1、 STD-BSI BS EN 50221-ENGL L777 = Lb24bb9 Ob47043 b29 D BRITISH STANDARD Common interface specification for conditional access and other digital video broadcasting decoder applications The European Standard EN 50221 : 1997 has the status of a British standard ICs 33.16.40 NO COPYING WITHOUT BSI PERMI
2、SSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 50221 : 1997 _ STD-BSI BS EN 5022L-ENGL 1997 = LbZLibbS ObLiSOL(L( 5b5 D BS EN 60221 : 1997 This British Standard, having been prepared under the direction of the Electrotechnicai Sector Board, was published under the authority of the Standards Board
3、and comes into effect on 15 August 1997 O BSI 1997 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPW100, Audio, video and multimedia systems and equipment, to Subcommittee EPLJ100/1, Receiving equipment, upon which the
4、following bodies were represented British Broadcasting Corporation British Educational Suppliers Association British Radio and Electronic Equipment Manufacturers Association British Telecommunications pic Radiocommunications Agency Radio Society of Great Britain Amendments issued since publication I
5、 Amd. No. 1 Text affected The following BSI references relate to the work on this standard: Committee reference EPL/100/1 Draft for comment 96409771 DC ISBN O 680 27694 5 I STD-BSI BS EN 50221-ENGL 1777 1624bb9 Ob49045 4Tl m BS EN 50221 : 1997 Contents Page Committees responsible Inside front cover
6、National foreword 11 Foreword 2 Text of EN 50221 3 O BSI 1997 i STD-BSI BS EN 50221-ENGL 1997 m Lb24bb9 Ob4904b 338 BS EN 50221 : 1997 National foreword This British Standard has been prepared by Subcommittee EPL/100/01, and is the English language version of EN 50221 : 1997, published by the Europe
7、an Committee for Electrotechnid Smdardization (CENELEC). This British Standard is published under the direction of the Electsotechnical Sector Board whose Technical Committee EPU100 has the responsibiliw to: - aid enquirers to understand the text; - present to the responsible international committee
8、 any enquiries on interpretation, or proposals for change, and keep UK interests informed; - monitor related intrnational and European developments and promulgate them intheuK. NOTE. International and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 C
9、hiswick High Road, London W4 4AL. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 86, an inside back cover and a back cover. O BS
10、I 1997 EUROPEAN STANDARD NORME EUROPEENNE EUROPISCHE NORM EN 50221 Feuruary 997 ICs 33.160.40 Descriptors: Telecasting, television receivers, decoders, interfaces, design, physical propertias, open systems interconnection, physical layers, data link layer, transport layer. session layer, application
11、 layer, protocols, man-machine syotetm. specifications English version Common interface specification for conditional access and other digital video broadcasting decoder applications Spcification dune interface commune pour laccs conditionnel et dautres applications dans un dcodeur de tlvision numri
12、que Fernsehrundf un kdecoder-Anwendungen Festlegung der einheitlichen Schnittstelle fr Zugriffsbeschrnkung und andere digitale This European Standard was approved by CENELEC on 199742-1 5. CENELEC merners are bod to comply with the CENICENELEC Internal Regulations which stipulate the condi foc givin
13、g this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards my be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official ver
14、sions (English, French, German). A versmn in any other language made by translation under the responsibility of a CENELEC member into its own Irnguage and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of
15、 Austria, Belgium, Denmark. Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, PwtuaJ. Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnicai Sndrrdio.oiOrr Comit Europeen de Normalisation El.cttot.c)inquir Europisches
16、Komitee fr Elektrotechniseha Normung Central secretariat: rue de Stassart 35, B - 1050 bruurb 1997 CENELEC - All rights o: axploiration in any form and by any means resed 4- )or CcwIUc adCast system, thus increasing thtir choice and anti-piracy options. The scope of this documenr is to describe this
17、 common intcmicc. The decoder, referred to in this specification as the host, includes those functions that 8n ncccssaq to receive scrambling and CA appiications, which will operate on an extemai module. WEG-2 video, audio and data in the CU. This specincabion data rats, CoNKRion use of multiple mod
18、ules. 5.4.2 Diu aud Command logical connections The Phyucal Layer shali support independent both-way logical connccions for the Transport Stream and for Co- Thc Truirpori Stream interface shall acccpi an MPEG-2 Transport Stream, consisting of a sequence of Trans- pon pwkas. either Contiguously or se
19、parated by null data The returned Transport Stream may havc some of tk uioomng transport packets returned in a descrambled form. The Transport Stream intufact is subject to ihc fdlowing restrictions: 1 When the module is the source cf a transport stnam its output shall compiy with ISO/IEC 13818-9. 2
