This file is raw output from pdftotext and may not be ideal for distribution. If you are a maintainer for Hackipedia, please sit down when you have time and clean this text version up. Source PDF: /mnt/main/jmc-storage/docs/SCTE/ANSI SCTE 018 Emergency Alert Messaging for Cable (J-STD-042A) (2007).pdf Like all conversions the text below should be fully readable as UTF-8 unicode text. --------------------------------------------------------------- ENGINEERING COMMITTEE Digital Video Subcommittee AMERICAN NATIONAL STANDARD ANSI/SCTE 18 2007 (J-STD-042A-2007: A Joint Standard Developed by SCTE and CEA) Emergency Alert Messaging for Cable Notice The Society of Cable Telecommunications Engineers (SCTE) Standards are intended to serve the public interest by providing specifications, test methods and procedures that promote uniformity of product, interchangeability and ultimately the long term reliability of broadband communications facilities. These documents shall not in any way preclude any member or non- member of SCTE from manufacturing or selling products not conforming to such documents, nor shall the existence of such standards preclude their voluntary use by those other than SCTE members, whether used domestically or internationally. SCTE assumes no obligations or liability whatsoever to any party who may adopt the Standards. Such adopting party assumes all risks associated with adoption of these Standards, and accepts full responsibility for any damage and/or claims arising from the adoption of such Standards. Attention is called to the possibility that implementation of this standard may require the use of subject matter covered by patent rights. By publication of this standard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. SCTE shall not be responsible for identifying patents for which a license may be required or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. Patent holders who believe that they hold patents which are essential to the implementation of this standard have been requested to provide information about those patents and any related licensing terms and conditions. Any such declarations made before or after publication of this document are available on the SCTE web site at http://www.scte.org. All Rights Reserved © Society of Cable Telecommunications Engineers, Inc. 2007 140 Philips Road Exton, PA i CONTENTS 1 Scope .......................................................................................................................................................... 1  2 Overview..................................................................................................................................................... 1  3 References................................................................................................................................................... 1  3.1 Normative References .......................................................................................................................... 1  3.1.1 Normative Reference List .............................................................................................................. 2  3.1.2 Normative Reference Acquisition ................................................................................................... 2  3.2 Informative References ........................................................................................................................ 3  3.2.1 Informative Reference List ............................................................................................................ 3  3.2.2 Informative Reference Acquisition ................................................................................................. 3  4 Compliance Notation................................................................................................................................... 3  5 Emergency Alert Message (Normative) ....................................................................................................... 3  5.1 Descriptors ........................................................................................................................................ 11  5.1.1 In-Band Details Channel Descriptor ............................................................................................ 12  5.1.2 In-Band Exception Channels Descriptor ...................................................................................... 12  5.1.3 Audio File Descriptor................................................................................................................... 13  5.1.3.1 Audio Format Constraints..................................................................................................... 15  5.1.4 User Private Descriptors .............................................................................................................. 16  6 Transmission Requirements (Normative) .................................................................................................. 