The present document specifies Progressive Download and Dynamic Adaptive Streaming over HTTP (3GP-DASH) for continuous media. The features are separated from the umbrella specification TS 26.234 to differentiate from RTP-based streaming that is specified and maintained in TS 26.234. Services relying exclusively on these features may be deployed independently from RTP-based PSS servers, for example by using standard HTTP/1.1 servers for hosting the services and in particular also for 5G Media Downlink Streaming when content is hosted on 5GMSd ASs as defined in the stage 2 specification in TS 26.501 as well as in the stage 3 specifications in TS 26.511 and TS 26.512. The specification covers the following aspects:

• System description (clause 5): describes the relationship to the PSS architecture and refines the architecture, interfaces and protocols that are defined in the present document.
• Progressive Download over HTTP (clause 6).
• 3GPP Dynamic Adaptive Streaming over HTTP (3GP-DASH) (clause 7) provides an overview of the architecture, the formats and the models that build the basis for 3GP-DASH. Also, 3GP-DASH Profiles provide identifiers and refers to a set of specific restrictions in this or other specifications.
• DASH: media presentation (clause 8) describes the data model of a Media Presentation. It also provides an overview on elements and attributes that may be used to describe components and properties of a media presentation in a Media Presentation Description (MPD).
• DASH: usage of the 3GP file format (clause 9) defines how segments can be formed based on the 3GP file format.
• Quality of Experience for Progressive Download and 3GP-DASH (clause 10).
• Server And Network-assisted DASH (SAND) (clause 13) introduces messages between DASH clients and network elements or between various network elements for the purpose to improve efficiency of streaming sessions by providing information about real-time operational characteristics of networks, servers, proxies, caches as well as DASH client's performance and status.
• Normative annexes for MPD schema (Annex B), Descriptor Scheme Definitions (Annex C), OMA DM QoE Management Object (Annex F), File format extensions for 3GPP DASH support (Annex G) and MIME type registration for MPD (Annex H).
• Informative annexes for client behaviour (Annex A), MPD examples (Annex D), and mapping MPD structure and semantics to SMIL (Annex E).