20、 Each output packet shall be contiguous if the module is the soucc of the packet or he input packet is contiguous. STD-BSI BS EN 50221-ENGL 1997 a Lb24bb9 b119055 340 Page 9 EN 50221:1997 3 A module shall introduce a constant deiay when processing an input transport packet, with a maximum deiay vari
21、ation (tmv) applied to any byte given by the following formula: un ilength-field_size; i+) 1 length-vphie-byte 8 WM * * m Page 11 EN 50221:1997 6.2 TSI - transport layer The transport layer used is the same as the WEG-2 System transport layer. Data travelling over the transport stream interface is o
22、rgamsed in WEG-2 Transport Packets. The whole WEG-2 multiplex is sent over this transport stream interface and is rtctwed back fully or partly desCrambled. if the packet is not scrambled, the module returns it as is. if it is scrambled and the packet belongs to the selected service and the module ca
23、n give access to that service, then the module returns the corresponding descrambled packet with the trans- port-scramblingcontrol flag set to 00. if scrambling is performed at Padretised Elementaiy Stream (PES) level, then the module reacts in the same way and under the same conditions as above, an
24、d returns the corresponding desCrambled PES with the PES-scsaxnbling-conmI flag set to 00. The transport packet and the PES packet arc completely debed in the MPEG-2 System specification i. 6.3 TSI - upper layers Apart from the Packctistd Elementary Stream, any layering or stnicturc of the MPEG-2 da
25、ta above the Trans- port Stream layer is not relevant to this specification. However he specincation does assume that the module will find and extract cerrain data requucdfor its operation, such as ECM and EMM messages, dircctly from theTransport Sueam. 7 The communication of data across the command
26、 interface is defined in terms of objects. The objects are coded by means of a general Tag-Length-Value coding derived from that used to code ASN. 1 syntax. Command Interface - Transport i*) 1 for (i=;iN;i+) 1 session-objcc-value byte apduo 8 uimsbf 8 uimsbf The SPDU is mats tobe supplied on a modui
27、e to supcrscdtcxuing rrcpces in the host or on another module. Rtsources with higher Version numbers duil be bachmds with previ- ous versions, so that applications requesting a previous version wiii have a fe#utcc with cxpatai behaviaur, Resources are used by an appiication creating a session to a f
28、csoufct (sa 7.2). By an imtphpti on process car- rid out by the Resource Manager he host will have identified ail avaiiable r)etbcr self-prwided or provided on another module, and can complete the session to the appropriate place. Oiot the Srnion has bcai created the application can then use the res
29、ourct by an exchange of objects accordmg lo tLr defined protocoi. Page 24 EN 50221:1997 An example of the use of the resource concept is the Low-Speed Communications fcspirct class (see 8.7.1). This provides a common mechanism for using a strial communications link - typically a modem or a return ch
30、annel on a cable mem. Resource typcs are defined for difertnt spttds of modem as identified by T-T recommendation numbers - e.g. V21, V.22, V.32bis. Most modem modems offer a range of spceds so that one modem may exhibit several resource types and the speed selection is made by creating a session to
31、 the pamcular resource type which offers it. 8.2.2 Reswrce identikr A resource identier consiss of 4 octets. The two most significant bits of the rst octet indicate whether the resource is public or private and hence the stnichue of the remainder of the field. Values of 0,l and 2 indicate a public r
32、esource. A value of 3 indicates a private resource. Public resourct classes have values allocated in the range 1 to 49 150, treating the rrsoura_id_typt fidd as thc most significant part of r#0urcc_class. Value O is resewed. The maximum (ailones) due of ali fields is reserved. Private resourcts are
33、identined by a private resourw definer, that is the organisatian that dcfints a private resource. Each private resource defina can dennt the Stnicnuc and content of the pn- vate-rcsmrcxjdmtity field in any way he chooses except that the maximum (ailones) vaiue is rcscived. Table 15: reswm-identifkr
34、ding 8.2.3 Appic8tions uid rrsource providers These are the two types of application iayer entity that can reside on a module. Applications rmlrc use of resources to perform tasks for the usex of ilength-vaiue;i+) data-byte I z Page 25 EN 50221:1997 Table 16: APDU coding Syntax No. of bits Mnemonic
35、APDUO 24 hbf 8 uhsbf The APDU is made of two parts : -a mandato header ma& da Tag value apdu-tag, indicating which parametn is sent within tht data field and a length value, coding the length of the following &ta field -tag and length-kid an coded according to the basic encoding rules of ASN. 1 131.
