JP2001203948A - Digital television broadcasting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital television broadcasting system which can switch services provided over networks without user's network switching operation. SOLUTION: This digital television broadcasting system transmits transmission data of each network and service numbers by transponders constituting the network as actual-NIT by a digital television broadcasting system which is providing services from multiple networks and also sends transmission data of other networks and service alteration information consisting of information regarding services of other networks to be added, deleted, or changed or information regarding the effective time when changes are made effective as other-NIT.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital television broadcasting system which provides services from a plurality of networks.

[0002]

2. Description of the Related Art It is assumed that a service from a plurality of broadcast transmitters, that is, a plurality of networks is received by one television broadcast receiver. Each network transmits a service number for each transponder configuring its own network, but does not transmit a service number for each transponder configuring another network.

For this reason, when the receiver switches the service (program) of the predetermined network currently being received to the service of another network, the user first switches the network. Then, after acquiring the service number of each transponder constituting the network, the program must be switched. Such an operation is troublesome for the user.

Therefore, for each network, a service number for each transponder forming another network and a service number for each transponder forming another network are transmitted. A system that obtains and stores such information from the network currently being received, and when a request for service switching across networks is requested, a system that switches services based on the information. Conceivable.

However, in such a system,
For each network, it is necessary to transmit the service number of each transponder configuring its own network and the service number of each transponder configuring another network. There is a problem that it becomes.

Further, in the case where each network transmits only the service number of each transponder constituting its own network, the receiver sequentially receives each network when the power is turned on.
The service number of each transponder constituting each network is sequentially obtained and stored, and when a service switching is requested across networks, the service switching is performed based on the information. A system that does this is conceivable. However, this method changes the service on the network that is not currently receiving,
If added or deleted, it is not possible to know the changed, added or deleted content unless the network is normally moved to the network, so that the service may not be switched smoothly.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital television broadcasting system that enables a user to switch services across networks without performing network switching operations.

[0008]

A digital television broadcasting system according to the present invention is a digital television broadcasting system which provides services from a plurality of networks. The service number for each transponder that constitutes the network is transmitted as actual-NIT, and the transmission parameters of other networks and services of other networks that are added, deleted or changed after the current time Information and service change information comprising information on the effective time at which addition, deletion or change becomes effective are transmitted as other-NIT, and the receiver
The actu transmitted for each network when the power is turned on
Receives al-NIT and other-NIT, stores transmission specifications for all networks, stores service change information for all networks, service change information table for all networks, and service numbers and service numbers for all networks Means for creating a service table storing a network corresponding to the service number, and when the user inputs a service number, recognizing the network corresponding to the input service number based on the service table, Means for selecting a program corresponding to, when receiving a service provided by a certain network, periodically acquiring the actual-NIT transmitted from the network, and acquiring the acquired actual-NIT
If the IT has been updated, a means for updating the service table based on the acquired actual-NIT, and when receiving a service provided by a certain network, other- If it is necessary to periodically acquire the NIT and update the service change information table, the means for updating the service change information table, and the current time, if any of the service change information in the service change information table is valid When the time coincides with the time, a means for updating the service table based on the service change information whose effective time coincides with the current time is provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electrical configuration of a digital broadcast receiver.

A tuner 1 receives a broadcast wave from an antenna, demodulates the broadcast wave, and outputs a transport stream (hereinafter abbreviated as TS). Reference numeral 2 denotes a TS for separating the TS output from the tuner 1 into video, audio, and other additional information.
It is a separation unit. The additional information is stored in the memory 3.

Reference numeral 5 denotes a video TS output from the TS separation unit 2.
Is a video processing unit that decodes and outputs video. Reference numeral 4 denotes an on-screen generation unit that generates an on-screen image such as a program guide screen. Reference numeral 10 denotes an image synthesizing unit for superimposing the on-screen image generated by the on-screen generating unit 4 on the video output obtained by the video processing unit 5 and displaying the image on the screen. The video signal obtained by the image synthesis unit 10 is sent to the video output terminal 7.

Reference numeral 6 denotes the audio TS output from the TS separation unit 2.
Is a voice processing unit for decoding and outputting voice.
The audio signal obtained by the audio processing unit 6 is sent to an audio output terminal 8. Reference numeral 9 denotes a CPU for controlling each unit of the digital broadcast receiver.

In this example, it is assumed that the digital broadcast receiver can receive a plurality of networks. Each network uses NIT (Network Information
As Table), actual-NIT and other-NIT are transmitted periodically.

The actual-NIT contains the transmission specifications of its own network and the service number of each transponder constituting its own network. The transmission specifications of the own network include transmission information such as the frequency, the orbit position of the satellite, and the modulation method for each transponder configuring the own network.

[0016] The other-NIT includes transmission data of another network and service change information. The transmission data of the other network includes transmission information such as a frequency, a satellite orbit position, and a modulation method for each transponder configuring the other network. The service change information includes information on services of other networks to be added, deleted, or changed after the current time, and information on a valid time at which the addition, deletion, or change becomes effective.

FIG. 2 shows an initial service table creation processing procedure performed by the digital broadcast receiver when the power is turned on.

