Receiver
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NIPPON HOSO KYOKAI
- Filing Date
- 2022-05-12
- Publication Date
- 2026-06-26
Smart Images
Figure 0007880735000002 
Figure 0007880735000003 
Figure 0007880735000004
Abstract
Description
Technical Field
[0001] The present invention relates to a receiving apparatus capable of receiving satellite broadcasting and simultaneous distribution of broadcasts using an Internet line.
Background Art
[0002] Satellite broadcasting is susceptible to the influence of rain attenuation, and there is a possibility that the broadcast cannot be received temporarily in the case of heavy rain disasters or the like. Hierarchical transmission is cited as a means of compensating for rain attenuation, but hierarchical transmission has a small transmission capacity and is limited, and the image quality cannot be said to be sufficient.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Patent Document 1 discloses a method of switching information via broadcast and information via the Internet. When the reception quality of satellite broadcasting deteriorates due to rain attenuation, it is conceivable to switch the broadcast using a broadcast satellite to simultaneous distribution of broadcasts using an Internet line. In this case, reception failure due to rain attenuation can be avoided. However, as in Patent Document 1, if the user is always connected to the Internet line and receives simultaneous distribution of broadcasts in parallel with satellite broadcasting, the burden on the user increases when using an Internet connection service that is not a flat rate system.
[0005] ]> In addition, the degree of deterioration of the reception quality of satellite broadcasting due to rain varies. Therefore, it is also assumed that the switching between the broadcast using a broadcast satellite and the simultaneous distribution of broadcasts using an Internet line occurs frequently. If such switching occurs frequently, it may cause annoyance to the user.
[0006] This invention was conceived in view of the aforementioned problems, and aims to provide a receiving device that allows users to continue watching satellite broadcasts by switching to simultaneous internet streaming when the reception quality deteriorates due to rain attenuation or other reasons, while minimizing the burden on the user. [Means for solving the problem]
[0007] As one embodiment of the present invention, a receiving device capable of receiving both broadcasts using a broadcasting satellite and simultaneous broadcast distribution using an internet line, comprising: a broadcast receiving unit for receiving broadcasts using the broadcasting satellite; a distribution receiving unit for receiving simultaneous broadcast distribution using the internet line; a switching unit for switching the output to an output device between broadcasts received by the broadcast receiving unit and distributions received by the distribution receiving unit; and a control unit for controlling the distribution receiving unit and the switching unit, wherein the control unit switches the output to the output device from broadcasts to simultaneous broadcast distribution when the data indicating the reception quality falls below a first threshold, and after switching to simultaneous broadcast distribution, switches the output to the output device from simultaneous broadcast distribution to broadcasts when the data indicating the reception quality rises to or above a second threshold, and the second threshold is set to a value offset from the first threshold to the side where the reception quality is better. Furthermore, in the receiving device, the control unit stops receiving the simultaneous broadcast distribution by the distribution receiving unit while the control unit is outputting the broadcast to the output device, and when the data indicating the reception quality falls below the second threshold while the control unit is outputting the broadcast to the output device, it starts receiving the simultaneous broadcast distribution by the distribution receiving unit, and when the data indicating the reception quality rises to or above the third threshold, the control unit stops receiving the simultaneous broadcast distribution by the distribution receiving unit, and the third threshold is set to a value offset from the second threshold to the side that improves the reception quality. [Effects of the Invention]
[0008] According to one aspect of the present invention, when the reception quality of satellite broadcasting deteriorates, users can continue watching by switching to simultaneous internet distribution while minimizing the burden on them. [Brief explanation of the drawing]
[0009] [Figure 1] This is a schematic diagram of a broadcasting system employing a receiving device according to the embodiment. [Figure 2] This is a timing chart illustrating the processing at the receiving device shown in Figure 1. [Figure 3] This is a flowchart illustrating the processing at the receiving device shown in Figure 1. [Figure 4] This is a timing chart for switching between BS broadcasting and simultaneous broadcast streaming, based on a comparison of reception quality and two thresholds. [Figure 5] This is a flowchart illustrating the process for Modification Example 1 in the receiving device shown in Figure 1. [Figure 6] This is a timing chart illustrating the processing involved in Modification 2 of the receiving device shown in Figure 1. [Figure 7] This is a flowchart illustrating the process for Modification 2 of the receiving device shown in Figure 1. [Modes for carrying out the invention]
[0010] Hereinafter, embodiments of the present invention will be described using the case where they are applied to the receiving device 1 of the broadcasting system 100 as an example. As shown in Figure 1, in the broadcasting system 100, the broadcasting satellite BS receives radio waves transmitted (uplinked) from the uplink master station MS to the broadcasting satellite BS. The broadcasting satellite BS converts the frequency of the received radio waves and then retransmits them to the ground. Furthermore, in the broadcasting system 100, the simultaneous distribution server SV installed at the broadcasting station outputs an IP streaming signal for simultaneous broadcast distribution to the internet line IN.
[0011] Antenna 20 (BS antenna) receives BS broadcast signals (broadcast waves) that have been retransmitted (downlinked) from the BS broadcasting satellite to the ground. Antenna 20 performs frequency conversion on the received BS broadcast signal to convert it to a lower frequency, generating a BS-IF (intermediate frequency) signal. The generated BS-IF signal is input to the receiving device 1. Here, BS-IF is the value obtained by subtracting the local oscillator frequency from the BS frequency.
[0012] The broadcasting system 100 includes a receiving device 1 capable of receiving both BS broadcasts using the broadcasting satellite BS and simultaneous broadcast distribution using the internet connection IN. The receiving device 1 includes a broadcast receiving unit 11, a distribution receiving unit 12, a switching unit 13, and a monitoring and control unit 14 (control unit).
[0013] The broadcast receiving unit 11 receives BS broadcasts. The broadcast receiving unit 11 is connected to the antenna 20 via input / output ports (not shown). The BS-IF signal is input to the broadcast receiving unit 11 from the antenna 20. The broadcast receiving unit 11 converts the input BS-IF signal into a video and audio baseband signal (for example, an HDMI signal: registered trademark, hereinafter omitted) and outputs it to the switching unit 13. In this specification, an HDMI signal is used as an example of a video and audio baseband signal. However, the video and audio baseband signal is not limited to an HDMI signal. Furthermore, the broadcast receiving unit 11 calculates data indicating the reception quality of the BS broadcast. Specifically, the broadcast receiving unit 11 calculates the C / N ratio of the input BS-IF signal. Here, C / N is the ratio of Carrier (signal) to Noise (noise). In this embodiment, the C / N ratio of the signal (BS-IF signal) input to the broadcast receiving unit 11 is used as data that numerically represents the reception quality of BS broadcasts. Hereafter, the reception quality of BS broadcasts will also be referred to as reception quality (C / N).
[0014] The distribution reception unit 12 receives the broadcast simultaneous distribution. The distribution reception unit 12 is connected to the Internet line IN via an input / output port (not shown). The connection mode between the distribution reception unit 12 and the Internet line IN can be either wired or wireless. The IP streaming signal output by the simultaneous distribution server SV is input to the distribution reception unit 12. The distribution reception unit 12 converts the IP streaming signal received via the Internet line IN into a baseband signal (HDMI signal) of video and audio, and outputs it to the switching unit 13.
