Cable television distribution network with video-on-demand transmission

Claim 2

A cable television distribution network comprising: a center (100) for providing cable television signals one or more optical network terminations (ONT i ), a fiber optic distribution network (101 to 107) extending from said center (100) to said optical network terminations (ONT i for transmission of said cable television signals from said center (100) to said optical network terminations (ONT i , a respective electrical access network extending from each one of said optical network terminations (ONT i to a respective one of a plurality of groups of subscribers (111), each respective electrical access network distributing said cable television signals to said respective one of Said plurality of groups of subscribers, and means (120 to 125) for providing, in addition to said cable television signals (KTV), subscriber-assigned video signals together with said cable television signals for transmission to said optical network terminations (ONT i ) via said fiber optic distribution network using wavelength-division multiplexing, said means for transmitting including: means (123 to 126) for converting said subscriber-assigned video signals into digital subscriber-assigned video signals, means for combining said digital subscriber-assigned video signals which are intended for subscribers connected to said optical network terminations (ONT i ) into a time-division-multiplexed signal (ZM), and means for optically distributing said time-division-multiplexed signal (ZM) with said cable television signals to said optical network terminations (ONT i ) using wavelength-division multiplexing, and wherein each respective one of said optical network terminations (ONT i ), includes: means (130 to 136, M 1 to M 6 ) for receiving said time-division-multiplexed signal (ZM) with said cable television signals, means for extracting from said time-division-multiplexed signal (ZM) said digital subscriber-assigned video signals (G 1 which are intended for subscribers connected to said respective one of said optical network terminations (ONT i ), and means for frequency-division-multiplexing said extracted digital subscriber-assigned video signals with said cable television signals and for distributing said frequency-division-multiplexed signals from said respective one of said optical network terminations (ONT 1 ) to the subscribers (111) connected to said respective one of said optical network terminations (ONT 1 .

Claim 3

A cable television distribution network as claimed in claim 1, wherein said means for combining said digital subscriber-assigned video signals comprises: a channel multiplexer (KM 1 to KM 64 ) which combines said digital subscriber-assigned video signals (KG 1 ) which are intended for subscribers (111) connected to said respective one of said optical network terminations (ONT 1 ) into a group multiplex signal (G 1 ) using time-division multiplexing, and a group multiplexer (GM) which combines said group multiplex signals (G 1 to G 64 ) for all of said optical network terminations into said time-division-multiplexed signal (ZM) (FIG. 2).

Claim 4

A cable television distribution network as claimed in claim 2, wherein in said group multiplexer (GM), said group multiplex signals (G 1 to G 64 ) are bit-interleaved.

Claim 5

A cable television distribution network as claimed in claim 2, wherein said means for extracting includes: a selector (133) which extracts said group multiplex signal (G 1 ) from said time-division-multiplexed signal (ZM), and a channel demultiplexer (134) which separates said group multiplex signal (G 1 ) into said digital subscriber-assigned video signals, and wherein said means for frequency-division-multiplexing includes: modulators (M 1 to M 6 ) which each modulate one of said digital subscriber-assigned video signals onto a respective subcarrier, and power combiners (135, 136) which combine said modulated subcarriers with said cable television signals using frequency-division multiplexing.

Claim 6

A cable television distribution network as claimed in claim 4, wherein each of the modulators (M 1 to M 6 ) modulates one of said digital subscriber-assigned video signals onto said respective subcarrier by amplitude-shift keying, and wherein said subcarriers lie in a frequency range (VOD, FIG. 3) which is not occupied by said cable television signals.

Claim 7

A cable television distribution network as claimed in claim 5, wherein said cable television distribution network comprises means for providing subscriber-assigned audio signals in addition to said subscriber-assigned video signals in a corresponding manner for transmission via said fiber optic distribution network.

Claim 8

A cable television distribution network as claimed in claim 1, wherein said means for converting said subscriber-assigned video signals are located remote from said center.

Claim 9

A cable television distribution network as claimed in claim 1, wherein said means for combining said digital subscriber-assigned video signals are located remote from said center.

Claim 10

A cable television distribution network as claimed in claim 1, wherein said means for converting said subscriber-assigned video signals and said means for combining said digital subscriber-assigned video signals are located remote from said center.

Claim 11

A cable television distribution network as claimed in claim 1, wherein said means for converting said subscriber-assigned video signals are located in said center.

Claim 12

A cable television distribution network as claimed in claim 1, wherein said means for combining said digital subscriber-assigned video signals are located in said center.

Claim 13

A cable television distribution network as claimed in claim 1, wherein said means for converting said subscriber-assigned video signals and said means for combining said digital subscriber-assigned video signals are located in said center.

