New Ancillary Services
`Using a Television Channel
`
`A data.-broadcas!i~g system implemented in France by the CCETT is discussed. Employing
`an ordmary telens1on channel, the system provides at least three new ancillary services, and
`more are under development. The first service accomplishes the automatic recording of pre(cid:173)
`selected programs for any user with a keypad, memory unit and VTR; the second provides
`scramblin~ and unscrambling of a television signal as for pay TV and theater projection;
`and the tb1rd uses the ANTI OPE teletext system to transmit "magazines" in page form to
`the borne v~e'.'er •. If the teletext system uses time-division multiplexing with an ordinary pro(cid:173)
`gram, subtitling m any of several languages is possible along with transmission on request
`of special news-flash pages. Otherwise, when magazine pages only are transmitted on the
`channel, a page rate of about 20,000 per minute (24 lines of 40 characters each) is possible.
`
`Introduction
`The arrival of so-called "still-picture
`broadcasting" on the international scene
`of a (CCIR) meeting started a new era for
`the development of broadcasting services.
`Of course, eleven years ago, it was pro(cid:173)
`posed to use time multiplex techniques for
`data transmission in a television channel,'
`but this was only for the use of broadcasters
`themselves and not for the public. Tech(cid:173)
`nological progress since then has raised the
`opportunity for new services, using data
`transmission and broadcasting, to be of(cid:173)
`fered to the public at large or to certain
`categories of the public. 2
`The first studies gave rise to a fully new
`service, independent from the usual pro(cid:173)
`gram, named the teletext service.3
`French agencies in the CCETT labora(cid:173)
`tories started studying such services in late
`1973. The conclusion based on the first
`experiments, held in Rennes, France, was
`that it was possible to implement on a
`normal television network a complemen(cid:173)
`tary data broadcasting network, on which
`the data related to a lot of different new
`services can be simultaneously transmitted
`for all the people in the coverage zone of
`the transmitters.
`
`The DIDON Data Broadcasting System
`Definition
`The data broadcasting system (called in
`French, DIDON,
`for Diffusion de
`Donnees) applies packet switching tech(cid:173)
`niques to broadcasting.4 It allows several
`digital data sources, each related to a given
`service, to share the transmission re(cid:173)
`source- namely, the free lines of a tele(cid:173)
`vision signal.
`Every data source is connected to the
`multiplexing system, called network data
`handler, through a standardized digital
`junction. Thus, any kind of data system
`may be connected on the network.
`
`Presented on 20 October 1976 at the Society's Tech(cid:173)
`n!c~l Conference in New York by Bernard Marti,
`CCETT (Jomt Center for the Study of Television and
`Telecommunications), B.P. 1266, 35013 Rennes Cedex,
`France. This paper was received on 23 August 1976.
`
`Within the coverage zone of television
`transmitters, anybody may use
`these
`broadcast services, subject only to the
`condition that they be able to access the
`particular data link.
`The general properties of such a network
`are:
`Transparency. Every user receives data
`as if he was directly connected to the data
`source through the digital junction.
`Speed regulation. Three elements are to
`be taken under consideration: the data
`source, the service terminal device, and the
`network itself. The fact is that the data
`broadcasting system is, by its nature, uni(cid:173)
`directional only and that the data source
`has no means to know the receiver's state.
`This is why an interface device, at the input
`of the network handler, works as a fictive
`receiver and avoids saturation of the ter(cid:173)
`minal devices.
`
`Transmission System
`Data from a source are available at the
`digital junction as 8-bit bytes. This infor(cid:173)
`mation stream is split into packets of no
`more than 32 bytes each.
`An 8-byte "title" is added to every
`packet by the network handler. This title
`contains the following service informa(cid:173)
`tion:
`(I) a clock run for data receiver bit
`synchronization;
`(2) framing code for byte synchroniza(cid:173)
`tion;
`(3) digital channel identification (i.e.,
`source identification);
`(4) packet sequence control code (the
`packets from a given source are numbered
`in sequence to detect a packet loss due to
`transmission errors); and
`(5) fill-in code (number of effective
`bytes in a given packet).
`The most important feature is the 3-byte
`channel identification allowing a large di(cid:173)
`versification of services; it permits open
`services with public access as well as closed
`services with scrambled or paid-access
`procedures.
`The line structure of a television signal
`
`By BERNARD MARTI
`
`makes it possible to associate to each free
`line one packet to be broadcast. To do that,
`every bit is transmitted as a pulse, with a
`repetition rate of 397 times the line fre(cid:173)
`quency in the European E, G, and L tele(cid:173)
`vision standards. These pulses, in a nonre(cid:173)
`turn-to-zero (NRZ) modulation, are fil(cid:173)
`tered to a raised cosine form so as to fit the
`television channel bandwith require(cid:173)
`ments.
