1、ETSI TS 101 735 1.1.1 (2000-07) Technical Specification Digital Audio Broadcasting (DAB); Internet Protocol (IP) datagram tunnelling 2 ETSI TS 1 O1 735 V1.l.l (2000-07) Reference DTS/JTC-DAB-12 Keywords audio, broadcasting, DAB, data, digital, internet, IP, protocol ETSI 650 Route des Lucioles F-O69
2、21 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Siret No 348 623 562 0001 7 - NAF 742 C Association but non lucratif enregistre la Sous-prfecture de Grasse (06) No 7803/88 Imoortant notice Individual copies of the present document can be downloaded from: http:/w.ets
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6、tandards Institute 2000. O European Broadcasting Union 2000. All rights reserved. ETSI 3 ETSI TS 1 O1 735 V1.l.l (2000-07) Contents Intellectual Property Rights 4 Foreword 4 1 Scope 5 2 References 5 3 Definitions and abbreviations 6 3.1 Definitions 6 3.2 Abbreviations . 7 4 Overall Description 7 5 5
7、.1 5.2 5.3 5.3.1 5.3.2 5.4 5.4.1 5.4.2 5.4.3 Coding 8 General . 8 Packet mode . network level . 8 Packet mode - transport level . 8 Coding of the MSC data groups 8 Repetition of MSC data groups . 9 Internet network layer . 9 Fragmentation of IP datagrams . 9 IP version signalling . 10 Internet trans
8、port layer protocol signalling . 10 History 11 ETSI 4 ETSI TS 1 O1 735 V1.l.l (2000-07) Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for E
9、TSI members and non-members, and can be found in ETSI SR O00 3 14: “Intellectual Propero Rights (IPRs); Essential, or potentially Essential, IPRs notifed to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (htti,:/w
10、ww.etsi.oxg/ii-). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR O00 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essent
11、ial to the present document. Foreword This Technical Specification (TS) has been produced by the Joint Technical Committee (JTC) Broadcast of the European Broadcasting Union (EBU), Comit Europen de Normalisation ELECtrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI
12、). NOTE 1: The EBUETSI JTC Broadcast was established in 1990 to Co-ordinate the drafting of standards in the specific field of broadcasting and related fields. Since 1995 the JTC Broadcast became a tripartite body by including in the Memorandum of Understanding also CENELEC, which is responsible for
13、 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, legal, programme-making and programme-exchange domains. The EBU has active members in about 60
14、 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 The Eureka Project 147 was established in 1987, with funding from the European Commission, to develop a sys
15、tem for the broadcasting of audio and data to fixed, portable or mobile receivers. Their work resulted in the publication of European Standard, ETS 300 401 i, for DAB (see note) which now has worldwide acceptance. The members of the Eureka Project 147 are drawn from broadcasting organizations and te
16、lecommunication providers together with companies from the professional and consumer electronics industry. NOTE 2: DAB is a registered trademark owned by one of the Eureka Project 147 partners. ETSI 5 ETSI TS 1 O1 735 V1.l.l (2000-07) 1 Scope The present document describes how to transport Internet
17、Protocol (IP) (RFC 791 2) datagrams in a Digital Audio Broadcasting (DAB) (ETS 300 401 i) packet mode service component, a technique further on referred to as IP tunnelling. The use of IP tunnelling provides DAB with a mechanism for the adaptation of Internet services to DAB and is also a key compon
18、ent for DAB services using two-way interaction with personal DAB as specified in TS 101 736 4. The use of IP tunnelling enables the use of IP as a common network layer protocol, end-to-end, for DAB data services. The IP tunnelling through DAB is unidirectional. The tunnel is created from the packet
19、mode encoder on the transmitting side, to the packet mode decoder on the receiving side, of the DAB system. 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. References are either specific (identified by date
20、 of publication, edition number, version number, etc.) or non-specific. For a specific reference, subsequent revisions do not apply. For a non-specific reference, the latest version applies. A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the
21、 same number. il ETSI ETS 300 401: “Radio broadcasting systems; Digital Audio Broadcasting (DAB) to mobile, portable and fixed receivers“. RFC 791 (198 1): “Internet Protocol (IP); Darpa Internet Program; Protocol Specification“, J. Postel. Pl 31 41 ETSI TS 101 756: “Digital Audio Broadcasting (DAB)
22、; Registered Tables“. ETSI TS 101 736: “Digital Audio Broadcasting (DAB); Network Independent Protocols for Interactive Services“. 51 ETSI TS 101 737: “Digital Audio Broadcasting (DAB); Interaction channel through Global System for Mobile communications (GSM) the Public switched Telecommunications S