Claim 14

A cable television distribution network comprising: a center (100) for providing cable television signals, one or more optical network terminations (ONT i ), a fiber optic distribution network (101 to 107) extending from said center (100) to said optical network terminations (ONT i ) for transmission of said cable television signals from said center (100) to said optical network terminations (ONT i ), a respective electrical access network extending from each one of said optical network terminations (ONT i ) to a respective one of a plurality of groups of subscribers (111), each respective electrical access network distributing said cable television signals to said respective one of said plurality of groups of subscribers, and means (120 to 125) for providing, in addition to said cable television signals (KTV), subscriber-assigned audio signals together with said cable television signals for transmission to said optical network terminations (ONT i ) via said fiber optic distribution network using wavelength-division multiplexing, said means for transmitting including: means (123 to 126) for converting said subscriber-assigned audio signals into digital subscriber-assigned audio signals, means for combining said digital subscriber-assigned audio signals which are intended for subscribers connected to said optical network terminations (ONT i ) into a time-division-multiplexed signal (ZM), and means for optically distributing said time-division-multiplexed signal (ZM) with said cable television signals to said optical network terminations (ONT i ) using wavelength-division multiplexing, and wherein each respective one of said optical network terminations (ONT i ), includes: means (130 to 136, M 1 to M 6 ) for receiving said time-division-multiplexed signal (ZM) with said cable television signals, means for extracting from said time-division-multiplexed signal (ZM) said digital subscriber-assigned audio signals (G 1 ) which are intended for subscribers connected to said respective one of said optical network terminations (ONT i ), and means for frequency-division-multiplexing said extracted digital subscriber-assigned audio signals with said cable television signals and for distributing said frequency-division-multiplexed signals from said respective one of said optical network terminations (ONT 1 ) to the subscribers (111) connected to said respective one of said optical network terminations (ONT 1 ).

Claim 15

A cable television distribution network comprising: a center (100) for providing cable television signals, one or more optical network terminations (ONT i ), a fiber optic distribution network (101 to 107) extending from said center (100) to said optical network terminations (ONT i ) for transmission of said cable television signals from said center (100) to said optical network terminations (ONT i ), a respective electrical access network extending from each one of said optical network terminations (ONT i ) to a respective one of a plurality of groups of subscribers (111), each respective electrical access network distributing said cable television signals to said respective one of said plurality of groups of subscribers, and means (120 to 125) for providing, in addition to said cable television signals (KTV), subscriber-assigned audio signals together with said cable television signals for transmission to said optical network terminations (ONT i ) via said fiber optic distribution network using wavelength-division multiplexing, said means for transmitting including: means (123 to 126) for converting said subscriber-assigned audio signals into digital subscriber-assigned audio signals, means for combining said digital subscriber-assigned audio signals which are intended for subscribers connected to said optical network terminations (ONT i ) into a time-division-multiplexed signal (ZM), and means for optically distributing said time-division-multiplexed signal (ZM) with said cable television signals to said optical network terminations (ONT i ) using wavelength-division multiplexing, and wherein each respective one of said optical network terminations (ONT i ), includes: means (130 to 136, M 1 to M 6 ) for receiving said time-division-multiplexed signal (ZM) with said cable television signals, means for extracting from said time-division-multiplexed signal (ZM) said digital subscriber-assigned audio signals (G 1 ) which are intended for subscribers connected to said respective one of said optical network terminations (ONT i ), and means for frequency-division-multiplexing said extracted digital subscriber-assigned audio signals with said cable television signals and for distributing said frequency-division-multiplexed signals from said respective one of said optical network terminations (ONT 1 ) to the subscribers (111) connected to said respective one of said optical network terminations (ONT 1 ).

Claim 16

A cable television distribution network as claimed in claim 13, wherein said means for combining said digital subscriber-assigned audio signals comprises: a channel multiplexer (KM 1 to KM 64 ) which combines said digital subscriber-assigned audio signals (KG 1 ) which are intended for subscribers (111) connected to said respective one of said optical network terminations (ONT 1 into a group multiplex signal (G 1 ) using time-division multiplexing, and a group multiplexer (GM) which combines said group multiplex signals (G 1 to G 64 ) for all of said optical network terminations into said time-division-multiplexed signal (ZM) (FIG. 2).

Claim 17

A cable television distribution network as claimed in claim 14, wherein in said group multiplexer (GM), said group multiplex signals (G 1 to G 64 ) are bit-interleaved.

Claim 18

A cable television distribution network as claimed in claim 14, wherein said means for extracting includes: a selector (133) which extracts said group multiplex signal (G 1 ) from said time-division-multiplexed signal (ZM), and a channel demultiplexer (134) which separates said group multiplex signal (G 1 ) into said digital subscriber-assigned audio signals, and wherein said means for frequency-division-multiplexing includes: modulators (M 1 to M 6 ) which each modulate one of said digital subscriber-assigned audio signals onto a respective subcarrier, and power combiners (135, 136) which combine said modulated subcarriers with said cable television signals using frequency-division multiplexing.

Claim 19

A cable television distribution network as claimed in claim 16, wherein each of the modulators (M 1 to M 6 ) modulates one of said digital subscriber-assigned audio signals onto said respective subcarrier by amplitude-shift keying, and wherein said subcarriers lie in a frequency range (VOD, FIG. 3) which is not occupied by said cable television signals.

Claim 20

A cable television distribution network as claimed in claim 17, wherein said cable television distribution network comprises means for providing subscriber-assigned video signals in addition to said subscriber-assigned audio signals in a corresponding manner for transmission via said fiber optic distribution network.

Claim 21

A cable television distribution network as claimed in claim 13, wherein said means for converting said subscriber-assigned audio signals and said means for combining said digital subscriber-assigned audio signals are located remote from said center.

Claim 22

A cable television distribution network as claimed in claim 13, wherein said means for converting said subscriber-assigned audio signals and said means for combining said digital subscriber-assigned audio signals are located in said center.