16  7 Emergency Alert Message Processing for Receiving Devices (Normative) .................................................. 17  7.1 General Requirements ....................................................................................................................... 17  7.2 Overlapping Message Processing ....................................................................................................... 18  7.3 Optional EAS Event ID Processing .................................................................................................... 18  7.4 Exception Processing ......................................................................................................................... 18  7.5 Alert Priority Processing ................................................................................................................... 19  7.6 Details Channel and Audio ................................................................................................................ 20  7.7 Text Processing.................................................................................................................................. 21  7.8 Optional Processing ........................................................................................................................... 21  8 Cable System Operational Issues (Informative) ......................................................................................... 21  8.1 Overlapping Messages Are Allowed ................................................................................................... 21  8.2 The Emergency Alert Message May be Repeated to Ensure its Reception .......................................... 22  8.3 Digital Transport Streams with Unscrambled Services ...................................................................... 22  8.4 Tuning to the Details Channel............................................................................................................ 22  9 Optional Processing (Informative)............................................................................................................. 22  9.1 Alert Originator Code and Event Code .............................................................................................. 22  9.2 Alert Event Start Time and Duration................................................................................................. 22  9.3 Alert Location Information................................................................................................................ 22  10 Time Shifted Emergency Alerts (Informative) ......................................................................................... 22  Annex A Receiving Device Emergency Alert Message Processing (Informative) .......................................... 23  Annex B Overlapping Message Example (Informative) ............................................................................... 27  ii Figures Figure 1 Emergency Alert Message Example Processing Flow Diagram .............................. 23 Figure 2 Example EAS Event Timeline ................................................................................... 27 Tables Table 1 Emergency Alert Message Format ................................................................................ 4 Table 2 EAS Originator Code (Informative).............................................................................. 6 Table 3 Example EAS Event Codes ............................................................................................ 7 Table 4 Alert Priority ................................................................................................................... 9 Table 5 County Subdivision Coding.......................................................................................... 10 Table 6 Descriptor Tags ............................................................................................................. 12 Table 7 Bit Stream Syntax for the In-Band Details Channel Descriptor .............................. 12 Table 8 Bit Stream Syntax for the In-Band Exception Channels Descriptor ....................... 13 Table 9 Bit-stream Syntax for Audio File Descriptor.............................................................. 14 Table 10 Audio Format Coding ................................................................................................. 15 Table 11 Audio Source Coding .................................................................................................. 15 Table 12 Audio Format Constraints ......................................................................................... 16 Table 13 User Private Descriptor Format ................................................................................ 16 Table 14 Parameters for Example EAS Event ......................................................................... 