1、 STD*ETSI TR 101 1Sb-ENGL 1777 3400855 025b5b8 911 TR 1 O1 196 1.1.1 (1997-12) Technical Repon Digital Video Broadcasting (DVB); Interaction channel for Cable TV distribution systems (CATV); Guidelines for the use of ETS 300 800 _ STD-ETSI TR LOI LSb-ENGL I777 3400855 025b5bS 858 2 TR 101 196 V1.l.I
2、 (1997-12) Reference DTWJTC-DVB-61 (b2000ics.PDF) Keywords broadcasting, digital, video, DVB, TV ETSI Secretariat Postai address F-O6921 Sophia Antipolis Cedex - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Siret No 348 623 562 00017 - NAF 742 C Association but n
3、on lucratif enregistre la Sous-Prfecture de Grasse (06) No 7803/88 Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 x.400 c= fr; a=atlac; p=etsi; s=secretariat internet secretariata et.si.fr http:llwww.etsi .fr Copyright Notific8tion No part may be reproduced except as authorized by written permission
4、 The copyright and the foregoing restriction extend to reproduction in ail media. O European Telecommunications Standards Institute 1997. O European Broadcasting Union 1997. All rights reserved. STDmETSI TR LO1 LSb-ENGL 1997 W 3400855 025b570 57T H 3 TR 101 196 Vl.l.1 (1997-12) Contents Intellectua
5、l Property Rights 4 1 Scope 5 2 References 5 3 Abbreviations . 5 4 System model 6 6 Specification outline 8 Lower physical layer specification . 10 6.3 MAC layer specification . 12 6.3.2 . 13 6.3.3 MAC messages . 14 7 Network architecture and services . 15 7.1 Examples of services 15 1.2 Examples of
6、 networks with interactive services . 16 7.3 I . 4 Frequency use . 16 7.5 Impairments analysis . 17 Tools provided by the physical and MAC layer 21 Capabilities and grades of NI 21 Upstream frequencies dynamic allocation . 22 9 Connections management 22 9.3 Disconnection protocol . . 24 10.1 Error p
7、erformance of the physical layer 24 10.2 Traffic 21 History 28 Foreword 4 5 Protocol stack model 7 6.1 6.2 6.3.1 MAC reference model . 12 Bit rates and framing 9 Possible links between servers and HFC networks 16 1.6 Dimensioning of netw 20 8 8.1 8.2 8.3 initialization and Set-up . 9.1 Connection pr
8、otocol and bandw . 9.2 Interface between MAC and me ) 10 Simulation of error performance and e dling . 24 10.3 Error handling . 27 - STD.ETS1 TR $01 Lb-ENGL 1797 m 3400855 025b572 40b M 4 TR 101 196 Vl.l.1 (1997-12) Intellectual Property Rights PRs essential or potentially essential to the present d
9、ocument may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members , and can be found in ETR 3 14: “intellectual Property Rights (iPRsJ; Essential, or potentially Essential, IPRs notified to ETSI in respect of ET
10、SI standards“, which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/www.etsi.fi/ipr). Pursuant to the ETSI Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to th
11、e existence of other PRs not referenced in ETR 314 (or the updates on http:/www.etsi.fr/ipr) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by Joint Technical Committee (JTC) of the European Broadcasting Union (EBU), Comi
12、t Europen de Normalisation Electrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI). NOTE: The EBU/ETSI JTC was established in 1990 to co-ordinate the drafting of standards in the specific field of broadcasting and related fields. Since 1995 the JTC became a triparti
13、te body by including in the Memorandum of Understanding also CENELEC, which is responsible for the standardization of radio and television receivers. The EBU is a professional association of broadcasting organizations whose work includes the co-ordination of its members activities in the technical,
14、legal, programme-making and programme-exchange domains. The EBU has active members in about 60 countries in the European broadcasting area; its headquarters is in Geneva. European Broadcasting Union CH-1218 GRAND SACONNEX (Geneva) Switzerland Tel: +41 22 717 21 11 Fax: +41 22 717 24 81 Digital Video
15、 Broadcasting (DVB) Project Founded in September 1993, the DVB Project is a market-led consortium of public and private sector organizations in the television industry. Is aim is to establish the fiamework for the introduction of MPEG2 based digital television services. Now comprising over 200 organ
16、izations from more than 25 countries around the world, DVB fosters market-led systems, which meet the real needs, and economic circumstances, of the consumer electronics and the broadcast industry. 5 TR 101 196 Vl.l.1 (1997-12) 1 Scope The present document gives guidelines for use of the DVB interac