[0015] The switching unit 13 switches the output to the output device 15 between the BS broadcast received by the broadcast reception unit 11 and the broadcast simultaneous distribution received by the distribution reception unit 12. The switching unit 13 outputs one of the HDMI signal input from the distribution reception unit 12 and the HDMI signal input from the broadcast reception unit 11 to the output device 15 connected to the switching unit 13. The output device 15 is, for example, a TV capable of outputting video information such as characters and images and audio information. The HDMI signal output to the output device 15 is switched between the HDMI signal input from the distribution reception unit 12 and the HDMI signal input from the broadcast reception unit 11 based on the instruction of the monitoring / control unit 14. Here, "selecting the BS broadcast" means setting the switching unit 13 so that the HDMI signal input from the broadcast reception unit 11 is output to the output device 15. "Selecting the broadcast simultaneous distribution" means setting the switching unit 13 so that the HDMI signal input from the distribution reception unit 12 is output to the output device 15.
[0016] The monitoring / control unit 14 (control unit) controls the distribution reception unit 12 and the switching unit 13. The monitoring / control unit 14 (control unit) monitors the reception quality of the BS broadcast. The monitoring / control unit 14 is a functional block that executes the processing defined in the program stored in a storage unit (not shown). The monitoring and control unit 14 acquires data (C / N) indicating the reception quality of BS broadcasts calculated by the broadcast receiving unit 11 at predetermined time intervals. The monitoring and control unit 14 confirms the reception quality of BS broadcasts by comparing the acquired C / N with a threshold. Based on the confirmed reception quality, the monitoring and control unit 14 controls the reception of simultaneous broadcast distribution by the distribution receiving unit 12. Based on the reception quality, the monitoring and control unit 14 switches the HDMI signal output to the output device 15 between the HDMI signal input from the distribution receiving unit 12 and the HDMI signal input from the broadcast receiving unit 11.
[0017] In other words, the monitoring and control unit 14 stops receiving the simultaneous broadcast distribution by the distribution receiving unit 12 while it is outputting the broadcast to the output device. When the monitoring and control unit 14 is outputting the broadcast to the output device 15, if the data indicating the reception quality falls below the second threshold Th2, it starts receiving the simultaneous broadcast distribution by the distribution receiving unit 12, and stops receiving the simultaneous broadcast distribution by the distribution receiving unit 12 when the data indicating the reception quality rises to or above the third threshold Th3 value. The third threshold Th3 is set to a value offset from the second threshold Th2 that results in better reception quality.
[0018] In this embodiment, three thresholds (first threshold Th1, second threshold Th2, and third threshold Th3) are provided as thresholds to be compared with C / N (see Figure 2). The first threshold is the threshold used to determine whether to switch the output to output device 15 from BS broadcasting to simultaneous broadcast distribution. The second threshold is the decision to switch the output to output device 15 from simultaneous broadcast distribution to BS broadcasting, This is the threshold used to determine when to begin preparations for switching to simultaneous broadcasting. The third threshold is used to determine when to terminate reception of simultaneous broadcast distribution or to initiate reception restrictions (bandwidth limitations).
[0019] As shown in Figure 2, in this embodiment, the first threshold Th1 is set to a value that improves reception quality beyond the C / N (required C / N) which is the reception limit for BS broadcasting. The second threshold Th2 is set to a value that improves reception quality beyond the first threshold Th1. The third threshold Th3 is set to a value that improves reception quality beyond the second threshold Th2. Therefore, the thresholds in C / N (the first threshold Th1 to the third threshold Th3) are set according to the following relationship. Th3>Th2>Th1>Required C / N
[0020] Here, the reception quality of BS broadcasts calculated by the broadcast receiving unit 11 fluctuates, and the C / N value also shows fluctuations of approximately ±1 dB. Therefore, it is preferable that the first threshold Th1 is set to a value that is at least 1.0 dB away from the required C / N value, on the side that improves reception quality. Note that the required C / N value varies depending on the video standard.
[0021] In this embodiment, the second threshold Th2 is used for two purposes: determining whether to switch from simultaneous broadcast distribution to BS broadcasting, and determining whether to start preparations for switching to simultaneous broadcast distribution. In receiving device 1, when the reception quality of BS broadcasts is good and there is no need to switch to simultaneous broadcast distribution, the distribution receiving unit 12 stops receiving simultaneous broadcast distribution. Therefore, in order for the distribution receiving unit 12 to receive simultaneous broadcast distribution, it is necessary to establish a connection to the internet line IN and receive the IP streaming signal output by the simultaneous distribution server SV to the internet line IN. In this embodiment, the value of the second threshold Th2 is set considering the time required to establish a connection to the internet line IN, ensuring sufficient time for receiving the broadcast simultaneous distribution and enabling output to the switching unit 13. This reduces the possibility that the broadcast simultaneous distribution output may not be ready when switching from BS broadcasting to broadcast simultaneous distribution.
[0022] In this embodiment, the second threshold Th2, which determines whether to switch (return) from simultaneous broadcast distribution to BS broadcasting, is set to a value that is offset from the first threshold Th1 to the side that results in better broadcast quality. During periods of rainfall attenuation, the reception quality of BS broadcasts may fluctuate depending on the conditions of rain clouds and other factors in the upper atmosphere. If the difference between the second threshold Th2 and the first threshold Th1 is small, a phenomenon known as chattering may occur, in which the output to the output device 15 frequently switches between BS broadcasting and simultaneous broadcast distribution. In this embodiment, in order to prevent chattering, the second threshold Th2 is set to a value that is offset by at least 1 dB, more preferably 2 dB, to the side where the reception quality is better than that of the first threshold Th1.
[0023] In this embodiment, the third threshold Th3, which determines the end of reception of simultaneous broadcast distribution, is set to a value that is offset from the second threshold Th2 to the side where the broadcast quality is better. This is to ensure that the reception of the simultaneous broadcast stream ends after the switch to BS broadcasting, rather than simultaneously with the switch from simultaneous broadcast streaming to BS broadcasting. After switching from simultaneous broadcast distribution to BS broadcasting, fluctuations in reception quality may cause the C / N ratio to fall below the second threshold Th2, which indicates worse reception quality. In such cases, simultaneous distribution may be repeatedly received and terminated. In this embodiment, to prevent such a situation from occurring, the third threshold Th3 is set to a value offset by at least 1 dB, more preferably 2 dB, to the side where reception quality is better than the second threshold Th2.
[0024] The operation of the receiving device 1 will be explained below with reference to the flowchart in Figure 3. As described above, the broadcast receiving unit 11 (see Figure 1) receives a continuous BS-IF signal from the antenna 20 that receives BS broadcasts. The broadcast receiving unit 11 converts the input BS-IF signal into an HDMI signal and outputs it to the switching unit 13, while simultaneously calculating the C / N ratio of the input BS-IF signal.
[0025] The monitoring and control unit 14 compares C / N with a threshold value according to the procedure of the flowchart in FIG. 3, and performs processing according to the comparison result. Specifically, the monitoring and control unit 14 acquires C / N indicating the reception quality of BS broadcast from the broadcast reception unit 11 at a predetermined time interval (step S101). The monitoring and control unit 14 compares the C / N acquired in step S101 with a third threshold value Th3 (step S102). The third threshold value Th3 is a threshold value used for determining the end of reception of simultaneous broadcast delivery. When the reception quality (C / N) drops below the third threshold value Th3 due to rainfall attenuation or the like at a stage where simultaneous broadcast delivery is not being received, the determination in step S102 is affirmed, and the process proceeds to step S103. In step S103, the monitoring and control unit 14 compares the C / N acquired in step S101 with a second threshold value Th2. The second threshold value Th2 is a threshold value used for determining the switch from simultaneous broadcast delivery to BS broadcast and for determining the start of preparation for receiving simultaneous broadcast delivery. When the reception quality (C / N) drops below the second threshold value Th2 due to rainfall attenuation or the like at a stage where simultaneous broadcast delivery is not being received, the determination in step S103 is affirmed, and the process proceeds to step S104.
