Implementing ATSC Mobile DTV
Jay Adrick – VP Broadcast Technology Harris Corporation
Understanding the MDTV System ATSC Mobile DTV Overview 4
Consumers receive mobile TV signal on DTV stations transmit mobile TV signal with many different devices via ATSC Mobile DTV addition of ATSC Mobile DTV system chip and module
ATSC DTV ILLUSTRATIVE EXAMPLE OF SPECTRUM SPLIT Mobile Broadcast phone System
Remaining digital Portable transport is used media to deliver mobile player signals
19.4 MbpsMPH of signal Spectrum Laptop + computer (dongle) ATSC Mobile ATSC Mobile DTV System DTV chip GPS device
A portion of digital transport is used for traditional TV signal Automobile- based TV What is ATSC Mobile DTV
• Optimized Mobile / Pedestrian / Handheld (MPH) transmission and reception system
• Embellishment to ATSC DTV standard
• Mobile DTV service within broadcasters’ existing DTV channel assignment and transmission infrastructure
• No outside service providers required but perhaps desired
• 100% backwards compatible addition to ATSC main transmission
• Transmitted spectrum identical to 8-VSB, so no additional FCC authorization ATSC Mobile DTV Features
• Robust physical layer – High immunity to drop-outs and burst noise – No need for receiver antenna diversity – Up to 12.5 db system gain over regular ATSC channel – High-Speed reception – up to 300 km/h • Data efficient and completely scalable – 3.667 Mbps of ATSC TS could provide up to 980 Kbps mobile/handheld service – Scalable coding for selectable robustness of signal – Efficiency ranges from 37% to 17% depending on the level of coding • Power savings for handheld devices due to bursted transmission – Allows receiver RF circuitry to be ON part-time to save battery life ATSC Mobile DTV Features
• IP based mobile payload – Supports stream and non real time file delivery – Enables cross media compatibility – Utilizes efficient AVC h.264 video coding and AAC-HE audio coding • Each RF channel is capable of delivering up to 8 individually coded mobile IP data streams (Ensemble) – Each IP data stream can support multiple services…Video+Audio, Audio only, Service Guide, NRT services, etc. – System maintains at least 4.7 Mbps legacy ATSC in TS
• System supports service protection which enables – Viewer identification – Access control – Paid service offerings ATSC M/H Features
• Electronic Service Guide system based on OMA – Bcast standard supports a variety of features – rapid channel changing – video on demand – banner advertising – Datacasting & podcasting – voting – E-commerce
• Easy integration into ATSC broadcast systems – Encoder(s), signaling, ESG and Mobile adaptor at studio – No changes/additions to the STL – Replacement exciter at transmitter ATSC Mobile DTV Major Layers
Presentation Layer Audio and Video Codecs
Captioning
Management Layer
Transport Streaming and Non-Real Time File Transfer
Electronic Service Guide
Physical Layer
RF Transmission and Forward Error Correction;
Compatibility with Legacy 8-VSB Receivers/Decoders ATSC Mobile DTV Layer Stack
Presentation Management
Phy RME ESG AFD -708 CEA
FLUTE HE-AAC AVC NTP SMT ETC. STKM RTCP LTKM. ALC RTP
UDP
IPv4 FIC
DATA RS Frame
Training TPC FIC M/H Payload FEC (SCCC) Sequences
Advanced Television Systems CommitteeATSC 8-VSB 8-Level Vestigial Sideband Modulation ATSC Mobile DTV Layer Stack Acronyms Deciphered
Presentation
Management Rich Electronic
Physical Media Service Environment Guide
File Delivery CEA-708 Captions Description over Active Format Unidirectional
Advanced Advanced Transport Audiio Coding Video Coding High-Efficiency
Term Asynchronous Real-Time Protocol Layered Protocol
Table, ETC. Table, Transport Network Time Short (Long) Service Map RTP Control Key Message Key Coding Protocol User Datagram Protocol
Internet Protocol version 4 Fast Information Channel Reed-Solomon Frame DATA Transmission Fast Mobile/Handheld Payload Training Parameter Information Forward Error Correction Sequences Channel Channel (Serial Concatenated Convolutional Coding)
Advanced Television Systems Committee 8-Level Vestigial Sideband Modulation ATSC Mobile DTV Station Architecture
• ATSC A/153 standardizes the characteristics of the emitted Mobile DTV signal and describes the functionality that resides within the signal. – A/153 does not standardize the method of implementation – It does guarantee transmission to receiver interoperability
• The following description of ATSC Mobile DTV station implementation reflects the product architecture developed by Harris and our team partners. • Other manufacturers may implement their products using another method. • Currently, there is limited interoperability between some manufacturers – Interface interoperability is under development in ATSC S5 – Harris equipment design reflects that activity Transmission System Pre-Processing
Legacy 8VSB Processing ATSC Mobile DTV Transmission System
SynchronyMNA Studio
STL M2X
Transmitter
Legacy 8VSB Processing System Architecture - ATSC Only
Studio Transmitter ATSC PSIP STL Generator MPEG-2 TS IP
ATSC Main Existing Channel ATSC ATSC Encoder(s) & Transmitter Exciter Service Multiplexer System Architecture with Basic ATSC Mobile DTV
Studio Transmitter ATSC PSIP STL Generator IP MPEG-2 TS
ATSC Main MPEG-2 TS Synchronous M2X Channel Mobile Network Exciter ATSC Adaptor Encoder(s) & Mobile Multiplexer w/ M/H Transmitter System Time Generator Preprocessor Service Multiplexer Mobile Preprocessor SFN Processor
