JPH11341379A - Digital broadcasting receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital broadcasting receiver which normally performs a channel selection operation of the current network, even when other network information tables do not exist. SOLUTION: In steps S2 and S3, transponder frequency array information and channel array information of the current network are acquired. In steps S4 and D5, transponder frequency array information of other network is acquired. In a step S6, it is decided whether another network information table reaches the maximum value of the number of other networks which can exist on an operation, and when it reaches a maximum value, the processing is finished. When the other network information table does not reach the maximum value of the number of other networks that can exist on an operation, in a step S8, it is decided whether or not a prescribed time has elapsed, and the processing is finished after the elapse of prescribed time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a digital broadcast receiver capable of receiving digital broadcasts on a plurality of networks.

[0002]

2. Description of the Related Art Recently, digital broadcasting using a communication satellite (CS) has appeared, and the transition from analog broadcasting to digital broadcasting is being studied for broadcasting satellites (BS) and terrestrial waves. . Digital broadcasting has features not available in analog broadcasting such as an electronic program guide, because additional information can be transmitted in addition to video signals and audio signals as program information. In addition, C currently being broadcast
In digital broadcasting by S, a plurality of networks exist, and a digital broadcast receiver capable of receiving digital broadcasting of the plurality of networks has been developed.

In the ARIB (Radio Telecommunications Industry Association) standard, when there are a plurality of networks, a network information table of another network is used as one of additional information in order to realize switching to another network. A certain other network information table is prepared. The network information table is collectively called NIT
, And the other network information table is referred to as NITo. The current network information table which is the network information table of the currently selected network is referred to as NITa.

[0004] Therefore, the digital broadcast receiver acquires the network ID and the transponder frequency array information based on the satellite distribution system descriptor in the other network information table NITo, and by using this, can switch the network. .

[0005]

A digital broadcast receiver capable of receiving digital broadcasts of a plurality of networks has the following problems to be solved. (1) The presence / absence of another network can only be determined by the other network information table NITo, but no other network exists and the other network information table NITO
Even if there is no o itself, the channel selection operation of the current network must be normally realized.

(2) In order to realize the channel selection operation, it is necessary to have the frequency arrangement information of the transponders by the satellite distribution system descriptor in the network information table NIT and the channel arrangement information of each transponder by the service list descriptor. However, in the other network information table NITo, of these two descriptors, the service list descriptor is not essential, and therefore, even if there is no channel arrangement information, the channel selection operation after network switching must be normally realized. .

(3) Also, when the reception environment of the digital broadcast receiver is in the co-listening mode in the apartment house, it is actually broadcast and is low despite being described in the network information table NIT. Some of the transponder frequencies may not be transmitted to the receiver. Even in such a case, the selection of the network must be normally realized.

(4) Further, since tens of transponders and hundreds of channels are present in each network, a digital broadcast receiver capable of receiving digital broadcasts from a plurality of networks is required. If all of the above information is stored, the required memory capacity increases. Therefore, information on those channels must be efficiently stored in the memory.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a digital broadcast receiver capable of receiving digital broadcasts of a plurality of networks, in which no other network information table exists. Even in such a case, it is an object of the present invention to provide a digital broadcast receiver capable of normally performing a channel selection operation of the current network. Another object of the present invention is to provide a digital broadcast receiver that can normally perform a channel selection operation after network switching even when the other network information table does not include channel arrangement information.

[0010] Still another object of the present invention is to provide a multi-apartment co-listening mode in which no trouble occurs,
An object of the present invention is to provide a digital broadcast receiver capable of normally selecting a network. Still another object of the present invention is to provide a digital broadcast receiver capable of receiving digital broadcasts of a plurality of networks, in which a memory capacity of information necessary for a channel selection operation of the current network or switching to another network is increased. It is to memorize efficiently without.