[0026] When the C / N acquired in step S101 is less than the second threshold value Th2 (C / N < Th2) (step S103, Yes), the monitoring and control unit 14 checks whether the output from the switching unit 13 to the output device 15 is BS broadcast (step S104). When the output from the switching unit 13 to the output device 15 is BS broadcast (step S104, Yes), the monitoring and control unit 14 checks whether simultaneous broadcast delivery is being received by the delivery reception unit 12 (step S105). At the first point when the reception quality (C / N) drops below the second threshold value Th2 due to rainfall attenuation or the like at a stage where simultaneous broadcast delivery is not being received, simultaneous broadcast delivery is not being received. In step S105, it is checked whether preparation for receiving simultaneous broadcast delivery is necessary.
[0027] If simultaneous broadcasting is not being received (step S105, No), the monitoring and control unit 14 starts preparing to receive the simultaneous broadcast (step S106). Specifically, the monitoring and control unit 14 establishes a connection between the distribution receiving unit 12 and the internet line IN, enabling the distribution receiving unit 12 to receive the IP streaming signal output by the simultaneous distribution server SV to the internet line IN. As a result, the receiving device 1 is ready to output the HDMI signal for simultaneous broadcast distribution to the output device 15 from the switching unit 13, replacing the HDMI signal for satellite broadcasting.
[0028] On the other hand, if simultaneous broadcast reception is already taking place (step S105, Yes), the process in step S106 is skipped. This is because the preparation for receiving the simultaneous broadcast has already been completed.
[0029] Next, the monitoring and control unit 14 checks whether the C / N obtained in step S101 is smaller than the first threshold Th1 (step S107). The first threshold Th1 is set to a value that is worse than the second threshold Th2 in terms of reception quality. If the C / N obtained in step S101 is smaller than the first threshold Th1 (step S107, Yes), then the current BS broadcast reception quality is of a quality that requires switching to simultaneous broadcast distribution. Therefore, the monitoring and control unit 14 switches the output to the output device 15 from BS broadcast to simultaneous broadcast distribution (step S108). Specifically, it outputs a command to the switching unit 13 to output the HDMI signal from the distribution reception unit 12 to the output device 15 instead of the MDMI signal from the broadcast reception unit 11 (simultaneous broadcast distribution selection).
[0030] Alternatively, a step to check whether the preparation for receiving the simultaneous broadcast is complete may be added between step S107 and step S108, and step S108 may be skipped if the preparation for receiving the simultaneous broadcast is not complete. The state in which the system is not ready to receive simultaneous broadcast distribution means, for example, that the connection to the simultaneous distribution server SV and authentication have not been completed, and therefore the simultaneous distribution signal (video and audio) cannot be output to the output device 15.
[0031] On the other hand, if the C / N obtained in step S101 is greater than the first threshold Th1 (step S107, No), it means that the current reception quality of the BS broadcast is not good enough to require switching from BS broadcasting to simultaneous broadcast distribution. In this case, the process in step S108 is skipped. This means that the processing at the time of obtaining the C / N is terminated.
[0032] Thus, when BS broadcasting is being output to output device 15, if the reception quality (C / N) deteriorates due to rain attenuation or other reasons, preparation for switching from BS broadcasting to simultaneous broadcast distribution begins when the reception quality (C / N) deteriorates below the second threshold Th2. Then, when the reception quality (C / N) deteriorates below the first threshold Th1, the switch from BS broadcasting to simultaneous broadcast distribution is performed.
[0033] Furthermore, in step S104 described above, if the output from the switching unit 13 to the output device 15 is not BS broadcasting (step S104, No), then the output from the switching unit 13 to the output device 15 will be simultaneous broadcast distribution. In this case, the current time is after the switch from BS broadcasting to simultaneous broadcast distribution, and the system is waiting to return to BS broadcasting. At this point, if the C / N is smaller than the second threshold Th2, it means that the reception quality of the BS broadcast is not of the quality required for switching (returning) from simultaneous broadcast distribution to BS broadcasting. In this case, the processing from steps S105 to S108 is not necessary and is therefore skipped. This completes the processing at the time of acquiring the C / N for this instance.
[0034] After switching to simultaneous broadcasting, if a new C / N is acquired (step S101), a comparison is performed between the acquired C / N and the third threshold Th3 (step S102). The C / N immediately after switching to simultaneous broadcasting is usually not greater than the third threshold Th3. In such cases, the judgment in step S102 is affirmed, and the process proceeds to step S103.
[0035] The monitoring and control unit 14 compares the C / N obtained in step S101 with the second threshold Th2 (step S103). In step S103, which is performed after switching to simultaneous broadcast distribution, the second threshold Th2 is used to determine whether to switch (return) from simultaneous broadcast distribution to BS broadcasting. If the reception quality improves after switching to simultaneous broadcast distribution, and the reception quality (C / N) obtained in step S101 becomes equal to or greater than the second threshold Th2 (C / N ≥ Th2), the judgment in step S103 is rejected (step S103, No), and the process proceeds to step S109.
[0036] Step S109 is the step for deciding whether to switch (return) from simultaneous broadcast streaming to BS broadcasting. The monitoring and control unit 14 checks whether the distribution receiving unit 12 is receiving a broadcast simultaneous distribution (step S109). If the distribution receiving unit 12 is receiving a broadcast simultaneous distribution (step S109, Yes), the monitoring and control unit 14 switches the output to the output device 15 from the broadcast simultaneous distribution to BS broadcasting. Specifically, it outputs a command to the switching unit 13 to output the HDMI signal from the broadcast receiving unit 11 to the output device 15 instead of the HDMI signal from the distribution receiving unit 12 (BS reception selection).
[0037] After switching from BS broadcasting to simultaneous broadcast distribution, the distribution receiving unit 12 continues to receive the simultaneous broadcast distribution. Therefore, if the C / N ratio is greater than the second threshold Th2 and the distribution receiving unit 12 is receiving the simultaneous broadcast distribution (step S109, Yes), then the current time is the point in time when the system is waiting to switch (return) from simultaneous broadcast distribution to BS broadcasting. At this point, if the C / N ratio is greater than the second threshold Th2, it means that the reception quality of the BS broadcast is good enough to allow switching (returning) to BS broadcasting. In such cases, the system will switch from simultaneous broadcast distribution to BS broadcasting (step S110).
[0038] On the other hand, if the distribution receiving unit 12 is not receiving the broadcast simultaneously (step S109, No), the monitoring and control unit 14 skips the process in step S110. This is because the current timeframe is after the switch from BS broadcasting to simultaneous broadcast streaming, and not a time when we are waiting for the switch (return) to BS broadcasting. As a result, the processing at the time of acquiring the C / N will be completed.
[0039] Then, at the next time C / N is acquired, if the reception quality (C / N) acquired in step S101 is equal to or greater than the third threshold Th3 (C / N ≥ Th3), the judgment in step S102 is rejected (step S102, No), and the process proceeds to step S111. Step S111 is the step of determining whether to stop receiving the simultaneous broadcast after switching from simultaneous broadcast to BS broadcast. The monitoring and control unit 14 checks whether the distribution receiving unit 12 is receiving the broadcast simultaneous distribution (step S111). If the distribution receiving unit 12 is receiving the broadcast simultaneous distribution (step S111, Yes), the monitoring and control unit 14 terminates the distribution receiving unit 12's reception of the broadcast simultaneous distribution (step S112).