IP Mobile IP Channel IP Switch Encoder(s) IP
Signaling Generator Electronic Service Products Key
Guide (optional) Transmission Products NRT Content Networking Products Station Manager/Server Partner Products Metadata (optional) Third Party Supplied System Architecture with Advanced ATSC Mobile DTV
Studio Transmitter ATSC PSIP STL Generator IP MPEG-2 TS
ATSC Main MPEG-2 TS Synchronous M2X Channel Mobile Network Exciter ATSC Adaptor Encoder(s) & Mobile Multiplexer w/ M/H Transmitter System Time Generator Preprocessor Service Multiplexer Mobile Preprocessor SFN Processor
IP Mobile IP Channel IP Switch Encoder(s) IP
Signaling Generator Electronic Service Products Key
Guide (optional) Transmission Products NRT Content Networking Products Station Manager/Server Partner Products Metadata (optional) Third Party Supplied System Architecture with Advanced ATSC Mobile DTV
Studio Transmitter ATSC PSIP STL Generator IP MPEG-2 TS
ATSC Main MPEG-2 TS Synchronous M2X Channel Mobile Network Exciter ATSC Adaptor Encoder(s) & Mobile Multiplexer w/ M/H Transmitter System Time Generator Preprocessor Service Multiplexer Mobile Preprocessor SFN Processor
IP Mobile IP Channel IP Switch Encoder(s) IP
Signaling Generator Electronic Service Products Key
Guide (optional) Transmission Products NRT Content Networking Products Station Manager/Server Partner Products Metadata (optional) Third Party Supplied System Architecture with Advanced ATSC M/H & SFN
Studio Transmitter ATSC PSIP STL Generator IP MPEG-2 TS
ATSC Main MPEG-2 TS Synchronous M2X Channel Mobile Network Exciter ATSC Adaptor Encoder(s) & Mobile Multiplexer w/ M/H Transmitter System Time Generator Preprocessor Service Multiplexer Mobile Preprocessor SFN Processor M2X IP Mobile IP Exciter ATSC
Channel IP Switch w/ M/H Transmitter Encoder(s) IP Preprocessor
Signaling Generator Electronic Service Products Key
Guide (optional) Transmission Products NRT Content Networking Products Station Manager/Server Partner Products Metadata (optional) Third Party Supplied System Architecture with Full ATSC M/H & SFN
Studio Transmitter ATSC PSIP STL Generator IP MPEG-2 TS
ATSC Main MPEG-2 TS Synchronous M2X Channel Mobile Network Exciter ATSC Adaptor Encoder(s) & Mobile Multiplexer w/ M/H Transmitter System Time Generator Preprocessor Service Multiplexer Mobile Preprocessor SFN Processor M2X Service IP IP IP Mobile Protection Exciter ATSC Channel IP Switch Encryptor w/ M/H Transmitter Encoder(s) Preprocessor (optional) IP
Signaling Generator Encryption Server Data Electronic Service Products Key Guide (optional) Transmission Products NRT Content Networking Products Station Manager/Server Partner Products Metadata (optional) Third Party Supplied ATSC Mobile DTV Encoder
• Function: Compresses and encodes audio/video program content into low bit rate IP packetized data streams for transmission to ATSC Mobile enabled receiving devices
• Requirement: One encoder for each real time program stream that is to be transmitted over the ATSC Mobile DTV system. Redundancy should be considered at N:1 level • Detailed Specifications: – Video • Encoding format – MPEG4 h.264 base profile v1.3 • Resolution – 416 x 240 Progressive scanning • Aspect ratio – 16 x 9 (Wide Screen) • Source video – Could be 1080I, 720P, 480P (ws) or 480I (ws) – Recommended to start with 16 x 9 format or convert prior to encoding – Encoder should respond to AFD (Automatic Format Descriptor) • Closed captioning – CEA 708 format ATSC Mobile DTV Encoder
• Detailed Specifications cont’d: – Audio • Encoding format – HE AAC v2.0 (High Efficiency Advanced Audio Codec version 2.0) • Sampling Frequency – 16, 22.05, 24 KHz. with SBR & 32, 44.1, 48 KHz. w/o SBR SBR = Spectral Band Replication • Audio format – Mono or Stereo (System is capable of supporting parametric surround) • Source audio – AES digital – Discrete or imbedded – Output • Packetized IP over UDP (User Datagram Protocol) with RTP (Real- time Transport Protocol) • RTP supports: – Payload-type identification - Indication of what kind of content is being carried – Sequence numbering - PDU sequence number – Time stamping - allow synchronization and jitter calculations ATSC Mobile Networking Adapter
• Function: Multi function platform that supports preprocessing of the Mobile DTV data; generates mobile synchronizing data for modulators; encapsulates processed mobile IP data in MPEG-2 transport packets; multiplexes mobile packets into the ATSC transport stream, generates FIC,TPC and Service ID signals, carousels and transmits signaling tables; injects announcement data and NRT files for datacasting; generates ATSC system time and synchronization/timing adjustment of the ATSC transport for distributed transmission networking. The ATSC Mobile DTV processing and distributed transmission timing are each treated as separate applications. • Requirements: One MNA per station. Redundancy should be considered on a 1:1 level. Application options to be selected depending on transmission system architecture. MNA should have hard by-pass capability for main ATSC transport stream to prevent disruption of main ATSC service. All timing information should be derived from GPS disciplined time base. MNA is to placed as last item in transmission chain prior to STL. Fast Information Channel (FIC) & Transmission Parameters Channel (TPC) • FIC Purpose: Rapid service scan, rapid service access – For each Ensemble • What Services (virtual channels) it contains • Whether it contains copy of GAT and/or SLT • Ensemble “protocol” version (structure of RS-Frame, etc.) – For each Service • Service ID • Status (normal/hidden, on/off air) • Whether or not it is access-controlled • Whether it is part of a multi-Ensemble service, and if so whether it is essential to a meaningful presentation • TPC Purpose: Carries data group and coding information – Subgroup, slot and parade numbers – Reed Solomon framing (inner code) numbers – SCCC (Outer code) details – FIC version number Harris SynchronyMNA Synchronous Mobile Networking Adaptor
