 3; Teleservice with upper layer interworking
In the terminal of the application connected to a PLMN and in the terminal of the application connected to a target network if one application is connected to a PLMN and the other one is connected to another type of system, but only lower layer interconnecting unit is used at the border of the two networks. In this case, the interconnecting unit makes the adaptation between the PLMN and the target network at the transmission level.
Figure 4; Teleservice with lower layer interworking
6.4 Existing Teleservices supported by PLMN
The subset of standardised teleservices shall be supported for interworking with teleservices provided on other networks. The means to support the following set of teleservices will be standardised:
– Emergency call;
– Short message service;
3GPP TS 22.003  describes the circuit teleservices.
The speech service as defined in international standards should be supported. The international reference for the speech is ITU-T Recommendation E.105 . Networks should contain interworking units which allow calls to be received from or destined to users of existing networks like PSTN or ISDN. This will include interworking units for generation of DTMF or other tones (the entire DTMF tone set would at minimum be available) and detection of DTMF tones.
A default speech codec shall be specified to provide speech service. The selected speech codec shall be capable of operating with minimum discernible loss of speech on handover between the GERAN and UTRAN.
6.4.2 Emergency Call
This service will use a speech component and may additionally include a data component. There are however compared to telephony reduced authentication requirements and a requirement for specific routing. Additionally Emergency Calls may have higher priority than normal calls. See 3GPP TS 22.101 for further details.
6.4.3 Short Message Service – Point to Point (SMS-PP)
A short message service point to point shall be supported. The short message service shall be provided seamlessly (as far as the user or the users terminal equipment is concerned) across the UTRAN and GERAN. A UE may, and the network shall, support the transport of SMS over WLAN and other IP Connectivity Access Networks (IP-CANs).
When short message services are transported over a generic IP-CAN:
– appropriate security mechanisms shall be supported;
– users registered from an SMS-capable UE will receive the SMS service over a generic IP-CAN while maintaining the format and functionality of SMS messages;
– the UE shall indicate its ability to send/receive SMS messages at registration;
– existing services that use SMS functionality shall not be degraded;
– the user experience shall be the same as across UTRAN and GERAN access.
Users registered from a UE capable of using another messaging service such as Immediate Messaging but not registered to receive the SMS service over a generic IP-CAN, will receive the SMS service using the other messaging service when service-level interworking is provided and if operator policy allows it. In case operator policy does not allow service-level interworking, then the message may be transported over CS or PS.
NOTE: The requirements for SMS-Immediate Messaging service-level interworking are defined in the 3GPP TS 22.340 .
When the sender’s identity is verified by the network operator, it shall be possible to convey this information as well as the verified identity of the sender (e.g. sender name), together with the SMS message, to the recipient.
6.4.4 Short Message Service – Cell Broadcast (SMS-CB)
A short message service cell broadcast shall be provided seamlessly (as far as the user or the users terminal equipment is concerned) across the UTRAN and GERAN.
6.5 Internet Access
3GPP specifications shall provide the means to interwork with external data networks. This interworking shall satisfy, within the constraints introduced by the mobile radio environment, the QoS requirements of the interworked-with network. The Internet is seen as the most important interworked-with network, therefore the specification of an optimised access to Internet will be part of the 3GPP specifications. The most important benefits achieved by the definition of Internet Access would be:
– Optimised transmission of IP traffic over the radio interface to minimise the amount of information transmitted.
– Optimised usage of encryption protocols/algorithms over the radio interface.
– Inter-operation of QoS mechanisms.
For the purposes of optimised access to Internet one or more of the generic bearers will be used. The QoS mechanisms defined for packet access mode will be harmonised with those defined for Internet (e.g. Differentiated Services).