`With that rate, the packet occupies the
`active part of the television line. A packet
`can be time-multiplexed in the television
`signal by use of every black line. Thus, two
`situations can occur, depending on whether
`or not a program is being aired.
`When the television signal carries a
`program, only the few lines of the field
`blanking interval are available. The bit(cid:173)
`rate capability is, for European systems, 50
`packetsjs per used line, in other words 12.8
`kb/s per used line. When no program is on
`the air, all lines may be used except those
`for vertical sync. A total bit rate of 4 Mb/s
`can be shared between all services. In June
`1977 at the Montreux exhibition, a pre(cid:173)
`sentation was made in the U.S. M/NTSC
`standard, leading to a rate of 9 kb/s per
`used line in the 4.2-MH 2 bandwidth.
`
`Implementation of New Services
`Using the DIDON Network
`General
`Three new services using the capabilities
`of the data broadcasting network have so
`far been experimented with at the CCETT;
`two are program-related, the other can be
`program-related or not.
`The two program-related services are,
`respectively, a service for automatic re(cid:173)
`cording of preselected programs, and a
`scrambled television service used, for in(cid:173)
`stance, in a pay-TV structure. The third
`has become known as the teletext system
`and is intended for displaying alphanu(cid:173)
`meric or graphic pages on a television
`screen.
`
`The EPEOS System
`For various reasons, most European
`countries usc their television transmitters
`under conditions different from those in the
`USA. It appears that in Europe the net(cid:173)
`work is underemployed. Moreover, many
`programs are missed by a potential part of
`their audience because of time constraints.
`In another area the market of consumer
`videotape recorders is not developing be(cid:173)
`cause of a lack of available software and
`because of the constraints of delivery pro-
`
`Vo/ume86 November /977 SMPTE Journal
`
`815
`
`Authorized licensed use limited to: Kirkland & Ellis LLP. Downloaded on March 04,2016 at 20:08:37 UTC from IEEE Xplore. Restrictions apply.
`
`APPLE EX. 1022
`Page 1
`
`

`
`cedures. All these remarks lead to the idea
`that the recording techniques could be used
`more efficiently if delivery concerns only
`the software itself and not the associated
`recording tape.
`An identification label is transmitted
`with every program in a particular channel
`of the DIDON network using the blanking
`interval free lines. With this label are as(cid:173)
`sociated codes for the remote control of a
`tape recorder. The user with keypad can
`record in a memory a list of up to fifteen
`labels. When one of these labels is broad(cid:173)
`cast, just before the associated program
`starts, the digital device used to receive this
`service sets the recorder on. Special codes
`are then transmitted for recording, for
`program interrupt if any, for end of inter(cid:173)
`rupt, and for program end. Every prese(cid:173)
`lected program is recorded with a footage,
`associated in the memory with the identi(cid:173)
`fication label. On playback, the user can
`call a given program: if it has been received,
`the footage recorded on a special track of
`the tape enables its automatic search to the
`desired playback. The French acronym
`''EPEOS" is used to signify this service for
`automatic recording of preselected pro(cid:173)
`gtams.5
`This service can be useful for the general
`public. It can also upgrade the efficiency
`of educational programs. It can be used for
`automatic mailing of special programs for
`particular segments of the public, such as
`businessmen and doctors.
`
`The Scrambled Television Service
`(Discrete System)
`Alone or associated with the one pre(cid:173)
`viously outlined, the "Discret" system
`television service6 makes it possible to se(cid:173)
`lect the part of the public that is interested
`in the reception of a given program. Vari(cid:173)
`ous criteria for this selection are possible:
`payment of a subscription for pay TV or
`association, with one or another profes(cid:173)
`sional or economic or political group.
`The television signal is scrambled by
`inverting and shifting some of the TV lines
`under the control of a pseudorandom gen(cid:173)
`erator. Reconstruction of the original pic(cid:173)
`ture is not possible for those who do not
`know the real structure of the generator
`and the value of a synchronizing "word"
`which sets up the generator at the begin(cid:173)
`ning of every frame. These elements are the
`key for unscrambling.
`Some of the key elements are to be found
`in the hardware-a small printed-circuit
`board that constitutes a read-only-memory
`(ROM). Others are transmitted as data
`packets. Comparison between the data
`from both these sources as well as with
`some built-in characteristics of the decoder
`make possible, first, the configuring of a
`
`ntiC;
`
`.... _,
`D t0
`D 1( 1)
`D t0
`l~)
`D t0
`D 10
`
`D
`
`Senroc
`
`D t Bro de
`
`t nQ n t or
`
`0
`0
`0
`0
`
`D I
`
`ource
`
`-{
`
`)
`
`~tern
`
`lw.~t4lef)
`
`.....
