356-S6e
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`
`3,934,079
`
`Jan. 20, 1976
`
`(54] BILATERAL COMMUNICATIONS SYSTEM
`FOR DISTRIBUTING COMMERICAL AND
`PREMIUM VIDEO SIGNALING ON AN
`ACCOUNTABLEBASIS
`Inventor: ie Wayne Barnhart, Dresher,
`[75]
`[73] Assignee:
`Jerrold Electronics Corporation,
`Horsham, Pa.
`.
`Oct. 26, 1973
`Filed:
`[22]
`[21] Appl. No.: 409,820
`
`12/1973 Wittig et al. ...ccecseecssssereeeeee 178/5.1
`3,777,053
`2/1974 Callas et al. ......ccceeee 17B/5
`3,790,700
`;
`;
`,
`Primary Examiner—Maynard R. Wilbur
`Assistant Examiner—S. C. Buczinski
`Attorney, Agent, or Firm—John M. Calimafde
`[57]
`ABSTRACT
`:
`“ae
`A bilateral communications system, as for CATV ap-
`plication, distributes commercially available and pre-
`mium video programming on a subscriber demand--
`-directly accountable basis. At
`least
`the premium
`video programming is impressed on the cable in a fre-
`(52), “US Chaussee 178/5.1; 178/DIG. 13; 325/31;|quency band and/or format not recoverable bya stan-
`325/308
`dard television receiver, absent receipt at a particular
`[SU]; nts Ce siiiieneiasiceincan HO4N 1/44
`subscriber location of a reception-authorizing message
`[58] Field of Search...... 178/5.1, DIG. 13; 325/308,
`from the system head end.
`end
`system head
`the
`325/31
`A central
`processor
`at
`sequentially polls cable subscribers under stored
`program control,
`permitting
`bilateral
`digital
`communications between the subscriber and the head
`end.
`
`
`
`[56]
`
`3,668,307
`3,733,430
`3,757,225
`
`References Cited
`UNITED STATES PATENTS
`G/1972 * Face et all. .isssovsssrccersssssareeee 178/5.1
`§/1973
`Thompson etal..
`
`Y/N973 UKE sceecceecssseccseecssecsneeesseees 178/5.1
`
`29 Claims, 6 Drawing Figures
`
`
`
`
`
`
`CHANNEL
`secectoR 47
`
`
`RECEIVE”
`
`‘WOT ABLE TA
`
`
` =
`ae Jord
`
`IDEO AT.
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 1
`
`,
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 1
`
`

`

`U.S. Patent
`
`Jan. 20, 1976
`
`Sheet 1 of5
`
`3,934,079
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`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 2
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 2
`
`
`

`

`U.S. Patent
`
`Jan. 20, 1976
`
`Sheet 2 of 5
`
`3,934,079
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`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 3
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 3
`
`
`
`
`
`
`

`

`
`
`
`
`U.S. Patent Jan.20,1976=Sheet30f5 3,934,079
`
`CHANNEL
`
`CONTROL 3200
`
`70 OTHER
`
`K|Qiy
` CHANNEL STATUS,
`
`|
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`SDP.
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 4
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 4
`
`

`

`
`
`U.S. Patent—Jan. 20, 1976 Sheet 4 of5 3,934,079
`
`
`
`REGISTERWhats} COUNTER PMC Exhibit 2031
`
`TERMINAL }
`CON TROL
`400
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`
`Apple v. PMC
`IPR2016-01520
`Page 5
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 5
`
`

`

`U.S. Patent
`
`Jan. 20, 1976
`
`Sheet 5 of 5
`
`3,934,079
`
`HEAD END
`
` G02
` CENTRAL
`PROCESSOR
`
`CAGLE
`
`SUBSCRIBER
`CONNECT/ONS
`CF
`
`F007
`
`
`
`FIGS
`
`FIG.S|FIG.4
`
`FIG.6
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 6
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 6
`
`

