1、 International Telecommunication Union ITU-T J.284TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2007) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Digital transmission of television signals Requirements and framework for gathering electr
2、onic content over IP-based network ITU-T Recommendation J.284 ITU-T Rec. J.284 (12/2007) i ITU-T Recommendation J.284 Requirements and framework for gathering electronic content over IP-based network Summary ITU-T Recommendation J.284 is for use of fast IP transmission for the delivery of news clips
3、 or other content materials from remote locations to broadcasters station. It defines a framework and requirements to provide a common platform for development of various specifications per specific demands. Source ITU-T Recommendation J.284 was approved on 14 December 2007 by ITU-T Study Group 9 (2
4、005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. J.284 (12/2007) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Sta
5、ndardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA),
6、which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall withi
7、n ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommend
8、ation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “
9、must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation
10、 may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of
11、this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent d
12、atabase at http:/www.itu.int/ITU-T/ipr/. ITU 2008 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. J.284 (12/2007) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 1 4 Abbreviations and acron
13、yms 1 5 Conventions 1 6 Use case 2 6.1 Basic configuration. 2 6.2 Live coverage . 2 6.3 Material transmission . 2 7 Assumed system model 3 8 Requirements 3 8.1 Session control 3 8.2 Transport. 4 8.3 Application layer 4 ITU-T Rec. J.284 (12/2007) 1 ITU-T Recommendation J.284 Requirements and framewor
14、k for gathering electronic content over IP-based network 1 Scope Recent deployment of high speed IP networks provides broadcasters and video distribution companies of a new means to gather content materials such as news clips, materials for production and video programs. Considering the growing dema
15、nd for the content material transmission over the IP networks, this Recommendation presents a common framework to cover various usages and aims to stimulate development of a specific system according to each purpose. 2 References The following ITU-T Recommendations and other references contain provi
16、sions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibi
17、lity of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommend
18、ation. ITU-R BT.1205 ITU-R Recommendation BT.1205 (1995), User requirements for the quality of baseband SDTV and HDTV signals when transmitted by digital Satellite News Gathering (SNG). 3 Definitions This Recommendation defines the following terms: 3.1 transaction initiator: One end that initiates a
19、 video transmission transaction operated by a human. 3.2 transaction recipient: One end that accepts a video transmission transaction automatically. 3.3 session client: One end that sets up a connection. 3.4 session server: One end that accepts a connection request. 3.5 remote terminal: Video termin
20、al at a remote site. 3.6 video server: Video server at a broadcasters station. 4 Abbreviations and acronyms None. 5 Conventions None. 2 ITU-T Rec. J.284 (12/2007) 6 Use case 6.1 Basic configuration A video terminal on site connects to a video server at broadcaster station through IP networks. 6.2 Li
21、ve coverage 1) Unidirectional This is a one-way report with no audiovisual interaction from the remote site to the station. A typical usage of this model is highway traffic monitoring or weather-monitoring camera. It may have remote control functionality in order to control the camera movement such
22、as pan, tilt, zoom, etc., according to the intention of a director in the station. For this usage, video and audio transmission shall be in real time with low latency. 2) Bidirectional This is a dialogue between the remote site and the station. A typical usage is dialogue between a reporter and an a
23、nchorman. In some cases, video transmission may be one way from the remote site to the station, but in many cases the reporter needs to receive video from the station in order to see the current on-the-air video. For this usage, video and audio transmission shall also be in real time with low latenc
24、y, whereas requirements for the quality may be different per direction. 6.3 Material transmission 1) Push operation The server at the station is operated automatically, and the terminal is operated by the reporter. The reporter collects new materials and transmits them to the station after some edit
25、ing, if possible. The server stores the received materials to be utilized for program production in the later stage. A typical usage of this model is video reporting from the area where the telecommunication environment is not rich. In this case, a director in the station sometimes needs to prioriti
26、ze the transmission sessions according to the new value. Another usage is transmission of video program from video aggregation station to own broadcasting station. For this usage, video transmission may take the form of file transmission, and it requires error-free transmission and high-picture qual
27、ity that is affordable for post-production. 2) Pull operation The terminal is operated automatically, and the server is operated by the director. The director initiates the transmission transaction to gather content materials at a remote terminal or remote subsidiary stations. This system may be enh
28、anced for on-line editing using the content streaming from the remote site. For this usage, active control of remote devices has great significance as well as picture quality. 3) Exchange An affiliation of the reporter and the director may be different. In such a case, the video server is not only t
29、he storing device but also a place for content exchange. Independent video journalists submit their video materials on the server, and directors search for materials for their program production. ITU-T Rec. J.284 (12/2007) 3 7 Assumed system model The system is constructed based on a client/server m
30、odel. Transaction relates the service aspects, such as use case described in clause 6, while session client/server acts as an enabler of the service set-up and control part. Audiovisual transport service is provided by transport module that includes media handling block such as codecs. It is desirab
31、le that the system is flexible enough to cover the variety of use cases. Therefore, a generic system model for transaction initiator and recipient is represented as in Figure 1. In this figure, transaction initiator is the site with a human operator, and he/she starts a session as a session client.