[0040] At this point, after switching from simultaneous broadcast distribution to BS broadcasting, the distribution receiving unit 12 continues to receive the simultaneous broadcast distribution. Therefore, if the C / N ratio is greater than the third threshold Th3 and the distribution receiving unit 12 is receiving the simultaneous broadcast distribution, then the current point in time is when the reception of the simultaneous broadcast distribution continues after switching from simultaneous broadcast distribution to BS broadcasting. At this point, if the C / N ratio is greater than the third threshold Th3, it means that the reception quality of the BS broadcast is good enough that switching to simultaneous broadcast distribution is not necessary. In such cases, in order to prevent an increase in communication volume, the distribution receiving unit 12 terminates the reception of the simultaneous broadcast distribution (step S112).
[0041] On the other hand, if the distribution receiving unit 12 is not receiving the broadcast simultaneously (step S111, No), the monitoring and control unit 14 skips the process in step S112. This is because the current point in time is not the time when reception of the simultaneous broadcast stream after the switch from simultaneous broadcast streaming to BS broadcasting is still ongoing. As a result, the processing at the time of acquiring the C / N will end.
[0042] Thus, while the monitoring and control unit 14 (control unit) is outputting BS broadcasts to the output device 15, the distribution and receiving unit 12 stops receiving simultaneous broadcasts. When the monitoring and control unit 14 is outputting BS broadcasts to the output device 15, if the data indicating reception quality (C / N) falls below the second threshold Th2, the distribution and reception unit 12 starts receiving simultaneous broadcasts. When the data (C / N) indicating the reception quality of the BS broadcast received by the broadcast receiving unit 11 falls below the first threshold Th1, the monitoring and control unit 14 switches the output to the output device 15 from BS broadcasting to simultaneous broadcast distribution. After switching to simultaneous broadcast distribution, the monitoring and control unit 14 switches the output to the output device 15 from simultaneous broadcast distribution to BS broadcasting when the data indicating reception quality (C / N) becomes equal to or greater than the second threshold Th2.
[0043] Next, the operation of the receiving device 1 will be explained using the timing chart in Figure 2. In clear weather conditions without rain attenuation, the reception quality (C / N) of BS broadcasts will be greater than the third threshold, Th3. For example, if rainfall attenuation occurs due to heavy rain, the C / N ratio decreases (from time t1 to time t2). If the C / N ratio continues to decrease and falls below the second threshold Th2 (time t3), the monitoring and control unit 14 starts receiving the broadcast simultaneous distribution from the distribution receiving unit 12 (Figure 3: step S106). This establishes a connection between the distribution receiving unit 12 and the internet line IN (time t4), and the distribution receiving unit 12 becomes able to receive the IP streaming signal output by the simultaneous distribution server SV to the internet line IN.
[0044] If the C / N ratio continues to decline and falls below the first threshold Th1 (time t5), the output to output device 15 is switched from BS broadcasting to simultaneous broadcast distribution. As a result, even if the C / N ratio further decreases and falls below the BS reception limit (from time t6 to time t7), the output device 15 (TV) will still be outputting the simultaneous broadcast, allowing TV viewers to continue watching without being significantly affected by rain attenuation.
[0045] Then, as the reception quality improves, the C / N ratio increases, and when the C / N ratio becomes greater than the second threshold Th2 (time t8), the output to the output device 15 is switched from simultaneous broadcast distribution to BS broadcasting. When the C / N ratio increases further and becomes greater than the third threshold Th3 (time t9), the connection between the distribution receiving unit 12 and the internet line IN is cut off, and the reception of simultaneous broadcast distribution by the distribution receiving unit 12 is terminated. Thus, the period during which simultaneous broadcast streaming is received is limited to periods of poor reception where the C / N ratio is lower than the BS reception limit, and the periods immediately before and after. Therefore, when using an internet connection service that is not a flat-rate service, the burden on the user can be reduced. Furthermore, if the C / N ratio decreases due to localized heavy rainfall, receiving device 1 located in an area where the C / N ratio has fallen below the second threshold Th2 will switch from BS broadcasting to simultaneous broadcast distribution to receive the broadcast. Then, when the C / N ratio recovers and rises above the third threshold Th3, receiving device 1 will switch from simultaneous broadcast distribution to BS broadcasting to receive the broadcast. This reduces the possibility that the number of receiving devices 1 receiving broadcasts via simultaneous broadcasting will continue to increase, for example, when the area affected by heavy rainfall moves over time. Furthermore, it reduces the possibility of the load on the simultaneous broadcasting server SV increasing over time, thus ensuring the continued provision of information to areas that need it.
[0046] [Comparative Example] Figure 4 is a timing chart for switching between BS broadcasting and simultaneous broadcast distribution, based on a comparison of reception quality (C / N) and two thresholds, ThA and ThB. In Figure 4, threshold ThB is the threshold used to determine whether to receive or terminate simultaneous broadcast distribution. Threshold ThA is the threshold used to determine whether to switch between BS broadcasting and simultaneous broadcast distribution. Threshold B is a value that indicates better reception quality than threshold ThA.
[0047] The reception quality (C / N) fluctuates. Therefore, during the reception quality recovery phase shown in Figure 4, the reception quality (C / N) may fluctuate above and below the threshold ThA. In the case of Figure 4, at time t1, the signal switches from simultaneous broadcast distribution to BS broadcasting, but immediately afterwards at time t2, it switches from BS broadcasting to simultaneous broadcast distribution, and then at time t3, it switches again from simultaneous broadcast distribution to BS broadcasting. Between time t1 and time t4, the output to the output device 15 frequently switches between BS broadcasting and simultaneous broadcast distribution (chattering), which raises concerns about the load on viewers watching the broadcast and the load on the output device 15.
[0048] In this embodiment, the first threshold Th1 used to determine whether to switch from BS broadcasting to simultaneous broadcast distribution and the second threshold Th2 used to determine whether to switch from simultaneous broadcast distribution to BS broadcasting are different values (see Figure 2). The second threshold Th2 is set to a value that results in better reception quality than the first threshold Th1, taking into account fluctuations in reception quality. Therefore, even if fluctuations occur in reception quality (C / N) near the first threshold Th1, the switch (return) from simultaneous broadcast distribution to BS broadcasting will not occur unless it exceeds the second threshold Th2, which is on the side of better reception quality than the first threshold Th1. Thus, in the receiving device 1 of this embodiment, the phenomenon of frequent switching between BS broadcasting and simultaneous broadcast distribution (chattering) to the output device 15, as in the comparative example shown in Figure 4, is less likely to occur.
[0049] Furthermore, in Figure 4, the same threshold ThB is used to determine the start and end of reception of the simultaneous broadcast. Here, after determining the start of reception of the simultaneous broadcast, time is required to establish a connection to the internet line IN and receive the simultaneous broadcast before the simultaneous broadcast can be output to the output device 15. Therefore, if the same threshold ThB is used to determine the start and end of reception for simultaneous broadcast streaming, it is possible that the preparation for receiving simultaneous broadcast streaming may not be completed by the time of the switch from BS broadcasting to simultaneous broadcast streaming. In such cases, a completely white screen, known as a "whiteout," will appear on the broadcast screen.
[0050] In this embodiment, different thresholds are used to determine the start and end of reception of simultaneous broadcast distribution. Taking into account fluctuations in reception quality, the third threshold Th3, used to determine the end of simultaneous broadcast distribution reception, is set to a value that is better for reception quality than the second threshold Th2, used to determine the start of simultaneous broadcast distribution reception. Therefore, a situation is ensured where simultaneous broadcast distribution can be received until the reception quality (C / N) becomes higher than the reception quality (C / N) at the time the start of simultaneous broadcast distribution reception was determined. As a result, situations like the comparative example shown in Figure 4, where the preparation for receiving simultaneous broadcast distribution is not completed by the time of the switch from BS broadcasting to simultaneous broadcast distribution, are less likely to occur.
