IEC_60728-9-2000_amd1-2005.pdf

INTERNATIONAL STANDARD IEC60728-9 2000AMENDMENT 12005-06 Amendment 1 Cabled distribution systems for television and sound signals Part 9:Interfaces of cables distribution systems for digitally modulated signals PRICE CODE IEC 2005 Droits de reproduction rservs Copyright-all rights reserved International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.ch H For price,see current catalogueCommission Electrotechnique InternationaleInternational Electrotechnical Commission LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 60728-9 Amend.1 IEC:2005(E)FOREWORD This amendment has been prepared by technical area 5:Cable networks for television signals,sound signals and interactive services of IEC technical committee 100:Audio,video and multimedia systems and equipment.The text of this amendment is based on the following documents:FDIS Report on voting 100/947/FDIS 100/977/RVD Full information on the voting for the approval of this amendment can be found in the report on voting indicated in the above table.The committee has decided that the contents of this amendment and the base publication will remain unchanged until the maintenance result date indicated on the IEC web site under http:/webstore.iec.ch in the data related to the specific publication.At this date,the publication will be reconfirmed,withdrawn,replaced by a revised edition,or amended._ Amend the title of this standard on the cover page,the title page and on pages 3 and 6 as follows:Cable networks for television signals,sound signals and interactive services Part 9:Interfaces for CATV/SMATV headends and similar professional equipment for DVB/MPEG-2 transport streams Page 2 CONTENTS Rename the existing Annex F,Annex G.Add the title of new Annex F as follows:Annex F(informative)Guidelines for the implementation and usage of the DVB Asynchronous Serial Interface(ASI)Page 6 2 Normative references Add the following new ETSI technical report:ETR 290:1997,Digital Video Broadcasting(DVB);Measurement guidelines for DVB systems Page 9 LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.60728-9 Amend.1 IEC:2005(E)3 3.2 Abbreviations Add the following new abbreviations:LF low frequency NTSC national television system committee PAL phase alternation line PCR program clock reference RB receiver buffer rx-clk receiver clock TB transmission buffer tx-clk transmission clock Page 17 4.4 Asynchronous Serial Interface(ASI)Replace the second paragraph by the following new text:A detailed specification of ASI is provided in Annex B.Implementation guidelines and deriving clocks from the MPEG-2 packets for ASI are provided in Annex E.Guidelines for the implementation and usage of ASI are laid down in Annex F.Page 47 Rename the existing Annex F,Annex G.Add a new Annex F as follows:LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.4 60728-9 Amend.1 IEC:2005(E)Annex F(informative)Guidelines for the implementation and usage of the DVB Asynchronous Serial Interface F.1 General The DVB Asynchronous Serial Interface(ASI)is a very popular standard interface for conveying MPEG-2 transport streams between professional equipment.However,there are concerns over interoperability in the market place,based on system integrators experiences with available equipment from multiple suppliers.This note is intended to explain some of the causes of problems and to offer guidelines to ASI implementers that will encourage maximum interoperability.This annex addresses interoperability issues specific to ASI data transmission links,and explicitly is not concerned with general MPEG-2 interoperability issues.An example of an ASI interoperability problem is where equipment receiving an ASI data stream occasionally drops out of lock,or never achieves lock at all.An example of a problem not addressed by these guidelines is where the video and audio on the output of a decoder have poor clock stability,because of PCR clock recovery problems at some point in the end-to-end equipment chain,for example resulting in LF wander in a regenerated PAL/NTSC subcarrier.This annex contains a clause providing a description of the design issues confronting ASI equipment designers(Clause F.2).This annex also contains a recommendation clause,which provides simple measures to improve interoperability between ASI equipment.There may be situations where systems will work outside these recommendations,depending on precise system and equipment implementation.F.2 ASI transmission links The ASI is a uni-directional transmission link to transfer data between professional digital video equipment.Figure F.1 presents an abstract model of an ASI transmission link.The model represents signals at the Layer 1/Layer 0 interface of Figure