[0011]

SUMMARY OF THE INVENTION The present invention is a digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal in order to solve the above-mentioned problems of the prior art. In a digital broadcast receiver capable of receiving digital broadcasts of a plurality of networks, a digital broadcast receiver having the following configuration is provided. (1) first acquisition means for acquiring transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; A second acquisition unit that acquires the transponder frequency array information of the other network by analyzing the other network information table of the other network not currently selected included in the additional information, and the first and second Storage means for storing the transponder frequency arrangement information and channel arrangement information of the current network and the transponder frequency arrangement information of the other network acquired by the acquisition means, and the number of other networks for which the other network information table may exist in operation. To the maximum value If the other network information table does not reach the maximum value of the number of other networks that can be present in operation, the second acquisition unit terminates the processing by the second acquisition unit. A digital broadcast receiver, comprising: control means for controlling so as to end processing by an acquisition means. (2) first obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; By analyzing the other network information table of the other network not currently selected included in the additional information, the transponder frequency array information of the other network can be obtained without performing the operation of acquiring the channel array information of the other network. Second acquisition means for acquiring, and control means for controlling to select and tune a transponder of a predetermined frequency in transponder frequency arrangement information of the other network when switching from the current network to the other network is performed. A third acquisition unit for analyzing the network information table of the other network which has newly become the current network by the control unit to newly acquire the channel arrangement information of the other network as the channel arrangement information of the current network; Storing means for storing the transponder frequency arrangement information and channel arrangement information of the current network and the transponder frequency arrangement information of the other network acquired by the first to third acquisition means. Digital broadcast receiver. (3) first obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; A second acquisition unit that acquires the transponder frequency array information of the other network by analyzing the other network information table of the other network not currently selected included in the additional information, and the first and second The storage means for storing the transponder frequency arrangement information and channel arrangement information of the current network and the transponder frequency arrangement information of the other network obtained by the obtaining means, and when the switching from the current network to the other network is performed, Other Digital broadcasting receiver, characterized in that by selecting the frequency of the transponder excluding the lowest frequency transponder in a transponder frequency sequence information network constructed by a control means for controlling so as to tune. (4) first obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; A second acquisition unit that acquires the transponder frequency array information of the other network by analyzing the other network information table of the other network not currently selected included in the additional information, and the first and second Storage means for storing the transponder frequency arrangement information and the channel arrangement information of the current network and the transponder frequency arrangement information of the other network in a predetermined area obtained by the acquisition means; and Switching Each time, the transponder frequency arrangement information and channel arrangement information of the current network and the transponder frequency arrangement information of the other network acquired by the first and second acquisition means for the predetermined area in the storage means. And updating means for updating by overwriting the digital broadcast.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital broadcast receiver according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a digital broadcast receiver according to the present invention;
2 and 3 are flowcharts for explaining the operation of the digital broadcast receiver of the present invention, and FIG. 4 is a diagram showing an example of a memory configuration for explaining the operation of the digital broadcast receiver of the present invention.

First, the overall configuration of a digital broadcast receiver according to the present invention will be described. In FIG. 1, an intermediate frequency (RF) signal received and received by an antenna (not shown) is transmitted to a network interface module (NIM).
Input to the unit 1. The NIM unit 1 tunes to a predetermined transponder frequency and demodulates it as a digital bit stream signal. The output of the NIM unit 1 is input to a descrambler unit 2, and if the bit stream signal is scrambled in a pay broadcast or the like, it is descrambled.
It is returned to a regular bit stream signal. If the bit stream signal is not scrambled, it passes through the descrambler unit 2 as it is.

The output of the descrambler 2 is input to the demultiplexer 3, which separates video information (video data) or audio signal (audio data), which is program information, from additional information (section data). This section data includes the above-described network information table NIT and the like.

The video data and audio data separated by the demultiplex unit 3 are input to an MPEG decoding unit 4 and are MPEG-decoded. As a result, the video signal and the audio signal are returned to normal. The section data separated by the demultiplex unit 3 is RA
It is temporarily stored in M9 and analyzed by the CPU 7. The video data and audio data output from the MPEG decoding unit 4 are converted into analog signals by the DA converter unit 5 and output. The video data converted into an analog signal is supplied to a display unit (not shown),
The audio data is supplied to a speaker (not shown).