[0051] [Example 1] In the above-described embodiment, an example was given in which the distribution receiving unit 12 connects to the internet line IN for a predetermined period before and after a reception failure to receive simultaneous broadcast distribution. In other words, an example was given in which the connection between the distribution receiving unit 12 and the internet line IN is disconnected except during the period of reception failure and the predetermined period before and after the reception failure. Alternatively, instead of blocking the connection between the distribution receiving unit 12 and the internet line IN, bandwidth limitations may be imposed on the reception of IP streaming distribution by the distribution receiving unit 12, excluding the period of poor reception and predetermined periods before and after it. The monitoring and control unit 14 limits the bandwidth of the simultaneous broadcast reception by the distribution and receiving unit 12 while the broadcast is being output to the output device. When the monitoring and control unit 14 is outputting the broadcast to the output device 15, it removes the bandwidth limit when the data indicating the reception quality falls below the second threshold Th2, and starts limiting the bandwidth of the simultaneous broadcast reception by the distribution and receiving unit 12 when the data indicating the reception quality rises to or above the third threshold Th3. The third threshold Th3 is set to a value offset from the second threshold Th2 that results in better reception quality.
[0052] As shown in the flowchart for Modification 1 (see Figure 5), in the process according to Modification 1, steps S205, S206, S211, and S212 differ from the flowchart of the embodiment described above (see Figure 3). In the case of Modification 1, in step S205, the monitoring and control unit 14 checks whether bandwidth limiting is in effect. If bandwidth limiting is not in effect, in step S206, the monitoring and control unit 14 applies bandwidth limiting to the reception of simultaneous broadcast distribution by the distribution receiving unit 12. Furthermore, if the reception quality (C / N) is above the third threshold Th3 (step S202, No) and no bandwidth limiting is applied (step S211, No), in step S212, the monitoring and control unit 14 applies bandwidth limiting to the reception of simultaneous broadcast distribution by the distribution receiving unit 12.
[0053] This means that the speed of receiving simultaneous broadcasts via the internet connection will be limited, reducing the amount of data used. Therefore, when using an internet connection service that is not a flat-rate plan, the burden on users can be reduced. Furthermore, removing the bandwidth restriction allows for a smooth transition from BS broadcasting to simultaneous broadcast streaming. Even while bandwidth restrictions are in place, the connection to the simultaneous streaming server SV and authentication are maintained. Therefore, compared to starting with establishing a connection to the internet line IN and then receiving the simultaneous broadcast stream, the time required to switch to simultaneous broadcast streaming can be reduced, and the possibility of broadcast interruptions occurring during the switch can be reduced. Note that the processing in steps S201-S204 and S207-S210 is the same as the processing in steps S101-S104 and S107-S110 described above.
[0054] Thus, while the monitoring and control unit 14 (control unit) is outputting BS broadcasts to the output device 15, it is limiting the bandwidth of the distribution and receiving unit 12's reception of simultaneous broadcast distributions. When the monitoring and control unit 14 is outputting BS broadcasts to the output device 15, if the data indicating reception quality (C / N) falls below the second threshold Th2, it removes the bandwidth limitation. When the data indicating reception quality (C / N) reaches or exceeds the third threshold Th3, the monitoring and control unit 14 starts bandwidth limiting for simultaneous broadcast distribution reception by the distribution and reception unit 12.
[0055] [Differentiation 2] In the above-described embodiment, an example was given in which the threshold used for determining whether to prepare for receiving simultaneous broadcast distribution and the threshold used for determining whether to switch from simultaneous broadcast distribution to BS broadcasting are the same threshold (second threshold Th2). For example, as shown in Figure 6, the threshold used to determine whether to prepare for receiving simultaneous broadcast distribution and the threshold used to determine whether to switch from simultaneous broadcast distribution to BS broadcasting may be different thresholds (fourth threshold Th4, second threshold Th2). In this case, the second threshold Th2 should be a value between the first threshold Th1 and the third threshold Th3. Here, it is necessary to avoid causing the aforementioned chattering. Considering fluctuations in reception quality (C / N), it is preferable that the second threshold Th2 is a value that improves reception quality by 1 dB, more preferably 2 dB, compared to the first threshold Th1. Furthermore, it is preferable that the second threshold Th2 is a value between the fourth threshold Th4 and the third threshold.
[0056] Furthermore, if the receiving device 1 is configured to impose bandwidth limitations on the reception of IP streaming distribution by the distribution receiving unit 12, the fourth threshold Th4 may be set to a value closer to the first threshold Th1. This is because removing the bandwidth limitation allows for a smooth switch from BS broadcasting to simultaneous broadcast distribution, thus reducing the time required for switching to simultaneous broadcast distribution compared to starting with establishing a connection to the internet line IN and then receiving the simultaneous broadcast distribution. In this case as well, considering fluctuations in reception quality (C / N), it is preferable that the fourth threshold Th4 is 1 dB, more preferably 2 dB, on the side of better reception quality than the first threshold Th1.
[0057] In other words, the monitoring and control unit 14 limits the bandwidth of the distribution receiver unit's reception of simultaneous broadcast distribution while it is outputting the broadcast to the output device 15. When the monitoring and control unit 14 is outputting the broadcast to the output device, if the data indicating reception quality falls below the fourth threshold Th4, it removes the bandwidth limitation. If the data indicating reception quality rises to or above the third threshold Th3, it begins bandwidth limitation on the distribution receiver unit 12's reception of simultaneous broadcast distribution. The third threshold Th3 is set to a value offset to the side that improves reception quality compared to the second threshold Th2, and the fourth threshold Th4 is set to a value between the first threshold Th1 and the second threshold Th2.
[0058] Figure 7 is a flowchart illustrating the process when the second threshold Th2, used to determine whether to switch from simultaneous broadcast distribution to BS broadcasting, is a value between the fourth threshold Th4, used to determine whether to prepare for receiving simultaneous broadcast distribution, and the third threshold Th3, used to determine whether to end the reception of simultaneous broadcast distribution. As shown in Figure 7, in the flowchart of the process in Modified Example 2, steps S303 and S304 differ from the flowchart of the embodiment described above (see Figure 5). In the case of the second modified example, in step S303, the monitoring and control unit 14 compares the reception quality (C / N) acquired in step S301 with the second threshold Th2. The second threshold Th2 is used to determine whether to switch from simultaneous broadcast distribution to BS broadcasting. If the reception quality (C / N) is greater than the second threshold Th2 (step S303, No), then the reception quality (C / N) is sufficient to allow switching (returning) from simultaneous broadcast distribution to BS broadcasting. In such cases, the process proceeds to step S310, where it is confirmed whether or not simultaneous broadcast distribution is currently being output to the output device 15.
[0059] Also, when the reception quality (C / N) is smaller than the second threshold Th2 (C / N < Th2) (step S303, Yes), the process proceeds to step S304, and the monitoring and control unit 14 compares the reception quality (C / N) acquired in step S301 with the fourth threshold Th4 used for determining the reception preparation for the broadcast simultaneous distribution. And when the reception quality (C / N) is smaller than the fourth threshold Th4 (C / N < Th4) (step S304, Yes), the process proceeds to step S305. When the reception quality (C / N) is larger than the fourth threshold Th4 (C / N ≧ Th4) (step S304, No), the processing at the current C / N acquisition timing ends.
