Digital Video Broadcast for Handheld devices
DVB-H
Broadcast Multimedia
Multimedia group
Adrian Hornsby
10/28/08

Voice communication …
In 1876, Alexander Graham Bell
\"Mr. Watson. Come here! I want you!\"
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Radio …
• 1860s, Scottish physicist, James Clerk Maxwell predicted the existence of radio waves
• 1886, German physicist, Heinrich Rudolph Hertz demonstrated that rapid variations of
electric current could be projected into space in the form of radio waves.
• 1895 ,Guglielmo Marconi, Italian inventor, sent and received his first radio signal, in
1899 across the English Channel and two years later received the letter \"S\", from England
to Newfoundland.
• Nikola Tesla and Nathan Stufflefield took out patents for wireless radio transmitters.
Nikola Tesla is now credited with being the first person to patent radio technology; the
Supreme Court overturned Marconi's patent in 1943 in favor of Tesla.
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Television …
• Television started in the 1920s as a Peepshow device.
• one viewer , 30 lines, tiny vertical screens,
• received in a large part of Europe via the 'short wave',
also used for radio.
• Audio sound was a separate short wave radio broadcast.
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Personal portable devices…
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Mobile phones …
Users worldwide
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Digital Media Revolution …
• New user experience
• New consumer demand
New digital devices + new digital
transmission systems =
New digital transmission standard
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Why did it happen ??
Soon more mobile phones than people ...
TV is the biggest and most popular media ...
... and the last one missing from mobile phones
... something is missing here !!!

How did it all started ...
• Research on DVB-T based mobile application
• Is DVB-T good for mobile ?
• Should we modify it ?
• Politic pressure
– Authorized secret research late 2000
(TM chairman)
• DVB-T SE (standard extension)
» Jukka Henriksson, Nokia
» Report in December 2001
» Adding 4k and inter-leaving
» Power consumption known problem but ...

How did it all started ...
• DVB-M (CM) Group formed based on reports
– launch in 2002 (Juha Salo, Nokia)
• Requirements accepted by CM mid-2002
– Co-existence with Mobile Phones
– Indoor scenarios
– Single antenna reception
– Reduced power consumption
• DVB-M (TM)
• Evaluate DVB-T for those requirements

DVB-T in short ...
• December 1995, DVB publish the DVB-T standards
(EN 300 744)
•
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DVB-T in short ...
• Terrestrial Digital Television Standard
• One-to-many broadband wireless data transport
– Video, audio, data (also IP, late addition)
– Scalable (cell size up to 100km)
– Huge capacity (54 channels, 5-32Mbit/s)
• Lead to the ASO (analog switch off)
• MPEG-2 transport stream based (flexible)
• OFDM multi-carrier modulation (2k and 8k mode)
– Carrier modulation QPSK, 16QAM, 64QAM
• All in all, DVB-T is pretty good and flexible
• So what is wrong really ??

DVB-T in short …
• OFDM, multi-carrier modulation (2k and 8k mode)
• Each sub-scarrier is modulated with conventionat
schemes (QAM)
2k: larger inter-carrier
→ Tolerance Doppler
8k: small inter-carrier
→ large symbole duration
→ maximum echo delays
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Multipaths effect ...
•Different environment, different propagation
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So why not DVB-T ??
• Designed for rooftop reception
• No power saving mechanism
• Inadequate impulse noise protection

How did it all started ...
• DVB-H (TM)
– Call for technology (Jan/Feb 2003)
– 12 responses
– 3 concept formed in April
– Final concept in August
– Standard accepted by TM in January 2004
– By ETSI in the end of 2004
» Now we have a new physical layer standard for
mobile devices

How did it all started ...
• DVB-CBMS (TM)
– Nokia’s initiative to ‘complete’ the work
• All layers need to be standardized
– 2003: early specifications of the interface to the
terminal for early trials
– 2004: detailed technical requirements for an
\"IPDC in DVB-H\" system
• Call for technologies started in autumn 2004
• First standards to TM in fall 2005
• DVB-IPDC to ETSI in 2006/2007

What really is DVB-H for ??
• DVB-H aims at providing digital TV reception to
mobile devices
• Combines traditional TV broadcast standards
with element specific to handheld devices
– Smaller screen
– Mobility
– Antennas
– Indoor coverage
– Reliance on battery power

What is DVB-H ??
• Transmission of data mainly done as IP frames
– Internet Protocol
• New video compression scheme (h.264)
– For lower bitrate and smaller screen size
– Approx. 390 Kbit/s per stream (mpeg2 was 3-4 Mbit/s)
• More suitable for broadcasting to mobile
environment

New features of DVB-H ..
• Time-slicing
• power saving and frequency handover
• MPE-FEC
• additional protection of the data link layer
• New 4k mode:
• trade-off between cell size and mobile reception
capability (Doppler and echo delays)
• New signaling scheme
• modified TPS bits and additional mpeg PSI/SI
tables (INT)

Time-slicing
Service 1
Capacity
Channel
Service 2
Service 3
Service 4
Time
• In DVB-T, services are multiplexed on the TS level at very high
frequency
• Service almost sent in parallel
• Very hard for decoder to only focus on one stream (specific TS packets)
• All data must be received, leading to high power consumption
• 8k, 16QAM ½ 1/8, 11.06Mbit/s
• 7412 TS packets/OFDM symbol, 1 symbol = 1008us
• 1 TS packet every 136us

Time-slicing
Burst
Off time
Capacity
Channel
Time
• IP service organized so that each services use
the full channel capacity one after another
– Burst transmission
– Seamless frequency handover
– Longer initial tunning delay

