2009年10月1日

ESG/EPG (2) - Protocol Used

Protocol Used

§ Each button pressed on the user's remote control is translated into the appropriate video protocol commands by the Set Top Box.

§ These protocols are typically Internet Group Management Protocol (IGMP) for multicast, and Real Time Streaming Protocol (RTSP) for VoD/nPVR.

§ These video protocol command messages are processed by the service provider's network differently according to type (multicast or unicast).


§ A whole ESG is delivered over DVB-H bearer utilizing one or several IP streams and using FLUTE protocol.

§ The ESG can be pulled by ESG Discovery Portal via 3G networks. It should also integrate the function of broadcasting ESG using the FLUTE IP carousel via DVB-H network.

§ The interactive delivery methods can also be utilizing HTTP protocol


§ The fifth and last layer of ESG layers corresponds to the delivery of the ESG containers using the FLUTE protocol.

§ In order to support efficient delivery and processing of individual fragments, ESG fragments are encapsulated into ESG containers before being transported over a FLUTE session.

§ Transported by FLUTE is to enable the optimal delivery of containers as files

§ ESG Transport is achieved by the use of FLUTE sessions

§ In both modes the single stream mode and the multiple stream mode ESG Containers are transported as files in Transport Objects in FLUTE sessions.

§ ESG is delivered via FLUTE/ALC on this CBMS-3 reference point between service application (ESG Server) and Terminal.


§ The purpose of file delivery via FLUTE is to deliver content in files. A file contains any type of data (e.g. Audio/Video file, Binary data, Still images, Text, ESG metadata).

§ While using FLUTE as the transport protocol for the ESG, it is mandatory to signal ESG Container ID and Version changes in the FDT.

§ The ESG Bootstrap Descriptors are transported on ALC/LCT as specified in TS 102 472 for FLUTE sessions.

§ An ESG Container is delivered as a file within a FLUTE session.


§ Transport Protocol - ESG Retrieval over Interactive Channel; ESG Query Requests and ESG Query Responses shall be transmitted by HTTP over TCP/IP.

§ File Delivery using HTTP: Files of a file delivery session may be made accessible via the interactive channel using HTTP. The retrieval procedure is defined according to the file repair procedure request/response mechanism. The URL of the HTTP server that delivers the file is indicated in the ESG by the HTTPAccessServerURL.


§ In time synchronization of FLUTE Session for streaming service, the terminal should use the Sender Reports sent in the RTCP streams of the streaming service to establish the time synchronization (NTP timestamp) and to schedule the update of the session with the new SDP file.


§ General ESG signalling can also support different Service Purchase and Protection (SPP) systems where SPP streams are using SDP.


http://docs.google.com/View?id=ddh56dhg_229gnpgjr32

§ The ESG is able to describe services delivered over unicast bearer using 3GPP PSS.

§ And 3GPP PSS describes how terminals can initiate and control a unicast streaming session. A PSS session can be initiated using one of the following:

  • An RTSP URL
  • An SDP file (either inlined in the ESG or retrieved using e.g. HTTP)

§ In the ESG, the associated delivery procedure description instance is clearly identified using a URI, to enable cross-referencing of in and out-of-band configuration files.

  • ESG prior to the content delivery session along with the session description (out-of-band of that session).
  • in-band within the content delivery session.


Electronic Service Guide (ESG) – PSI/SI Information

§ http://docs.google.com/View?id=ddh56dhg_1733wv4htpg

§ The ESG provides the user with information about the available services.

§ Service discovery in DVB-T networks is based purely on the PSI/SI information carried in the transport stream.

§ DVB-H networks also rely on the PSI/SI information with IP specific extensions, but in addition, the Electronic Service Guide (ESG) is introduced for service and content discovery.

§ It can know where to find the ESG data in the stream thanks to the PSI/SI tables.

§ Available channels and services are found by using the Program Map Table (PMT) and the Program Association Table (PAT), where the services are mapped.

§ The Event Information Table (EIT) in DVB-SI can be utilized to supply program related information. Basic information includes title, start time, duration and synopsis etc.

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