[0060] As a result, the fourth threshold Th4 used for determining to start the reception preparation for the broadcast simultaneous distribution and the second threshold Th2 used for determining the switching from the broadcast simultaneous distribution to the BS broadcast are different values, so the reception period of the broadcast simultaneous distribution can be controlled more finely. Thus, when using an Internet connection service that is not a flat-rate system, a reduction in the burden on the user can be expected. Note that the processing of steps S301, S302, S305 to S313 is the same as the processing of the above-described steps S101, S102, S104 to S112 (see FIG. 3), respectively.
[0061] In this way, when the threshold used for determining to start the reception preparation for the broadcast simultaneous distribution and the threshold used for determining the switching from the broadcast simultaneous distribution to the BS broadcast are set to different values, the processing process becomes more complex compared to the processing of FIG. 3 when these thresholds are the same value. Therefore, when there is little need to control the reception period of the broadcast simultaneous distribution more finely, it can be said that setting the threshold used for determining to start the reception preparation for the broadcast simultaneous distribution and the threshold used for determining the switching from the broadcast simultaneous distribution to the BS broadcast to the same value can simplify the program that defines the processing process.
[0062] In this way, while the monitoring and control unit 14 (control unit) outputs the BS broadcast to the output device 15, it places a bandwidth restriction on the reception of the broadcast simultaneous distribution by the distribution reception unit 12. When the monitoring and control unit 14 is outputting BS broadcasts to the output device 15, if the data indicating reception quality (C / N) falls below the fourth threshold Th4, it removes the bandwidth limitation. When the data (C / N) indicating the reception quality of the BS broadcast received by the broadcast receiving unit 11 falls below the first threshold Th1, the monitoring and control unit 14 switches the output to the output device 15 from BS broadcasting to simultaneous broadcast distribution. After switching to simultaneous broadcast distribution, the monitoring and control unit 14 switches the output to the output device 15 from simultaneous broadcast distribution to BS broadcasting when the data indicating reception quality (C / N) becomes equal to or greater than the second threshold Th2. When the data indicating reception quality (C / N) reaches or exceeds the third threshold Th3, the monitoring and control unit 14 starts bandwidth limiting for simultaneous broadcast distribution reception by the distribution and reception unit 12. In Modification 2, an example is shown where the monitoring and control unit 14 controls the start and end of bandwidth restriction for the distribution receiving unit 12 to receive simultaneous broadcast distribution. The monitoring and control unit 14 may also control the stop and start of reception of simultaneous broadcast distribution by the distribution receiving unit 12.
[0063] [Difference 3] In the above-described embodiment, an example was given in which C / N was used as data indicating reception quality. As data indicating reception quality, MER and BER calculated by the broadcast receiving unit 11 may be used.
[0064] (a) MER (Modulation Error Ratio) is the modulation error ratio of a digital signal. A higher MER value indicates better reception quality, while a lower MER value indicates worse reception quality. (b) BER (Bit Error Rate) is the bit error rate that indicates how many of the transmitted 1s and 0s were incorrect, and can be expressed by the following formula. BER = Number of error bits / Number of transmitted bits (1) From equation (1) above, as the number of error bits increases due to rain attenuation, the BER value increases. A higher BER value indicates worse reception quality, while a lower BER value indicates better reception quality. Therefore, when using BER as data to indicate reception quality, the graph shown in Figure 2 will be inverted vertically.
[0065] Even when using MER or BER, the reception quality of BS broadcasts can be checked by comparing it with three thresholds, and the reception / stopping of simultaneous broadcast distribution can be controlled. As a result, for example, if the reception quality of BS broadcasting deteriorates due to rain attenuation, the output to the output device 15 is switched from BS broadcasting using the broadcasting satellite BS to simultaneous broadcast distribution using the internet connection, thus allowing viewers to continue watching broadcasts while avoiding reception problems caused by rain attenuation. When the reception quality recovers, the output to the output device 15 is switched back from simultaneous broadcast distribution to BS broadcasting, thus reducing the burden on users when using an internet connection service that is not a flat-rate service. Furthermore, by using two different thresholds (first threshold Th1, second threshold Th2) for switching between BS broadcasting and simultaneous broadcast distribution, the possibility of chattering occurring can be reduced.
[0066] [Differentiation Example 4] In the above-described embodiment, an example was given in which the reception quality is compared with predetermined thresholds (first threshold Th1, second threshold Th2, third threshold Th3). These thresholds (first threshold Th1, second threshold Th2, third threshold Th3) may be made changeable.
[0067] The operating modes of the receiving device 1 include fixed line mode 1, fixed line mode 2, mobile line mode 1, mobile line mode 2, and rain-resistant broadcast priority mode. This explanation will use an example where the thresholds for each of these modes are different. Here, fixed-line mode 1 is an operating mode for situations where an increase in communication charges is tolerable to some extent, such as with flat-rate internet connection services, and it is a mode that prioritizes the stability of broadcast reception. Fixed-line mode 2 is the operating mode for flat-rate internet connection services when the communication speed is slow and it takes time to establish a connection. Mobile line mode 1 is the operating mode when you want to reduce data usage while ensuring stability. Mobile line mode 2 is the operating mode when you want to reduce data usage even at the expense of security. Rain-resistant wired broadcast mode is the operating mode when receiving BS broadcasts is prioritized during rainfall. Table 1 below shows examples of thresholds for each operating mode (first threshold Th1, second threshold Th2, third threshold Th3).
[0068] [Table 1]
[0069] The second threshold Th2 in fixed-line mode 2 is set to a value offset by 1.0 dB compared to the second threshold Th2 in fixed-line mode 1, on the side of better reception quality. This is because the communication speed in fixed-line mode 2 is slower than that of fixed-line mode 1, and the time required to establish communication is longer than in fixed-line mode 1. As a result, in fixed-line mode 2, preparation for receiving simultaneous broadcast distribution begins at an earlier time than in fixed-line mode 1. Furthermore, the third threshold Th3 for fixed-line mode 2 is set to a value that is 1.0 dB offset to the side with better reception quality than the third threshold Th3 for fixed-line mode 1.
[0070] This is because if only the second threshold Th2 in fixed-line mode 2 is set to a value that is 1.0 dB offset towards the side with better reception quality, the difference between the second threshold Th2 and the third threshold Th3 will become small, which may result in frequent reception / reception interruptions of simultaneous broadcast distribution due to fluctuations in reception quality. To prevent this from happening, the value of the third threshold Th3 in fixed-line mode 2 is offset by the same amount as the second threshold Th2 in fixed-line mode 2, so that it is on the side with better reception quality than the third threshold Th3 in fixed-line mode 1.
[0071] In mobile line mode 1, the first threshold Th1 is set to a value that is offset to the side that results in worse reception quality compared to fixed line mode 2. Furthermore, the second threshold Th2, which is used to determine the start / end of simultaneous broadcast reception, is set to a value that is offset to the side that results in worse reception quality, following the first threshold Th1. As a result, unless the reception quality deteriorates compared to fixed-line mode 2, the preparation for receiving simultaneous broadcast distribution and the switch from BS broadcast to simultaneous broadcast distribution will not occur, which is expected to reduce data usage.
[0072] In mobile network mode 2, the second threshold Th2, used to determine the start / end of simultaneous broadcast reception, and the third threshold Th3, used to determine the end of simultaneous broadcast reception, are set to values that are offset to the side where reception quality is worse than in mobile network mode 1. This means that the switch from BS broadcasting to simultaneous broadcast distribution will not occur unless the reception quality deteriorates compared to mobile network mode 1, thus reducing data usage. Furthermore, since a third threshold, Th3, is set in conjunction with the second threshold, Th2, it is possible to optimize the reception period for simultaneous broadcast distribution.