• Detailed Specifications: – Inputs • SMPTE 310M/ASI (selectable) for ATSC Transport Input • Isolated content data Ethernet port for program encoded data, signaling data, ESG, and NRT file data • Ethernet port for system configuration, monitoring and control • GPS antenna (Internal GPS receiver) – Outputs • SMPTE 310M/ASI selectable X 4 • One output protected by hard by-pass relay APEX M2X ATSC M/H Exciter
• Function: Generates ATSC 8VSB main service signal modulation while post- processing Mobile DTV content with RS coding, trellis coding, serial concantinated coding and adds training signals for enhanced Mobile DTV reception. • Requirement: One exciter per transmitter is required. Redundancy should be considered on a 1:1 level. • Detailed Specifications: – Inputs • SMPTE 310M or ASI Transport stream (selectable) • Optional GPS antenna used for precise frequency or DTS (SFN) operation • External 10 MHz and 1 PPS reference • RF samples for adaptive correction • Ethernet for configuration, monitoring and control – Output • 8VSB modulated RF signal on assigned channel – .100 Watt maximum output power APEX M2X ATSC Mobile Exciter Service and Content Discovery
• Signaling – A/153 Part 3 – Fast Information Channel (embedded) – Service Signaling Channel (IP) – Essential information, required to • display services to the receiver user • play audio/video content • Announcement – A/153 Part 4 – Optional OMA BCAST Service Guide (IP) – Additional metadata for services and programs – Springboard for advanced services, NRT and other file based offerings Service Signaling Channel • Collection of binary tables – Transmitted as a well-known multicast UDP/IP stream – Different data is encapsulated in each ensemble • Service Map Table (SMT) MANDATORY – Describes services type, IP addresses, codecs … – May include current program information • Service Labeling Table (SLT) – Adds human-readable names to fast frequency scan • Guide Access Table (GAT) – How to acquire Service Guide, if present • Cell Info Table (CIT) – Supports service hand-off when roaming • Rating Region Table (RRT) – As in A/65 Signaling - User Experience
• Media Plays! • Channel Info – Major, minor number – Short name – Service category (TV, Radio) – Typically scanned and cached • “What’s On Now” – Title – Genre, Rating, Duration – Available once tuned to ensemble • Others may not be populated or up to date Signaling Generator Functions
• Service Provisioning – Ensemble IDs – Service IDs and types – Component configuration • Metadata Collector – Program listings • TitanTV, Tribune, … • Program editor • Main channel PSIP ingest • PMCP integration • Table Generator – Creates tables and future schedule for upload to MNA – FIC built from data by MNA Signaling Generator Integration
• System element responsible for constructing SSC tables – Tables (SMT) are dynamic with current program – Tables (SMT, SLT) must be sent once per M/H frame • A/153 does not standardize signaling to mux interface • Architectural choices for integration: – Monolithic integration with mobile mux/preprocessor – External IP stream generator - encapsulation in mux – External table loader - SSC carousel and scheduler in mux • E.g., approach used by Roundbox Broadcast Server and Harris SMNA Announcement
• OMA BCAST Service Guide (SG/ESG/EPG) • SG provides metadata for the broadcaster’s content that can be incorporated into a richer program guide • Basic features include – Delivery of channel icons – Complete program titles and descriptions, genre, ratings – Information for upcoming as well as current programs • Set of files delivered as FLUTE/UDP/IP streams • Signaled as a (hidden) non-A/V service – Discovery bootstrapped by FIC, GAT and SMT Announcement Relationship with Signaling • Some overlap with Signaling layer: – IP multicast parameters – Title – Start time/duration – Genre category – Content advisory • When there’s conflicting info, receiver shall use Signaling – Service Signaling Channel always takes precedence over Announcement • Signaling is mandatory, Announcement is optional • When used, it must be compliant with the following: – M/H Service Guide is compliant OMA BCAST Service Guide, as further constrained by A/153 Part 4 • More than one ESG is permitted – Receiver technology will support aggregation of guides Basic SG - User Experience • Signaling experience enhanced • Richer channel info – Icon, URL, description • Richer program info – Description • “What’s Coming Up” – Future programming for all channels on a broadcast • Amount may be tuned by broadcaster – Receiver aggregation • May be cached for all broadcasts Announcement Server Functions
