ITU-T SERIES J SUPP 2-1998 Guidelines for the Implementation of Annex A of Recommendation J 112 Transmission Systems for Interactive Cable Television Services Example of Digital f.pdf
《ITU-T SERIES J SUPP 2-1998 Guidelines for the Implementation of Annex A of Recommendation J 112 Transmission Systems for Interactive Cable Television Services Example of Digital f.pdf》由会员分享,可在线阅读,更多相关《ITU-T SERIES J SUPP 2-1998 Guidelines for the Implementation of Annex A of Recommendation J 112 Transmission Systems for Interactive Cable Television Services Example of Digital f.pdf(30页珍藏版)》请在麦多课文档分享上搜索。
1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Series J Supplement 2 (1 1/98) SERIES J: TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Guidelines for the implementation of Annex A of Recommendation J.112, “Transmission systems fo
2、r interactive cable television services“ Example of Digital Video Broadcasting (DVB) interaction channel for cable television distribution ITU-T J-SERIES RECOMMENDATIONS TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS General Recommendations General specifications for analog
3、ue sound-programme transmission Performance characteristics of analogue sound-programme circuits Equipment and lines used for analogue sound-programme circuits Digital encoders for analogue sound-programme signals Digital transmission of sound-programme signals Circuits for analogue television trans
4、mission Analogue television transmission over metallic lines and interconnection with radio-relay links Digital transmission of television signals Ancillary digital services for television transmission Operational requirements and methods for television transmission Interactive systems for digital t
5、elevision distribution Transport of MPEG-2 signals on packetised networks Measurement of the quality of service Digital television distribution through local subscriber networks J. 1-J.9 5.10-J.19 5.20-5.29 J.30-J.39 J.40-J.49 J.50-J.59 J .6 all users of this Recommendation are therefore encouraged
6、to investigate the possibility 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. 111 IT-T Recommendation J. 1 10 (1 997), Basic principles for a worldwide common family of systems
7、for the provision of interactive television services. IT-T Recommendation J. 1 12 (1998), Transmission systemsfor interactive cable television services. ITU-T Recommendation J.83 (1997), Digital multi-programme systems for television, sound und data services for cable distribution. ITU-T Recommendat
8、ions 1.363 series, B-ISDN ATM Adaptation Layer specification. Pl 31 41 3 Abbreviations For the purposes of this Supplement, the following abbreviations apply: AAL 5 ATM Adaptation Layer 5 ATM Asynchronous Transfer Mode BC Broadcast Channel BIM Broadcast Interface Module BRA Basic Rate Access CATV Ca
9、bleTV J series - Supplement 2 (11/98) 1 CB radio DAVIC DVB EMC FIP HFC IB IC ID IEEE IIM INA IP IRD ISDN LAN LLC MAC MPEG NIU ONU OOB os1 PSTN RC RCC RIP RMS SDH SMATV SNR STB STU TCP TDMA TS Citizens Band radio Digital Audio Visual Council Digital Video Broadcasting Project1 ElectroMagnetic Compati
10、bility Forward Interaction Path Hybrid Fibre Coax In-Band Interaction Channel JDentifier Institute of Electrical and Electronics Engineers Interactive Interface Module Interactive Network Adapter Internet Protocol Integrated Receiver Decoder Integrated Services Digital Network Local Area Network Lin
11、k Layer Control Media Access Control Moving Picture Expert Group Network Interface Unit Optical Node Unit Out-of-Band Open Systems Interconnection Public Switched Telephone Network Return Channel Return Channel - Cable Return Interaction Path Root Mean Square Synchronous Digital Hierarchy Satellite
12、Master Antenna Television Signal-to-Noise power Ratio Set Top Box Set Top Unit Transmission Control Protocol Time Division Multiple Access Transport Stream The Digital Video Broadcasting Project (DVB) is a consortium of broadcasters, manufacturers, network operators and regulatory bodies created for
13、 designing sandards for the delivery of digital television. 2 J series - Supplement 2 (11/98 - uc Upstream Channel VCI Virtual Channel Identifier VPI Virtual Path Identifier 4 System model Figure 1 shows the system model which is to be used within DVB for interactive services i. Broadcast Broadcast
14、Channel Channel Set Top Box (STB) Interaction TO906770-99/dOl Interaction Channel network dependent Figure 1 - Generic system reference model or interactive systems In the system model, two channels are established between the service provider and the user: - Broadcast Channel (BC): A unidirectional
15、 broadband BC including video, audio and data. BC is established from the service provider to the users. It may include the Forward Interaction Path (FIP). - Interaction Channel (IC): A bidirectional interaction channel is established between the service provider and the user for interaction purpose
16、s. It is formed by: Return Interaction Path (RIP): From the user to the service provider. It is used to make requests to the service provider or to answer questions. Also commonly known as Return Channel (RC) or Upstream Channel (W. Forward Interaction Path (FIP): From the service provider to the us
17、er. It is used to provide some sort of information by the service provider to the user and any other required communication for the interactive service provision. It may be embedded into the BC. It is possible that this channel is not required in some simple implementations which make use of the BC
18、for the carriage of data to the user. J series - Supplement 2 (11198) 3 In this Supplement the word “channel“ denotes logical link and “path corresponds to a physical link. The user terminal is formed by the Network Interface Unit (NIU) consisting of the Broadcast Interface Module (BIM) and the Inte
19、ractive Interface Module (IIM) and the Set Top Unit (STU). The user terminal provides interface for both broadcast and interaction channels. The interface between the user terminal and the interaction network is via the IIM. The interactive system is composed of FIP (downstream) and RIP (upstream).
20、The general concept is to use FIP to act as a transmission medium for MAC control channel and to carry a part of the downstream data. This allows the NIUs to adapt to the network and send synchronized information upstream. RIP is divided into time slots which can be used by different users, using th
21、e technique of Time Division Multiple Access (TDMA). One MAC control channel is used to control up to 8 UCs, which are all divided into time slots. A time marker and an upstream counter at the INA is sent periodically to the NIUs, so that all NIUs work with synchronized clock and same upstream count
22、er value. This gives the opportunity to the INA to assign time slots to different users. Three major access modes are provided with this system. The first one is based on contention access, which lets users send information at any time with the risk of having a collision with other users transmissio
23、ns. The second and third modes are contention-less-based, where the INA either provides a finite amount of slots to a specific NIU, or a given bit rate requested by a NIU until the INA stops the connection on NIUs demand. These access modes are dynamically shared among time slots, which allows NIUs
24、to know when contention-based transmission is or is not allowed. This is to avoid a collision for the two contention-less-based access modes. Periodically, the INA will indicate to new users that they have the possibility to go through sign-on procedure, in order to give them the opportunity to sync
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
本资源只提供5页预览,全部文档请下载后查看!喜欢就下载吧,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ITUTSERIESJSUPP21998GUIDELINESFORTHEIMPLEMENTATIONOFANNEXAOFRECOMMENDATIONJ112TRANSMISSIONSYSTEMSFORINTERACTIVECABLETELEVISIONSERVICESEXAMPLEOFDIGITALFPDF

链接地址:http://www.mydoc123.com/p-803317.html