scope:

The present document provides a study on the media handling aspects of conversational services in 5G, taking as baseline the Stage-1 requirements developed in TS 22.261 [2], as well as the Stage-2 architecture for 5G systems developed in TS 23.501 [3]. This includes the investigation of the following areas:

- Media handling aspects of the 5G system architecture in relation to 3GPP conversational services, e.g., Multimedia Telephony Service over IMS (MTSI) in TS 26.114 [4] and IMS-based Telepresence Service in TS 26.223 [5].

- Relevance and potential reuse of components in existing 3GPP conversational services (e.g., MTSI, IMS-based telepresence, etc.) in the context of 5G systems and related Stage-2 architecture, e.g., use of MTSI features for supporting voice and video calls, use of MTSI, MS-MTSI and IMS-telepresence features for supporting multi-party conferencing, and applicability of existing QoE monitoring and QoS handling mechanisms.

- Potential enhancements to existing 3GPP conversational services (e.g., MTSI, IMS-based telepresence, etc.) towards better fulfilling the Stage-1 requirements in TS 22.261, e.g., in terms of criteria such as latency and bandwidth efficiency, while also taking into consideration the Stage-2 architecture for 5G systems:

- In case existing codecs are unable to address 5G application requirements, new media codec requirements for 3GPP conversational services may be developed.

- The need for, and potential use of, new QoS media handling mechanisms in 5G systems such as traffic classification and codec-aware network elements in the context of 3GPP conversational services.

The gap analysis of the above areas and associated recommendations and conclusions for the proposed improvements are documented in the present document.