Dvb h
This presentation is the property of its rightful owner.
Sponsored Links
1 / 20

DVB-H PowerPoint PPT Presentation


  • 83 Views
  • Uploaded on
  • Presentation posted in: General

DVB-H. digital video broadcasting for handheld devices Björn Forss Magnus Melin. Introduction. Convergence of digital media and communication give users possibility to consume most digital content also in mobile environment

Download Presentation

DVB-H

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Dvb h

DVB-H

digital video broadcasting for handheld devices

Björn Forss

Magnus Melin


Introduction

Introduction

  • Convergence of digital media and communication give users possibility to consume most digital content also in mobile environment

  • The emerging DVB-H standard aims to provide digital TV reception in mobile devices

    • Earlier known as DVB-X

  • DVB-H is being standardized by and ad hoc group of the DVB organization

    • Expected to be standardized in the first quarter of 2004

  • DVB-H combines traditional television broadcast standards with elements specific to handheld devices; mobility, smaller screens and antennas, indoor coverage and reliance on battery power 


Motivation for creating dvb h

Motivation for creating DVB-H

  • Why not use UMTS?

    • Not scalable for mass content delivery

    • For delivery of mass media content, broadcast networks should be preferred over point-to-point cellular networks

  • Why not use DVB-T?

    • Was designed for rooftop reception

    • Need for an efficient power saving mechanism

    • Inadequate impulse noise protection

  • Why not use DAB?

    • Designed for devices with similar power constraints but too narrow spectrum is assigned for data transmission

DAB = Digital Audio Broadcasting


Dvb t

DVB-T

  • Terrestrial Digital Television Standard

    • Used in 36 countries world wide

  • One-to-many broadband wireless data transport

    • Video, audio, data and – importantly – IP packets

    • Scalable: cell size up to 100km (DVB-H cell size is smaller)

    • Huge capacity: 54 channels each 5-32Mbit/s

  • Shut down of analog TV will free up huge frequency capacity for DVB-T usage

DVB-T = Digital Video Broadcasting - Terrestrial


Dvb t 2

DVB-T (2)

  • Developed for MPEG-2 stream distribution, but can basically carry any data

    • Flexible, has many modes, 4.98-31.67 Mbit/s @ C/N=25dB

  • COFDM multicarrier modulation with 2k and 8k modes

    • One DVB channel is ~8MHz

      • 1705 sub carriers (spacing: 4464 Hz) - 2k mode

      • 6817 sub carriers (spacing: 1116 Hz) - 8k mode

    • Carrier modulation: QPSK, 16 QAM or 64 QAM

    • Error correction: convolutional code and Salomon-Reed

  • Basic mode in Finland:

    • 64 QAM, code rate = 2/3, guard interval 1/8

    • Gives 22.12 Mbits/s capacity when C/N=19.2 dB and 8 MHz channel

  • COFDM = Coded Orthogonal Frequency Division MultiplexingC/N = Carrier to Noise ratio


Mobile reception of dvb t

Mobile reception of DVB-T

  • DVB-T includes hierarchical modes where two transport streams can be sent simultaneously

    • Low capacity, high capacity

  • DVB-T can also be used for broadcast to mobile devices, but a suitable mode have to be selected

    • 8k 64 QAM: < 50 km/h

    • 2k QPSK: > 400 km/h tolerable

  • A separate network for DVB-H is desired

    • Optimization of speed, coverage and capacity


2k 4k or 8k and why

2k, 4k or 8k and why?

  • A small number of sub-carrier provides (like in 2k):

    • large inter-carrier spacing -> gives tolerance to the echoes affected by Doppler

    • short symbol duration ->limits the maximum delay of accepted echoes

  • A large number of sub-carriers (like in 8k):

    • small inter-carrier spacing but a large symbol duration

  • In short, the choice of the sub-carrier number has no impact on the broadcast capacity but on the trade-of between Doppler acceptance and maximum echo delays


Dvb h mission

DVB-H mission

  • Make it “… possible to transmit in one DVB transport stream both DVB-H and DVB-T components in such a way that existing DVB-T receivers which cannot decode the DVB-H portion are not disturbed by this DVB-H portion.”


