13.1 Introduction

26.2473GPPProgressive Download and Dynamic Adaptive Streaming over HTTP (3GP-DASH)Release 17Transparent end-to-end Packet-switched Streaming Service (PSS)TS

Server and Network Assisted DASH (SAND) functionality is specified in ISO/IEC 23009-5 [54]. SAND support in PSS is described in TS 26.233 [2]. An overview of SAND functionality in ISO/IEC 23009-5 [54], 3GPP-targeted architectural considerations for SAND support, and initial use cases for SAND in context of 3GPP are described in TR 26.957 [55].

This clause describes the following:

– SAND modes to use for 3GP-DASH described in clause 13.2

– DANE discovery procedures for SAND described in clause 13.3

– SAND messages and protocols to use for 3GP-DASH described in clause 13.4

– Normative behaviors on SAND message handling for DANE and 3GP-DASH client described in clause 13.5

– Use of SAND functionality for enabling network assistance, proxy caching and consistent QoE/QoS described in clauses 13.6, 13.7 and 13.8, respectively

– XML schema for SAND extension messages, described in clause 13.9

– Use of SAND functionality for enabling SAND for Multi-Network support (SAND4M) in clause 13.10.