Signal switching device, signal switching method, and program

Abstract

To provide a signal switching device capable of transmitting a normal TS signal from a normal standby system (B system) to a transmitter by performing a switching to the B system in the case where an abnormality occurs in the TS signal of a system (an A system) while being used.SOLUTION: According to an embodiment, a signal switching device comprises: a plurality of systems that receives a TS signal of a broadcasting program and provides them to a distributer; and a control part that determines each system for providing the TS signal to the distributer from the plurality of systems. Each of the distributer plurality of system contains: a reception part that receives the TS signal; an abnormality detection part that detects an abnormality in the TS signal or an own system; and a memory that stores the TS signal to be received by the reception part before the provision to the distributor. In the case where the abnormality is detected in the distributor by the abnormality detection part of the system providing the TS signal, the control part switches the system providing the TS signal to the distributor to the system that the abnormality is not detected, and provides the TS signal to be stored in the memory of the system to be switched to the distributor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a signal switch, a signal switching method, and a program for seamlessly switching a TS signal for digital television broadcasting among a plurality of systems.

Background Art

[0002] Conventionally, in digital television broadcasting, when an abnormality occurs in a TS (Transport Stream) signal of a broadcast program, an abnormal signal is transmitted in the broadcast wave transmitted from a television transmitter.

[0003] A signal switch for switching the TS signal system is installed in front of the transmitter. When an abnormality is found in the TS signal input to the transmitter, the signal switch issues an alarm and switches from the abnormal system to a normal system to normalize the television broadcast. Note that such switching can be performed not only automatically by the signal switch but also manually.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, until the switchover from the abnormal TS signal to the normal TS signal is completed, an abnormal broadcast wave is transmitted from the transmitter.

[0006] Therefore, when an abnormality occurs in the TS signal, a technique for performing switching to a normal system without transmitting an abnormal broadcast wave is desired.

[0007] The problem to be solved by the present invention is to provide a signal switch, a signal switching method, and a program that, when an abnormality occurs in the TS signal of the system (System A) during use, can switch to the normal system (System B) before the abnormal TS signal is sent to the transmitter and send a normal TS signal from System B to the transmitter.

Means for Solving the Problem

[0008] The signal switch of the embodiment includes a plurality of systems for receiving the TS signal of the broadcast program and providing it to the distributor, and a control unit for determining, from the plurality of systems, the system that provides the TS signal to the distributor. Each of the plurality of systems includes a receiving unit for receiving the TS signal, an abnormality detection unit for detecting an abnormality in the TS signal or its own system, and a memory for storing the TS signal received by the receiving unit before it is provided to the distributor. When an abnormality is detected by the abnormality detection unit of the system that is currently providing the TS signal to the distributor, the control unit switches the system that provides the TS signal to the distributor to a system in which no abnormality has been detected, and provides the TS signal stored in the memory of the switched system to the distributor.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0010] Embodiments of the present invention will be described below with reference to the drawings. The drawings are schematic or conceptual, and the relationships between the thickness and width of each part, the ratio of the sizes between parts, etc. are not necessarily the same as those in reality. Also, even when representing the same part, the dimensions and ratios may be shown differently in the drawings. In the present specification and each figure, the same reference numerals are assigned to the same elements as those described above with respect to the previously shown figures, and detailed descriptions and duplicate descriptions are omitted as appropriate.

[0011] FIG. 1 is a conceptual diagram showing a configuration example of a signal switch to which the signal switching method according to an embodiment of the present invention is applied.

[0012] The signal switch 10 of the present embodiment includes a plurality of lines A and B for receiving a TS signal of a broadcast program and providing it to a distributor 32, a control unit 30 for controlling the line that provides the TS signal from the plurality of lines A and B to the distributor 32, a changeover switch 31, and a distributor 32.

[0013] Note that in FIG. 1, as an example, two lines A and B are illustrated as the plurality of lines. In the following description, with reference to FIG. 1, the signal switch 10 having two lines A and B will be described. However, in the signal switch 10 of the present invention, the plurality of lines are not limited to two lines, and it should be noted that there may be cases where three or more lines are provided.