`

`1
`
`3,934,079
`
`BILATERAL COMMUNICATIONS SYSTEM FOR
`DISTRIBUTING COMMERICAL AND PREMIUM
`VIDEO SIGNALING ON AN ACCOUNTABLEBASIS
`
`DISCLOSURE OF INVENTION
`
`additional head end controlled peripheral items, ¢.g.,
`additional television receivers; security devices; print-
`ers or recorders and so forth.
`The above and other features and advantages of the
`present invention will become more clear from the
`following detailed description of a specific illustrative
`embodiment thereof, considered below in conjunction
`This invention relates to electronic signal distribution
`with the accompanying drawing, in which:
`systems and, more specifically,
`to a bilateral signal
`translating system fordistributing commercial and sup-
`FIGS. 1-5 schematically depict a composite bilateral
`plementary video programming from a central head
`signaling system employing the principles of the pres-
`end location to plural spaced subscriber stations, and
`ent invention; and
`FIG. 6 depicts the spacial arrangement of FIGS. 1-5.
`for providing bilateral signaling between the head end
`and subscriberstations.
`All structural elements depicted in FIGS. 1-5 and dis-
`cussed below are identified by three reference numer-
`Community antenna television (CATV) system oper-
`ators have for some time been desirous of providing
`als, the first of which identifies the particular figure on
`premium video programming(such as first run theater
`which that element may be found.
`Referring now to FIGS. 1-5, there is shown a spe-
`and movies, special sporting events, and the like) to
`cific,
`illustrative bilateral signaling system wherein
`supplement the locally available “off-air” commercial
`common, head end equipment (FIG. 5) communicates
`television signals distributed by coaxial cable. Prefera-
`20
`
`bly, the premium videois to be distributed onadirectly via a coaxial cable network 500 with a plurality of
`subscriber stations. One suchstation is shown in detail
`accountable basis — i.e., with separate fees charged for
`in FIGS. 1-4,
`each premium program received at each subscriber
`station.
`A standard television receiver 144 at the subscriber
`location is connected to the cable via a mixer 140 and
`Moreover, a projected growth area for the CATV
`business involves data communications from system
`IF amplifier and filter 142, the local oscillation for the
`mixer 140 being supplied by a voltage controlled oscil-
`subscribers to the head end. Such reverse signaling
`permits the provision of various commercial services
`lator 138. The video signals impressed on the cable via
`over the cable network — e.g., ordering of identifiable
`the head end equipment comprise locally available
`commercial “off-air” programs, and a plurality of pre-
`goods and services by subscribers.
`However, only limited endeavors into such full ser-
`mium, private programs. Atleast the private programs
`vice pay-TV as above-described have been employed
`are impressed on the cable 500 in a frequency band
`to date.
`which does not correspond to any of the standard
`broadcast channels, and thus cannot be received by a
`It is an object of the present invention to provide
`improved CATVsystem signaling apparatus.
`standard receiver connected to the cable. For purposes
`of concreteness here,it will be assumed that all of the
`Morespecifically,it is an object of the present inven-
`tion to provide a CATVsystem for providing premium
`video channels do not correspond in frequencies to
`standard channel allocations. In a manner discussed
`video programs on a subscriber demand-directly ac-
`countable basis, and wherein provision is made for
`below, each such videosignalis selected for viewing by
`reverse signaling from subscribers to the system head
`supplying a proper control voltage to the voltage con-
`end.
`trolled oscillator 138 such that the heterodyning mixer-
`amplifier 140-142 converts the desiredsignalto a pre-
`The above and other objects of the present invention
`are realized in a specific,
`illustrative bilateral cable
`selected channel for the standard receiver, e.g., to a
`video signaling system wherein computer controlled
`locally unused one of channels 3 or4.
`head end equipment impresses upon the system cable
`To a substantial measure, much of the discussion
`for distribution to all system subscribers plural com-
`below will consider the particular manner in which a
`mercial and premium video programs, and also digital
`subscriber requests (electronically) that he be permit-
`ted to view a program, and the manner in which an
`signaling. At least all of the premium video programs
`are at frequency allocations and/or of formats making
`authorization command ts
`issued by the head end
`them unrecoverable by standard television receivers
`equipment to permit that reception. Then also, discus-
`sion will be had regarding other digital bilateral com-
`connected directly to the cable.
`munications between the subscribers and the head end.
`Each subscriber station includes electronic terminal
`equipmentconnected to the cable, comprising a termi-
`By way of general overview, the equipment at the
`subscriber station includes a subscriber control module
`nal control unit for establishing bilateral serial digital
`signaling with the head end responsive to address and
`200 for developing and entering viewing requests (i.e.,
`command wordsissued to the cable by the head end.
`channel selection) and information to be transmitted to
`the head end; a channelselector module 100 for imple-
`The subscriber terminal includes loop-connected sub-
`menting reception of a television signal requested for
`scriber controller, channel selecting and channel con-
`trol modules which cooperate with head end produced
`viewing by the subscriber at the control module 200
`and authorized by the head end; and a channel control
`reception authorization commands for providing to a
`module 300 which acts as an interface for communica-
`subscriber a selected premium (or commercial) video
`tions between the subscriber station and the head end.
`program in a format recoverable by a standard re-
`ceiver. A subscriber actuated controller keyboard in-
`Any one of the modules 100, 200 or 300 can generate
`cludes command and data keys for transmitting infor-
`messages (in general formed of an operation code
`{command portion] and a data portion) which circu-
`mation to the system head end — possibly totally unre-
`late between the modules 100, 300, 200 via serial data
`lated to video reception, as to order goodsorservices;
`links 160, 260 and 249, respectively. Where informa-
`respond to polling requests; or the like.
`tion is to be transmitted from the head end to the sub-
`In accordance with one aspect of the present inven-
`scriber equipment, it is transmitted via the cable 500
`tion, a subscriber location may include one or more
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 7
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
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`IPR2016-01520
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`

