Virtual channels for a multiplexed analog component (MAC) television system

• US 5,200,823 A
• Filed: 03/29/1991
• Issued: 04/06/1993
• Est. Priority Date: 03/29/1991
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Gammie, Keith, Yoneda, Robert, Sheldrick, Wayne
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Metjahic, Safet
• Application Number:
  US07/677,555
• Time in Patent Office: 739 Days
• Field of Search: 358/145, 358/143, 358/144, 358/142, 358/141, 358/14, 358/86, 358/146, 358/147, 380/21
• US Class Current: 348/473
• CPC Class Codes: H04N 5/602 for digital sound signals
• CPC Class Codes: H04N 7/083 with signal insertion during the vertical and the horizontal blanking interval , e.g. MAC data signals
• CPC Class Codes: H04N 7/0882 for the transmission of character code signals, e.g. for teletext circuits for the digital non-picture data signal H04N7/035
• CPC Class Codes: H04N 7/0888 Subscription systems therefor
• CPC Class Codes: H04N 7/17363 at or near the user terminal

Abstract

A decoder for use in a television system. The decoder includes a receiver for receiving a television signal having at least one channel. Each channel of the television signal includes video and audio components. A channel maps the channel received by the receiver to a plurality of virtual channels. A first virtual channel utilizes a first combination of video and audio components of the received channel and a second virtual channel utilizes a second combination of video and audio components of the same received channel different than the first combination. A selector allows a subscriber to select one of the virtual channels. Linked text pages may also be mapped to one or more of the virtual channels.

Claims

1. A decoder for use in a television system, said decoder comprising:

a receiver for receiving a television signal including a linked sequence of text pages wherein each text page is accompanied by information identifying the next text page in the linked sequence of text pages;

a memory for storing a channel map for mapping the linked sequence of text pages to a plurality of virtual channels, each virtual channel having text pages of the linked sequence of text pages mapped thereto in accordance with root text pages defining a first text page on each of said virtual channels and root page spacings defining a number of text pages mapped to each of said virtual channels, a final text page of a first virtual channel linked to the root text page of a second virtual channel; and

a selector for selecting ones of said virtual channels to display the linked sequence of text pages in accordance with the channel map stored in said memory.

3. The decoder according to claim 1, wherein said memory is a non-volatile memory.

4. The decoder according to claim 1, wherein said memory stores a channel map in which each virtual channel has the same number of linked text pages mapped thereto.

2. An encoder for transmitting a linked sequence of text pages to a plurality of remotely located decoders, said encoder comprising:

means for generating a channel map for mapping the linked sequence of text pages to a plurality of virtual channels, each virtual channel having text pages of the linked sequence of text pages mapped thereto in accordance with root text pages defining a first text page on each virtual channel and root page spacings defining a number of text pages mapped to each virtual channel, a final text page of a first virtual channel linked to the root text page of a second virtual channel; and

a transmitter for transmitting a television signal comprising the linked sequence of text pages and the channel map to said remotely located decoders.

5. A television system for transmitting and displaying a linked sequence of text pages, comprising:

an encoder including;

means for generating a channel map for mapping the linked sequence of text pages to at least two virtual channels, each virtual channel having text pages of the linked sequence of text pages mapped thereto in accordance with root text pages defining a first text page on each virtual channel and root page spacings defining a number of text pages mapped to each virtual channel, a final text page of a first virtual channel linked to the root text page of a second virtual channel; and

a transmitter for transmitting a television signal comprising the linked sequence of text pages and the channel map; and

a decoder comprising;

a receiver for receiving the television signal;

a memory coupled to said receiver for storing the channel map; and

a selector for selecting ones of the virtual channels to display the linked sequence of text pages in accordance with the channel map stored in said memory.

6. The television system according to claim 5 wherein each page of the linked sequence is accompanied by information identifying the next page in the sequence.

7. The television system according to claim 5 wherein said selector includes means for sequentially selecting text pages of the linked sequence of text pages.

8. A method of transmitting a linked sequence of text pages to a plurality of decoders in a television system, comprising the steps of:

generating a channel map for mapping the linked sequence of text pages to at least two virtual channels, each virtual channel having text pages of the linked sequence of text pages mapped thereto in accordance with root text pages defining a first text page on each virtual channel and root page spacings defining a number of text pages mapped to each virtual channel, a final text page of a first virtual channel linked to the root text page of a second virtual channel; and

transmitting a television signal comprising the linked sequence of text pages and the channel map.

9. A method of displaying a linked sequence of text pages transmitted with a television signal in a television system, the method comprising the steps of:

storing a channel map mapping the linked sequence of text pages to at least two virtual channels, each virtual channel having text pages of the linked sequence of text pages mapped thereto in accordance with root text pages defining a first text page on each virtual channel and root page spacings defining a number of text pages mapped to each virtual channel, a final text page of a first virtual channel linked to the root text page of a second virtual channel; and

selecting ones of the virtual channels to display the linked sequence of text pages in accordance with the stored channel map.