[0014] The same TS signal is input to the signal switch 10 as a program signal for broadcasting according to the number of lines. Therefore, two TS signals TS1 and TS2 are input to the signal switch 10 having two lines A and B. If the signal switch 10 has three lines, three TS signals are input.

[0015] The TS signal TS1 is input from the input terminal 21A to the line A, and the TS signal TS2 is input from the input terminal 21B to the line B.

[0016] The line A includes, in addition to the input terminal 21A, a receiving unit 22A, an abnormality detection unit 24A, a memory 26A, and an output terminal 28A.

[0017] System B also has the same configuration as System A and includes a receiving unit 22B, an abnormality detection unit 24B, a memory 26B, and an output terminal 28B in addition to the input terminal 21B.

[0018] The receiving unit 22A receives the TS signal TS1 input from the input terminal 21A and outputs it to the memory 26A. Similarly, the receiving unit 22B receives the TS signal TS2 input from the input terminal 21B and outputs it to the memory 26B.

[0019] The memories 26A and 26B can be realized by a shift register, an SRAM, or the like. The memory 26A stores the TS signal TS1 output from the receiving unit 22A at predetermined time lengths, such as, for example, 50 μs. Similarly, the memory 26B stores the TS signal TS2 output from the receiving unit 22B at the same predetermined time lengths as the memory 26A, such as 50 μs.

[0020] Thus, for each of the systems A and B, before the TS signals are provided to the distributor 32, the same TS signal data TS1 and TS2 can be held in the memories 26A and 26B, respectively, at the same timing.

[0021] The abnormality detection unit 24A detects an abnormality in the TS signal TS1 or System A. An abnormality in System A is, for example, that the wiring in System A is disconnected and the TS signal TS1 does not reach. An abnormality in the TS signal TS1 is, for example, that even if the wiring in System A is normal, there is a problem with the TS signal TS1 itself. When the abnormality detection unit 24A detects such an abnormality, it outputs an alarm Ra to the control unit 30.

[0022] Similarly, the abnormality detection unit 24B detects an abnormality in the TS signal TS2 or system B. An abnormality in system B means, for example, that the wiring in system B is disconnected and the TS signal TS2 cannot be received. An abnormality in the TS signal TS2 means, for example, that there is a problem with the TS signal TS2 itself even though the wiring in system B is normal. When the abnormality detection unit 24B detects such an abnormality, it outputs an alarm Rb to the control unit 30.

[0023] The method for detecting abnormalities performed by the abnormality detection units 24A and 24B is not particularly limited in this application. For example, it can be performed by detecting the synchronization byte, checking the TSP counter on the dummy byte, checking the Reed - Solomon error, checking the IIP packet, etc.

[0024] Since these are all known techniques, detailed explanations are omitted, but a brief explanation is given below.

[0025] First, the abnormality detection by detecting the synchronization byte will be explained. There is always "47h" at the beginning of the TS packet. Therefore, when the abnormality detection units 24A and 24B cannot detect "47h" at the beginning of the TS packet, or when the period of "47h" cannot be detected periodically at 204 - byte intervals, it is determined as an abnormality.

[0026] Next, the abnormality detection by checking the TSP counter on the dummy byte will be explained. There is a counter part that increments for each TS packet on the dummy byte. The abnormality detection units 24A and 24B check whether the TSP counter is incrementing normally and continuously, and when the continuity is lost, it is determined as an abnormality.

[0027] Next, the abnormality detection by checking the Reed - Solomon error will be explained. The abnormality detection units 24A and 24B check whether the Reed - Solomon code of the TS packet is correct, and when there is an error in the Reed - Solomon code, it is determined as an abnormality.

[0028] Finally, the abnormal detection by checking the IIP packets will be described. The abnormal detection units 24A and 24B check if there is an IIP packet in one frame, and if no IIP packet can be confirmed in one frame, it is determined as abnormal.

[0029] The output terminal 28A is a terminal for outputting the TS signal TS1 stored in the memory 26A to the distributor 32. The output terminal 28B is a terminal for outputting the TS signal TS2 stored in the memory 26B to the distributor 32.

[0030] The control unit 30 determines the system that provides the TS signal to the distributor 32 from the plurality of systems A and B, that is, the main system, and performs control such as switching the changeover switch 31 to the output terminal 28 of the main system.