`

`3,934,079
`
`and a subscriber terminal control module 400 (FIG. 4)
`to the channel control unit 300 from which it is circu-
`lated to the modules 200 and 100. Similarly, where
`information is to be transmitted from the subscriber
`equipmentto the head end, it is circulated by the mod-
`ules 200 and 100 for loading into appropriate registers
`in the channel control module 300 - whereupon it
`flows outward via the terminal contro] unit 400 and
`cable 500 to the head end.
`The particular way in which television reception is
`implemented will now be considered, reference being
`made to FIG. 1. Assume that a subscriber wishes to
`watch a particular channel (designated by an arbitrary
`number such as 25). He depresses a “channel select”
`control key 202 at his hand-set keyboard unit 201, also
`depressing the particular data character keys 2 and 5.
`By FIG. 2 structure considered below, a message is
`formed comprising a channel select operation code,
`and the decimal numerals 2 and 5. This message is
`transmitted from the subscriber contro! module 200 to
`a transceiver 101 in the channel selector module 100
`and moreparticularly into a shift register 102 included
`in the transceiver. At an appropriate time when the
`messageis fully contained in the shift register 102 (de-
`termined by system timing in a conventional manner, as
`by counting system clock pulses, not further considered
`or shown herein), a command decoder 100 examines
`the operation code storage portion of the shift register
`102. For the particular assumed (channel select) mes-
`sage the command decoder 106 (assumedto be latch-
`ing, and thus signal preserving) generates a high level
`“CS” (channelselect) signal. The CSsignal, identifying
`that a channel select mode of operation is being ef-
`fected, is distributed as illustrated in FIG. 1. Among
`other functions, the CS signal passes through an OR
`gate 108 to enable a latchregister 104,i.e., to load into
`the register 104 the data contained in the shift register
`102 (the desired channel
`information 25 for the as-
`sumed message).
`A digital comparator 112 has as the two input groups
`connected thereto the fixed contents of the register
`104, and the changing contents of a counter 114 which
`is cycled by output pulses from an oscillator 110. The
`binary counter 114 includes a sufficient number of
`stages such that it will pass through an outputstate
`corresponding to the highest channel number em-
`ployed in the system. Accordingly, for the single count-
`ing cycle undergone by the counter 114,
`i.e., as it
`passes from aninitial count state 00...Oto Il... 1,
`it will pass through the BCD equivalent of the stored
`message during the count sequence. Accordingly, when
`this “match” condition obtains between the two com-
`parator 112 inputs (and only then) an output match
`signal ‘‘M” will be generated.
`in accordance
`Examining now a shift register 124,
`with one aspect ofthe present invention this shift regis-
`ter will contain one and only one binary 1
`in oneofits
`n stages, the particular stage containing the | identify-
`ing which channel has been selected for viewing. To
`implement this, the Boolean variables M and CS dis-
`cussed above, and OT (comprising the output of the
`shift register 124) are supplied to a combinatorial net-
`work 120 which executes a Boolean function CS-M +
`OT-CS'. Some reflection will show that a |
`is supplied
`to the input of the channel selectstoring shift register
`124 during a channel select (CS) mode of operation
`only for the single counter 114 state corresponding to
`the contents of the register 104 when the match (M)
`
`0
`
`5
`
`20
`
`25
`
`30
`
`60
`
`65
`
`4
`signalis high (the first expression in the Boolean state-
