Advanced Television Broadcasting In A Digital …...for the delivery of digital programming relative to the current broadband digital distribution systems. However, there are now quite

Advanced Television Advanced Television Broadcasting In A Digital Broadcasting In A Digital Broadband Distribution Broadband Distribution EnvironmentEnvironment

October 19, 2000October 19, 2000Brian HolmesBrian HolmesIan OliverIan Oliver

142nd Technical Conference

Digital Broadband DistributionDigital Broadband Distribution

October 19 , 2000October 19 , 2000

Technical ChallengesTechnical Challenges

• maintenance of programming integrity (e.g. image quality, meta-data) across multiple distribution platforms;

• transcoding of the broadcast content as required to enter and depart any given distribution model;

• management of not only the broadcaster’s own distribution network, but those networks operated by others (e.g. Cable TV companies) upon which the broadcaster may depend to reach the viewer.



Non Technical ChallengesNon Technical Challenges

• bureaucratic and legal matters related to obtaining carriage over any given distribution model;

• the attraction of revenue from all possible sources (e.g. advertisers, sponsors, paid-programming, and viewers) by which the broadcasting organization survives and, in particular, funds engineering activities.



OpportunitiesOpportunities

• Delivery of multiple image formats (under established industry standards) across multiple distribution models in order to reach viewers across a wider demographic and geographic spectrum than previously possible;

• Delivery of content which includes ancillary programming and meta-data thus increasing the value to the viewer of the original content and, ideally, the corresponding revenue to the broadcaster;



OpportunitiesOpportunities

• The divestiture of responsibility and related cost for the operation and maintenance of distribution networks to organizations focused solely thereon. Thus potentially allowing the broadcaster to focus on the technical and operational requirements of producing high-value content while allocating fewer resources to its actual delivery.



A Little Bit of CATV HistoryA Little Bit of CATV History--The Dark The Dark DaysDays

• Broadcast Mode - one-way from headend to subscriber;

• Limited Bandwidth - 330 and 450 MHz typical;

• Poor Signal Quality - 42db C/N at subscriber;

• No Network Management - response to subscriber calls;

• Low Overall Network Reliability - as low as 70%;

• No Industry-wide Standards - almost entirely ad-hoc;

• Minimal Capital Investment - profit/share price critical.



Broadband HFC as Being Built TodayBroadband HFC as Being Built Today

• Bi-directional Systems - data returned from subscriber and network elements;

• High Bandwidth - 750MHz typical, 870MHz max forward, 35+ MHz return;

•78 Analog, 100 + MPEG-2 video program streams with statistical multiplex;

•Digital programming carried on 64 or 256 QAM modulation schemes;




•High speed IP services up to 10 Mb/s typically using QPSK or QAM modulation schemes;

•Class-5 telephony services over HFC using switched circuit techniques over RF and IP telephony service in current trials;

•Improved Signal Quality - >55db C/N at subscriber;

• Network Management - active telemetry, network operation centers, visibility to devices in premises;

• Higher Overall Network Reliability - >90% now, >99.999% is target.




• Multiple Industry Standards

• Bellcore, (NEBS)

• EIA, IEEE, SCTE

• Vendor-driven, de-facto standards

• Massive Capital Investment

• $650 US/s.f. base-building facility cost

• $80k US to $120k US per plant mile (new build)

• >$4M US for typical major facility equipment



Typical HFC Network ArchitectureTypical HFC Network Architecture

LocalOrigination

WEB

TELCO

Fiber

Primary Hub

RedundantPrimary Ring

Multiple OC-48'sAM Fiber

RedundantSecondary Ring

SecondaryHub

Optical Node

RF Line Extender

Multi-Tap

Cable AccessUnit

MasterHeadend

Television

Telephone

Computer



AT&T Broadband dual ring star/busAT&T Broadband dual ring star/bus



Antec’s pointAntec’s point--toto--multipoint multipoint HFC networkHFC network



Direct Broadcast SatelliteDirect Broadcast Satellite

• In excess of 200 program streams, each MPEG-2 encoded and statistically multiplexed onto Ku-band satellite channels;

•QPSK modulation employed in the satellite channel;

•Uni-directional transmission;

• An average data rate per satellite transponder channel of 27 Mb/s;

•Return path (i.e. from customer premise to central/billing system) via POTS dial-up.