`
`Multiple•
`
`- (IIC•t.ot"...
`
`....
`
`Vi4't•
`
`ltWUI
`
`k
`
`Fig. I. Data broadcasting network.
`
`Clock non In
`
`Fig. 2. Content of a data packet.
`
`OF DATA PACKET IN A TV LIN
`
`N R Z odu latlon
`
`0
`
`rind coalne lolt one
`
`Fig. 3. Modulation standards.
`
`programmable pseudorandom generator
`to be identical with that of the emitting
`side, and second, the phasing of these two
`generators to make them start in phase at
`the beginning of each frame. Line fre(cid:173)
`quency shift keeps them in phase if, and
`only if, they have the same structure.
`The problems that have not been com-
`
`pletely solved are related to sound scram(cid:173)
`bling. However first-generation scrambling
`and unscrambling units were used for an
`experiment held in Clermont Ferrand early
`in 1977. Many cinemas and theaters
`equipped with large-screen projectors re(cid:173)
`ceived and decoded scrambled television
`programs from one transmitter while pri-
`
`816
`
`SMPTE Journal November /'977 Volume 86
`
`Authorized licensed use limited to: Kirkland & Ellis LLP. Downloaded on March 04,2016 at 20:08:37 UTC from IEEE Xplore. Restrictions apply.
`
`APPLE EX. 1022
`Page 2
`
`

`
`CO TRQl
`
`OR
`
`DISC
`MEMORY
`
`CONTROL SYSTEM
`,------< MINICOMPUT R )
`
`Fig. 4. Teletext editing system.
`
`vale receivers could not unscramble the
`received signal. Thousands of spectators in
`various categories were invited to these
`showings and the experiment could be ex(cid:173)
`tended in the near future.
`
`The Teletext Service (ANT/OPE)
`ANTIOPE Teletext is the name of a
`new broadcasting service that involves
`broadcasting of text pages for them to be
`displayed on the screen of a domestic tcle-
`
`vision rcccivcr.7 T he french acronym may
`be tra nslated as "Digital S ignal Processing
`Conversion to Printed Page Images on
`Home Television Receivers." These pages
`are organized as "magazines" for educa(cid:173)
`tion, entertainment or information pur(cid:173)
`poses. This service can be fully independent
`from the usual television service. However,
`when the data supporting the teletext are
`broadcast while a normal program is on,
`some of the pages might be used to subtitle
`the program itself.
`The display characteristics of the service
`depend on the properties of the television
`tube and their choice has been made ac(cid:173)
`cording to the data obtained about those
`properties.H
`
`We may sum up the main characteristics
`of the system as follows:
`Every digital channel may transmit a
`magazine of up to 999 pages. Each page
`can contain 24 lines of 40 characters each,
`plus a one-line title, for service information.
`This title may be displayed or not. A
`character may be alphanumeric or graphic,
`colored on a black background or black on
`a colored background, with any one of
`seven possible colors (white, blue, green,
`red, cyan, yellow or magenta). The char(cid:173)
`acter in any one of four possible sizes, can
`be flashing or steady. The system has
`multialphabet capabilities which makes it
`possible to write some pages in French or
`English and others in Russian or Arabic.
`Editing System. The pages of the mag(cid:173)
`azine are written with a special keyboard
`and kept in a refresh memory to permit
`continuous display on the screen of the
`control monitor.
`In the memory, every character is rep(cid:173)
`resented by a 16 bit word (7 bits for the
`character code in an extended ASCII set,
`and the remaining 9 bits for display func(cid:173)
`tions such as color, graphics, and steady vs
`flashing display).
`A computer translates these data into a
`byte stream, according to a programming
`language- ANTIOPE that is compatible
`with the international standards for data
`
`Digital
`
`------,
`
`Junctleoo
`~----
`1
`I
`I
`I
`I
`I
`I
`I
`,_ .....
`
`I
`I
`
`Fig. 5. The Teletext recei~er.
`
`Keypad
`..
`J
`t
`2
`4 s • v
`I
`t
`c 0
`p
`
`l t
`
`Marti: New Ancillary Services Using a Television Channel
`
`817
`
`Authorized licensed use limited to: Kirkland & Ellis LLP. Downloaded on March 04,2016 at 20:08:37 UTC from IEEE Xplore. Restrictions apply.
`
`APPLE EX. 1022
`Page 3
`
`

`
`communication between digital equip(cid:173)
`ments. Color functions, graphics, etc. that
`are not implemented on usual line printers
`are transmitted by use of standardized se(cid:173)
`quences of two characters called "escape
`sequences." The translated page is then
`stored on a magnetic disc which contains
`the whole magazine. The computer reads
`out the disc file and sends its contents to the
`multiplexing device of DIDON (or any
`other network) via an appropriate modem).