17、tion channel for Cable TV distribution systems (CATV) specification ETS 300 800 i. Hybrid Fibre Coax (HFC) networks are a subclass of CATV networks in which the subscribers are divided into groups by using optical transmission technology in the trunk network. The CATV infrastnictures can support the
18、 implementation of the RC for interactive services suitable for DVB broadcasting systems. CATV can be used to implement interactive services in the DVB environment, providing a bi-directional communication path between the user terminal and the service provider. 2 Ref e rences References may be made
19、 to: a) specific versions of publications (identified by date of publication, edition number, version number, etc.), in which case, subsequent revisions to the referenced document do not apply; or b) all versions up to and including the identified version (identified by “up to and including“ before
20、the version identity); or c) all versions subsequent to and including the identified version (identified by “onwards“ following the version identity); or d) publications without mention of a specific version, in which case the latest version applies. A non-specific reference to an ETS shall also be
21、taken to refer to later versions published as an EN with the same number. il ETS 300 800: “Digital Video Broadcasting (DVB); interaction channel for Cable TV distribution systems (CATV)“. (known also as the “DVB-RCC spec). EN 300 429: “Digital Video Broadcasting (DVB); Framing structure, channel cod
22、ing and modulation for cable systems“. (known also as the “DVB-C spec). ITU-T Recommendation 1.363: “B-ISDN ATM Adaptation Layer (AAL) specification“. Pl 31 3 Abbreviations For the purposes of the present document, the following abbreviations apply: AAL5 ATM BC BIM BRA CATV CB radio DAVIC EMC RP HFC
23、 IB IC ID EEE IIM ATM Adaptation Layer 5 Asynchronous Transfer Mode Broadcast Channel Broadcast Interface Module Basic Rate Access Cable TV distribution system Citizens Band radio Digital Audio - Visual Council ElectroMagnetic Compatibility Forward Interaction Path Hybrid Fibre Coax In-Band Interact
24、ion Channel IDentifier Institute of Electrical and Electronics Engineers Interactive Interface Module INA IP IRD IS DN LAN LLC MAC MPEG NIU ONU OOB os1 PSTN RC RCC RIP RMS SDH SMATV SNR STB STU TCP TDMA TS uc VCI VPI 6 TR 101 196 V1.1.1 (1997-12) Interactive Network Adapter Internet Protocol Integra
25、ted Receiver Decoder Integrated Services Digital Network Local Area Network Link Layer Control Media Access Control Moving Picture Export Group Network Interface Unit Optical Node Unit Out-Of-B and Open Systems Interconnection Public Switched Telephone Network Return Channel Return Channel - Cable R
26、eturn Interaction Path Root Mean Square Synchronous Digital Hierarchy Satellite Master Antenna Television Signal to Noise power Ratio Set Top Box Set Top Unit Transmission Control Protocol Time Division Multiple Access Transport Stream Upstream Channel Virtual Channel Identifier Virtual Path Identif
27、ier 4 System model Figure 1 shows the system model which is to be used within DVB for interactive services. in the system model, two channels are established between the service provider and the user: - Broadcast Channel (BC) : A unidirectional broadband BC including video, audio and data. BC is est
28、ablished from the service provider to the users. It may include the Forward interaction Path (FIP). Interaction Channel (IC) : A Bi-directional interaction channel is established between the service provider and the user for interaction purposes. It is formed by: - - Return Interaction Path (RIP): F
29、rom 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 (UC). Forward Interaction Path (FIP) : From the service provider to the user. It is used to provide some sort of informatio
30、n 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 for the carriage of data to the user. In the pres
31、ent document the word “channel“ denotes logical link and “path“ corresponds to a physical link. The user terminal is formed by the Network Interface Unit (NIV) (consisting of the Broadcast Interface Module (BIM) and the Interactive Interface Module (IIM) and the Set Top Unit (STU). The user terminal
32、 provides interface for both broadcast and interaction channels. The interface between the user terminal and the interaction network is via the IIM. - 7 n TR 101 196 V1.l.l (1997-12) Interaction Channel Interaction path network independent network dependent tt I I networkindependent II II Figure 1:
33、Generic system reference model for interactive systems The interactive system is composed of FIP (downstream) and RIP (upstream). 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