Dvb h system elements

  • Timesliced:

  • Service 1

  • Service 2

  • Service 3

  • Not timesliced:

  • Service 4

1

2

3

1

2

3

1

2

3

1

2

4

DVB-H system elements

  • Time slicing for power saving

    • Time between the bursts gives the power saving (off time)

  • MPE-FEC for performance

  • 4k mode was chosen to provide mobility in medium SFNs

  • Extended TPS bits for efficient signaling

MPE = Multiprotocoll encapsulationFEC= Forward Error CorrectionSFN= Single Frequency Network


Ip datacast ipdc

IP Datacast (IPDC)

  • “IP datacasting is a service where digital content formats, software applications, programming interfaces and multimedia services are combined through IP (Internet Protocol) with digital broadcasting.” <http://www.ipdc-forum.com/about/>

    • All content delivered as IP packets

    • Connectivity layer convergence

  • DVB-H combined with IP datacasting enables distribution of many kinds of digital content

    • TV broadcast, music, games etc.


Dvb t and dvb h coexistence

DVB-T

ETS 300 744

8k, 2k

Time Slicing

MPE FEC

DVB-T RF in

IP-out

, 4k, TPS

DVB-H CODEC

DVB-T and DVB-H coexistence


Ipdc over dvb h business

IPDC over DVB-H business

  • New forms of multimedia enjoyment for consumers

  • New market opportunities for telecommunication and broadcasting industries

  • High bandwidth and high transmission speeds but insensitive to number of recipients  attractive from a business perspective

IPDC = IP Datacast


Network design flexibility signaling

Network Design Flexibility & Signaling

  • Different datacast network operator and cellular network operator

  • Digital broadcast infrastructure

  • More transmission sites than normal broadcast networks required, but less than normal cellular phone networks – existing masts can be reused

  • Cellular networks used for payment and administrative data

  • Cellular network and broadcast network can share same core network

Mobile Operator

ISP

UTMS

Base station

Core

DVB-T

Broadcasters

DVB-H

transmitter

IP

Backbone

Mux

DVB-H

Broadcasters

Broadcast operator


Dvb h features pros

Cost efficient delivery of broadcast content to a large audience

Low time to market

Low complexity

Not heavily affected of peak usage (during special events etc.)

Flexible transport stream sharing between DVB-T and DVB-H possible

Based on DVB-T with minimal changes

Fulfils most commercial requirements

Allows seamless handover

No adverse effect on DVB-T

IP allows encryption

DVB-H features/pros


Dvb h features cons

DVB-H features/cons

  • Only IP based services possible

  • Reduced power saving when total bit rate for DVB-H services is very low (no big “bursts” possible)


Mobile terminal

Mobile Terminal

  • FE = Front End, contains radio receiver and demultiplexor

FE

CPU

Media

decoder

Display

WLAN

Cellular

Link


Power consumption and handover

Power consumption and handover

  • IP encapsulation allows sending the data in bursts to the mobile station and this saves energy (battery power)

  • Power consumption and handover

    • 2 Mbit buffer

    • Handover possible during off time (services can be used even if the terminal has moved during off time)


C n performance

C/N Performance

  • RS decoder utilizing the Time Slice buffer

  • Virtual time interleaver

  • 10% TS PER tolerated

  • Doppler and CN improved in mobile and portable

  • Impulse interference tolerance improved

  • Possibility to vary the level of robustness


Nokia s 7700 with support for dvb h

Nokia’s 7700 with support for DVB-H

“The Nokia 7700 will support the Nokia Streamer SU-6 accessory, the first mobile IP Datacast receiver designed to demonstrate the mobile phone television experience using the DVB-H network. The Nokia Streamer can be attached to the Nokia 7700 like a battery pack, and will be used in pilot projects to showcase the future of digital broadcasting on mobile devices.” <http://press.nokia.com/PR/200310/922406_5.html>


References

References

  • DVB-H – digital TV for handhelds? Jukka Henriksson, Nokia

  • Content Distribution Using Wireless Broadcast and Multicast Communication Networks. Janne Aaltonen, Thesis for Degree of Doctor, Tampere University of Technology

  • IP Datacasting Technology - Bringing TV to the Mobile Phone, White Paper <http://www.nokia.com/BaseProject/Sites/NOKIA_MAIN_18022/CDA/Categories/AboutNokia/Press/WhitePapers/_Content/_Static_Files/ipdatacastingtechnology.pdf>

  • DVB <http://www.dvb.org/index.php?id=20>

  • Cable & Satellite International <http://www.cable-satellite.com/main_news.htm>

  • Sonera medialab <http://www.medialab.sonera.fi/projects/ipdcmhp/ >

  • EE-Times Junko Yoshida, <http://www.eetimes.com/sys/news/OEG20030310S0049>

  • Performance analysis and low power VLSI implementation of DVB-T receiver<http://www.signal.uu.se/Courses/Semabstracts/ofdm2.pdf>

  • DVB-T: New Operative Modes For Digital Terrestrial TV, Gerard Faria, <http://www.broadcastpapers.com/tvtran/HarrisDVBTNewOpModes.doc>


  • Login