The Framework for Live Uplink Streaming (FLUS) is an enabler for live media streaming from a source entity to a sink entity. FLUS offers an IMS-based and a non-IMS-based instantiation. The IMS/MTSI-based instantiation enables the establishment of live media streaming between two UEs or between a source entity and a sink entity, within and across operator networks. Compared with MTSI, where limited types of QoS for speech or video media are used, FLUS can provide a wider range of QoS operation, e.g., in the maximum delay, available bandwidth or target packet loss rate. In the non-IMS-based instantiation, it is possible to operate FLUS as a more generic framework that is controlled through a RESTful API and that supports other media plane protocols (i.e. not based on IMS or MTSI). In addition to providing a wider range of QoS operation over radio links, other advanced functionalities of FLUS, such as the signalling of immersive media, can be used to complement existing 3GPP services.

The present document defines a FLUS source entity and a FLUS sink entity that can support point-to-point transmission of speech/audio, video, and text. It defines media handling (e.g., signalling, transport, packet-loss handling, and adaptation). The goal is to ensure a reliable and interoperable service with a predictable media quality while allowing for flexibility in the service offerings. A FLUS source entity, which may be embedded in a single UE, or distributed among a UE and separate audio-visual capture devices, may support all or a subset of the features specified in this document. When used as a generic framework, only the F-C procedures for establishing the FLUS session are required to be supported by the FLUS source and the FLUS sink entities, and no other feature or procedure specified in this document is mandated. Impact on the service quality and network capacity is left to the discretion of the implementation and the service utilizing the framework. For example, configuration of media formats and codecs follows the requirements of the respective service. When offered as part of a 3GPP IMS/MTSI service, the FLUS source and the FLUS sink entities are required to support the IMS control plane and media plane procedures, and the service quality is determined by the MTSI service policy. The specification is written in a forward-compatible way in order to allow additions of media components and functionality in releases beyond Release 15.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

• References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.