Protocol Study – Protocol Stack (DVB-H, FLO and MBMS)

Protocol Stack (DVB-H, FLO and MBMS)

Protocol Stack – DVB:

http://docs.google.com/View?id=ddh56dhg_171fd5gqkf2

Service Access Points on the broadcast network

Solution	Service Access Points on the broadcast network Description	Service Access Points on the broadcast network Description
DVB-H	DVB Signalling	Access point mainly used by tuning and mobility management enablers to obtain relevant configuration information.
Streaming	AV Streaming	Access Point for all Audio/Video streams delivered over the Broadcast network
Download	File/Data Download	Access Point for all data delivered over the Broadcast network via FLUTE (one time or carousel based)
IP MC	IP Multicast	Access point to IP multicast for application specific usage of IP multicast.
UDP MC	UDP Multicast	Access point to UDP multicast for application specific usage of IP multicast datagram services.

Enabling Services

Enabling Services	Description
Subscription Management (optional)	Subscription Management manages rights acquisition and keeps track of rights acquired for the terminal and controls the decryption process of service content in the terminal.
Tuning	Basic frequency tuning and scanning, selection of IP platform, tuning to PIDs of multicast IP addresses selected by the terminal, basic handover support for Mobility Management.
AV-Codec	On the terminal side, enables decoding and rendering of Audio/Video content. On the head-end, takes care of encoding Audio/Video content.
ESG	Receive Electronic Service Guide(s), maintains ESG cache, notification of ESG-using applications of updates.
File receiver	§ File carousel receiver and management of received files. § Post delivery repair of incomplete received files. § Notification of file consuming applications of new file arrivals and updates.
Mobility Management	Enables Handover and Roaming functionality.

DVB-H Protocol Stack

§ In DVB-H protocol stack (in L1/L2), TPS is carried as part of the physical layer (L1) and the PSI/SI is carried within the data link layer (L2).

§ The Protocol Stack & Interface in DVB-H: (CBMS-1 ~ CBMS-7 between function entities: See later section)

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

§ The RTP protocol is used for streaming services, where audio, video and subtitling are delivered in real time.

§ The FLUTE protocol is specified for file delivery services in which all the file data is first downloaded and stored into the terminal before being accessed by applications.

§ Post- repair and reception report data is delivered using FLUTE (point-to-multipoint) or using HTTP and TCP for point-to-point connection.

§ For SPP (Service Purchase and Protection), KSM (key stream messages) and KMM (key management messages) are delivered over UDP.

MBMS – Protocol Stack

§ In both delivery services the resulting UDP flows are mapped to MBMS IP multicast bearers.

§ http://docs.google.com/View?id=ddh56dhg_175g78nq33t

For Download Delivery:

§ Discrete objects such as still images, multimedia streams encapsulated in file formats, or other binary data are transported using the FLUTE protocol (RFC 3926) when delivering content over MBMS bearers.

§ To deliver a file in a broadcast session, FLUTE provides mechanisms to signal and map the properties of a file to the Asynchronous Layered Coding (ALC) protocol such that receivers can assign these parameters to the received files.

For Streaming Delivery:

§ Streaming data such as video streams, audio programs, or timed text are encapsulated in RTP and then transported over the streaming delivery network.

§ In this case, AL-FEC is applied on UDP flows, either individually or on bundles of flows.

§ The FEC streaming framework is based on top of the UDP layer, and operates on RTP packets or, more precisely, on UDP flows, incoming on the same or different UDP ports.

§ The streaming framework provides significant flexibility in terms of code rates, protection periods, and so on.

§ Original UDP payloads become source packets by appending a 3 byte FEC source payload ID field at the end of each UDP payload.

§ Real-time MBMS streaming services mainly target classical mobile TV services. For these services the MBMS FEC streaming framework, including the Raptor codes, plays an important role.

§ The legacy RTP packets and the UDP port information are used to generate Raptor repair symbols.

FLO Protocol Stack:

http://docs.google.com/View?id=ddh56dhg_177gh6bz9f8