First, actual-NIT and other-NIT transmitted from a predetermined network are acquired and stored (step 1). That is, the CPU 9 controls the tuner 1 to switch a transponder to be received by a transponder corresponding to a predetermined network. As a result, a transport stream corresponding to a predetermined network is sent to the TS separation unit 2 via the tuner 1. The TS separation unit 2 converts the transport stream into ac
The tual-NIT and the other-NIT are acquired and stored in the memory 3.

Next, it is determined whether or not there is another network that has not acquired the actual-NIT and other-NIT (step 2).

If there is another network that has not acquired the actual-NIT and other-NIT, the transponders are sequentially switched (step 3), and the actual-NIT and other-NIT transmitted from the other network are sequentially switched. Acquire and store the NIT (step 1).

From all networks, actual-NIT and
If other-NIT is acquired, create a service change information table that stores service change information for all networks and a service table that allows the user to switch services without performing network switching operations. (Step 4). Thereafter, the normal operation is performed.

The service table is a table in which service numbers for all networks and networks corresponding to each service number are stored as shown in an example in FIG. In this example, service numbers 101 to 105 are service numbers for network A, and service numbers 111 to 115 are service numbers for network B.

When the user enters the service number, C
Since the PU 9 can recognize the network corresponding to the input service number from the service table, the PU 9 can receive the program corresponding to the input service number without causing the user to perform a network switching operation. Become like

FIG. 4 shows actual-NIT acquisition processing performed by the CPU 9 during normal operation.

When the actual-NIT acquisition timing comes (step 11), the actual-NIT is acquired (step 1).
2). That is, the CPU 9 outputs an actual-NIT acquisition command to the TS separation unit 2 at the actual-NIT acquisition timing. When receiving the actual-NIT acquisition command, the TS separation unit 2 extracts the actual-NIT from the currently received transport stream.
-Acquire the NIT and store it in the memory 3.

Next, the actual-NIT for the currently receiving network acquired this time is compared with the actual-NIT for the same network acquired last time (step 13).
When the service of the network currently being received has been changed, the CPU 9 sets the service according to the changed information.
The service table is updated (step 14).

FIG. 5 shows a process of acquiring the other-NIT performed by the CPU 9 during the normal operation.

When the other-NIT acquisition timing comes (step 21), the other-NIT is acquired (step 2).
2). In other words, the CPU 9 outputs the other-NIT acquisition command to the TS separation unit 2 at the timing of acquiring the other-NIT. When receiving the other-NIT acquisition command, the TS separation unit 2 converts the other-NIT acquisition command from the currently received transport stream to other-NIT.
The NIT is acquired and stored in the memory 3.

Next, the service change information included in the other-NIT acquired this time is compared with the service change information table, and if there is newly added service change information, the service change information table is added to the service change information table. Information is added (step 23).

FIG. 6 shows a service table update processing procedure based on service change information performed by the CPU 9 during normal operation.

When the current time information is obtained (step 3
1) It is determined whether the effective time of any service change information in the service change information table matches the current time (step 32).

If the current time does not match the valid time of any service change information, the process returns to step 31.
If the current time matches the valid time of any of the service change information, the service table is updated according to the corresponding service change information (step 33). Then, the service change information is deleted from the service change information table (step 34).

[0033]

According to the present invention, a service can be switched over a network without a user performing a network switching operation.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an electrical configuration of a digital broadcast receiver.

FIG. 2 is a flowchart illustrating an initial service table creation process performed by a digital receiver when power is turned on.

FIG. 3 is a schematic diagram illustrating an example of a service table.

FIG. 4 is a flowchart showing a procedure of an actual-NIT acquisition process performed by a CPU 9 during a normal operation.

FIG. 5 is a flowchart showing a procedure of another-NIT acquisition processing performed by a CPU 9 during a normal operation.

FIG. 6 is a flowchart showing a service table update processing procedure based on service change information performed by a CPU 9 during a normal operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tuner 2 TS separation part 3 Memory 4 On-screen generation part 5 Video processing part 6 Audio processing part 9 CPU 10 Image synthesis part

Claims (1)

[Claims] In a digital television broadcasting system which provides services from a plurality of networks, transmission specifications of its own network, service numbers of transponders constituting its network, and Is transmitted as an actual-NIT, information on the transmission specifications of other networks, and services of other networks that will be added, deleted or changed after the current time, and the effective time when the addition, deletion or change becomes effective The service change information consisting of information related to each network is transmitted as other-NIT, and when the power is turned on, the receiver receives the actual-NIT and other-NIT transmitted for each network and And the service change information for all networks. Means for creating a service change information table, and a service table storing service numbers for all networks and networks corresponding to the respective service numbers.If the user inputs a service number, based on the service table, A means for selecting a program corresponding to a service number by recognizing a network corresponding to the input service number. When a service provided by a certain network is received, an actual transmitted from the network is received. -NIT
If the acquired actual-NIT has been updated, a means for updating the service table based on the acquired actual-NIT, a service provided by a certain network is received Sometimes other-NIT sent from the network
Means for periodically updating the service change information table, and when updating the service change information table, means for updating the service change information table, and when the current time is the effective time of any service change information in the service change information table Means for updating the service table based on the service change information whose effective time matches the current time when the service time matches the current time.