• Service Provisioning – Enhancement of signaling • SG Delivery Provisioning – FLUTE and IP parameters – Partitioning of guide data • Data type • Time window – Bitrate (per partition) – One or more SGs • Metadata Collector – Enhancement of signaling – Additional media delivery • Channel logos Announcement Server Integration • Element responsible for SG delivery • Architecture need not be as coupled to mux as signaling – External generation of FLUTE streams – IP streams encapsulated by mux • Common config and data with signaling generator – Service and component details – Program metadata • Typically shares hardware with signaling – E.g., Upgrade to Roundbox Server Broadcast Guide Configuration
• Strongly influenced by assumptions about receiver SG acquisition behavior • Acquisition of long-term guides (e.g., 7 days) – Second receiver? – Offline or manual scan and download? – Interaction channel? • Many receivers/apps have none of the above • Announcement server must be able to provide partitioned guide – Short-term to support “now and soon” programming – Long-term acquired during viewing (or scans, by more capable receivers) Additional Guide Scenarios
• A/153 supports signaling of SGs outside the current broadcast – Receiver can aggregate – Classical “time grid” views may only be realistic with market guide • SG from interactive channel – Likely the only common mechanism for market guide • SG from external broadcast – Requires multi-receiver or offline download device Advanced SG Features • Richer information means the user spends more time in the guide or mobile TV application • Broadcaster opportunity for – Advertising and co-promotion – Interstitial content – Adjunct content delivery – Links to additional content – Interactivity • Broadcast SG can be a key enabler of additional content, if provided in a standardized way OMA SG Based Media and Interactivity
• OMA BCAST SG can support additional features not explicitly called out in A/153 • Preview data variants – Zapping • Interactivity – Service and program- associated interactive media documents • Many servers and devices have existing support for some of these features, but … • Lack of consensus in industry? Mobile DTV Widgets • Mobile DTV initial focus: Television services • Widgets add broadcast data services to the mix • Types: Global or Synchronized – Global: Not associated with a TV/radio service, e.g. news – Synchronized: Associated with and synchronized to TV channel/program, e.g. merchandising Non-Real-Time Content Delivery
• A familiar idea whose time has come? • Convergence of multiple factors: – Evolution of existing ATSC broadcast data standards – New classes of devices that are “DTVs” – Mobile DTV infrastructure relies on file delivery for SG – Similar efforts such as OMA DCD • ATSC NRT Standard – Applies to fixed and mobile ATSC – V1.0 in development in S13-1 AHG • Set of “modes” for push data • Extensible set of content types: media files, RSS, web bundles, … – Mobile: SG extensions to provide content guide – Standalone services - synchronized proposed in 2.0 NRT Server Integration
• Element responsible for NRT Service Delivery • Service management – Service type, data source, Bandwidth configuration • Content ingest (e.g., RSS) – From local provisioning, broadcaster source or service bureau • Stream generation – FLUTE/UDP/IP streams – Dynamic bandwidth management • Co-resident/co-located with Announcement Server Planning for Implementation Bandwidth Requirements
Main Channel Basics
• ATSC A/53 has 19.39 Mbps payload capability • The FCC requires all digital broadcasters to provide at a minimum 1 SD NTSC quality free-to-air program service • ATSC program guide (PSIP) requires about 0.5 Mbps
• Typical SD service in MPEG2 requires 2-4 Mbps
• Typical HD service in MPEG2 requires 10-14 Mbps Bandwidth Requirements
Mobile DTV Basics
• ATSC Mobile DTV channels are scaleable in number and level of robustness • Robustness is a function of coding level and it also drives payload efficiency – Half rate = 37% , Mixed rate = 26% , Quarter rate=17% • Streams with the same level of robustness (coding) can be assembled into an ensemble • Main channel contribution is made in increments – .917mbps, 1.83mbps, 2.750mbps, 3.667mbps, 4.584mbps 5.501mbps, 6.418mbps, 7.334mbps Bandwidth Requirements
Mobile DTV Basics
• Full details of bandwidth allocation for ATSC A/153 Mobile DTV can be found in the ATSC A/153 standards documents, Section 2 Page 63
• The following are some sample use cases that were detailed by OMVC members: ATSC Mobile Broadcast Scenarios
Assumptions • VIDEO – Three Options High Quality Medium Quality Lower Quality 500 kbps 400 kbps 256 kbps
• AUDIO – Three Options High Quality Medium Quality Lower Quality 32 kbps 24 kbps 16 kbps
• CODING – Two Options SCCC Outer Code SCCC Outer Code 1/4, 1/4, 1/4, 1/4 1/2, 1/4, 1/4, 1/4 Efficiency = 17.1% Efficiency = 26.4%
• Notes: – A range of 0 to 200 kbps is reserved for overhead (ESG, null bits, etc.), this value has been adjusted to try to optimize scenarios – The bit rate of still images is negligible for purposes of this document – NRT and other data delivery via M/H is not considered in this document – Refer to ATSC A/153 Section 2 Chart 6.1 for complete details Case 1 - One max-quality program
One max-quality program - 1/2, 1/4, 1/4, 1/4 Video bit rate 768 kbps Audio bitrate 24 kbps Overhead 176 kbps Total MH bandwidth 3.668 Mbps Remaining Legacy DTV Bandwidth 15.722 Mbps
One max-quality program - 1/4, 1/4, 1/4, 1/4 Video bit rate 768 kbps Audio bitrate 24 kbps Overhead 148 kbps Total MH bandwidth 5.502 Mbps Remaining Legacy DTV Bandwidth 13.888 Mbps Case 2 - One mid-quality program