`ment CS:M). Thus one and only one1 will be stored in
`the register 124,
`in a shift register stage dependent
`upon the contents of the register 104 — and thereby
`also corresponding to the channel selected for viewing
`by the subscriber.
`The second Boolean expression OT-CS' is employed
`sincethe shift register 104 may be driven by a common
`clock with a channel authorization storing shift register
`126 considered below. Thus, for channel authorization
`(CA) processing discussed below,
`the binary word
`stored in the register 124 simply recycles to resume and
`retain its original status in the register 124,
`By the aboveoperation, the channelselectshift regis-
`ter 124 has a binary |
`in a particular one ofits stages
`corresponding to a channel selected for viewing by a
`subscriber. However, the subscriber may or may not be
`authorized (and thus able) to receive the requested
`message. As a general matter, the FIG. 1 apparatus
`contains a channel authorization shift register 126
`which has stored therein, pursuant to the commands
`issued by the system head end shownin FIG. 5, n-l’s in
`its N stages, each of the 1’s (andits relative position in
`the register 126) enabling reception of a particular
`program channel. Thus, the head endissuesto all sub-
`scribers a series of messages to permit reception of the
`standard broadcast programs without
`request, and
`without any attendant premium fee. Correspondingly,
`the head end will permit reception of a premium pro-
`gram only after the subscriber has requested that pro-
`gram as by simply entering a channel selection re-
`quest), the head end also generatinga billing message
`uponeffecting such authorization, A further “premium
`- TV” control key may be required if verification is
`desired for pay-TV billing purposes.
`For the particular channel request operation dis-
`cussed above,the binary | in the channelselect register
`will reside in a stage of the shift register coupled to one
`input of a particular AND gate 128,, of any array 128.
`The other input to the ANDgate 128,,is coupled to a
`particular stage of the channel authorization shift regis-
`ter 126 which controls viewing of the program on chan-
`nel 25. There similarly exists plural additional gates
`128; for all other system channels.
`Assume first that the subscriber has already been
`authorized reception of the program 25 (an appropri-
`ate | in the register 126), either becauseit is a standard
`broadcast channel or because the program has previ-
`ously been requested by the subscriber. Under such
`conditions the AND gate 128is fully enabled and the
`output high gate voltage passes to an input ofa resis-
`tance network 136 (e.g., a ladder network; a summing
`network; or the like). The differing input excitations
`for the resistance network 136 eachresult in a particu-
`lar and unique output voltage coupled to the control
`node of the voltage controlled oscillator 138, depen-
`dent upon which one (if any) of the gates 128 is en-
`abled. For the assumed case, the gate 128.,, generates a
`particular voltage which constrains the VCO 138 to
`provide precisely that
`local oscillation frequency
`which, when mixed with the ensemble of programs on
`the cable, translates program 25 into the frequency
`band of the IF amplifier 142 for delivery in a receivable
`spectrum allocation to the standard television receiver
`144. Thus, the viewer is automatically provided at his
`receiver with the program which he requested with his
`hand-set keyboard 201, all operations occurring at
`electronic speed to provide no significant delay be-
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page8
`
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`Apple v. PMC
`IPR2016-01520
`Page 8
`
`

