Digital cellular telecommunications system (Phase 2+); (GSM) Universal Mobile Telecommunications System (UMTS); LTE; Service requirements for the Internet Protocol (IP) multimedia core network subsystem (IMS); Stage 1 (V13.3.0; 3GPP TS 22.228 version 13.3
"This TS defines the service requirements from users"" and operators"" perspective for the support of IP multimedia applications through the IMS. IP multimedia applications are supported by IP multimedia sessions in the IM CN Subsystem. IP multimedia sessions use IP connectivity bearers (e.g. GPRS as a bearer). Examples of IP multimedia applications include speech communication@ real time multimedia applications@ shared online whiteboards etc. This TS@ in general@ does not standardise usage of IP multimedia applications@ but instead identifies the requirements to enable their support. In order to align IP multimedia applications wherever possible with non-3GPP IP applications@ the general approach is to adopt non-3GPP IP based solutions. The existing legacy tele- and supplementary services shall not be re-standardised as IP multimedia applications@ and multimedia equivalent applications may be created with toolkits."