[0031] By default, the control unit 30 can set, for example, system A as the main system and system B as the standby system. In this case, if no alarm Ra is output from the abnormal detection unit 24A, the control unit 30 controls the changeover switch 31 to connect to the output terminal 28A in order to output the TS signal TS1 stored in the memory 26A to the distributor 32.

[0032] When an alarm Ra is output from the abnormal detection unit 24A while system A is operating as the main system, the control unit 30 controls the changeover switch 31 to connect to the output terminal 28B in order to output the normal TS signal TS2 stored in the memory 26B to the distributor 32 before the abnormal detected TS signal TS1 is output from the memory 26A. As a result, system B becomes the main system and system A becomes the standby system, so that the abnormal detected TS signal TS1 is not output to the distributor 32. The abnormality of the TS signal TS1 in system A does not affect the output after the distributor 32 while system B is operating as the main system.

[0033] Similarly, when the system B is operating as the main system and an alarm Rb is output from the abnormality detection unit 24B, the control unit 30 controls the changeover switch 31 to connect to the output terminal 28A in order to output the normal TS signal TS1 stored in the memory 26A to the distributor 32 before the abnormal TS signal TS2 detected is output from the memory 26B. As a result, the system A becomes the main system and the system B switches to the standby system, so that the abnormal TS signal TS2 is not output to the distributor 32. The abnormality of the TS signal TS2 in the system B does not affect the output after the distributor 32 while the system A is operating as the main system.

[0034] In this way, a normal TS signal is output to the distributor 32. The distributor 32 distributes the normal TS signal into a plurality of TS signals (for example, two TS signals in the example of FIG. 1) according to the number of transmitters and modulators in the subsequent stage, and outputs them to the transmitters and modulators in the subsequent stage.

[0035] In this way, the signal switch 10 stores the TS signals received in each system in the memory 26 for each system. When an abnormality in the main system itself (for example, the system A) or an abnormality in the TS signal (for example, the TS signal TS1) sent to the main system is detected, the TS signal of the main system is not output to the distributor 32, but the standby system (for example, the system B) is switched to a new main system, and the normal TS signal (for example, the TS signal TS2) of the new main system is output to the distributor 32. As a result, even when an abnormality is detected in the main system, system switching can be achieved without outputting an abnormal TS signal to the transmitter or modulator.

[0036] Next, an operation example of the signal switch to which the signal switching method of the present embodiment is applied will be described.

[0037] FIG. 2 is a flowchart showing an operation example of the signal switch to which the signal switching method of the present embodiment is applied.

[0038] As shown in FIG. 1, assume that the signal switch 10 has two channels A and B. In this case, the same TS signals TS1 and TS2 are input to the signal switch 10 for channels A and B. That is, the TS signal TS1 is input to channel A from the input terminal 21A, and the TS signal TS2 is input to channel B from the input terminal 21B (S1). Currently, assume that the signal switch 10 is operating normally with channel A as the main channel and channel B as the standby channel.

[0039] The TS signal TS1 input from the input terminal 21A is received by the receiving unit 22A and output from the receiving unit 22A to the memory 26A. Similarly, the TS signal TS2 input from the input terminal 21B is received by the receiving unit 22B and output from the receiving unit 22B to the memory 26B (S2).

[0040] The TS signal TS1 output from the receiving unit 22A is stored in the memory 26A at predetermined time intervals, such as every 50 μs. Similarly, the TS signal TS2 output from the receiving unit 22B is also stored in the memory 26B at predetermined time intervals, such as every 50 μs (S3).

[0041] Currently, since channel A is the main channel, the control unit 30 connects the switching switch 31 to the output terminal 28A. Therefore, as long as the abnormality detection unit 24A does not detect an abnormality and does not output an alarm Ra from the abnormality detection unit 24A to the control unit 30 (S4: No), the TS signal TS1 stored in the memory 26A is output from the memory 26A to the distributor 32 (S5).

[0042] Then, in the distributor 32, the TS signal TS1 is distributed into a plurality of TS signals (e.g., two TS signals in the example of FIG. 1) according to the number of transmitters or modulators in the subsequent stage, and output to the transmitters or modulators in the subsequent stage (S8).