`

`3,934,079
`
`5
`tween the channel request and the provision of video.
`Assume nowthatthe channel “25”selected for view-
`ing has not been authorized. Accordingly, the AND
`gate 128,, is not switched responsiveto the | registered
`in the corresponding channelselect shift register 124
`stage. Whenthis condition obtains, no enabling input is
`supplied to the resistance network 136 and no receiv-
`able video is generated by the heterodyne structure
`138-140-142.
`When the above conditionsprevail, the outputs ofall
`of the gates 128 are low,thus providing a high outputat
`an OR-NOT gate 132. The output of the gate 132,
`together with the channel select mode signaling CS
`signal, switches an AND gate 134, the output of which
`essentially conveys the message that a channel has been
`selected butthatits reception has not yet been enabled.
`This output message of the gate 134 is registered in a
`particular service request (SR) stage of the shift regis-
`ter 102.
`As above noted, all of the messages in the modules
`100-300-200 circulate therebetween. As described
`below each message will circulate through all
`three
`modules, being quashed only after it returns through
`the
`complete
`circulation
`path
`100-160-300-260-200-249 to its originating module.
`Accordingly, the channel select message in the trans-
`ceiver 101, with the enabled SR flag bit, next moves to
`the channel control 300 transceiver 310 from whichit
`is extracted and propagatesto the head end by a proce-
`dure described below. A stored program controlled
`central processor 502 at the head end determines that
`the subscriber has requested a program for which he
`has not yet received authorization. Accordingly, the
`head end equipment under stored program control
`distributes a channel authorization message which per-
`mits the particular subscriber
`to receive the key-
`requested video, the computer program also generating
`billing information, as by printed form via an input
`output peripheral equipment item 507.
`The channel authorization message propagates in
`digital form modulating a data subcarrier over the
`cable network 500; is received at the terminal control
`400 at the subscriber location; is loaded into a channel
`authorization register 342 in the channel control mod-
`ule 300; shifts therefrom into the transceiver 310 in the
`module 300; thereafter passes in the manner above
`discussed to a transceiver 240 in the module 200 via
`the data link 260; and eventually moves into the de-
`sired transceiver 101 shift register 102 by way of lead
`249,
`The FIG. 1 apparatus loads the channel authorization
`shift register 126 with the channel authorization mes-
`sage stored in the shift register 102 in a manner analo-
`gousto that considered above for channelselect opera-
`tion. That
`is,
`the command decoder 106 notes the
`channel authorization operation code, and generates
`an enabled output CA signal. The CA signal passes
`through the OR gate 108 to load the register 104
`which,in this case, is loaded with the channel number
`whichis authorized for reception (e.g., 25”), and also
`a single authorization bit “A” which is of one binary
`value when the head endis enabling authorization, and
`of the other value when the head end is removing the
`powerto watch a program.As before, the data portion
`of the contents of register 104, the comparator 112,
`and the counter 114 generate a match signal M which
`occurs at a time which identifies the data contents of
`register 104. The signals M, CA, A, and an additional
`
`0
`
`25
`
`35
`
`40
`
`50
`
`55
`
`60
`
`65
`
`6
`Boolean variable OUT comprising the output of the
`shift register 126 are supplied as inputs to a combinato-
`rial network 130. The network 130 supplies the data
`inputofthe shift register 126 with the Boolean function
`CA:-M:A + CA‘OUT:M' + OUT-CA’ of the input vari-
`ables. Thefirst term of this expression loads (or clears)
`a particular shift register stage in accordance with the
`incoming authorization message;
`the second factor
`simply reloads the previously obtaining contents of the
`shift register during a channel authorization message as
`to channels having nothing to do with that message (the
`M' variable component); and the final combinatorial
`function simply reloads the shift register contents in
`their entirety during a non-channel authorization mes-
`sage, e.g., during a channel select message.
`The above discussion has thus shown the manner in
`which the channel selection and channel authorization
`functions are implemented, and the particular way in
`which reception of premium video signals are re-
`quested; effected; and accountedfor as a business mat-
`ter.
`Wenoteat this point several “housekeeping” elec-
`tronic functions which obtain for the loop transmission
`between the modules 100-300-200. First, a system
`clocking timer 116 blocks an ANDgate 118in the loop
`path (i.e., connected to the output of the transceiver
`101 shift register 102) at spaced periods of time. This
`results in an all zero operation code at such times,
`whichis treated by the system as the operation code for
`a so-called ‘empty message” train. The otherintercon-
`nected system modules 300 and 200 inspect the opera-
`tion code stored in the operation code portion of the
`transceiver shift register therein for the incidence of
`such an emptytrain, which signals an appropriate time
`for such modules to load an outgoing message into the
`transceiver for propagation.
`Moreover, the command decoder 106 in module 100
`also produces an output signal when an emptytrain has
`propagated
`through
`the
`entire
`loop
`100-160-300-260-200-249 to return to the shift regis-
`ter 102. The decoder 106 energizes a word generator
`115 (in this case, simply a selected set oflines) which
`loads the operation code of a display message into the
`operation code storage portion ofthe shift register 102.
`As will become clear from the discussion below in
`conjunction with FIG, 2, the visual display at the sub-
`scriber control equipment will respond to a display
`train by presenting the data portion of the display mes-
`sage train (which corresponds to the channel being
`viewed).
`Finally, as is a general system rule, the module 100,
`200 or 300 which generates the message quashes that
`message. Thus, the command decoder 106 blocks mes-
`sage transmission (by disabling the gate 118) whenit
`notes that a display message (which it necessarily pro-
`duced) has comefull circle to again reside in the shift
`register 102.
`Weconsider now in more particular detail the sub-
`scriber control equipment module 200 shownin FIG. 2,
`ie.,
`the typically small keyboard-display structure
`given to a subscriber with which he enters commands
`and data. The discussion above has considered the
`character select control key of the key ensemble 201
`followed by data keys 204 of the subscriber keyboard
`201. The control key field may include as well other
`command or mode keys such as “response”’ (to trans-
`mit data to the system head end, possibly for purposes
`totally unrelated from video reception), a “send” key
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 9
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 9
`
`