23、ystem (PSTN); Integrated Services Digital Network (ISDN) and Digital Enhanced Cordless Telecommunications (DECT)“. RFC 761 (1980): “DOD standard; Transmission Control Protocol“. 61 71 RFC 793 (198 1): “Transmission Control Protocol (TCP); Darpa Internet Program; Protocol Specification“, J. Postel. E
24、TSI 6 ETSI TS 1 O1 735 V1.l.l (2000-07) 3 3.1 Definitions and abbreviations Definitions For the list of DAB definitions see ETS 300 401 i. For the purposes of the present document the following terms and definitions also apply: Fragmentation: method specified in the Internet Protocol for splitting a
25、n IP datagram into several new IP datagrams to adjust for limited datagram sizes depending on the physical network used as the Internet data link layer. At the end point is payload of the fragments reassembled and delivered to the Internet transport layer, as if it had been sent in a single IP datag
26、ram. Interaction Channel (IC): telecommunication or data communication channel used in parallel with DAB to provide an individual bi-directional communication link. Internet: international collection of IP networks, which are connected together, to virtually form a single global network. See also IP
27、 network. Internet application layer: application layer in the Internet protocol stack. At this level users invoke application programs that exchange data with an application protocol. The Internet application layer interacts with one of the transport protocols in the Internet transport layer in ord
28、er to send or receive data. Internet data link layer: data link layer in the Internet protocol stack. This layer includes all the functionality that depends on the various physical networks which together build up the IP network. Internet network layer: network layer in the Internet protocol stack.
29、The primary task of this layer is to provide a mechanism for network independent communication from one machine to another. The Internet network layer uses the Internet Protocol (IP) to route datagrams between machines independent of the physical network the machine is connected to. Internet Protoco
30、l (LP): network layer protocol used on the Internet. Provides routing of datagrams from a machine to another independent from the physical networks. Internet transport layer: transport layer in the Internet protocol stack. The primary task of this layer is to provide communication from one applicati
31、on program to another, often called end-to-end communication. The transport layer uses a transport protocol to provide either connection-oriented or connection-less data transport. The most widely used transport protocols in IP networks are; the connection-oriented TCP and the connection-less UDP. 1
32、p network one or several connected physical networks, that uses the Internet Protocol (IP) on the network level. An IP network may, or may not, be connected to the global Internet. Sometimes an IP network is referred to as “an internet“, spelled with a lower-case i. Maximum Transfer Unit (MTU): larg
33、est size of an IP datagram that can be accepted for transfer by the Internet data link layer. Request For Comments (RET): name of specification published by the Internet Engineering Task Force (IETF). Used for publication of Internet standards. Transport Control Protocol (TCP): internet transport la
34、yer protocol that provides a reliable connection-oriented transport. Tunnelling: technique in which a datagram is encapsulated in a protocol on higher or the same level and passed across the transport system. This could be seen as a tunnel between to nodes in the network, where the datagrams are enc
35、apsulated at the starting point and decapsulated at the end point. For IP tunnelling within DAB, the tunnel is created between the packet mode encoder and the packet mode decoder. User Datagram Protocol (UDP): internet transport layer protocol that provides an unreliable connection-less transport. E
36、TSI 7 0th TP UDP TCP ETSI TS 1 O1 735 V1.l.l (2000-07) Internet transport layer 3.2 Abbreviations For the purposes of the present document the following abbreviations apply: CA DAB IC IETF IP MSC MTU RFC sc TCP TP UDP Conditional Access Digital Audio Broadcasting Interaction Channel Internet Enginee
37、ring Task Force Internet Protocol Main Service Channel Maximum Transfer Unit Request For Comments Service Component Transmission Control Protocol Transport layer Protocol User Datagram Protocol 4 Overall Description This clause gives an overall view of how IP datagrams are mapped into the DAB system
38、 when IP tunnelling is used. The specification of the Internet Protocol (IP) is done by IETF and is published in RFC 791 2. The protocol stack used for IP tunnelling in DAB is shown in figure 1. The IP datagrams are tunnelled through a DAB packet mode service component (SC). This is done by encapsul
39、ating the IP datagram in an MSC data group on packet mode transport level, as described in clause 5. From the IP point of view the packet mode SC will act as the Internet data link layer. There is no support within the present document for the use of other DAB transport mechanisms than packet mode.