32、In some cases, reverse session set-up procedure is required in order to tunnel a firewall. It should be noted that the transaction initiator can be a remote terminal or a video server at a station. It depends on which side the human starts the operation. It is also taken into account that this basic
33、 system model can be cascaded to realize a “relay“ operation. Figure 1 System model for electronic content material gathering 8 Requirements The following are requirement items to be covered in the electronic news gathering (ENG) system as described in clause 6. 8.1 Session control 1) Name resolutio
34、n A hostname should be able to be used for an identifier of the server in addition to IP address. The server address may be resolved from a content ID such as unique material identifier (UMID). 2) Authentication An operator and his/her affiliation should be authorized at the server side. The server
35、should be able to refuse the connection attempt except pre-registered terminals. 3) Capability exchange The server and terminal should be able to show its capability at the connecting procedure. Capability information should include transmission protocol, usage bandwidth, available disk space, the s
36、ize of content material, encoding rate and employed codec. 4) Mobility support The terminal should be able to access to the server from any location if the network is reachable. 4 ITU-T Rec. J.284 (12/2007) 5) Firewall traversal The terminal should be able to access to the server inside of NAT/Firew
37、all. 8.2 Transport 1) Error control Error control mechanism should be supported in order to reduce or cancel the influence of transmission error. Error free transmission should be provided for non-real time transmission. Error control mechanism for real-time transmission should not damage the real-t
38、ime feature. 2) Stability for severe channel condition The non-real time transmission means should fully utilize the available bandwidth that is limited physically or assigned from the network operator even if the transmission link is high delay. The transmission means should have a vital check func
39、tionality of a remote system. 3) Resume The transmission pause or resume should be supported. The session prioritization may be supported in order to control the transmission rate of each session. 4) Integrity check Data identity check function should be supported between transmitter side and receiv
40、er side for non-real time transmission. Received data malicious alteration may be detected for real-time transmission. 5) Eavesdropping Transmission data should be protected against third party. 6) Transport control Mutually relating multiple streams should be received simultaneously and synchronize
41、d at field and/or frame precision. The receiver should be able to control bandwidth usage. 7) Delay Transmission delay should be low enough for bidirectional live coverage. 8.3 Application layer The system based on this Recommendation shall have a common operation mode for codec, encoding rate, and
42、picture format, etc. NOTE Actual operating parameters shall be defined in the specific system Recommendation based on the requirements defined in this Recommendation. Contribution quality shall be fulfilled as defined in ITU-R BT.1205. (Quality degradation: 12% DSCQS, recovery time: 1 s after a brea
43、k of 50 ms, Maximum relative sound/vision delay: 2 ms per coded element). Received and stored data should be accessible randomly per field/frame precision. Stored file format should be a generic and an international/industry standard. Remote files should be accessible per field/frame precision for s
44、treaming. Meta data may be attached to the content files in order to utilize the content by applications, such as encoding format, etc. Printed in Switzerland Geneva, 2008 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall n
45、etwork operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable net
46、works and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Se
47、ries N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone transmission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Teleg
48、raph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