One mid-quality program - 1/2, 1/4, 1/4, 1/4 Video bit rate 400 kbps Audio bitrate 24 kbps Overhead 60 kbps Total MH bandwidth 1.834 Mbps Remaining Legacy DTV Bandwidth 17.556 Mbps
One mid-quality program - 1/4, 1/4, 1/4, 1/4 Video bit rate 400 kbps Audio bitrate 24 kbps Overhead 46 kbps Total MH bandwidth 2.751 Mbps Remaining Legacy DTV Bandwidth 16.639 Mbps Case 3 - Two mid-quality programs
Two mid-quality programs - 1/2, 1/4, 1/4, 1/4 Video bit rate 800 kbps Audio bitrate 48 kbps Overhead 120 kbps Total MH bandwidth 3.668 Mbps Remaining Legacy DTV Bandwidth 15.722 Mbps
Two mid-quality programs - 1/4, 1/4, 1/4, 1/4 Video bit rate 800 kbps Audio bitrate 48 kbps Overhead 92 kbps Total MH bandwidth 5.502 Mbps Remaining Legacy DTV Bandwidth 13.888 Mbps Case 4 - Two high-quality programs
Two high-quality programs - 1/2, 1/4, 1/4, 1/4 Video bit rate 1100 kbps Audio bitrate 48 kbps Overhead 62 kbps Total MH bandwidth 4.585 Mbps Remaining Legacy DTV Bandwidth 14.805 Mbps
Two high-quality programs - 1/4, 1/4, 1/4, 1/4 Video bit rate 1100 kbps Audio bitrate 48 kbps Overhead 106 kbps Total MH bandwidth 7.336 Mbps Remaining Legacy DTV Bandwidth 12.054 Mbps Case 5 - Four mid-quality programs
Four mid-quality programs - 1/2, 1/4, 1/4, 1/4 Video bit rate 1600 kbps Audio bitrate 96 kbps Overhead 240 kbps Total MH bandwidth 7.336 Mbps Remaining Legacy DTV Bandwidth 12.054 Mbps
Four mid-quality programs - 1/4, 1/4, 1/4, 1/4 Video bit rate 1600 kbps Audio bitrate 96 kbps Overhead 185 kbps Total MH bandwidth 11.004 Mbps Remaining Legacy DTV Bandwidth 8.386 Mbps Case 6 - Two mid-quality and one high-quality programs
Two mid-quality and one high-quality programs - 1/2, 1/4, 1/4, 1/4 Video bit rate 1350 kbps Audio bitrate 72 kbps Overhead 30 kbps Total MH bandwidth 5.502 Mbps Remaining Legacy DTV Bandwidth 13.888 Mbps
Two mid-quality and one high-quality programs - 1/4, 1/4, 1/4, 1/4 Video bit rate 1350 kbps Audio bitrate 72 kbps Overhead 146 kbps Total MH bandwidth 9.17 Mbps Remaining Legacy DTV Bandwidth 10.22 Mbps Half Rate Mode
SCCC Outer Code Rate (for each Group Region) PDRP MDRL A B C D P NoG NP ET (=EP) (Kbps) (Mbps) 1 202 34.1 312.2 0.917
2 407 34.3 629.1 1.834 3 612 34.4 945.9 2.750 4 817 34.4 1262.8 3.667 1/2 1/2 1/2 1/2 48 5 1021 34.4 1578.1 4.584 6 1226 34.4 1894.9 5.501 7 1431 34.5 2211.8 6.418 8 1636 34.5 2528.7 7.334
PDRP = Payload Data Rate for Ensemble
MDRL = Main Data Rate applied to MDTV
12-Apr-11 Mixed Rate Mode
SCCC Outer Code Rate (for each Group Region) PDRP MDRL A B C D P NoG NP ET (=EP) (Kbps) (Mbps) 1 155 26.1 239.6 0.917
2 313 26.4 483.8 1.834 3 471 26.5 728.0 2.750 4 628 26.5 970.7 3.667 1/2 1/4 1/4 1/4 48 5 786 26.5 1214.9 4.584 6 944 26.5 1459.1 5.501 7 1102 26.5 1703.3 6.418 8 1259 26.5 1946.0 7.334
PDRP = Payload Data Rate for Ensemble
MDRL = Main Data Rate applied to MDTV
12-Apr-11 Quarter Rate Mode
SCCC Outer Code Rate (for each Group Region) PDRP MDRL A B C D P NoG NP ET (=EP) (Kbps) (Mbps) 1 202 16.9 154.6 0.917
2 407 17.0 312.2 1.834 3 612 17.1 471.4 2.750 4 817 17.2 629.1 3.667 1/4 1/4 1/4 1/4 48 5 1021 17.2 786.7 4.584 6 1226 17.2 945.5 5.501 7 1431 17.2 1103.6 6.418 8 1636 17.2 1262.8 7.334
PDRP = Payload Data Rate for Ensemble
MDRL = Main Data Rate applied to MDTV
12-Apr-11 Mobile System - Studio • Equipment at Studio – Selenio Mobile Encoder System
• 3 RU 17 Slot Frame
– Signaling Server • 1 RU Dell Server ChassisRoundBox ESG Server • Also supports ESG option
– IP Hub (Customer Supplied) RoundBox ESG Server RoundBox ESG Server
– SynchronyMNA Mobile Networking Adapter • 1 RU Signal I/O at Studio
• Transport Stream • RF – From ATSC main multiplexer to – GPS Antenna to SynchronyMNA SynchronyMNA input – Harris offers as option – could – From SynchronyMNA to STL be central antenna with DA input • IP Networks • SMPTE 310M preferred but will also support ASI – Mobile Program Content – Must be isolated network • Video • Encoder output(s) – SD Widescreen – Up to 5 per frame • SDI interface per mobile stream • Signaling Server output • IF HD – down convert to SD- • NRT Server (optional) WS • External IP delivered services • Audio – Configuration & Control – AES 48 KHz sample rate locked • IP port on each device to video • Preferred to support external – Discrete or imbedded access by permission Mobile DTV System IP Management
• ATSC MDTV is a combination of transport stream, RF and IP technologies • Encoding, signaling, ESG, service protection, NRT delivery and multiplexing all require management of the IP domain • MAC and IP address management is essential and air critical • External access to Synchrony, Roundbox Data Server, NetVX and the M2X is very desirable and enables rapid troubleshooting and configuration – Access can be on a supervised basis Where in the transport stream
• The mobile system must be installed as the last item in the chain of equipment prior to the STL. – No additional multiplexing can be inserted after the mobile stream
• Common sources of problems are Nielsen NAVE encoders, rate shaping devices, transport processors (DTP), transport format converters (ASI to 310M) and some multichannel STL’s…if installed down stream of the mobile system STL Considerations
• Stable 19.39 Mbps link is essential
• No drop or add of MPEG-2 packets allowed • SMPTE 310M interface is highly desirable at both ends of the link • System has been tested over RF Microwave, Fiber and Copper links • Network to ASI or SMPTE 310M converters are known sources of stability problems • Some RF link systems have known stability issues Mobile System - Transmitter