[0073] In the rain-resistant broadcast priority mode, the second threshold Th2, used to determine when to start receiving simultaneous broadcasts and when to switch from simultaneous broadcasts to BS broadcasts; the third threshold, used to determine when to end the reception of simultaneous broadcasts; and the first threshold Th1, used to determine when to switch from BS broadcasts to simultaneous broadcasts, are all set to values that result in worse reception quality compared to mobile line mode 2. This is expected to reduce data usage.
[0074] [Difference 5] In the above-described embodiment, an example was given in which reception quality (C / N) and thresholds (first threshold Th1, second threshold Th2, third threshold Th3) are simply compared. As mentioned above, reception quality fluctuates, and the C / N value also fluctuates by approximately ±1 dB. Therefore, instead of simply comparing the reception quality calculated by the broadcast receiving unit 11 with a threshold, it is also possible to calculate a moving average of reception quality (C / N) and compare the moving average with the threshold.
[0075] Specifically, the reception quality (C / N) is repeatedly calculated at predetermined intervals in the broadcast receiving unit 11. The monitoring and control unit 14 may calculate the average value of the C / N over the past n times (for example, 3 times), including the current time, and compare the calculated C / N with a threshold. In this case, fluctuations (volatility) in reception quality are leveled out, so the difference between each threshold (the difference between the first threshold Th1 and the second threshold Th2, and the difference between the second threshold Th2 and the third threshold Th3) can be reduced. This can shorten the reception period for simultaneous broadcast distribution, and is expected to reduce the burden on users when using non-flat-rate internet connection services.
[0076] The following lists the operation and effects of the receiving device 1 according to the embodiment, along with its configuration. (1) The receiving device 1 is capable of receiving both BS broadcasts (broadcasts) using the broadcasting satellite BS and simultaneous broadcast distributions using the internet connection IN. The receiving device 1 includes a broadcast receiving unit 11 for receiving BS broadcasts, a distribution receiving unit 12 for receiving simultaneous broadcast distributions, a switching unit 13 for switching the output to the output device 15 between the BS broadcasts received by the broadcast receiving unit 11 and the simultaneous broadcast distributions received by the distribution receiving unit 12, and a monitoring and control unit 14 (control unit) for controlling the distribution receiving unit 12 and the switching unit 13. When the data (C / N) indicating the reception quality of the BS broadcast received by the broadcast receiving unit 11 falls below the first threshold Th1, the monitoring and control unit 14 switches the output to the output device 15 from BS broadcasting to simultaneous broadcast distribution. After switching to simultaneous broadcast distribution, the monitoring and control unit 14 switches the output to the output device 15 from simultaneous broadcast distribution to BS broadcasting when the data indicating reception quality (C / N) becomes equal to or greater than the second threshold Th2. The second threshold, Th2, is set to a value that is offset from the first threshold, Th1, to the side that results in better reception quality.
[0077] For example, if the reception quality of BS broadcasts deteriorates due to rain attenuation, BS broadcasts using broadcasting satellites can be switched to simultaneous broadcast distribution using the internet, thus avoiding reception problems caused by rain attenuation and allowing viewers to continue watching the broadcast. The second threshold Th2 is a value that is better in terms of reception quality than the first threshold Th1. Therefore, the switch from simultaneous broadcasting to BS broadcasting will not occur unless the reception quality is better than when switching from BS broadcasting to simultaneous broadcasting. Since reception quality fluctuates, if the switch between BS broadcasting and simultaneous broadcasting is performed using only the first threshold Th1, there is a possibility that the phenomenon of frequent switching between BS broadcasting and simultaneous broadcasting (chattering) will occur. By providing a first threshold Th1 for switching from BS broadcasting to simultaneous broadcasting and a second threshold Th2 for switching from simultaneous broadcasting to BS broadcasting, the possibility of chattering occurring can be effectively suppressed.
[0078] (2) The monitoring and control unit 14 (control unit) stops receiving simultaneous broadcast distribution by the distribution receiving unit 12 while it is outputting BS broadcast to the output device 15. When the monitoring and control unit 14 (control unit) is outputting BS broadcasts to the output device 15, if the data indicating reception quality (C / N) falls below the second threshold Th2, it establishes a connection to the internet line IN of the distribution receiving unit 12 and starts receiving simultaneous broadcasts. The monitoring and control unit 14 (control unit) disconnects the connection between the distribution receiving unit 12 and the internet line IN and stops receiving the broadcast simultaneously when the data indicating reception quality (C / N) exceeds the third threshold Th3. The third threshold, Th3, is set to a value that is offset from the second threshold, Th2, to the side that results in better reception quality.
[0079] As long as the reception quality is such that output to the output device 15 for simultaneous broadcast distribution and preparation for receiving simultaneous broadcast distribution is not required, reception of simultaneous broadcast distribution via the Internet line IN will be stopped. This will reduce the burden on users when using internet connection services that are not on a flat-rate plan. Furthermore, it allows for preparation time to switch to simultaneous broadcasting, enabling a smooth transition from BS broadcasting to simultaneous broadcasting. Furthermore, once the reception quality of BS broadcasts deteriorates to a level that requires switching to simultaneous broadcast streaming, and then recovers to a level that no longer requires simultaneous broadcast streaming, reception of simultaneous broadcast streaming via the internet connection will be stopped. This also reduces the burden on users when using non-flat-rate internet connection services. Furthermore, the threshold for switching from simultaneous broadcast distribution to BS broadcasting and the threshold for starting reception of simultaneous broadcast distribution by the distribution receiving unit 12 are the same, which simplifies the processing program.
[0080] (3) The monitoring and control unit 14 (control unit) limits the bandwidth of the distribution receiving unit 12 for simultaneous broadcast distribution while it is outputting BS broadcasts to the output device 15. When the monitoring and control unit 14 (control unit) is outputting BS broadcasts to the output device 15, if the data indicating reception quality (C / N) falls below the second threshold Th2, it removes the bandwidth limitation. When the data indicating reception quality (C / N) reaches or exceeds the third threshold Th3, the monitoring and control unit 14 (control unit) starts bandwidth limiting for simultaneous broadcast distribution reception by the distribution receiving unit 12. The third threshold, Th3, is set to a value that is offset from the second threshold, Th2, to the side that results in better reception quality.
[0081] While the reception quality is such that it does not require output for simultaneous broadcast distribution or preparation for simultaneous broadcast distribution output, bandwidth limitations will be imposed on the reception of simultaneous broadcast distribution via the Internet connection IN. This allows for lower communication charges via the internet connection compared to when bandwidth restrictions are not applied. Therefore, it can reduce the burden on users when using internet connection services that are not flat-rate. Furthermore, removing bandwidth restrictions allows for a quicker switch to simultaneous broadcast streaming of BS broadcasts. Compared to starting the process from scratch, which involves establishing an internet connection and then receiving the simultaneous broadcast stream, this reduces the time required to switch to simultaneous broadcast streaming and minimizes the possibility of viewing interruptions during the switch. Furthermore, once reception quality deteriorates to a level that requires switching to simultaneous broadcast streaming, and then recovers to a level that no longer requires simultaneous broadcast streaming, bandwidth restrictions are placed on the reception of simultaneous broadcast streaming via the internet connection, thereby reducing the amount of data transmitted via the internet connection. This also reduces the burden on users when using non-flat-rate internet connection services. Furthermore, the threshold for switching from simultaneous broadcast distribution to BS broadcasting and the threshold for starting reception of simultaneous broadcast distribution by the distribution receiving unit 12 are the same, which simplifies the processing program.