27 iii Emergency Alert Messaging for Cable 1 Scope This standard defines an Emergency Alert signaling method for use by cable TV systems to signal emergencies to digital receiving devices that are offered for retail sale. Such devices include digital set-top boxes that are sold to consumers at retail, digital TV receivers, and digital video recorders. The Emergency Alert signaling (EAS) scheme defined in this standard allows a cable operator to disseminate emergency alert information related to state and local-level emergencies and warnings in an efficient way, while minimizing disruption to programming. While it is possible for a cable operator to comply with EAS requirements by simply replacing the source signal for all programs with an emergency information channel, such switching is disruptive to viewing, is overly intrusive for many kinds of local warnings and is overly-complex for the cable operator to implement in a digital cable environment where each transport stream may carry many programs that would have to be individually interrupted. Based on the priority level of the alert, the Emergency Alert message may instruct the receiving device to force-tune to a designated emergency broadcast channel. Section 5 of this standard defines the syntax of the Emergency Alert message and related descriptors. This message is in the form of a standard MPEG-2 table and, when necessary, is delivered in-band on cable transport streams that carry one or more programs in-the-clear. Receiving devices without Point Of Deployment (POD)1 modules in place process such messages in accordance with requirements described in Section 7 of this standard. For programs that are scrambled on a cable system, the Emergency Alert message is delivered to the POD module using the cable system’s forward data channel. The POD module processes the message as necessary and delivers it to the receiving device out-of-band. As used in this standard, “out-of-band” refers to the Extended Channel interface defined in ANSI/SCTE 28 2004 [5]. As delivered to the receiving device by the POD module, the Emergency Alert message is in the form of an MPEG-2 table as defined in Section 5 of this standard. The receiving device then processes the message in accordance with Section 7 of this standard. The behavior of receiving devices in response to user actions, such as channel changes or accessing on-screen displays, where such user actions relate to acquisition and processing of Emergency Alert messages, is out of scope of this standard. 2 Overview Emergency message support for receiving devices involves the following elements: a) A signaling scheme to identify the presence of an Emergency Alert. 2 b) The start time and expected duration of the alert event. c) A textual description of the emergency alert. d) An indication of the availability and location of the “details” channel, an audio/video service pertaining to the alert. e) An indication whether the event is of sufficient importance that tuning to the details channel shall be done unconditionally. f) A pointer to an optional audio channel that can be used to replace the audio of the current service for the duration of the Emergency Alert message. This standard defines a cable_emergency_alert() message in the form of an MPEG-2 private_section() (per MPEG-2 Systems [2] Table 2-30), compatible with MPEG-2 transport. 3 References 3.1 Normative References The following standards contain provisions that, through reference in this text, constitute normative provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and 1 The Point Of Deployment module is also known as a CableCARD™ device. 2 For example, a flood warning might start at 4pm and last for 8 hours. 1 parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards listed in Section 3.1.1. 3.1.1 Normative Reference List 1. ATSC A/65C, Program and System Information Protocol for Terrestrial Broadcast and Cable, with Amendment No. 1, January 2006 2. ITU-T Rec. H.222.0 | ISO/IEC 13818-1:2000, Information Technology—Generic coding of moving pictures and associated audio information - Part 1: Systems 3. FCC Rules, 47 C.F.R. Part 11, Emergency Alert System (EAS) (revised as of 11/10/2005) 4. FIPS PUB 6-4, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, 8/31/90 (with minor editorial corrections January 2005) 5. ANSI/SCTE 28 2004, HOST-POD Interface Standard 6. CEA-542-B, Cable Television Channel Identification Plan, July 2003 7. ISO/IEC 13818-6:1998—Information technology—Generic coding of moving pictures and associated audio information -- Part 6: Extensions for DSM-CC 8. ANSI/SCTE 90-1 2005, SCTE Application Platform Standard OCAP 1.0 Profile 9. ANSI/SCTE 106 2005, DOCSIS Set-Top Gateway (DSG) Specification 10. ANSI/SCTE 55-1 2002, Digital Broadband Delivery System: Out Of Band Transport Part 1: Mode A 11. ANSI/SCTE 55-2 2002, Digital Broadband Delivery System: Out Of Band Transport Part 2: Mode B 12. IEEE 802-2001/A2, Standard for Local and Metropolitan Area Networks: Overview