`

`3,934,079
`
`7
`to indicate the end of a response message, andthelike.
`The unit has a display 232, which may advantageously
`comprise a digital display of the contents of a register
`230 decoded to conform to the particular display im-
`plementation as known to those skilled in the art.
`To generate a message, e.g., the channel select mes-
`sage considered above,
`the subscriber depresses the
`character select key followed by appropriate data keys
`to identify the channel desired. Depression of each key
`generates plural data bits which are loadedinto a regis-
`ter 206 the contents of which are operated upon by a
`decoder 208. Thus, responsive to each key depressed
`on the keyboard 201, one of a plurality of command
`key lines is energized (the particular one dependent
`upon the character selected), The decoder 208 ener-
`gizes the upper outputline if any numerical data keyis
`depressed.
`The output of the decoder 208 forms one group of
`inputs to a sequential logic network 210, which also
`receives as inputs the outputs thereof, and selected
`control signals from the command decoder portion 242
`of the subscriber control module 200 transceiver 240.
`It is observed at this point that the construction of the
`transceivers 240 and 310 in the modules 200 and 300
`parallel that of the transceiver 101 in the module 100.
`Briefly, the function of the sequential logic network is
`to control gating for the subscriber module 200, de-
`pending upon which mode the equipment has been
`operating in (i.e., which was the last depressed com-
`mand key) and which key is currently being depressed
`to request new service, either by way of new command
`or new data.
`After the character select key is depressed (it need
`not again be depressed — the system [i.e., the sequen-
`tial network 210] remains in the character select mode
`independentof the numberof channel changes made),
`the data key entered information (identifying the de-
`sired channel “25” in the above assumed example) is
`passed from the output of the key recording register
`206 into the data portion of the transceiver 240 under
`control of gating 250 actuated by the sequence logic
`network 210. When the command decoder 242 next
`recognizes that an empty train operation code is con-
`tained in the transceiver 240, an appropriate enabling
`signal
`is supplied to a translation matrix 214 which
`converts a signal preserved in the sequentiallogic net-
`work 210 (indicating that the equipmentis operating in
`the channel select mode) into a plural bit channel se-
`lect operation code. This binary command passes via
`the gates 250 into the operation code portion of the
`transceiver 240. Thus, the transceiver 240 contains the
`channel select operation code and the numberof the
`particular channel desired. This composite character
`select word thenshifts from the shift register portion of
`transceiver 240 into the transceiver 101 of the channel
`select module 100 for execution in the manner above
`described.
`When the character select message has come full
`circle to again reside in the transceiver 240, the charac-
`ter select operation code is detected by module 200
`and employed for various purposes. First, it enables the
`gates 250 via an OR gate 244to pass the data portion
`of the contents of transceiver 240 into a register 230
`for display, such that the subscriber can see the identifi-
`cation of the channel being viewed. Since the data
`circulates at very rapid electronic speed, the display
`appears substantially coincident to the viewer with his
`depression of the keys. Then also, the message having
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`20
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`25
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`30
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`35
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`40
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`45
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`50
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`35
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`60
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`65
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`8
`comefull circle, an OR-NOTgate 246 disables an AND
`gate 248 to quash the character select message.It will
`be observed also that a display command detected by