34、 network and send synchronized information upstream. RIP is divided into time slots which can be used by different users, using the 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 u
35、pstream counter at the INA is sent periodically to the NIUS, so that all NlUs work with synchronized clock and same upstream counter 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
36、 contention access, which lets users send information at any time with the risk to have a collision with other users transmissions. 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 u
37、ntil the INA stops the connection on NIUs demand. These access modes are dynamically shared among time slots, which allows MUS 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 indi
38、cate to new users that they have the possibility to go through sign-on procedure, in order to give them the opportunity to synchronize their clock to the network clock, without risking collisions with already active users. This is done by leaving a larger time interval for new users to send their in
39、formation, taking into account the propagation time required from the INA to the NIUS and back. 5 Protocol stack model For asymmetric interactive services supporting broadcast to the home with narrowband RC, a simple communication model consists of the following layers: Network dependent physical la
40、yer: Where all the physical (electrical) transmission parameters are defined. Network dependent access mechanism layer: Defines all the relevant data structures and communication protocols like data containers, etc. Network independent application layer: Is the interactive application software and r
41、untime environments (e.g. home shopping application, script interpreter, etc.). DVB-RCC (ETS 300 800 l) addresses the lower two layers (the physical and transport) leaving the application layer open to competitive market forces. STD ETSI TR LOL LSb-ENGL 8 TR 101 196 Vl.1.l (1997-12) A simplified mod
42、el of the OS1 layers was adopted to facilitate the production of specifications for these nodes. Figure 2 points out the lower layers of the simplified model and identifies some of the key parameters for the lower two layers. Following the user requirements for interactive services, no attempt will
43、be made to consider higher medium layers in the present document. Layer Structure for Generic System Reference Model i Proprietary i i layers 1 Highermedium 1 I layers ; Network Independent I Protocols , Access mechanism Packet structure Modulation Channel coding Freq. range Filtering Equalisation I
44、 Power (Network Dependent Protocols) Figure 2: Layer structure for generic system reference model The present document addresses the HFCKATV network specific aspects only. The network independent protocols will be specified separately. Specif cat ion outline A multiple access scheme is defined in or
45、der to have different users share the same transmission media. Downstream information is sent broadcast to all users of the networks. Thus, an address assignment exists for each user which allows the INA to send information singlecast to one particular user. Two addresses are stored in Set Top Boxes
46、 (STB) in order to identify users on the network MAC address: be hard coded in the MU or be provided by external source. NSAP address: It is a l-bit value representing a network address. This address is provided by higher layers during communication. It is a 48-bit value representing the unique MAC
47、address of the NIU. This MAC address may Upstream infomation may come from any user in the network and shall therefore also be differentiated at the INA using the set of addresses defined above. This interactive system is based either on Out-Of-Band (OOB) or In-Band (IB) downstream signalling. Howev
48、er, STBs do not need to support both systems. in the case of OOB signalling, a Forward Information Path (FIP) is added. The presence of this added FIP is in that case mandatory. However, it is also possible to send higher bit rate downstream information through a DVB-C channel whose frequency is ind
49、icated in the FP. in the case of IB signalling, the FIP is embedded into the MPEG2-TS of a DVB-C channel. It is not mandatory to include the FJP in all DVB-C channels. NOTE: Both systems can provide the same quality of service. However, the overall system architecture will differ between networks using IB STBs and OOB STBs. Both types of systems may exist on the same networks under the condition that different frequencies are used for each system. STD-ETSI TR 101 LSb-ENGL 1997 3Li00855 025b57b T98 9 TR 101 196 V1.1.1 (1997-12) Upstream and OOB downst