40、The definitions of Internet transport layer protocols are not within the scope of the present document. However, the most commonly used protocols in the Internet transport layer are UDP (RFC 761 6) and TCP (RFC 793 7). UDP can be used for datagram oriented unidirectional transport point-to-point, as
41、 well as for datagram oriented multicast and broadcast transport. TCP is used for connection oriented point-to-point transport and requires an interaction channel for the return flow of acknowledgements. See also TS 101 736 4 and TS 101 737 5. It is also possible to use other protocols, than UDP or
42、TCP, on the Internet transport layer. However, if the application layer requires uni- or bi-directional communication then it has to be taken into account. In the case of bi-directional communication an IC is required for the return link, see TS 101 736 4 and TS 101 737 5. Application protocol Inter
43、net application layer I I I I IP Internet network layer Internet data link layer 1 Packet mode - MSC Data Groups Packet mode - packets DAB-MSC packet mode sub-channel Packet mode-transport level Packet mode-network level Packet mode-data link level Figure 1 : Protocol stack for IP-tunnelling in a DA
44、B packet mode service component ETSI 8 ETSI TS 1 O1 735 V1.l.l (2000-07) IP Datagram IP Header 5 Coding Data 5.1 General MSC Data Group Data Group Header The tunnelling of IP datagrams through DAB is to be done by encapsulating the IP datagrams into the MSC data groups. The encapsulation is done by
45、carrying the IP datagram as payload in the MSC data group data field, as shown in figure 2. The mapping of an IP datagram onto an MSC data group is one-to-one, e.i. one IP datagram in one MSC data group. CRC (optional) Data Group Data Field Packets Figure 2: Encapsulation of an IP datagram in an MSC
46、 data group Packet Packet Data Field CRC I I I Packet Packet Data Field CRC Header Header 5.2 Packet mode - network level The coding on packet mode network level shall be done according to ETS 300 401 i. 5.3 Packet mode - transport level 5.3.1 Coding of the MSC data groups The coding on packet mode
47、transport level shall be done according to ETS 300 401 i. For the following fields within the MSC data group special conditions shall apply when IP tunnelling is used: Data group type: for IP tunnelling the following data group types are used: b3 bo O O O O: O O O 1: O O 1 O: other: Rfu. General dat
48、a; used for encapsulated IP datagrams; CA messages (see ETS 300 401 i, subclause 9.3.2.1); General data and CA parameters; used for encapsulated IP datagrams and CA parameters; NOTE: The Rfu values of the DAB protocol field may be defined within TS 101 756 3, without a formal update of the present d
49、ocument. ETSI 9 ETSI TS 1 O1 735 V1.l.l (2000-07) IP Datagram larger than MTU MSC data group data field: this field shall carry exactly one IP datagram. The size of the data field shall be set to the size of the IP datagram (incl. header and payload of the IP datagram). The transmitter side sets the maximum allowed size of the MSC data group data field, this restriction is referred to as the Maximum Transfer Unit (MTU). The MTU shall be in the range of 576 to 8 191 bytes. Where 576 byte is the smallest size of the MTU allowed by IP (RF