The components of these circuits are controlled by the CPU 7. The ROM 8 stores a control program for causing the CPU 7 to operate. The nonvolatile memory 6 is a so-called last memory, and stores various data in order to restore a state immediately before the power is turned off when the power of the receiver is turned on.

The operation of the digital broadcast receiver according to the present invention thus configured will be described in detail below. FIG.
In step S1, when the power is turned on in step S1, in step S2, the CPU 7 tunes to the initial transponder stored in the nonvolatile memory 6 in advance.
The NIM unit 1 is controlled. Note that this initial transponder is the transponder that was selected just before the power was turned off.
Alternatively, the user usually selects an initial transponder set manually, but is not limited to this.

In step S2, the current network information table NITa is extracted from the tuned transponder data stream, and the transponder frequency arrangement information of the current network is obtained from the satellite distribution system descriptor therein. The transponder frequency array information of the current network is stored in the RAM 9. Also,
The channel arrangement information of the current network is acquired from the service list descriptor and stored in the RAM 9.

FIG. 4 shows an example of a memory configuration of the RAM 9. The transponder frequency array information of the current network is stored at addresses 0X000000 to 0X0000FF, and the channel array information of the current network is stored at addresses 0X000100 to
Stored in 0X001FFF.

Next, in step S4, another network information table NITo is extracted from the data stream of the transponder tuned in the same manner, and a network ID is obtained. Then, in step S5, the transponder frequency arrangement information of another network for each acquired network ID is acquired from the satellite distribution system descriptor, and stored in the RAM 9.

At this time, as described above, there may be no other network or a plurality of other networks. Therefore, in the present invention, the following processing is performed. In step S6, it is determined whether or not the number of extracted other network information tables NITo has reached the maximum number that can exist in operation.
The process proceeds to the normal channel selection processing of No. 7. If the number of network information tables NIT that can exist in operation is four, the number of other network information tables NITo that can exist in operation is three.

Further, in step S8, it is determined whether or not a fixed time (retransmission cycle × (maximum number of networks−1)) derived from the retransmission cycle of the other network information table NITo has elapsed. Then, the process proceeds to the normal channel selection process in step S7. This is because it can be determined that all the other existing network information tables NITo should have been obtained if the above-mentioned predetermined time has elapsed.

The other network information table NI extracted by the processing of steps S6 and S8
When the number of To reaches the maximum number, it is possible to immediately proceed to the normal channel selection processing, and further, the other network information table NIT
o does not exist or other network information table N
Even when the number of ITOs is smaller than the maximum number, it is possible to acquire the information necessary for selecting the current network or switching to another network in the shortest time, and immediately proceed to the normal channel selection processing.

If the number of other network information tables NITo is, for example, 3, the transponder frequency arrangement information of another network is stored in the RAM 9 as shown in FIG. 4, for example. The transponder frequency array information of the other network 1 is stored at addresses 0X002000 to 0X0020FF, the transponder frequency array information of the other network 2 is stored at addresses 0X002100 to 0X0021FF, and the other network 3 is stored.
The transponder frequency array information of address 0X002200 ~
Stored at 0X0022FF.

Through the above series of processing, even if the number of other networks does not reach the maximum number or no other networks exist, the channel selection operation of the current network is normally realized.

The other network information table NIT
Obtain transponder frequency array information at o
Since the data is stored in the AM 9, switching to another network is also possible. After switching to another network, the other network becomes the current network, and channel arrangement information is obtained by the processing of steps S1 to S3 in FIG. Therefore, the channel selection operation after the network switching is also normally realized. Since only the transponder frequency arrangement information of the other network is acquired without performing the operation of acquiring the channel arrangement information of the other network, the analysis processing of the other network information table NITo is performed promptly. In addition, the memory capacity of the RAM 9 can be the minimum memory capacity for network switching.

Next, a specific operation when a network switching request is made will be described. FIG. 3 shows a case where a user issues a network switching request from the network having the network ID 1 to the network having the network ID 2. In step S10, when a network switching request is made, in step S11, a transponder having the maximum frequency is searched from the transponder frequency array information acquired from the network information table NITo of network ID2.