Time-slicing
• The off-time period provides up to 90% of power saving
• The receiver has to know when the next interesting
burst (service being consumed) is arriving
– Real-time signalling
– PSI/SI not sliced
Channel
Capacity Time

Time-slicing
Off time
Capacity
Channel
Serving Adj.
C1 C2
Adj.
Listening to C2 Listening to C3
C3
Time
• Time-slicing permits the monitoring of neighboring cells during off-
time
• In DVB-T, would need 2 frontends

MPE-FEC
• Multi-Protocol Encapsulation with Forward Error Correction
– Reed-Solomon coding on IP datagrams
• Higher error resistance
– Virtual interleaving, FEC placed in separate sections
– Receiver can ignore FEC sections
Application data table RS data table
IP data Parity Bytes
(191 columns) (64 col.)
1024 rows max
RS
Codewords

Multi-protocol Encapsulation (MPE)
• IP encapsulation into MPEG-2 TS packets
40 ... 4080 bytes
IP datagram Header Payload
16 ... 4095 bytes
MP sections Header Payload Header Payload Header Payload
188 bytes
TS packets Header Payload Header Payload Header Payload

4k mode
• 4k: 3409 carriers
• Compromised between 2k (1705 ca.) and 8k (6817 ca.)
• Increased mobility by two compared to 8k
• SFN cell size double compared to 2k
• 4k is an option, 2k and 8k can be used for specific
environment (rural, dense city)

Signaling with TPS-bits
• Physical layer extensions
• Reserved information channel with tunning
parameters (Time-slice, MPE-FEC, Cell ID, ...)
• Very robust signalling scheme allowing TPS
lock even with very low C/N values
• Faster to access signalling than demodulating
and decoding the PSI/SI or the MPE sections

DVB-H codec

Service Information
• Main difference between DVB-T and DVB-H
• DVB-H does not utilize all the service
information table defined by DVB (PSI/SI)
• DVB-H uses IP based Information system,
“service guide” rather than the traditional PSI/
SI from DVB

Service Guide
• Electronic Service Guide (ESG)
– XML based service definition

Service Guide

Service Structure

DVB-H Protocol Stack

DVB-H delivery mechanisms
• File Delivery over Unidirectional Transport
(FLUTE) protocol
– File download (download first, then consume)
• Real-time Transport Protocol (RTP)
– Streaming (consume while downloading)
– Without RTCP report (broadcast)

FLUTE
• Asynchronous (non-real time) broadcasting of
audio, video, and data files
• Download and store at the receiver for future
playback
– IETF RMT WG
– RFC 3926
“FLUTE is a protocol for the unidirectional delivery
of files over the Internet, which is particularly suited
to multicast networks. The specification builds on
Asynchronous Layered Coding (ALC), the base protocol
designed for massively scalable multicast distribution.”

FLUTE
A Receiver
D C B A FDT
D
B
C
Receiver gets content of the carousel from the FDT
Receiver can select which message to download

FLUTE
Taken from Jani Peltotalo (TUT) /File Delivery over DVB-H, FLUTE

RTP- Real-Time Transport Protocol
• RTP provides end-to-end network delivery
services for the transmission of real-time data
• RTP is network and transport-protocol
independent, though it is often used over UDP.

RTP- Real-Time Transport Protocol
• Use SDP file extracted from ESG to get tune in
and decoding information necessary for the
player to understand and decode the RTP
stream and its payload
v=0
o=QTSS_Play_List 1460227057 502868560 IN IP4 130.230.50.48
s=stream­32
c=IN IP4 239.252.80.5/1
b=AS:375
t=0 0
a=x­broadcastcontrol:RTSP
m=video 5004 RTP/AVP 96
b=AS:248
a=rtpmap:96 MP4V­ES/90000
a=control:trackID=1
a=cliprect:0,0,240,320
a=fmtp:96 profile­level­id=1;config=000001B0F3000001B50EE040C0CF0000010000000120008440FA285020F0A21F
a=mpeg4­esid:201
m=audio 5006 RTP/AVP 97
b=AS:127
a=rtpmap:97 mpeg4­generic/44100/2
a=control:trackID=2
a=fmtp:97 profile­level­id=1;mode=AAC­hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1210
a=mpeg4­esid:101

Typical receiver architecture
DVB-H receiver
IP stream tuner
h.264 decoding
RTP parsing
IP Demux
AAC decoding A/V player
A/V data decoding
FLUTE/ALC FEC decompression
parsing decoding (gzip)
Channel
Selection
Bootstrap XML
ESG parsing
XML ESG
parsing
presentation
File
ESG
Application
Database
ESG handling

DVB-H
DVB-T/H T-DMB MediaFlo MBMS Wifi WiMAX
in S-Band
DVB-T
MPEG2-TS DAB Eureka 147 Mobile UMTS IEEE 802.11 IEEE 802.16e
Technology DVB-T
IP over MPEG2-TS MPEG2-TS DAB/ETI EV-DO EV-DO a,b,g,n Mobile WiMAX
2.3 GHz
2.4-2.5 GHz
Frequence 2.5 GHz
UHF or L-Band 2.2 GHz MSS VHF or L-Band UHF 2 GHz ~5 GHz
Band 3.3 GHz
3.4-3.8 GHz
Number of TV
12 30
Broadcast
20 to 30 20 to 30 6 ? 12-16 (MBS)
Channels (with 3 carriers) (source Qualcomm)
(256kbits/s)
Programme
Guide MPG
MPEG2-TS PSI/SI (T)
& CBMS - ESG DAB UDDI SAP ?
(Media Program
CBMS - ESG (H)
Guide)
Content
Description
Standardisati DVB Consorsium
DVB Consorsium ETSI Korea AAC QUALCOMM 3GPP IEEE IEEE
ETSI
on Group