• Equipment at Transmitter – APEX M2X Exciter • Replaces existing ATSC exciter • Ideal configuration is transmitter with exciter change over system – Allows mobile installation without interrupting operations • 2 RU configuration is smaller than previous Harris ATSC exciters • Exciter requires external PC or lap top PC for configuration • Web GUI support remote configuration and monitoring (TBD) Signal I/O at Transmitter
• Transport Stream • IP Network – From STL or TS DA to exciter – Configuration & Control input • IP port on M2X • SMPTE 310M preferred but will • Preferred to support external also support ASI access by permission • RF • Local PC or Laptop to configure – GPS Antenna to M2X input • Harris offers as option – could be central antenna with DA – RTAC RF Samples • Same as APEX • Sample ports to M2X inputs – 10 MHz Frequency Reference • Output available to support other plant requirements Understanding Mobile Coverage & Reception • ATSC Mobile DTV reception is based on different planning factors than terrestrial DTV reception – Receive antenna height 45” vs. 30 ft. – Receive antenna gain -20db to -3db vs. 0db – System SNR 3.5 – 7.0db vs. 15db
• Field testing has shown that the “radio horizon” is the limit to reliable mobile/handheld coverage – Typically line of sight from TX antenna to receiver – Limitations typically are terrain and buildings – Flat terrain + tall towers + H&V pol + max power = 35 -45 mile coverage Targeted MDTV Coverage
• Broadcasters have indicated that they are most concerned with delivering coverage to: – Urban canyon areas – Interiors of large buildings – Urban areas that are terrain shielded
“Signal Saturation” vs “Coverage Contours” will become the principal criteria for successful performance
12-
Apr- Achieving Signal Saturation
• Circular polarization – Discussion to follow
• Maximized Power from main TX site – Achieved by low antenna gain and high transmitter power output
• Gap fillers and Repeaters – Synchronized or OTA Why Circular Polarization is Important Polarization Mismatch Loss (Depolarization) HP VP Caused by misalignment between the CP transmit and receive antenna
9
6
3 PML dB
0 0 153045607590 Why Circular Polarization is Important Small scale fading occurs when multiple signals arrive at the receiver from nearby reflecting objects HP The vector addition of all multi- VP CP path components create variations in the received signal strength Signal Power
Receiver Displacement CP results in improved signal availability
20
Signal Power dB Horizontal polarization 10
Mean 0
σ −= 7.18 dB -10 98 % Service -20 0 Receiver Displacement 180 360 20 Signal Power dB Vertical polarization 10
Mean 0
σ −= 7.19 dB -10
98 % Service -20 0 Receiver Displacement 180 360 20
Signal Power dB Circular polarization 10
Mean 0 σ −= 8.14 dB -10 98 % Service -20 0 Receiver Displacement 180 360
700 MHz Test Results Summary - UHF
8 O S 6 F W F M Circular Polarization O O I A 4 P O C L H E D E L O 2 N E U D B V S A U E 0 E Horizontal Polarization R A I H E R I -2 L A E C D Vertical Polarization A I L -4 N E
Margin Improvement (dB) Improvement Margin G -6
•On average, circular polarization offers 5 dB margin improvement
over horizontal polarization •On average, circular polarization offers 7.5 dB margin improvement over vertical polarization
12-
Apr- Test Results Summary - UHF
Greatest Margin Occurs at 33% Vertical Component
6 Full CP
5
4 Optimum Range 3
2 Horizontal Polarization Baseline
Margin Improvement (dB) 1 Vertical Polarization Baseline 0 0 102030405060708090100 % Vertical Polarization More than 4 dB of margin improvement with 20% < Vpol < 50%
12-
Apr- What about VHF? Results Summary - VHF
CPOL
Circular Polarization
VPOL Horizontal Polarization Vertical Polarization Margin Improvement (dB)
•On average, circular polarization offers 3.5 dB margin improvement over horizontal polarization •On average, circular polarization offers 4.5 dB margin improvement over vertical polarization
Frequency 210 MHz VHF Observations
• On a small handheld receiver, VHF provides: • Less polarization discrimination • Greater orientational immunity •“Omni Polarized” • On average circular polarization provided 3.5 dB of margin improvement over horizontal polarization
Great news for VHF….right? VHF Observations
Average Received Signal Strength UHF vs. VHF
Link Budget Differences Average Field Strength
VHF UHF UHF VHF Adjusted VHF
Antenna Gain ‐3.1 dB 0.0 dB Open ‐31.8 dBm ‐56.0 dBm ‐53.3 dBm Tx Power ‐4.0 dB 0.0 dB Woods ‐38.2 dBm ‐55.7 dBm ‐53.0 dBm Tx Cable 3.6 dB 0.0 dB Office ‐45.2 dBm ‐72.0 dBm ‐69.3 dBm Rx Cable 0.5 dB 0.0 dB House ‐57.9 dBm ‐75.2 dBm ‐72.5 dBm Rx Ant. VSWR ‐9.5 dB 0.0 dB Free space loss 9.8 dB 0.0 dB Vehicle ‐40.6 dBm ‐64.9 dBm ‐62.2 dBm
Adjustment Factor ‐2.7 dB 0.0 dB Avg ‐42.7 dBm ‐64.8 dBm ‐62.1 dBm VHFVHF hadhad 19.419.4 dBdB lessless averageaverage signalsignal strengthstrength thanthan UHFUHF Small Receive Antennas
Harold Wheeler defined the fundamental limitations of electrically small antennas based on their size
a
3 Max power factor: P max = (ka)
a = antenna volume radius k = 2π/λ Wheeler Limit
Solve for the max power ratio difference between 210 MHz and 700 MHz
3 ⎡⎛ 2π ⎞ ⎤ ⎢⎜ a⎟ ⎥ 3 ρ ⎜ λ ⎟ ⎛⎛ λ ⎞ ⎞ v = log10 ⎢⎝ v ⎠ ⎥ = log10 ⎜⎜ u ⎟ ⎟ −≈ 15dB ρ ⎢ 3 ⎥ ⎜⎜ λ ⎟ ⎟ u ⎢⎛ 2π ⎞ ⎥ ⎝⎝ v ⎠ ⎠ ⎜ a⎟ ⎣⎢⎝ λu ⎠ ⎦⎥
Wheeler Limit dictates the best VHF/UHF receive ratio of an electrically small antenna will be -15 dB Implementing ATSC Mobile DTV
Questions?
