1、 International Telecommunication Union ITU-T J.1101TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (06/2012) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Switched digital video over cable networks Functional requirements for IP-based switched
2、digital video using data over cable service interface specifications Recommendation ITU-T J.1101 Rec. ITU-T J.1101 (06/2012) i Recommendation ITU-T J.1101 Functional requirements for IP-based switched digital video using data over cable service interface specifications Summary Recommendation ITU-T J
3、.1101 describes the functional requirements of IP-based switched digital video (SDV) using data over cable service interface specifications (DOCSIS) in a digital cable network. The cable broadcasting system has been changed to use resources efficiently and transmit them to easily accommodate the var
4、ying needs of subscribers. Therefore, it is necessary to define the functional requirements of IP-based SDV for maintaining quality of service (QoS) and using bandwidth effectively in a hybrid fibre/coaxial (HFC) network environment. This Recommendation contains descriptions of the functional requir
5、ements of transmission, subscriber and control functions of IP-based SDV on IP-based cable networks. History Edition Recommendation Approval Study Group 1.0 ITU-T J.1101 2012-06-13 9 ii Rec. ITU-T J.1101 (06/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations special
6、ized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization 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 wit
7、h a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), 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 Reco
8、mmendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within 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 c
9、onciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recomm
10、endation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “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 par
11、ty. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property R
12、ights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers
13、 are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permi
14、ssion of ITU. Rec. ITU-T J.1101 (06/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 1 4 Abbreviations and acronyms 2 5 Conventions 2 6 Reference model . 3 6.1 Transmission function 3 6.2 Subscriber fu
15、nction . 3 6.3 Control function 4 7 Functional requirements . 4 7.1 Transmission functional requirement . 4 7.2 Control function 5 7.3 Subscriber function . 7 Bibliography. 9 Rec. ITU-T J.1101 (06/2012) 1 Recommendation ITU-T J.1101 Functional requirements for IP-based switched digital video using d
16、ata over cable service interface specifications 1 Scope This Recommendation defines the functional requirements of IP-based switched digital video (SDV) using data over cable service interface specifications (DOCSIS). The functionalities described in this Recommendation are defined according to the
17、requirements of cable television system operators. The IP-based SDV is the service mechanism for providing interfaces and functionalities to enable cable television system operators to offer quality of service (QoS)-guaranteed broadcasting. SDV is a service mechanism for distributing digital video v
18、ia RF-based cable networks; an IP-based SDV is a support SDV function which works via IP-based cable networks. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of
19、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 possibility of applying the most recent edition of the Recommendations and other references listed below. A list
20、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 Recommendation. ITU-T J.210 Recommendation ITU-T J.210 (2006), Downstream RF interface for cable modem termination
21、systems. ITU-T J.222.1 Recommendation ITU-T J.222.1 (2007), Third-generation transmission systems for interactive cable television services IP cable modems: Physical layer specification. ITU-T J.222.2 Recommendation ITU-T J.222.2 (2007), Third-generation transmission systems for interactive cable te
22、levision services IP cable modems: MAC and Upper Layer protocols. 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Recommendation This Recommendation defines the following term: 3.2.1 IP-based switched digital video (SDV): A service mechanism which provides interfaces and fu
23、nctionalities to enable cable television system operators to offer QoS-guaranteed broadcasting and multicasting. 2 Rec. ITU-T J.1101 (06/2012) 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: CCP Channel Charge Protocol CMTS Cable Modem Termination Syst
24、em DEPI Downstream External PHY Interface DOCSIS Data Over Cable Service Interface Specifications GBE Giga Bit Ethernet HFC Hybrid Fibre/Coaxial IGMP Internet Group Management Protocol IPC Inter-Process Communications MAC Media Access Control MDD MAC Domain Descriptor NSI Network Service Interface R
25、PC Remote Procedure Call SDV Switched Digital Video SIP Session Initiation Protocol STB Set-Top Box VSI Video Service Interface 5 Conventions In this Recommendation: The keywords “is required to“ indicate a requirement which must be strictly followed and from which no deviation is permitted if confo
26、rmance to this Recommendation is to be claimed. The keywords “is recommended“ indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. The keywords “is prohibited from“ indicate a requirement which must be stri
27、ctly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. The keywords “can optionally“ indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendors imp
28、lementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. In this Recommendation, the words shall, shall not, should and ma
29、y sometimes appear, in which case they are to be interpreted, respectively, as is required to, is prohibited from, is recommended, and can optionally. The appearance of such phrases or keywords in an appendix or in material explicitly marked as informative are to be interpreted as having no normativ
