Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/16—Analogue secrecy systems; Analogue subscription systems
  • H04N7/166—Passage/non-passage of the television signal, e.g. jamming, band suppression
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04H—BROADCAST COMMUNICATION
  • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
  • H04H20/65—Arrangements characterised by transmission systems for broadcast
  • H04H20/76—Wired systems
  • H04H20/77—Wired systems using carrier waves

Definitions

• the present invention relates to a method and means for telecommunication in a system comprising a plurality of selectable channels.
• the system may be said to relate to a cable TV system comprising a plurality of chan ⁇ nels for which subscription may be made to any desired number, and the invention will be discussed below essenti ⁇ ally with reference to such a system, without however being restricted to exactly such systems.
• Certain known cable TV systems comprising a plurality of channels are designed in such a manner that one has to select one or some of the selectable channels already when the subscription is made, which channels are then connected up at the subscriber and which will then remain permanently connected up.
• the systems are comparatively limited with respect to the number of possible channels. Further, these known systems suffer from the drawback that it is comparat ⁇ ively complicated to change from one selection of channels to a different one, in as much as such a change normally requires a service man to visit the subscriber in order to carry out the necessary switching there.
• the present invention has aimed at providing a method and means for telecommunication in a system comprising a plurality of selectable channels, which do not suffer from the just mentioned limitations and drawbacks.
• the telecommunication should be carried out so as is defined in principle in the characterizing . clause of claim 1.
• the equipment should be so designed, as is defined in principle in the characterizing clause of claim 4.
• the system comprises an input line 10 which may be connected through cables 11, 12, 13 to a plurality of sub ⁇ scribers A, B, C etc., each having a blocking means 14, 15 and 16, respectively. Further, the system comprises a controlling computer D and an obfuscation signal generator S, which last mentioned has an obfuscation output line' 17 connected to each one of the the blocking means 14-16 through lines 18, 19 and 20, respectively. Further, the obfuscation signal generator S is connected to each one of the blocking means 14-16 through a line 28 to send "clock" pulses to the blocking means.
• the controlling computer D has an output line 21 connected to each one of the blocking means 14-16 through lines 22, 23 and 24, respectively.
• the system according to the invention is adapted to operate in the following manner:
• the entire offer of programs is passed, through line 10, to all subscribers A, B, C etc., which may select freely between the channels for which a subscription has been made, whereas the programs on the other channels are obfuscated in a suitable manner.
• the obfuscation may be directed to the picture only, or the sound only, or both.
• the control of which channels at the respective subscriber A, B, C etc., that should be permitted to pass on, and which are to be obfuscated, is carried out by the centrally located computer, which has been set in advance in accordance with the subscriptions made.
• system is adapted to operate in the following manner:
• Over line 10 e.g. twenty program channels TV1 - TV20 are passed to each one of the subscribers A, B, C etc.
• the obfuscation signal generator S sends, through line 28, a plurality of "clock" pulses to each one of the blocking means 14-16, which each, in dependence of signals from the computer D, is set into an individual state that permits the signal on certain channels to pass undisturbed whereas it is obfuscated on other channels.
• the periodicity of the obfuscation is choosen to a such a value that the partial picture frequency dif ⁇ fers from certain integer multiples of the periodicity of the obfuscation, i.e. the time lag between the obfuscations on one and the same channel.
• the number of "clock" pulses may correspond to the number of selectable channels, e.g. twenty clock pulses per pulse train, or may the number of clock pulses be an integer multiple of ths number of selectable chan ⁇ nels.
• each subscrip ⁇ tion may be made by a written or . oral agreement, which is followed by a corresponding programming of the computer. It may also be performed over ordinary telephone lines with the necessary modems.
• a reversed arrangement with respect to the payment has also been contemplated, i.e. a system wherein each subscri ⁇ ber has a possibility to select one channel each time from the full channel offer, wherein his particular channel selection is determined and registered periodically with very short intervals to then be billed him retroactively, e.g. each month.
• the system may be comple ⁇ mented by some type of a credit card and/or a "personal code", similar to what is used with bank note machines, at the same time as some sort of a "censorship" with respect to time and/or program content may be exercised.

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Multimedia (AREA)
• Time-Division Multiplex Systems (AREA)
• Television Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20363372

Family Applications (1)

Country Status (4)

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Family Cites Families (4)

• 1986
  • 1986-02-05 SE SE8600521A patent/SE8600521L/xx unknown
• 1987
  • 1987-02-04 AU AU70237/87A patent/AU7023787A/en not_active Abandoned
  • 1987-02-04 WO PCT/SE1987/000052 patent/WO1987004882A1/en not_active Ceased
  • 1987-02-04 EP EP19870901160 patent/EP0256084A1/de not_active Withdrawn

Non-Patent Citations (1)

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