`the transceiver command decoder 242 similarly oper-
`ates via the OR gate 244to load the register 230 with
`the data contents of the transceiver 240. Thus,
`the
`display 232 is refreshed by display messages.
`Turning now to the channel control module 300,it is
`the office of this module to extract appropriate mes-
`sages circulating between the transceivers of the mod-
`ules 100, 200 and 300 for transmission to head end
`equipment (such as television reception requests, re-
`sponse mode date, and the like) by loading such mes-
`sages in a message register 352. It is the further func-
`tion of the channel control module 300 to receive mes-
`sages transmitted by the head end in an appropriate
`module 300 register; and at an appropriate time to load
`such messagesinto the transceiver 310 for circulation
`between the transceivers 310, 240 and 101.
`Operation of the channel control module 300 pro-
`ceeds under control of a commandregister 368 which
`receives messages transmitted from the head end via
`the subscriber terminal control unit 400 considered
`below. The incoming message loadedinto the register
`368 includes two portions, a register and operational
`. modeidentifying portion 370, and an equipmentidenti-
`fying portion 372, The equipment identifying message
`componentin register 368 determines whether or not
`the message stored in the composite register 368 is for
`the composite equipment controlled by the structure of
`FIGS. 1, 2 and 3 — it being clear that any subscriber
`location may include additional equipment items com-
`municating with the head end via data loading and
`reading busses 382 and 380. Such other peripherals
`may comprise, for example, security equipment, con-
`sumption registers (gas or electric meters, or the like)
`for remote reading; printers, readers or the like.
`A decoder 378 responds to the equipment identifying
`contents of the register 368 and, assuming that the
`decoder confirms that the message is indeed intended
`for the apparatus of FIGS. 1-3, provides an enabling
`signal for loading a decoder 376 with the information
`contained in the modeand register data portion 370 of
`the register 368. The output of the decoder 376 is an
`enabling one or more of a signal ensemble G,—G,
`which contro] the operational mode of plural registers
`contained in the channel control module 300. Assume
`first that in incoming digital word from the head endis
`a channel authorization message. The decoder 376 will
`provide a high G, output which supplies data clocking
`pulses to a channel authorization shift register 342 by
`enabling a gate 350. The channel authorization mes-
`sage would then pass into the enabled register 342 from
`the head end, cable 500, and terminal control unit 400
`downa load data bus 382 into the register 342. Some-
`time later, when the command decoder portion 314 of
`the transceiver 310 notes an empty train in the trans-
`ceiver, a command decodersignal passes the channel
`authorization message from the register 342 through
`enabled gating 347 into the data portion of the trans-
`ceiver 310. A translation matrix 338 also responds to
`the decoded empty train signal for loading the pre-
`scribed channel authorization operation code into the
`portion of the transceiver shift register therefor. The
`channel authorization message loaded into the trans-
`ceiver 310 then simply circulates into the transceiver
`240 and, therefrom, into the transceiver 101 for execu-
`tion in the manner above described.
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 10
`
`PMC Exhibit 2031
`Apple v. PMC
`IPR2016-01520
`Page 10
`
`

`

`3,934,079
`
`The message register 352 included in the channel
`control module 300 is employed to temporarily store
`outgoing(i.e., “response’’) messages generated by the
`subscriber at the keyboard 201 until
`the register is
`interrogated for reading and transmission to the head
`end. To this end, an AND gate 376is partially enabled
`by a response mode decoded output from the com-
`mand decoder 314 and enters the resulting following
`response message present at the output ofthe receiver
`310 into the message receiver 310 via an OR gate 354,
`the requisite clocking for the shift register 352 during
`such loading being provided by an OR gate 361 and an
`enabled (G,) AND gate 360.
`Whenthe head enddesires to interrogate the register
`352,it issues a command which generates high G, a