Satellite distribution of DTV
and MobileTV content.
Presented at: Regional Seminar on DTV Broadcasting, Algiers, December 2007
By:
Joost Verbrugge
Broadband Systems
Professional Equipment
IP Software
Contents
•
•
•
•
•
•
•
Why Digital Terrestrial TV ?
The way to Analog Switch Off
Single Frequency Networks
The primary distribution network
Why Satellite ?
Application examples
What about Mobile-TV ?
– What is mobile TV ?
– Technologies and standards
– Primary distribution of content for Mobile-TV
• Conclusions
2
Why Digital Terrestrial TV ?
• From analog to digital TV transmission: why?
– Robustness of the signal
– Constant picture quality
– New applications come in digital version only:
• Interactivity
• High definition TV
• Mobile TV
– More efficient use of spectrum (4-6 times)
– Savings in operational cost of network
• Competitive with Cable, DTH, TelcoTV (IPTV)
– Availibility of low cost Set Top Boxes/receivers.
3
The way to Analog Switch Off
• Some definitions
– Standards
• DVB-T, ATSC-8VSB, ISDB-T
– Digital Switch-0ver (DSO)
• The start of digital transmission for public television
– Analog Switch-Off (ASO)
• The end of analog transmission for public television
– Simulcasting
• Period of simultaneous analog and digital transmission
of the same TV programming
• This period allows viewers to convert from analog to
digital reception (Set Top Box, decoder, antenna)
– Digital Dividend
• Savings in spectrum thanks to conversion to digital
transmission; can be re-used/sold for new applications.
• Remember: dividend comes after investment...
4
The way to Analog Switch Off
Every country has to decide on timing of
– Step 1: decide on standard (DVB-T ?)
– Step 2: Digital Switch Over plan (DSO)
• Including Frequency Plan, SFN/MFN, Capex plan...
– Step 3: Decide on Analog Switch Off date (ASO)
– Step 4: Build network with 95+% coverage
• Simulcasting from DSO to ASO
– Step 5: Decide on spectrum allocation after ASO
– Step 6: Grant licences/spectrum for new services
– Step 7: ASO
• start of savings, start of new income
– Step 8...88: license new services including mobileTV,
HDTV, multiplexes of above, (Wimax), (DAB), ...
5
Single Frequency Networks
• Digital TV using COFDM allows SFN operation
– One frequency for all transmitters in large area
– Saves on frequencies used
– Allows other (better) network topologies
• More transmitters with less power to cover area
• Requirements for SFN operation:
– Each transmitter must radiate:
• On the same frequency
• At the same time
• The same data bits
6
Single Frequency Networks
• Requirements for SFN Operation: implementation
– Frequency and Time reference (e.g. GPS)
– MIP specification and insertion by ‘SFN adapter’
– Carefull design of network:
• Guard time selection defines maximum distances between
transmitters
• Power levels should avoid intersymbol interference (noise)
• Primary distribution network must deliver signal multiplex
intact (bit by bit identical) and on time at transmitter.
• Local content insertion per SFN area (market)
– Allows local advertising in local language
– Allows re-use of frequencies in non adjacent areas
7
Single Frequency Networks
Local markets served by several SFN’s
SFN 3
SFN 1
DVB-H
SFN 3
SFN 1
SFN 1
SFN 2
DVB-H
SFN 3
DVB-H
DVB-H
SFN 2
DVB-H
DVB-H
SFN 2
DVB-H
DVB-H
SFN 2
DVB-H
DVB-H
SFN 1
SFN 2
DVB-H
SFN 2
DVB-H
8
DVB-H
SFN 1
SFN 1 DVB-H
DVB-H
The primary distribution network
• What? :
– The Primary Distribution Network brings the signal
stream (multiplex) to all transmitters in the DTT
network.
• How? :
– Terrestrial :
• fibre with SDH, ATM, ...protocols
• Private IP based networks
– Micro Wave : Point to point links
– SATELLITE based primary distribution network
– Combination of above (redundancy)
9
The primary distribution network
• Why Satellite ?
– Fast and reliable deployment possible
• Once ‘on air’, the complete footprint has access to signal
– High and constant signal quality over entire footprint
– Integrity of original signal stream (SFN !)
