VIRTUAL CHANNEL TABLE FOR A BROADCAST PROTOCOL AND METHOD OF BROADCASTING AND RECEIVING BROADCAST SIGNALS USING THE SAME

Abstract

A virtual channel table for broadcasting protocol and a method for broadcasting by using the virtual channel table includes identification information identifying and permitting discrimination of active and inactive channels contained in the virtual channel table. At a receiver, the virtual channel table transmitted from the transmitting side is parsed, thereby determining whether the current received channel is an active or inactive channel.

Claims

1-30. (canceled)

31. A method of processing a digital broadcasting signal in a digital television receiver, comprising: receiving a digital broadcasting signal including program and system information protocol (PSIP) data including a virtual channel table (VCT), wherein the VCT includes a table ID field, a major_channel_number field, a minor_channel_number field, a program number field or service status information, the program number field being set to zero for an inactive channel, the service status information indicating whether a virtual channel is an inactive channel, wherein the inactive channel is a channel that is not presently carrying a broadcast program; however, the same inactive channel is supposed to carry a broadcast program at later time from a broadcasting station; and processing the virtual channel based on information in the VCT, wherein when the virtual channel is currently inactive, the receiver is capable of skipping over the virtual channel while a user is surfing.

32. The method of claim 31, wherein the digital broadcasting signal is a digital terrestrial broadcast signal.

33. The method of claim 31, wherein the digital broadcasting signal is a digital cable broadcast signal.

34. The method of claim 31, wherein the service status information is included in a statement of a for_loop in a bit stream syntax of the VCT.

35. The method of claim 31, wherein the digital broadcasting signal further includes a program map table (PMT).

36. A digital television receiver processing a digital broadcasting signal, comprising: a tuner configured to receive a digital broadcasting signal including program and system information protocol (PSIP) data including a virtual channel table (VCT), wherein the VCT includes a table ID field, a major_channel_number field, a minor_channel_number field, a program number field or service status information, the program number field being set to zero for an inactive channel, the service status information indicating whether a virtual channel is an inactive channel, wherein the inactive channel is a channel that is not presently carrying a broadcast program; however, the same inactive channel is supposed to carry a broadcast program at later time from a broadcasting station; and a processor configured to process the virtual channel based on information in the VCT, wherein when the virtual channel is currently inactive, the receiver is capable of skipping over the virtual channel while a user is surfing.

37. The digital television receiver of claim 36, wherein the digital broadcasting signal is a digital terrestrial broadcast signal.

38. The digital television receiver of claim 36, wherein the digital broadcasting signal is a digital cable broadcast signal.

39. The digital television receiver of claim 36, wherein the service status information is included in a statement of a for_loop in a bit stream syntax of the VCT.

40. The digital television receiver of claim 36, wherein the digital broadcasting signal further includes a program map table (PMT).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0038] In the drawings:

[0039] FIG. 1 is a diagram illustrating the bit stream syntax of a general virtual channel table for terrestrial broadcast;

[0040] FIG. 2 is a diagram illustrating an example of executing schedule broadcasting by using four virtual channels in a broadcast station;

[0041] FIG. 3 is a diagram illustrating the bit stream syntax of a virtual channel table for terrestrial broadcast according to an embodiment of the present invention;

[0042] FIG. 4 is a diagram illustrating the bit stream syntax of a virtual channel table for cable according to another embodiment of the present invention;

[0043] FIG. 5 is chart listing various descriptors available according to a program and system information protocol of an advanced television systems committee standard digital television broadcast;

[0044] FIG. 6 is block diagram illustrating a digital television (DTV) receiver according to an embodiment of the present invention;

[0045] FIG. 7 is a diagram illustrating a preferred embodiment process of handling active and inactive channels for display in response to a user selection key;

[0046] FIG. 8 is a flowchart illustrating a preferred embodiment process of producing a display of a program or an electronic program guide (EPG) according to a channel or EPG selection key input by a user.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which is illustrated in the accompanying drawings.

[0048] According to the present invention, a virtual channel table for a broadcast protocol comprises identification information capable of identifying and permitting discrimination between active and inactive channels in the bit stream syntax thereof. A transmitting side, namely, a broadcast station transmits the virtual channel table having the identification information to receivers. Each of receivers parses the virtual channel table received, thereby determining whether the channel currently selected is an active channel or an inactive channel.

[0049] The identification information, which is capable of identifying and permitting discrimination between an active channel and an inactive channel under the standard of the PSIP, is contained in at least one field of the virtual channel table of the above protocol, such that only active channels being currently broadcast arc displayed to TV viewers.

[0050] Hereinafter, preferred embodiments of a virtual channel table and a method according to the present invention will be in detail described with reference to FIGS. 3 and 4.

[0051] In order for a digital television receiver and a digital cable broadcast receiver to parse the virtual channel table and thus to determine whether the channel selected currently is an active channel or an inactive channel, the bit stream syntax of the virtual channel table may be corrected.

[0052] For example, the fact that channels 51-2 and 51-8 are not broadcast at the current time 20:15, but are going to be broadcast in the future, should be recognized in a digital television receiver and a cable broadcast receiver. In a preferred embodiment, the identification information capable of identifying an inactive channel is contained in the program number field program_number, the service location descriptor field service_location_descriptor and/or other reserved fields contained in the bit stream syntax of the virtual channel table.