30、e intent. Rec. ITU-T J.1101 (06/2012) 3 6 Reference model As shown in Figure 1, functionally IP-based SDV using the DOCSIS system can be categorized into three parts, for example, Transmission function, Subscriber function and Control function. J.1101(12)_F01SessionmanagementfunctionResourcemanageme
31、ntfunctionDOCSIS upstreamMastercontrolfunctionDOCSIS downstreamNSI/GBEControl functionIPC/RPCHFC RFinterfaceRF channelsSubscriber functionSDVreceiverfunctionSDVclientfunctionTransmission functionSDVtransmissionfunctionDownstreamPHYfunctionVideo streamGBE/VSIIPbackboneVideo serverDownstream video ser
32、vice flowDownstream data service flowDownstream RF signalUpstream data flowProgram informationSDV control signalFigure 1 Diagram of an IP-based switched digital video system 6.1 Transmission function The transmission function processes the DOCSIS frame header and transmits it to the multicast servic
33、e group. The transmission function consists of an SDV transmission function and a downstream PHY function. The SDV transmission function processes service flow and packet header processing on the DOCSIS MAC layer ITU-T J.222.2. The downstream PHY function transmits the DOCSIS header processed video
34、stream to the subscriber. 6.1.1 SDV transmission function The SDV transmission function processes service flow and does packet header processing on the DOCSIS MAC layer. 6.1.2 Downstream PHY function The downstream PHY ITU-T J.222.1 function transmits the DOCSIS header processed video stream to the
35、subscriber. 6.2 Subscriber function The subscriber function processes the video data stream from the transmission function. The subscriber function consists of the SDV client service function and SDV receiver function. The subscriber function also sends request information of an SDV video service pr
36、ogramme to the control function. 6.2.1 SDV client function The SDV client function recovers an IP-based received video data stream from an MPEG-2 based video stream and outputs it to the set-top box (STB). 4 Rec. ITU-T J.1101 (06/2012) 6.2.2 SDV receiver function The SDV receiver function processes
37、physical signal processing; it is a function of the DOCSIS cable modem. 6.3 Control function The control function creates a service group for the authorized subscriber and manages the channel resources of the transmission function. The control function consists of a session management function, reso
38、urce management function and a master control function. 6.3.1 Session management function The session management function periodically transmits service information of video programmes, and sets the transmission path for video data streaming. 6.3.2 Resource management function The resource managemen
39、t function controls the frequency channel resource, and it allocates the frequency of the modular cable modem termination system (CMTS). 6.3.3 Master control function The master control function controls SDV transmission, and manages the modular CMTS ITU-T J.210. 7 Functional requirements 7.1 Transm
40、ission functional requirement 7.1.1 SDV transmission function 7.1.1.1 Service flow processing The SDV transmission function is required to obtain the following information for input packets. Packet type (e.g., channel bonding or not, high priority or not, unicast/multicast/broadcast) Service flow ID
41、 Downstream service ID list Transmission priority Available downstream transmission channel list. The SDV transmission function is required to classify the service flow using the destination IP group address and departure information. 7.1.1.2 Scheduling The SDV transmission function is required to r
42、eceive the control data from the control function as follows: MDD message transmission interval transmission mode of downstream channels MDD message downstream channel ID. The SDV transmission function is required to schedule the service flow as follows: decide the available downstream channel multi
43、plex DOCSIS management message (e.g., MDD) and multicast video data packet. Rec. ITU-T J.1101 (06/2012) 5 The SDV transmission function is recommended to minimize the delay in transmission time. 7.1.1.3 MAC header processing The SDV transmission function is required to process the packet according t
44、o transmission priority. The SDV transmission function is required to create the DOCSIS MAC header according to the service flow information of the input packet. 7.1.1.4 MPEG-2 TS convergence The SDV transmission function is required to place the DOCSIS MAC frame in the queue. The SDV transmission f
45、unction requires the DOCSIS MAC frame to map to MPEG-2 TS. The SDV transmission function is required to output the multiplexing MPEG-2 TS. 7.1.1.5 Downstream PHY interface The SDV transmission function is recommended to interface with the downstream PHY function using the downstream external PHY int
46、erface (DEPI). 7.1.1.6 SDV transmission controlling The SDV transmission function is required to receive the information from the master control function as follows: service flow control information multicast message information hardware control information of SDV transmission function performance a
47、nd statistical information of SDV transmission function. 7.1.2 Downstream PHY function 7.1.2.1 Downstream PHY The downstream PHY function is required to process the channel coding from MPEG-2 TS. The downstream PHY function is required to process the digital modulation signal from the channel coded
48、data. The downstream PHY function is required to transmit the modulated symbol stream on the RF frequency. The downstream PHY function is required to control the signal power level of the transmitted signal. 7.1.2.2 Downstream MAC interface The downstream PHY function is recommended to interface wit
49、h the SDV transmission function or master control function using the DEPI protocol. 7.2 Control function 7.2.1 Session management function 7.2.1.1 Session management protocol processing The session management function is recommended to interface with the SDV client function using the session initiation protocol/channel charge protocol (SIP/CCP). 7.2.1.2 Session information management The session management function is recommended to transmit the programme ID and IP group address to the SDV client function. 6 Rec. ITU-T J.1101 (
