Method for avoiding switch-over delays when changing channels in digital television transmission systems
A method for avoiding switch-over delays when changing channels in digital television transmission systems is based on a television transmission system in which a plurality of channels (K 1 , . . . , Kn) are transmitted in time-division-multiplexed fashion in a data stream ( 5 ). An overview channel comprising television picture information items from a plurality of the transmitted channels is provided at the transmitting end. The overview channel is decoded in the television receiver, and the picture information items of the selected channel that are provided in the overview channel are represented while changing channels.
1. A method for avoiding switch-over delays when changing channels in digital television transmission systems, in which a plurality of channels are transmitted in time-division-multiplexed fashion in a data stream, an overview channel comprising television picture information items from a plurality of the transmitted channels being provided at the transmitting end, the method comprising:
decoding of the overview channel in the television receiver;
when changing channels in the television receiver, displaying the television picture information of the selected channel that is provided in the overview channel,
wherein only a portion of the time slots used for the overview channel in the data stream is used for the decoding of the overview channel in the television receiver.
2. The method according to claim 1 , wherein the television picture information of the selected channel that is shown in the television receiver is a still picture.
3. The method according to claim 1 , wherein the television picture information of the selected channel that is shown in the television receiver is a still picture sequence.
4. The method according to claim 1 , wherein the frequency of the decoding of television picture information items from the overview channel, for a given channel, is performed according to a predetermined time function.
5. The method according to claim 1 , wherein television picture information items from the overview channel are decoded in the television receiver only for a portion of the transmitted channels.
6. The method according to claim 1 , wherein the digital television transmission system is a television transmission system for battery-operated and/or mobile terminals, in particular mobile telephones and personal digital assistants.
7. The method according to claim 6 , wherein the digital television transmission system is Digital Video Broadcasting-Handheld (DVB-H).
8. A method for avoiding switch-over delays when changing channels in digital television transmission systems, in which a plurality of channels are transmitted in time-division-multiplexed fashion in a data stream, an overview channel comprising television picture information items from a plurality of the transmitted channels being provided at the transmitting end, the method comprising:
decoding of the overview channel in the television receiver;
when changing channels in the television receiver, displaying the television picture information of the selected channel that is provided in the overview channel,
wherein a monitoring list is managed in the television receiver, the channels to be decoded from the overview channel being entered in said monitoring list, and in that, after a program change from a first channel to a second channel, the first channel is automatically adopted into the monitoring list.
9. A method for avoiding switch-over delays when changing channels in digital television transmission systems in which a plurality of channels are transmitted in time-division-multiplexed fashion in a data stream, comprising the following steps carried out in the television receiver:
decoding the currently selected channel, and decoding and temporarily storing television picture information items from all channels in the data stream apart from the currently selected channel, wherein the frequency of the decoding of television picture information items from a monitored channel is performed according to a predetermined time function;
temporarily storing the television picture information items of the monitored channel; and
when changing channels to the monitored channel, displaying the stored television picture information items of the monitored channel,
wherein a monitoring list is managed in the television receiver, those channels from which television picture information items are intended to be decoded and temporarily stored being entered into said monitoring list, and in that, after a program change from a first channel to a second channel, the first channel is automatically adopted into the monitoring list.
10. The method according to claim 9 , wherein television picture information items with regard to only a portion of the channels contained in the data stream excluding the currently selected channel are decoded and temporarily stored.
11. The method according to claim 9 , wherein the temporarily stored television picture information items of the selected channel are a still picture.
12. The method according to claim 9 , wherein the temporarily stored television picture information items of the selected channel are a still picture sequence.
13. A method for avoiding switch-over delays when changing channels in digital television transmission systems in which a plurality of channels are transmitted in time-division-multiplexed fashion in a data stream, comprising the following steps carried out in the television receiver:
decoding the currently selected channel and decoding television picture information items from at least one other, monitored channel, wherein the television picture information items of a monitored channel are in each case decoded every m time division multiplex cycles, m being an integer where m>2;
temporarily storing the television picture information items of the monitored channel; and
when changing channels to the monitored channel, displaying the stored television picture information items of the monitored channel,
wherein the frequency of the decoding of television picture information items from a monitored channel is performed according to a predetermined time function.
14. A method for avoiding switch-over delays when changing channels in digital television transmission systems in which a plurality of channels are transmitted in time-division-multiplexed fashion in a data stream, comprising the following steps carried out in the television receiver:
decoding the currently selected channel and decoding television picture information items from at least one other, monitored channel, wherein the television picture information items of all the monitored channels are in each case decoded in the same time division multiplex cycle;
temporarily storing the television picture information items of the monitored channel; and
when changing channels to the monitored channel, displaying the stored television picture information items of the monitored channel,
wherein the frequency of the decoding of television picture information items from a monitored channel is performed according to a predetermined time function.