[email protected] Thank You Non-Obvious Considerations for adding MobileDTV
Rich Chernock Background • “Obvious” changes to DTV stations have been discussed – Encoders, Mux, Exciter… • Successful addition of Mobile DTV requires paying attention to a number of “non-obvious” considerations – Metadata & Workflow – Viewing Habits – Video & Audio – Interactivity – Security Metadata & Workflow Workflow – station operations Scheduling, traffic, automation… Sources for metadata Signaling: Metadata about what’s on right now Used for tuning/informing viewer what they’re watching ESG: Metadata about what’s on in the future Promotional – entice the viewer to watch later Information may be duplicated between signaling & ESG If so, signaling always wins Adding mobile workflow • Unlikely that new listing, traffic, automation systems be put into place for Mobile content – Therefore: Common workflow for fixed and mobile ATSC • Common schedule information sources for fixed and mobile – Mobile scheduling likely to be driven by existing workflow elements (see above) – Simulcast likely initially, separate mobile schedule will evolve • Common operational staff – Mobile likely to be one more thing added to existing burden ATSC Mobile Metadata Layers
• Static Signaling: A/153 Tuning Information OMA BCAST Extensions • Dynamic Signaling: A/153 Tuning + information Aggregated ESG about current event
Long Term ESG • Short Term ESG: A/153 Descriptive information about now/next + a bit (in this broadcast) Short Term ESG • Long Term ESG: A/153 Descriptive information Dynamic Signaling about extended schedule (in this broadcast) • Aggregated ESG: A/153 Descriptive information Static Signaling about extended schedule (in this & other broadcasts)
Need to think through: • OMA BCAST Extensions: ESG features not Which of these is important to your specified nor disallowed in A/153 station? Which will consume your bandwidth? Which might come from another path? Expected Delivery Approach for Mobile Metadata • Static Signaling: In each Ensemble – rapid - required
• Dynamic Signaling: In each Ensemble – rapid - dynamic OMA BCAST Extensions portion optional
Aggregated ESG • Short Term ESG: In each Ensemble (info for all ensembles in broadcast signal) – moderate rate - Long Term ESG optional
Short Term ESG • Long Term ESG: In each Ensemble (info for all ensembles in broadcast signal) – trickle – optional (may Dynamic Signaling not be carried, due to BW overhead) Static Signaling • Aggregated ESG: Pull from interaction channel (source?) – not broadcast - optional
• OMA BCAST Extensions: Pull from interaction channel (source?) – not broadcast – optional (may not be supported in receivers) DMA View – Likely Scenario for Metadata
WABC M/H Receiver
WDEF Interaction Channel (Aggregated)
OMA BCAST Extensions WGHI Broadcast Aggregated ESG (for this broadcast) LongTerm ESG
Short Term ESG WJKL Service Dynamic Signaling Provider
Static Signaling ATSC Fixed compared to ATSC Mobile
Remote GUI(s) Encoder(s) ATSC Fixed Time
Traffic/Program PSIP System Generator MUX Automation System
F ATSC Mobile only I Listing R Staging E Service Server W A Remote GUI(s) L L
Time Service Mux Traffic/Program M/H Signaling System and IP Automation Announcemen Encap Schedule info & sources System t common for Fixed & F I Mobile. R Listing Staging E Service Server W A Linkages and L Encoder(s) relationships established L for fixed can be leveraged for mobile Unified Metadata Management Metadata Workflow Recommendation
¾Continue utilizing existing workflow components and connections by adding Mobile signaling and ESG generation to your PSIP generator More on Workflow: Interactivity & NRT
• M/H supports Interactivity & NRT services • These services must become part of the station workflow – Incorporated into scheduling systems – No manual operator involvement • Interactivity needs to be scheduled as part of an event (or interstitial) – Loosely synchronized or Tightly synchronized – May require involvement of traffic/automation systems – Information flow to M/H Metadata generator & interactivity inserter • NRT services are effectively scheduled events – Similarly, need to be part of the station’s workflow – Information flow to M/H Metadata generator & NRT server M/H Station Architecture with Interactivity
Remote GUI(s)
Time
FI R Listing Staging E Service Server W A M/H Signaling and L Announcement L
Traffic/Program System Service Mux Automation IP Encap System
Interactivity Insertion
FI R E W A L L Encoder(s) Viewing Habits: Observations ATSC Fixed Appointment TV DVR Mainly full show oriented ATSC Mobile Opportunistic – ex: Avoid boredom while waiting Information seeking Quick update on News, Weather, Sports Portable content (Get now, view later) Likely to be mixture of short clips and full shows Viewing Habits: Implications What content for Mobile? Simulcast of fixed content likely initially (it’s easy to do) Over time – predict that separate M/H content will evolve • Need to be able to support simulcast & separate schedules in workflow Short form / cyclic content may be important NRT may become an important delivery mechanism Content (Video) Consideration: Will large screen content suffice for very small screens? Artistic reasons Large vs Small screen composition Where’s the ball? World cup experience over DVB-H Legible text? Can the textual elements actually be read on small screens? ¾Even if the schedule is the same, it may be necessary to have “different” content for mobile vs fixed Content (Audio) DTV provides the capability for high quality audio High dynamic range, many channels (up to 5.1) Quite suitable for in-home viewing Mobile DTV has different use case (mostly) Often noisy environment Tiny transducers / earbuds Low power amplifier Stereo/mono Need to take these differences into account Pre-processing can help alleviate problems Isolation – preferential treatment of dialog may help Post-processing (pref adjustable for conditions) Appropriate downmix from multi channel Interactivity Interactivity offers advanced features, BUT: Don’t forget local interactivity… Where do the clicks land?? Need to have servers to respond to interactions* Who makes the content? New lifecycle and management considerations Scheduling/inserting interactive content Workflow considerations * TV “Mass” effect: As opposed to internet, responses to TV
Interactiveinteractivity content can overwhelm from server within farms station or outside? Security (aka Service Protection aka CA) New domain for most broadcasters Need to decide on a business/operational model Encrypted / Pay? Encrypted / Free? Need to have encryption/key management function Select a vendor Need new business workflow Customer management/billing Bandwidth considerations May restrict service protection to connected devices only Or – may need to support both Summary
• Integrate mobile workflow into existing station operations • Consider what the viewing habits will be when considering mobile services • “One size fits all” may not be a good operating paradigm • Interactivity requires consideration of new issues • As does security Thanks
Rich Chernock [email protected] Thank You The Business of Mobile
In Public Broadcasting
Joe Igoe – VP/CTO, WGBH Agenda
• What we’re doing • Why we did it • What went wrong • Rights • Radio • Industry business factors What We’re Doing at WGBH
• WGBH – 700kW ERP on 19 – WGBH HD
VT Sullivan Rochester York – WGBH SD (4x3 for cable) Merrimack Strafford ME-1
indham – Mobile DTV NH-2 NH-1 Manchester Keene Rockingham Cheshire Hillsborough
Essex
Lowell Gloucester • WGBX – 500 kW ERP on 43 Franklin Gardner MA-6 MA-5 MA-1 Middlesex Worcester MA-7 – WGBX HD MA-8 Hampshire MA-3 D19 A2Boston Worcester Suffolk
– World SD Norfolk Hampden MA-2 – Kids SD MA-9 Tolland Bristol Windham Providence Plymouth MA-10 Providence CT-1 – Create SD MA-4 artford RI-2 Barnstable Kent New Bedford Barnstable Town CT-2 Norwich Newport iddlesex New London Newport Washington RI-1 Dukes What We’re Doing at WGBH
• Mobile DTV Service rollout: – December 2009 • Launched WGBH-HD simulcast – March 2010 • Added ‘GBH Kids, WGBH-FM and WCRB-FM simulcasts – September 2010 • Devices finally hit retail – November 2010 • Added two more audio streams – BSO and Jazz What We’re Doing at WGBH
• Today’s services:
WGBH-FM Create-SD WCRB-FM BSO ‘GBH Kids-SD Jazz
Mobile DTV WGBH (TV) World-SD ‘GBH Kids (TV)
WGBH-SD* WGBX-HD
WGBH-HD What We’re Doing at WGBH
• Possible future services: – Additional WGBH audio services – English as a second language instructional – Local college radio carriage – PRX services – Public safety voice/data – Datacasting Why Launch Mobile DTV?