[0043] However, in step S4, when an abnormality is detected by the abnormality detection unit 24A and an alarm Ra is output from the abnormality detection unit 24A to the control unit 30 (S4: Yes), before the TS signal TS1 detected as abnormal is output from the memory 26A by the control unit 30, the changeover switch 31 is connected to the output terminal 28B (S6).

[0044] As a result, system B becomes the main system and system A is switched to the standby system, and the abnormal TS signal TS1 is not output to the distributor 32, but the normal TS signal TS2 stored in the memory 26B is output to the distributor 32 (S7).

[0045] In this way, a normal TS signal TS2 is output to the distributor 32. Even when the TS signal TS2 is output in this way, the process proceeds to step S8 described above. In the distributor 32, the TS signal TS2 is distributed into a plurality of TS signals (for example, two TS signals in the example of FIG. 1) according to the number of transmitters and modulators in the subsequent stage, and is output to the transmitters and modulators in the subsequent stage (S8).

[0046] As described above, according to the signal switch 10 to which the signal switching method of the present embodiment is applied, the TS signals TS1 and TS2 received in each of the systems A and B are stored in the memories 26A and 26B for each of the systems A and B. When an abnormality in the main system (for example, system A) itself or its TS signal (for example, TS signal TS1) is detected, the TS signal of the main system is not output to the distributor 32, and the standby system (for example, system B) is switched to a new main system, and the normal TS signal (for example, TS signal TS2) of the new main system (for example, system B) is output to the distributor 32. Therefore, even when an abnormality is detected, an abnormal TS signal is not output to the transmitter or modulator, and system switching is realized.

[0047] Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0048] 10 Signal switcher A and B systems 21 Input terminal 22 Receiver 24 Abnormality detection unit 26 Memory 28 Output terminal 30 Control unit 31 Switch 32 Distributor

Claims

1. A plurality of lines for receiving a TS signal of a broadcast program and providing it to a distributor, and a control unit that determines a line for providing the TS signal to the distributor from the plurality of lines, Each of the plurality of lines includes a receiving unit that receives the TS signal, an abnormality detection unit that detects an abnormality in the TS signal or its own line, and a memory that stores the TS signal received by the receiving unit before providing it to the distributor. When an abnormality is detected by the abnormality detection unit of the line currently providing the TS signal to the distributor, the control unit switches the line for providing the TS signal to the distributor to a line in which no abnormality has been detected, and provides the TS signal stored in the memory of the switched line to the distributor. A signal switcher.

2. The signal switcher according to claim 1, further comprising the distributor.

3. The signal switcher according to claim 1, wherein the plurality of lines are two or more lines.

4. The signal switcher according to claim 1, wherein the memory stores the TS signal received by the receiving unit at predetermined time lengths.

5. When the control unit switches the line for providing the TS signal to the distributor to a line in which no abnormality has been detected, before the TS signal stored in the memory of the line in which the abnormality has been detected is provided to the distributor, the TS signal stored in the memory of the switched line is controlled to be provided to the distributor. The signal switcher according to claim 1.

6. A signal switching method applied to a signal switcher having a plurality of lines for receiving a TS signal of a broadcast program and providing it to a distributor, When each of the plurality of lines receives the TS signal, it detects an abnormality in the TS signal or its own line, stores the received TS signal in a memory before providing it to the distributor, When an abnormality is detected in the system that is currently providing the TS signal to the distributor, switch the system that provides the TS signal to the distributor from the current system to a system in which no abnormality has been detected. A signal switching method for providing the TS signal stored in the memory of the switched system to the distributor. **Claim 7** A program applicable to a signal switch having a plurality of systems for receiving a TS signal of a broadcast program and providing it to a distributor, In the plurality of systems, a function of receiving the TS signal, detecting an abnormality in the TS signal or the own system, and storing the received TS signal in a memory before providing it to the distributor, When an abnormality is detected in the system that is currently providing the TS signal to the distributor, a function of switching the system that provides the TS signal to the distributor from the current system to a system in which no abnormality has been detected, A program for causing a processor of the signal switch to realize a function of providing the TS signal stored in the memory of the switched system to the distributor.

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