– No (re)multiplexers in network
– Constant delay, no (variable) ‘latency’ (SFN!)
– Full redundancy possible
– Less or no service interruptions in primary network
– No fiber breakdown, no power supplies, no equipment in signal path, ...
– Long term committment possible (opex cost control)
– Scalable with limited Capex (investment cost)
10
The primary distribution network
• Why (not) Satellite ?: challenges and solutions:
• Cost ? (perception of cost...?)
–
–
–
–
Initial (opex) cost an be an issue (first DSO phase)
Break-even between 50 and 100 sites
Opex cost under control by long term agreements
Save cost by efficient modulation schemes (S ->S2)
• Availability ?
– New possibilities coming (Arabsat, NileSat, ...)
– Ground equipment standardized from multiple
vendors
11
The primary distribution network
• Why Satellite: network operator considerations:
– Fast network deployment possible
– SFN operation easy to implement
– Flexibility in network build-up
• Additional repeaters can be added when/where needed
• No additional (distribution) cost when adding sites.
–
–
–
–
–
12
Full coverage (ASO!) at limited cost
Most equipment centralized at one site (playout/uplink)
Network management & control easier/lower cost
Limited maintenance (transmitter sites only)
Only one service operator
Application examples:
Integrated tranceiver possibilities:
Small power gap-filler
Medium power tranceiver
High power transmitter
Horizon - Amplifier
+ 3rd party amplifier
without COFDM
+ 3rd party Transmitter
13
Application examples:
Local markets served by several SFN’s
SFN 3
SFN 1
DVB-T
SFN 3
SFN 1
SFN 1
SFN 2
DVB-T
SFN 3
DVB-T
DVB-T
SFN 2
DVB-T
DVB-T
SFN 2
DVB-T
DVB-T
SFN 2
DVB-T
DVB-T
SFN 1
SFN 2
DVB-T
SFN 2
DVB-T
14
DVB-T
SFN 1
SFN 1 DVB-T
DVB-T
Application examples:
Concentrator Deconcentrator for DVB-T (Newtec-Technology):
Proprietary Transport stream
ASI TSa
ASI TSa
P1a, P2a, P3a,...
P1a, P2a, P3a,...
ASI TSb
P1b, P2b, P3b,...
ASI TSc
P1c, P2c, P3c,...
ASI TSb
ASI
CONCENTRATOR
MPEG/DVB/
ATSC
Transmission
channel
ASI TSd
ASI
DECONCENTRATOR
P1b, P2b, P3b,...
ASI TSc
P1c, P2c, P3c,...
ASI TSd
P1d, P2d, P3d,...
P1d, P2d, P3d,...
Exact copies
ASI TSx = MPEG Transport Stream x on ASI
Px = Program x
15
Application examples:
Local market content insertion
16
Application examples:
• Basic primary distribution concept
Sat demod
One transport stream
includes national and
all local channels
Local drop
Transmitter
site
COFDM
&
up conv
Ampli & filter
National
and local
feeds
17
Encapsula
tor into TS
Satellite
modulator
Application examples:
Network monitoring & control
Broadcast TS
Sat3play
modem
Remote site
Central Hub
S3Play Hub
NM station
18
Sat demod
Local drop
DVB-H SSPA
DVB-H mod
What about Mobile-TV ?
What is Mobile TV ?
Old dream of
“Television wherever you go”
Casio 1983
Sinclair 1977
RCA 1963
Seiko 1984
Sony 1982
Sony 1990
19
What about Mobile-TV ?
• What is Mobile TV anno 2008?
• TV on your mobile
• TV in your car
• TV on the go
(PSP, iPod, etc...)
20
What about Mobile-TV ?
• Dream of “Television wherever you go”
Mobile TV at this moment is:
•
•
•
•
•
•
•
21
High quality TV for small screens on the move
Broadcast network with indoor coverage
Large number of channels instantly available
Choise of handsets, in-car sets, etc. ...
Personal Phone + TV integrated
Includes ESG, radio, VoD possibilities
Provides regional/local content (?)
What about Mobile-TV ?
