AN IP BASED FILE DELIVERY PLATFORM FOR

MOBILE MULTIMEDIA BROADCASTING

July 20, 2005

Presenter: Jean-Michel Bouffard

Content

1. Introduction

2. System Overview

3. Broadcast File Server

4. Service Announcement System

5. Broadcast Download Manager

6. Conclusion

1. Introduction

• Mobile digital broadcast networks like DAB, DMB and DVB-H are becoming popular.

• These digital networks will provide:– High capacity downlink channels– Capabilities to transport IP packets

• IP tunneling protocols currently exist for DAB and DVB-H

• IP could become the common data transport mechanism

- Context -

1. Introduction

• DAB– ETSI ES 201 735,

Internet Protocol (IP) datagram tunneling

- IP transport -

• DVB-H– ETSI EN 302 304,

Transmission System for Handheld Terminals (DVB-H)

1. Introduction

• Develop server and client applications that are using reliable multicast protocols over IP

• Validate the feasibility of a user-centric file download manager in a broadcast environment

• Propose a delivery sessions announcement mechanism

- Goals -

2. System Overview- Diagram -

2. System Overview

• Server platform– Located in broadcaster’s facilities– Provides the file services management capabilities– Creates and sends services announcement

• DAB delivery platform– IP tunneling through a DAB packet mode

subchannel– Using CRC’s experimental DAB delivery platform

• CRC-Dr.Muxlab• CRC-Dr.IPMux

- Components -

2. System Overview

• Client platform– “Listens” to services announcement– Presents the information as a typical

Internet download manager GUI

– Activates the file delivery sessions requested by the user

– Manages the downloaded content

- Components -

• Services management• INRIA Flute

application• Announcer

3. Broadcast File Server- Server modules -

3. Broadcast File Server

• Creation of the services

• Parameters selection:– Name, id, bandwidth, packet size,

destination (IP address + port), type of protection, level of protection and content.

• Monitoring of file transfers and announcement system

- Services management -

3. Broadcast File Server- User interface -

Announcement related information

Services related information

Server configuration

3. Broadcast File Server

• INRIA MCLv3 project– Open source implementation of FLUTE (File

Delivery over Unidirectional Transport) (RFC 3926)

– Built over ALC (Asynchronous Layered Coding) (RFC 3450)

– Compatible with different types of FEC (Forward Error Correction)

• RS and LDPC included

• API available to add other FEC scheme

- INRIA Flute application -

4. Service Announcement System

• Built using standard IETF protocols– SDP (Session Description Protocol)– SAP (Session Announcement Protocol)

• Listens to a well-known multicast address and port

• Constructs a guide of all advertised file delivery sessions

• Provides sessions details without having to connect to it.

- Details -

4. Service Announcement System

• Contains the information about multimedia sessions– User name, session id, version, network type,

address type, address, session name, timestamps, etc.

• Attributes added to be compliant with Flute protocol– Flute session ID– Number of layers– Packet size– Type of optimization (needed by INRIA Flute)

- SDP (RFC 2327) -

4. Service Announcement System

• “How” to send the descriptions– Standard IP address and port

• Address: 224.2.127.254• Port: 9875

– Possibility to compress and/or encrypt the descriptions

• “When” to send the description– Delays between annoucement calculated

according to random values and number of descriptions to prevent network bursts

- SAP (RFC 2974) -

4. Service Announcement System

• Clients are always aware of services availability

• Helps better manage the client storage capacity

• Other types of multimedia services can use SAP/SDP without interfering with the file transmission

• Easy to add services by adding announcement packets

• Requires very little bandwidth

- Advantages -

• User-centric file download manager in a broadcast environment– Flexible– User-friendly– Usable as a test system for the

transmission of files– Offering an Internet-like download

manager

5. Broadcast Download Manager- Context -

• Announcement listener

• Service access module• Flute management

module– Using INRIA ALC

library

5. Broadcast Download Manager- Modules -

• “File browser” tab– Manage local content

• “Search” tab– Search announced file services

– User selects the content to download in this tab

• “Download” tab– Status of the active file services

• Downloading, completed, error, etc.• Estimated percentage completed

5. Broadcast Download Manager- Services access module -

5. Broadcast Download Manager- User interface -

• Replaces the INRIA Flute application• Uses the INRIA ALC library wrapped in the

JNI interface• Provides access to all the statistics about the

file transfer– Source data received, FEC data received, session

status, ALC errors.

• Provides an estimation of remaining transfer time (ETA)

5. Broadcast Download Manager- Flute management module -

6. Conclusion

• The platform proved to be flexible and easy to use

• Large file services have been successfully delivered using a DAB broadcast channel

• User experience similar to Internet file sharing software

• Announcement system helps making the process simple.

- Results -

6. Conclusion

• Service scheduling in time (EPG)• Using multiple ALC layers to distribute the

transfer in different DAB subchannels• Add file type association capabilities to the

Download manager (like many web browsers)

• Could be used as a testing tool for different FEC technologies.

- Future improvements -

Thank You

Questions ?