[0082] (4) The monitoring and control unit 14 (control unit) limits the bandwidth of the distribution receiving unit 12 for simultaneous broadcast distribution while it is outputting BS broadcasts to the output device 15. When the monitoring and control unit 14 (control unit) is outputting BS broadcasts to the output device 15, if the data indicating reception quality (C / N) falls below the fourth threshold Th4, it removes the bandwidth limitation. The fourth threshold, Th4, is set to a value that is offset from the first threshold, Th1, to the side that results in better reception quality. When the data indicating reception quality (C / N) reaches or exceeds the third threshold Th3, the monitoring and control unit 14 (control unit) starts bandwidth limiting for simultaneous broadcast distribution reception by the distribution receiving unit 12. The third threshold, Th3, is set to a value that is offset from the second threshold, Th2, to the side that results in better reception quality.
[0083] Eliminating bandwidth limitations allows for a smooth transition from BS broadcasting to simultaneous broadcast streaming. This reduces the time required to switch to simultaneous broadcast streaming compared to starting the internet connection setup and subsequent reception of simultaneous broadcast streaming from scratch. Therefore, the fourth threshold Th4, used to determine when to begin preparing for simultaneous broadcast streaming, can be brought closer to the first threshold Th1, used for switching from BS broadcasting to simultaneous broadcast streaming. Therefore, since the reception period for simultaneous broadcast streaming can be shortened, it is expected that the burden on users of non-flat-rate internet connection services will be reduced.
[0084] (5) The first threshold Th1 (first threshold) is set to a value that is offset to the side that improves reception quality compared to the lower limit (BS reception limit) that defines the reception limit for BS broadcasting using the broadcasting satellite BS. This configuration allows for switching to simultaneous broadcast streaming before poor reception caused by factors such as rain attenuation renders BS broadcasts, which utilize broadcasting satellites, unwatchable.
[0085] (6) The data that defines the reception quality is at least one of C / N, MER, and BER. This data is existing information generated by the broadcast receiving unit that receives satellite broadcasts. There is no need to define new data indicating reception quality and to prepare a separate process for calculating reception quality. Since it is only necessary to incorporate the above functions into existing satellite broadcast receiving equipment, a reduction in the cost of manufacturing receiving equipment can be expected.
[0086] The embodiments and modifications of the present invention have been described above. The present invention is not limited to the embodiments and modifications described above. It can be modified as appropriate within the scope of the technical idea of the invention. Furthermore, the embodiments and modifications do not necessarily have to be used independently. The embodiments and modifications may be combined. [Explanation of symbols]
[0087] 1: Receiving device 11: Broadcast receiving unit 12: Distribution receiving unit 13: Switching section 14: Monitoring and Control Unit (Control Unit) 15: Output devices 20: Antenna 100: Broadcasting System BS: Broadcasting satellite IN: Internet connection MS: Uplink Main Station SV: Simultaneous streaming server
Claims
1. A receiving device capable of receiving both broadcasts using broadcasting satellites and simultaneous broadcast distribution using the internet, Broadcast receiving unit using the aforementioned broadcasting satellite, A distribution receiving unit that receives simultaneous broadcast distribution using the aforementioned internet line, A switching unit that switches the output to the output device between the broadcast received by the broadcast receiving unit and the distribution received by the distribution receiving unit, The system comprises a distribution receiving unit and a control unit that controls the switching unit, The control unit, When the data indicating the reception quality of the broadcast received by the broadcast receiving unit falls below a first threshold, the output to the output device is switched from the broadcast to simultaneous broadcast distribution. After switching to simultaneous broadcast distribution, if the data indicating reception quality exceeds the second threshold, the output to the output device is switched from simultaneous broadcast distribution to the broadcast. The second threshold is set to a value offset from the first threshold to the side that improves the reception quality. The control unit, While the aforementioned broadcast is being output to the output device, the distribution receiving unit stops receiving the simultaneous broadcast. The control unit, When the aforementioned broadcast is being output to the output device, if the data indicating the reception quality falls below the second threshold, the distribution receiving unit starts receiving the simultaneous broadcast. The control unit, When the data indicating the reception quality exceeds the third threshold, the distribution receiving unit stops receiving the broadcast simultaneously. A receiving device in which the third threshold is set to a value offset from the second threshold to the side that improves the reception quality.
2. A receiving device capable of receiving both broadcasts using a broadcasting satellite and simultaneous broadcast distribution using an internet connection, Broadcast receiving unit using the aforementioned broadcasting satellite, A distribution receiving unit that receives simultaneous broadcast distribution using the aforementioned internet line, A switching unit that switches the output to the output device between the broadcast received by the broadcast receiving unit and the distribution received by the distribution receiving unit, The system comprises a distribution receiving unit and a control unit that controls the switching unit, The control unit, When the data indicating the reception quality of the broadcast received by the broadcast receiving unit falls below a first threshold, the output to the output device is switched from the broadcast to simultaneous broadcast distribution. After switching to simultaneous broadcast distribution, if the data indicating reception quality exceeds the second threshold, the output to the output device is switched from simultaneous broadcast distribution to the broadcast. The second threshold is set to a value offset from the first threshold to the side that improves the reception quality. The control unit, While the aforementioned broadcast is being output to the output device, bandwidth limitations are applied to the reception of the simultaneous broadcast by the distribution receiving unit. The control unit, When the aforementioned broadcast is being output to the output device, if the data indicating the reception quality falls below the second threshold, the bandwidth limitation is removed. The control unit, When the data indicating the reception quality exceeds the third threshold, the distribution receiving unit starts limiting the bandwidth of the simultaneous broadcast distribution. A receiving device in which the third threshold is set to a value offset from the second threshold to the side that improves the reception quality.
3. A receiving device capable of receiving both broadcasts using a broadcasting satellite and simultaneous broadcast distribution using an internet connection, Broadcast receiving unit using the aforementioned broadcasting satellite, A distribution receiving unit that receives simultaneous broadcast distribution using the aforementioned internet line, A switching unit that switches the output to the output device between the broadcast received by the broadcast receiving unit and the distribution received by the distribution receiving unit, The system comprises a distribution receiving unit and a control unit that controls the switching unit, The control unit, When the data indicating the reception quality of the broadcast received by the broadcast receiving unit falls below a first threshold, the output to the output device is switched from the broadcast to simultaneous broadcast distribution. After switching to simultaneous broadcast distribution, if the data indicating reception quality exceeds the second threshold, the output to the output device is switched from simultaneous broadcast distribution to the broadcast. The second threshold is set to a value offset from the first threshold to the side that improves the reception quality. The control unit, While the aforementioned broadcast is being output to the output device, bandwidth limitations are applied to the reception of the simultaneous broadcast by the distribution receiving unit. The control unit, When the aforementioned broadcast is being output to the output device, if the data indicating the reception quality falls below the fourth threshold, the bandwidth limitation is removed. The control unit, When the data indicating the reception quality exceeds the third threshold, the distribution receiving unit starts limiting the bandwidth of the simultaneous broadcast distribution. The third threshold is set to a value that is offset from the second threshold to the side that improves the reception quality. The receiving device wherein the fourth threshold is set to a value between the first threshold and the second threshold.
4. The receiving device according to any one of claims 1 to 3, wherein the first threshold is set to a value offset to the side that improves the reception quality, compared to the lower limit value that defines the reception limit of broadcasts using the broadcasting satellite.
5. The receiving device according to claim 4, wherein the data defining the reception quality is at least one of C / N, MER, and BER.