• Dream of “Television wherever you go”
Still some challenges to face/solve:
• Agree on standards
• Have frequency spectrum available
• Combine telecom and TV worlds to realise
personal TV handset.
• Create working business models
• Adjust regulation (must-carry, protection of
minors, content rights, etc...)
• Build/adapt transmission networks
• Increase battery lifetime
22
What about Mobile-TV ?
Technologies and standards: overview
Existing
Announced
•
•
•
•
•
•
•CMMB
•DVB-SH
•MBMS
•A-VSB
•ATSC-M/H
•Wimax
S-DMB
T-DMB
DVB-H
MediaFLO
DAB-IP
ISDB-T
Bold = Satellite Delivery
23
What about Mobile-TV ?
Additional information on standards and technology:
• DVB info on www.dvb.org and www.dvb-h.org
• Standards on www.etsi.org
• Comparison of bearer technologies by
bmco-forum on www.bmcoforum.org
• Link budget paper on www.bmcoforum.org
• Paper on MediaFLO at www.floforum.org
24
Delivery of Mobile TV by Satellite
What ?
• Direct reception of satellite signal by handset
• Used in Korea (S-DMB)
• Announced in China (CMMB), Europe (DVB-SH) and
Middle East (S2M)
• All systems use dedicated beams in S-band
• All systems need terrestrial transceivers for indoor
reception in S-band, synchronized with direct beam.
• Tranceivers need signal stream from primary
distribution (=satellite) ahead of direct beam.
25
Delivery of Mobile TV by Satellite
• Advantages
– Country wide coverage from day 1
– Uniform reception performance
– S-band: antenna diversity techniques possible
• Disadvantages:
– Dedicated satellite needed (+back-up?)
– No direct indoor reception possible
• Challenges:
– Dense terrestrial network needed for indoor reception
– S-band: propagation more difficult for indoor than UHF/L
– Limited number of handsets available (except Korea?)
26
Primary distribution for mobile TV
What ?
• Signal distribution to transmitter towers, gapfillers, transceivers for mobile TV
• Needed with all standards/technologies
• Identical stream to all transmitters (SFN)
• Mostly Ku-band, C-band also possible
Alternatives ?
• Terrestrial distribution over fiber
• Existing backbones, ATM, IP-networks
• Microwave
27
Primary distribution of mobile TV
• Advantages
–
–
–
–
Rapid deployment/extension of network possible
Most cost-effective for larger number of towers (>100)
Easy implementation of SFN network
Easy network management possible
• Disadvantages
– (perception of initial) cost
• Challenges
–
–
–
–
28
Integrated transceiver availability
Local content solutions
Network management solutions
Back-up questions/solutions
Primary Distribution network :
• Differences DTT versus Mobile TV :
• For DVB-T versus DVB-H:
– Technology: almost identical
– Network: requirement for indoor coverage !!!
• More signal strength needed
• More tranceivers/gapfillers needed (deep indoor)
• SFN operation required
– Satellite requirements for distribution:
• Less bandwidth for DVB-H bouquet (5-8 Mbit/sec)
• More gapfillers for DVB-H -> smaller receiver dishes
29
Application examples: DVB-T and H combined
30
Conclusions for Mobile-TV :
• Good Mobile-TV reception ...
– Means good indoor coverage …
– Means many transmitters (1000+…)
transceivers
gap-fillers
– Means Single Frequency Network Operation…
– Means exact frequency/timing requirements…
• …means Satellite distribution to transmitters !
31
Conclusions for DVB-T and H:
• Digital Terrestrial TV needs large broadcast
network with full (outdoor) coverage to allow
ASO. (50-500 sites)
• Mobile TV needs broadcast network with good
outdoor and indoor coverage. (1000+ sites)
• Satellite distribution is cost effective for 100+
sites and allows rapid deployment of network
• Flexible local content distribution possible
• SFN and MFN operation possible
• More channels/lower cost with DVB-S2
• Centralized monitoring and control possible
• Solutions for different standards, markets.
32
Satellite distribution of Digital-TV
and Mobile-TV content
Thank You !
Questions ?
Mail to : [email protected]
33