Typical Direct Broadcast SatelliteTypical Direct Broadcast Satellite

Satellite dish

Satellite

Television

IBM Compatible

Aquisition, Processing andUplink

Telco Data Return

Uplink Ku-Band Downlink



MMDSMMDS

The MMDS (Multichannel Microwave Multi-point Distribution Service) distribution model is in-fact similar to the ATSC broadcast model that the broadcasters are familiar with.

•MMDS band at 2.4 GHz can support up to 33-6 MHz channels;

•Channel modulation is typically 64 QAM modulation to transmit at a rate of 27 Mb/s per RF channel thus carrying up to 12 digitally compressed MPEG-2 streams per channel;



MMDSMMDS

• As of the end of 1999, the number of MMDS subscribers in the US was estimated to be about 1.2 million. As a distribution model, MMDS presents to the broadcaster practically the same challenges and opportunities as the cable TV distribution model.

•One advantage the MMDS operators offer broadcasters over DBS operators is, since they are local terrestrial-based service providers, there is easier access to the local broadcasters’ signals for acquisition and trancoding into suitable transmission formats.



LMDSLMDS

LMDS (Local Multipoint Distribution Systems) systems use a bi-directional, full duplex wireless microwave technique for the connection to the end user.

•Since the frequency of operation is in the 28 GHz region and a transmission spectrum in excess of 1,000 MHz has been allocated to these systems, very high data transmission rates are possible. Indications are that up to 155 Mb/s (OC-3 rates) maybe available to each end user.

•These systems are now in trial and limited commercial launch in some urban markets.



LMDSLMDS

• Video content delivery over these types of systems typically employs a “wireless DSL” modulation technique to place the MPEG-2 stream into the carrier channel.

•The formation of the Wireless DSL Consortium may increase activity based on this technology.



LMDSLMDS

Television

IBM Compatible

CPE

Telephone

Switch Centre/Headend

RedundantBackbone

(typically fiber)

"Cellular-like" basestation Point-of-Presence

LocalOrigination

WEB

TELCO

Fiber



xDSL xDSL

• Telco’s, with their existing extensive infrastructure of copper twisted-pair cable and new Competitive Local Exchange Carriers ,are implementing DSL service offerings over twisted-pair copper infrastructure.

•New deep fiber-based systems are being built. These systems are taking fiber to clusters of 8 homes or, in some cases, using passive optical networks, directly into the home.

•Since these are switched networks, the apparent channel capacity is almost unlimited.



xDSLxDSL

Advanced Copper

ONU

ENU

Deep Fiber

Fiber to the Home OpticalAccess

Unit

EthernetBroadband RF

VideoNarrowband

Voice

OpticalNetwork

Unit

ElectricalNetwork

Unit

Fiber to thecurb

DSL

Primary HubDigital Point of

Presence (PoP)

DigitalPoP

Central Office/Headend

WEB

TELCO

Fiber

LocalOrigination

SONETRing

xDSL VoiceData Video

POTS + xDSL



US Distribution Network SummaryUS Distribution Network Summary--19991999

15%

80%

Over-the-AirATSCCATV

DBS

MMDS

LMDS

xDSL



US Network Technology SummaryUS Network Technology Summary--20052005

?LMDS?

HFC?

MMDS?

DBS?

Passive Optical Networks?

Copper xDSL?

Direct Optical?

Over-The Air?



HFC FacilitiesHFC Facilities

nn 5000 s.f. to 20,000 s.f. conforming to zoning requirements and n5000 s.f. to 20,000 s.f. conforming to zoning requirements and neighbourhood eighbourhood environmentenvironment




nn Civil Works and Landscaping to suit siteCivil Works and Landscaping to suit site

nn CoCo--located cellular telephony base stationlocated cellular telephony base station




nn Service vehicle access and parkingService vehicle access and parking

nn Satellite dishes and original facility (at right) to be deSatellite dishes and original facility (at right) to be de--commissioned and removedcommissioned and removed




nn Dual Redundant GeneratorsDual Redundant Generators

nn 72 Hour Runtime with On72 Hour Runtime with On--site fuel supplysite fuel supply



nn Main Power ServiceMain Power Service

nn Backup Generator Automatic Transfer SwitchesBackup Generator Automatic Transfer Switches





nn 48V Rectifiers and Main Distribution Breakers48V Rectifiers and Main Distribution Breakers