`When necessary, the page can be called
`back in the editing system and corrected or
`updated before it is sent back to be broad(cid:173)
`cast.
`The Receiving Set. The user has a
`modified television receiver that gets RGB
`signals from a teletext decoder
`With the keypad that is associated with
`the decoder and employing the data re(cid:173)
`ceiver and the television receiver (for re(cid:173)
`mote control) the user selects the number
`of the chosen data channel on which the
`desired magazine is transmitted. The data
`receiver excludes all the packets having
`addresses different from the one entered,
`and the title of every packet kept. The de(cid:173)
`coder receives only the data concerning the
`chosen magazine.
`The user may then dial the pages he
`wants to receive. The decoder keeps the
`data having a page title corresponding to
`the page number dialed. It translates from
`ANTIOPE language to 16-bit words and
`fills in its refresh memory, which drives the
`
`character and special-effects generators for
`displaying the text on the screen.
`When the teletext magazines are time(cid:173)
`division multiplexed with an ordinary
`program, the available bit rate allows a
`page rate of roughly 50 per minute on each
`used line. Thus, it is possible to broadcast
`some magazines with only a few pages in
`each in order to limit access time. In addi(cid:173)
`tion to broadcasting the pages repeatedly
`at set intervals, it is possible to broadcast
`special pages to display news flashes su(cid:173)
`perimposed on the television program.
`When the user requests a news-flash page,
`it appears only if something new has hap(cid:173)
`pened, and it disappears at the user's re(cid:173)
`quest. One or more subtitle pages, in any of
`several languages, related to the program
`being broadcast may also be added to the
`magazines.
`Use of the whole channel for data
`broadcasting (without multiplexing) make
`subtitles and news flashes impossible, but
`the maximum page rate of roughly 20,000
`pages per minute allows many more com(cid:173)
`plete magazines to be broadcast.
`
`Conclusion
`Here we have described the implemen(cid:173)
`tation of new services on a television
`broadcasting network. It is clear, however,
`that they can be used very well (and per(cid:173)
`haps sooner) on cable-television networks.
`The services which have been described are
`not the only ones that could be imple-
`
`mented on television networks by use of the
`data broadcasting system. Others are
`under investigation in the CCETT labo(cid:173)
`ratories, and some are of great interest even
`at a very early stage in their development.
`Among these, we may mention the systems
`for analog still-picture broadcasting, the
`systems for graphical communication, the
`use of fast telefax for broadcasting news(cid:173)
`papers. The next few years will see exper(cid:173)
`imentation with these future services, while
`those we have described in this paper will
`be already in service.
`References
`I. J. Guillermin et al., "Transmission of Remote
`Control and Identification Signals Within Audio
`and Video Channels in Radio and Television
`Broadcasting," paper presented at lEE 25th Con(cid:173)
`ference, 1966.
`2. Y. Guinet, "Nouveaux Services Offerts par un
`Systeme de Diffusion de Donnees par Paquets,"
`E.B.U. Rev .. 149: Feb. 1975.
`3. T. Johnson, Teletext Financial Times. 1974; G. A.
`McKenzie,
`"ORACLE - An
`Information
`Broadcasting Service Using Data Transmission in
`the Vertical Interval," J. SMPTE. 83:6-10, Jan.
`1974; and S. M. Edwardson and A. Gee, "CEE·
`FAX: A Proposed New Broadcasting Service," J.
`SMPT£.83: 14-19,Jan.l974.
`4. Y. Noirel, "Un Systeme Experimental de Donnees
`par Paquets," Radiodiff et TV. 40. Nov. 1975.
`5. G. Degoulet et al., "EPEOS- Systeme d'Enre(cid:173)
`gistrement de Programmes," Radiodiff et TV. 40.
`Nov. 1975.
`6. B. Marti and M. Mauduit, "Discret, Systeme de
`Television Cryptee," Radiodiff et TV. 40, Nov.
`1975.
`7. C. Schwartz, B. Marti and A. Poignet, "Specifica(cid:173)
`tion Preliminaire du Systeme de Teletexte AN(cid:173)
`TIOPE," Radiodiff et TV. 67. April-May 1977.
`8. R. J. Zavada, "Report on Home Receiver Image
`Area Test," J. SMPTE, 83:304-316, Apr. 1974.
`
`818
`
`SMPTE Journal November 1977 Volume 86
`
`Authorized licensed use limited to: Kirkland & Ellis LLP. Downloaded on March 04,2016 at 20:08:37 UTC from IEEE Xplore. Restrictions apply.
`
`APPLE EX. 1022
`Page 4