36、 - a conditional body of variable length equal to the length coded by length-field The mu bodies arc described in the following subciausts. This list maybe txtmded infontrevasiws. 8.3.2 Chaining of APDU data fidds The &ta fidd which is in an APDU may be split into severai blocks of smalls sizes ifnq
37、mnd by the trans- mission and mxpion bufotr sizes ofthe host or ofthe module. This mccmism is &le far a few AFDUs oniy. The chaining is perfonmi by using two di&rent +-tag vatues (M-apdu-tag and L-u-tag). AU blocks of data fidd, except the last one is sent within a APDU with a M-apdu-tag vihr. This
38、tag vam indi- cates that more data will be suit in another APDU. The last block of data fidd is QI Mthlli a APDU with a L-apdu-tag value. When the last block is received, the receiving entity COIYOICOPQ JI the redved data fields. This mechanism is valid for aii APDUs with two defined tag vai- (M-aph
39、-tag rod L-rpdp_ty). It is illas- trat& in figure 13 below. 1 mu Single mu Equivalent chained APD Figure 13: illustration of the chaining mechadm 8.3.3 Transportation of APDU ririthm SPDU An integer number of APDUs belonging to the same session can k muptd intkbob) daiu SPW 8.4 System Management Res
40、ources 8.4.1 Resource Manager The Resource Manager is a nswrcc providedby the host. There is only QIIC intk cbr rb it can sapport any number of sessions. It controis the acquisition and provision of rcsmrs io J1- AWd communication protocol is defined between the module and the host to Qainr . lk-eac
41、hoinp vidt. The protml is used nnt by the host to interrogate each transpm P m LD &termme *what resources, if any, arc pnscnted for use on that transport connection. Tbea it ir & tonndout 4. STD-BSI BS EN 50?2L-ENGL L997 m lb24bb9 Ob349072 Y2T Page 26 EN 50221 : 1 997 the total tsurccs available. It
42、 is then used pcriodidy when esoufcts change to update the common view of available resources. The Resource Manager is provided by the host and cannot bc suptlseded by a fcsource on a module. Any attempt to provide a Resource Manager resource by a module shall be ignond by the host. 8.4. I. 1 When a
43、 module is plugged in or the host is powered up one or perhaps two transport c0Mccti011 arc created to the moduie, serving an appiication anor a resource prwider. nie first tbmg an application or rcfource provider does is to request a session to the Resource Manager murce, which is invariabiy create
44、d since the Resource Manager has no session limit. The Resource Manager then sends a Profile Enquiry to the application or resource provider which responds with a Prole Reply listing the resources it prwidcs (if any). The applica- tion or rrsource provider must now wait for a Proiie Change object. w
45、hilst waiting for Pmie Change it can neither create sessions to other #ourcfs nor can it accept sessions hm other appiications, murning a reply of CSOU OUT CC non-exismt or rrsaurcteximbut IUKmdab - le asappropriatc. Resource Manager Protocol When it has asked for profiles on aii transport co1IIIcct
46、io11s and received Prafiie Replies the host buitds a list of available remmes. Wherc two or more rtsouces match in both class and type the host keeps the one with the highcst version number in its list. Where the version numbers match also the host keeps all rcscnms and chooses one a! random when a
47、create session request is rr#ived for it. Ona the hosi has Wt its fcx)21lcc list it sends a hie Change object on aii ament Resource Manager sessions, and thoJe appications that wish to can then ask the host for its list ofrtsources using the ProfiieEnqUjr object. When it rcaivcs the Profde Change na
48、tification for the nrSt tirne the appiication or nsour# provider can interrogate thc host with a Role Enquisr ad receive a Rufiie Reply with the hosts list of available resources. After this nrst operation ofthe Profile Change protocol the appiicatb or rcsomce pmvider is now frte to mate or accept o
49、ther sessions. Its session to the Resoura Managa persists to dbw fanher Profile Change notification by the host fiom time to time. Ifa fesouTcc pmviderwishestonotify achangc in the profile of CS(NECS it pwds it r Raak Cbangc to the host The host replies with a Me Enq- to which the rcsowa pwda rcph in tnrn with its updattdrtsourcc iist- Thehost processes thisand, ifthis resuits inaxry ttbt hairorm mmm iut, and rcceiw an updated rtsouce list ifthey wish the host will issue a Pmle C