[0053] FIG. 3 is a diagram illustrating the bit stream syntax of a virtual channel table for terrestrial broadcast according to an embodiment of the present invention. To indicate that a corresponding channel is an inactive channel, the value of the program number field program_number is set to 0. And, since there are no audio and video signals of the current service location descriptor, the value of the number elements field number_elements of the service location descriptor service_location_descriptor is set to 0. Also, or alternatively, to indicate that the corresponding channel is an inactive channel, the service location descriptor service_location_descriptor (see FIG. 5) is not contained in the virtual channel table. In other words, the digital television receiver and the cable broadcast receiver, the service location descriptor field should be contained in the virtual channel table only in a case where the corresponding channel is the active channel. If the corresponding channel is an inactive channel, however, the service location descriptor field is not contained in the virtual channel table.

[0054] In a preferred embodiment, in order to recognize the fact that the corresponding channel is an inactive channel in a more apparent manner, 1 bit of the reserved field of 6 bits for each channel is assigned to define a flag indicative of an inactive channel. In the preferred embodiment, 1 bit in the reserved field between the hidden field hidden and the service type field service_type in the statement of the for_loop is assigned to define a flag indicative of an inactive channel. For example, in a case where the flag indicative of the inactive channel is 1, the corresponding channel is an active channel, and if the flag is 0, the corresponding channel is an inactive channel.

[0055] In the preferred embodiment, the above three cases may be added as requirements in the document A/65. Any of all of the three cases may be added in the document A/65.

[0056] As mentioned above, since the information on an inactive channel is contained in the virtual channel table, the digital television receiver can determine whether the virtual channel currently received is an active channel or an inactive channel by parsing only the virtual channel table. For example, if the value of the program number field program_number in the virtual channel table is 0, if the value of the information on the inactive channel defined by assigning a predetermined bit in the reserved field is 0, or if the service location descriptor field service_location_descriptor is not contained in the virtual channel table, the major channel number field major_channel_number and the minor channel number field minor_channel_number defined in the bit stream syntax of the virtual channel table currently transmitted determine that the current virtual channel is an inactive channel.

[0057] On the other hand, if an inactive channel has been determined under the above process, the digital television receiver can skip the inactive channel, without displaying it on the screen, upon channel conversion by means of a channel up key or a channel down key.

[0058] FIG. 4 is a diagram illustrating the bit stream syntax of a virtual channel table for cable according to another embodiment. As shown, the virtual channel table may be applied to cable broadcasting in the same manner as above.

[0059] FIG. 6 shows a block diagram of a preferred embodiment of a digital television (DTV) receiver. A demodulator converts an RF signal to a baseband signal after channel error collection. Then, a transport decoder separates several signals, such as audio, video, PSIP, etc. and outputs the audio and video streams to audio and video decoders, and a PSIP data stream to a PSIP decoder. The PSIP Decoder decodes the PSIP data stream for storing PSIP data in a PSIP database, and provides output to a user interface (UI) module for showing an active program or an EPG display.

[0060] Now, the PSIP decoder will be explained. A PSIP parser parses PSIP tables (VCT,EIT,STT,RRT,ETT,MGT) and the result is output to PSIP main section. One can distinguish between active and inactive channels by the parsing result A section filter separates a necessary section from the PSIP data that was output by the transport decoder and outputs the necessary data to the PSIP Parser.

[0061] A PSIP manager controls the PSIP database (DB). The PSIP Main section controls the transport decoder for receiving tables of PSIP data. The PSIP Application Program Interface (APT) provides an output to allow an external module to access PSIP DB. The Channel Manager and EPG Task components arc operated by user selection signal of the channel key and/or EPG Key. If the user selects the channel key, the channel manager outputs the channel changing signal to the demodulator and transport decoder. In this case, a user can see an active channel. If the user selects the EPG key, the EPG Task component controls the PSIP Decoder to support an EPG display Mode. In this case, a user can see both active and inactive channels, displayed in an EPG screen.

[0062] FIG. 7 shows channel surfing by using of the PSIP according to an embodiment of the present invention. At first, a channel is selected by a TV-user. And the transport decoder prepares to receive many signals, such as audio, video and PSIP transport packets. Next, the PSIP Decoder sets a PID value of (0x1FFB) into the transport decoder to select the terrestrial virtual channel table (TVCT) of the PSIP, and gets the audio and video (A/V) PID) values for the active virtual channels. (Inactive virtual channels don't have A/V PID values, but have channel information for the EPG Service.) Then, the PSIP Decoder makes a channel map for the PSIP, sends it to the channel manager, to be used for tuning active channels. Then, the channel manager sets A/V PIDs (Video PID 0x21, Audio PID 0x24) for virtual channel number (68-1) selected by the TV-user. The transport decoder receives the A/V transport packets, sends them to the A/V decoder(s), and finally the DTV channel will be serviced.

[0063] FIG. 8 shows a flowchart illustrating channel tuning and EPG Display. The user can see only the active channels displayed when tuning channels, but when the user receives the EPG Service, he/she sees an EPG display which includes all of the virtual channels, including the inactive channels.

[0064] As is apparent from the foregoing description, a virtual channel table for a broadcast protocol, and a method of broadcasting by using the virtual channel table are capable of including the identification information capable of identifying and permitting discrimination between active and inactive channels in a transmitting side, and in a receiving side parsing the virtual channel table to thereby determine whether the channel currently selected is the active channel or the inactive channel. Therefore, inactive channels may be skipped, without being displayed, upon the channel conversion by using a channel up key or a channel down key such that the TV viewer can enjoy channel surfing in a convenient manner, without viewing a black screen. In addition, the virtual channel table may be transmitted, while containing the inactive channels therein, thereby making it possible to provide a more abundant electronic program service.

[0065] It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.