• A smaller “universe” is less competition – Any market will likely have 20 or fewer Mobile DTV channels – Similar to early days of PBS – Increase percentage of captured channel surfers – Fewer channels give us a larger share – Reintroduce our content to viewers • Competitive advantage restored to broadcasters relative to cable channels Why Launch Mobile DTV?
• Mobile DTV shows good stewardship of spectrum by public broadcasters
• One-time capital cost to implement simulcasts
• There is demand but current options aren’t great: – Cellular carriers offer video for a fee • Availability of some free services critical to market adoption – Cellular carrier networks overburdened • Much higher revenue selling data services than video services Why Launch Mobile DTV?
• Free-to-air 1Seg system very successful in Japan – 2006: service launched – 2009: 30M units in service • nearly 25% of population – 2011: 80M+ devices in service • over 60% of population, 75% of phones • 40% of population are “frequent viewers”
113 Why Launch Mobile DTV?
• Possible US market growth potential: • Consider capturing even a small percentage of: • 150 million mobile phones sold per year • 50 million portable media players • 40 million laptops • 10 million portable game systems • 15 million autos • 13 million navigation systems Why Launch Mobile DTV?
• Usage and Demographics – DC Test: • 65% used it daily • 22% watch 3 times or more per day • Local news most popular content – PBS does well with those under 6 and over 60 • Mobile DTV most appealing to those in between • Gen Y demographic has some similar characteristics to our strongest supporters Why Launch Mobile DTV?
• Demographics from DC test: Why Launch Mobile DTV?
• Why did we do this so early? – Already doing encoder/mux project in 2009 • Final equipment choices were: – Harmonic encoders and muxes – Thomson/Grass Mobile DTV encoders, mux, exciter – Positive press coverage locally, nationally – Great visibility on first products in local retail • Online buzz with early adopter crowd Why Launch Mobile DTV? What Went Wrong?
• Very sensitive timing between mux and exciter – Needed to swap out 310/ASI TS converter • Old converter was reclocking • Exciter buffer over/underflows created issues in DTV receivers – Needed to add 1PPS reference for mux • Issue with TiVo, Windows Media Center units • Configuration issue • Ambiguity in standard between GV and Roundbox • Reception not great with early devices • Tx antenna is H-pol only Mobile DTV Rights
• What is it? Do we have rights to do it? – We’ve been simulcasting TV for quite a while • HD DTV, SD DTV, Analog = large, medium, medium • HD DTV, SD DTV, MDTV = large, medium, small Mobile DTV Rights
• Simulcast of main channel is nothing new – Same content, same transmitter, same antenna, same pattern, same frequency, etc.
• Non-simulcast channels – Unlimited rights for lots of content on multicast channels
• This issue definitely needs more discussion, but don’t let anyone confuse “mobile rights” with Mobile DTV rights – Mobile DTV is broadcast, not streaming, mobile app, etc. Mobile DTV Rights
• Mobile DTV “Radio” – What isn’t it? • Mobile DTV is NOT streaming – What is it? • HD Radio: – a terrestrial digital audio broadcast in the VHF band • Mobile DTV Radio – a terrestrial digital audio broadcast in the U/VHF band • CPB music blanket license covers all broadcasts • Currently seems that audio services are covered Mobile DTV Rights
• Rights – Consult your own legal resources – WGBH will continue to work on this issue and share information with anyone interested A Case for Radio
• Radio on Mobile DTV can take less than 1% of your capacity – You could do HD + 50 audio services – Audio encoders are cheap – With conditional access, some of these could be commercial and carried for a fee – Simple audio-only receiver could be made for under $50 – Think about nationwide services • Share services between stations • Offer wide carriage to commercial partners? Industry Support
• Pearl / MCV formed in April 2010
• Cox, Belo, Scripps, Gannett, Hearst, Media General, Meredith, Post-Newsweek, Raycom
• 2011 plans include: – NYC, LA, Chicago, Philadelphia, SF, Dallas, DC, Atlanta, Houston, Detroit, Tampa, Phoenix, Minneapolis, Orlando, Portland, etc. Industry Support
• Formed September 2010
• Represents ~414 commercial stations
• Combined DTV coverage of 90% of US homes
• 47 of top 50 markets Industry Support
• Commercial broadcasters may now see spectrum as a use-it-or-lose-it resource – Most broadcast a single HD service – Doesn’t tell a great story about the need for TV spectrum
• Mobile DTV service rollouts not waiting for receiver market
• Uncertainty about future of TV spectrum benefits Mobile DTV progress in the near term Questions? Thank You