This is because, as described above, for example, in the case of the co-listening mode in an apartment house, a part of the low transponder frequency is actually broadcast, despite being described in the network information table NIT. May not be transmitted to the receiver. Step S12
Then, it is determined whether or not a transponder having the maximum frequency has been found, and if not, the process returns to step S11. If a transponder having the maximum frequency is found, step S13
Move on to

Then, in step S13, tuning to the transponder having the maximum frequency is performed. In the present embodiment, as the most preferred embodiment, a transponder having the maximum frequency is searched and tuned to this.
In some cases, the tuning may be performed from the transponder having the maximum frequency to the second transponder or the like. At least, tune to the transponder of the frequency excluding the transponder of the lowest frequency. More preferably, the transponder is tuned to a higher frequency than the center frequency.

The processing in steps S14 to S21 in FIG. 3 is the same as the processing in steps S2 to S9 in FIG. The network after the switching in steps S14 and S15 is the network that has newly become the current network.

Next, the operation of storing various information in the RAM 9 which is a memory for storing information necessary for selecting a current network or switching to another network will be described in detail. When switching to another network is performed by the processing of FIG. 3, the RAM 9 stores steps S14 to S14 of FIG.
Instead of adding and storing the “transponder frequency arrangement information of the current network”, “channel arrangement information of the current network”, and “transponder frequency arrangement information of another network” newly acquired in the processing up to S21, Before switching, the information is overwritten on the area where the information is stored.

That is, the maximum value of the memory capacity necessary for the information to be stored in the RAM 9 is calculated in advance, and a memory area corresponding to the memory capacity is secured in the RAM 9. Then, every time the network is switched, the information stored in the RAM 9 is updated. In the example of FIG. 4, as described above, the address 0X0000
00 to 0X0000FF is transponder frequency arrangement information of the current network, addresses 0X000100 to 0X001FFF are channel arrangement information of the current network, addresses 0X002000 to 0X0020FF
Is the transponder frequency arrangement information of the other network 1,
Addresses 0X002100 to 0X0021FF are transponder frequency array information of the other network 2, and addresses 0X002200 to 0X0022
FF is transponder frequency arrangement information of the other network 3.

However, the memory capacity required for each piece of information changes every time the network is switched. Therefore, R
The address at which each piece of information is stored in the AM 9 is not fixed, but a memory area defined by the total memory capacity of each piece of information is fixed. FIG.
In the example, addresses 0X000000 to 0X002300 are fixed memory areas, and the internal address arrangement changes each time the network is switched.

[0034]

As described above in detail, the digital broadcast receiver of the present invention analyzes the current network information table of the current network to obtain the transponder frequency arrangement information and the channel arrangement information of the current network. 1 obtaining means, and second obtaining means for obtaining transponder frequency array information of another network by analyzing the other network information table, wherein the other network information table has the maximum number of other networks that can exist in operation. If the value has reached the value, the processing by the second acquisition means is terminated, and if the other network information table does not reach the maximum value of the number of other networks that can exist in operation, the second network information table does not reach the second value after a predetermined time has elapsed. And control means for controlling to end the processing by the acquisition means. Network is not present, even if there is no other network information table itself, normally it is possible to perform the tuning operation of the current network. In addition, it is possible to acquire the information necessary for the channel selection operation of the current network and the switching to another network in a minimum processing time.

Further, when switching from the current network to another network is performed, the control means controls to select and tune a transponder of a predetermined frequency in the transponder frequency arrangement information of the other network, and the control means newly controls the tuning. A third acquisition unit that newly acquires the channel arrangement information of the other network as the channel arrangement information of the current network by analyzing the network information table of the other network that has become the current network; Means for storing the transponder frequency arrangement information and the channel arrangement information of the current network and the transponder frequency arrangement information of the other network. Even if it is not included, normally it can perform channel selection operation after network switching, moreover, it is possible to use memory efficiently.