nn AA--B Redundancy and Allowance for GrowthB Redundancy and Allowance for Growth




nn 48V Rectifiers48V Rectifiersnn Modular Construction, Hot Swappable, N+1 RedundantModular Construction, Hot Swappable, N+1 Redundant



nn 48V Plant Battery Strings48V Plant Battery Strings

nn AA--B Redundancy and Allowance for GrowthB Redundancy and Allowance for Growth




nn 48V Distribution Bay in Equipment Room48V Distribution Bay in Equipment Room

nn AA--B Redundancy with Diverse Routing of ConductorsB Redundancy with Diverse Routing of Conductors




nn UninterruptibleUninterruptible Power Supply (UPS) for NonPower Supply (UPS) for Non--48V Equipment48V Equipment

nn 100kVA, 3100kVA, 3--phase, 20 minute Runtimephase, 20 minute Runtime




nn Environmental Temperature and Humidity Control SystemEnvironmental Temperature and Humidity Control System

nn Ducted and Ducted and UnUn--ducted, N+1 Redundancyducted, N+1 Redundancy




nn Equipment RacksEquipment Racks

nn 19” Cabinet, 24” Open Racks, NEBS and EIA Standards19” Cabinet, 24” Open Racks, NEBS and EIA Standards

HFC Inside PlantHFC Inside Plant



nn CATV EquipmentCATV Equipment

nn Receivers, Modulators, Processors, Routers, Digital Transport EqReceivers, Modulators, Processors, Routers, Digital Transport Equipmentuipment




nn CATV ModulatorsCATV Modulators

nn MicroMicro--Processor Controlled, Frequency AgileProcessor Controlled, Frequency Agile




nn RF Distribution Network MonitoringRF Distribution Network Monitoring

nn Ingress Monitoring Forward and Return SweepIngress Monitoring Forward and Return Sweep




nn Telephony HDTSTelephony HDTS

nn Expansion Space for Future Installation of Equipment RacksExpansion Space for Future Installation of Equipment Racks




nn Telephony Equipment and RF Telephony Equipment and RF Cobining Cobining Network RacksNetwork Racks

nn Interface of Switched Telephony Network to RF Broadband DistribuInterface of Switched Telephony Network to RF Broadband Distribution Networktion Network




nn Auxiliary Framing and Cable RackingAuxiliary Framing and Cable Rackingnn MultiMulti--Level, GRLevel, GR--1275 Compliant1275 Compliant




nn RF Combining Network (Rear View)RF Combining Network (Rear View)

nn Size is Proportional to HomesSize is Proportional to Homes--PassedPassed




nn RF Combining NetworkRF Combining Network

nn Physical and Electrical of Video, Voice and Data ServicePhysical and Electrical of Video, Voice and Data Service

HFC ConvergenceHFC Convergence



Conclusions Conclusions

Broadcasters, as the first builders and operators of a wide-band signal delivery system serving the general public, have the oldest and least capable infrastructure for the delivery of digital programming relative to the current broadband digital distribution systems.

However, there are now quite a few fiber, copper and wireless multi-channel distribution networks available to the broadcaster, and these distribution technologies are currently responsible for signal delivery to the majority of the end users..




Broadcasters are ideally positioned to:

•Acquire local content and to provide same in real time;

•Provide local digital storage (archiving) of content for web-based and video-on-demand applications to support delivery of non-real-time content to targeted audiences;

•Co-develop new services with distribution system operators, including web-based services, to obtain a share of any potential revenue stream;




•Create new services and products based on local content;

•Avoid capital and operating costs related to distribution network ownership;

•Produce high quality content on increasingly digital-based production systems for SDTV and (eventually) lower cost HDTV systems,

•Access a skilled pool of production personnel.




“If you are not in real time, you’re dead. Swarms need real time communications.”(Note1)

The challenge to today’s broadcasters is to find new, attractive and relevant ways to provide real time local content to the viewing public.

Today’s broadcast engineer is faced with the challenge of implementing and operating the technical systems required to produce and deliver, by whatever means are appropriate, the content to viewers wherever and whenever they might be.

Note 1 - Kevin Kelly, New Rules for a New Economy

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Advanced Television Broadcasting In A Digital …...for the delivery of digital programming relative to the current broadband digital distribution systems. However, there are now quite