and Architecture, March 2004 3.1.2 Normative Reference Acquisition ATSC Standards: • Advanced Television Systems Committee (ATSC), 1750 K Street N.W., Suite 1200, Washington, DC 20006; Phone 202-872-9160; Fax 202-872-9161; Internet http://www.atsc.org/ IEC Standards: • Global Engineering Documents, World Headquarters, 15 Inverness Way East, Englewood, CO USA 80112- 5776; Phone 800-854-7179; Fax 303-397-2740; Internet http://global.ihs.com; Email global@ihs.com • IEC Central Office, 3, rue de Varembe, PO Box 131, CH-1211 Geneva 20, Switzerland; Phone +41 22 919 02 11; Fax +41 22 919 03 00; Internet http://www.iec.ch; Email pubinfor@iec.ch ITU Standards: • International Telecommunication Union, Place des Nations, CH-1211 Geneva 20, Switzerland; Phone +41 22 730 5111; Fax +41 22 733 7256; Internet http://www.itu.ch/publications/bookstore.html Email itumail@itu.int FCC Rules • U.S. Code of Federal Regulations (C.F.R.), U.S. Government Printing Office, Washington, D.C. 2040; http://www.fcc.gov/wtb/rules.html FIPS Standards: • National Institute of Standards and Technology; http://www.itl.nist.gov/fipspubs/ SCTE Standards: • Society of Cable Telecommunications Engineers (SCTE), 140 Philips Road, Exton PA 19341; Phone 800-542- 5040; Fax 610-363-5898; Internet http://www.scte.org; Email standards@scte.org 2 IEEE Standards: • Global Engineering Documents, World Headquarters, 15 Inverness Way East, Englewood, CO USA 80112- 5776; Phone 800-854-7179; Fax 303-397-2740; Internet http://global.ihs.com; Email global@ihs.com 3.2 Informative References 3.2.1 Informative Reference List 13. ATSC A/53E with Amendment No. 1, Digital Television Standard , April 2006 14. ANSI/SCTE 65 2002, Service Information Delivered Out-of-Band for Digital Cable Television 15. IEEE OUI Registration Authority 3.2.2 Informative Reference Acquisition ATSC Standards: • Advanced Television Systems Committee (ATSC), 1750 K Street N.W., Suite 1200, Washington, DC 20006; Phone 202-872-9160; Fax 202-872-9161; Internet http://www.atsc.org/ IEEE OUI Registration Authority: • http://standards.ieee.org/regauth/oui/index.shtml SCTE Standards: • Society of Cable Telecommunications Engineers (SCTE), 140 Philips Road, Exton PA 19341; Phone 800-542- 5040; Fax 610-363-5898; Internet http://www.scte.org; Email standards@scte.org 4 Compliance Notation As used in this standard, “shall” denotes a mandatory provision of the standard. “Should” denotes a provision that is recommended but not mandatory. “May” denotes a feature, whose presence does not preclude compliance, that may or may not be present at the option of the implementer. “Optional” denotes items that may or may not be present in a compliant implementation. 5 Emergency Alert Message (Normative) The cable_emergency_alert() message shall be delivered to the receiving device in packets identified with the SI_base_PID (per SCTE 28 [5] Section 8.9.1) value. For transport streams carrying one or more programs in the clear, packets identified by PID 0x1FFB shall be used. For out-of-band use on the Extended Channel, SI_base_PID value 0x1FFC shall be used. The syntax of the cable_emergency_alert() message that shall be used is defined in Table 1. Acronyms uimsbf, bslbf, and rpchof are as defined in ISO/IEC 13818-1 [2] Section 2.2.6. The MPEG-2 table_ID for this message is 0xD8. Refer to ISO/IEC 13818-1 [2] MPEG-2 systems for a description of the fields common to the MPEG-2 private section syntax. The cable_emergency_alert() message is limited to 4096 bytes maximum length, which means that the section_length field may have a maximum value of 4093 decimal. table_ID—This is an 8-bit field which shall be set to 0xD8, identifying this table as the cable_emergency_alert() message. section_syntax_indicator—This 1-bit field shall be set to ‘1’. It denotes that the table section follows the generic MPEG-2 section syntax beyond the section_length field zero—This 1-bit field shall be set to ‘0’. 3 Syntax Bits Description cable emergency alert() { table_ID 8 uimsbf value 0xD8 section_syntax_indicator 1 ‘1’ zero 1 ‘0’ reserved 2 ‘11’ section_length 12 uimsbf table_id_extension 16 uimsbf ‘0x0000’ reserved 2 ‘11’ sequence_number 5 uimsbf current_next_indicator 1 bslbf section_number 8 uimsbf last_section_number 8 uimsbf protocol_version 8 uimsbf EAS_event_ID 16 uimsbf EAS_originator_code 24 uimsbf three ASCII characters EAS_event_code_length 8 uimsbf EAS_event_code var uimsbf nature_of_activation_text_length 8 uimsbf nature_of_activation_text() var uimsbf alert_message_time_remaining 8 uimsbf seconds range 0..120 event_start_time 32 uimsbf event_duration 16 uimsbf minutes range 15..6000 reserved 12 bslbf alert_priority 4 uimsbf details_OOB_source_ID 16 uimsbf reserved 6 ‘111111’ details_major_channel_number 10 uimsbf reserved 6 ‘111111’ details_minor_channel_number 10 uimsbf audio_OOB_source_ID 16 uimsbf alert_text_length 16 uimsbf alert_text() var Per ATSC A/65C [1], Sec. 6.10 location_code_count 8 uimsbf range 1..31 for (i=0; i