Further, when switching from the current network to the other network is performed, the control means controls to select and tune a transponder having a frequency excluding the transponder having the lowest frequency in the transponder frequency arrangement information of the other network. Therefore, it is possible to avoid a problem assumed in the case of the co-listening mode in the apartment house.

Further, every time the current network is switched to another network, the transponder frequency arrangement information and channel arrangement information of the current network and the transponder frequency arrangement information of the other network are overwritten in a predetermined area in the storage means. And updating means for updating the current network, it is possible to efficiently store the information necessary for the channel selection operation of the current network and the switching to another network without increasing the memory capacity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the present invention.

FIG. 3 is a flowchart for explaining the operation of the present invention.

FIG. 4 is a diagram showing an example of a memory configuration for explaining the operation of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Network interface module part 2 Descrambler part 3 Demultiplex part 4 MPEG decoding part 5 DA converter part 6 Non-volatile memory 7 CPU 8 ROM 9 RAM

Claims (5)

[Claims] 1. A digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal, wherein the digital broadcast receiver can receive digital broadcasts on a plurality of networks. First obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; A second acquisition unit that acquires the transponder frequency array information of the other network by analyzing the other network information table of the other network that is not currently selected and that is acquired by the first and second acquisition units. The transponder of the current network Storage means for storing frequency array information and channel array information and transponder frequency array information of the other network; and when the other network information table has reached the maximum value of the number of other networks that can be present in operation, the second 2
When the other network information table does not reach the maximum value of the number of other networks that can be present in operation, the second network information table is terminated after a predetermined time elapses.
And a control means for controlling the end of the processing by the obtaining means. 2. A digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal, wherein the digital broadcast receiver can receive digital broadcasts on a plurality of networks. First obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; Analyzing the other network information table of the other network not currently selected included in the second network to obtain the transponder frequency array information of the other network without performing the operation of obtaining the channel array information of the other network. Acquisition means; When switching from the network to the other network, control means for controlling to select and tune a transponder of a predetermined frequency in the transponder frequency array information of the other network, and a control means for newly controlling the current network by the control means. A third acquisition unit that newly acquires the channel arrangement information of the other network as the channel arrangement information of the current network by analyzing the resulting network information table of the other network; and the first to third acquisition units. A digital broadcast receiver comprising: a storage unit that stores the transponder frequency arrangement information and channel arrangement information of the current network and the transponder frequency arrangement information of the other network acquired by the above method. 3. A digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal, wherein the digital broadcast receiver can receive digital broadcasts on a plurality of networks. First obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; A second acquisition unit that acquires the transponder frequency array information of the other network by analyzing the other network information table of the other network that is not currently selected and that is acquired by the first and second acquisition units. The transponder of the current network Storage means for storing frequency arrangement information, channel arrangement information, and transponder frequency arrangement information of the other network; and when switching from the current network to the other network, the most frequency in the transponder frequency arrangement information of the other network. Control means for selecting and tuning a transponder having a frequency excluding a transponder having a low frequency. 4. The digital broadcast receiver according to claim 3, wherein the transponder of the frequency excluding the transponder with the lowest frequency in the transponder frequency arrangement information of the other network is the transponder with the highest frequency. . 5. A digital broadcast receiver for receiving a digital broadcast in which additional information is transmitted in addition to a video signal and an audio signal, wherein the digital broadcast receiver can receive digital broadcasts on a plurality of networks. First obtaining means for obtaining transponder frequency arrangement information and channel arrangement information of the current network by analyzing a current network information table of a current network which is a currently selected network included in the additional information; A second acquisition unit that acquires the transponder frequency array information of the other network by analyzing the other network information table of the other network that is not currently selected and that is acquired by the first and second acquisition units. The transponder of the current network Storage means for storing frequency arrangement information, channel arrangement information, and transponder frequency arrangement information of the other network in a predetermined area, and each time switching from the current network to the other network is performed, the storage means Updating means for updating the predetermined area by overwriting transponder frequency arrangement information and channel arrangement information of the current network and transponder frequency arrangement information of the other network acquired by the first and second acquisition means; A digital broadcast receiver characterized by comprising: